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1

Investigation of oscillatory problems of hydraulic generating units equipped with Francis turbines  

Microsoft Academic Search

In the paper a method is presented for the study of oscillatory problems of hydraulic generating units equipped with Francis turbines. The accurate equations of the turbine are implemented for the simulation, taking into account water hammer effect. Partial derivatives of turbine flow rate and torque with respect to head and gate opening are deduced from real measurements for the

D. N. Konidaris; J. A. Tegopoulos

1997-01-01

2

The application of hydraulics in the 2,000 kW wind turbine generator  

NASA Technical Reports Server (NTRS)

A 2000 kW turbine generator using hydraulic power in two of its control systems is being built under the management of NASA Lewis Research Center. The hydraulic systems providing the control torques and forces for the yaw and blade pitch control systems are discussed. The yaw-drive-system hydraulic supply provides the power for positioning the nacelle so that the rotary axis is kept in line with the direction of the prevailing wind, as well as pressure to the yaw and high speed shaft brakes. The pitch-change-mechanism hydraulic system provides the actuation to the pitch change mechanism and permits feathering of the blades during an emergency situation. It operates in conjunction with the overall windmill computer system, with the feather control permitting slewing control flow to pass from the servo valve to the actuators without restriction.

Onufreiczuk, S.

1978-01-01

3

Development of the water-lubricated thrust bearing of the hydraulic turbine generator  

NASA Astrophysics Data System (ADS)

In hydropower plant, a large quantities of turbine oil is used as machine control pressure oil and lubricating oil. If the oil leak out from hydropower plant, it flows into a river. And such oil spill has an adverse effect on natural environment because the oil does not degrade easily. Therefore the KANSAI and Hitachi Mitsubishi Hydro developed the water-lubricated thrust bearing for vertical type hydraulic turbine generator. The water-lubricated bearing has advantages in risk avoidance of river pollution because it does not need oil. For proceeding the development of the water-lubricated thrust bearing, we studied following items. The first is the examination of the trial products of water lubricating liquid. The second is the study of bearing structure which can satisfy bearing performance such as temperature characteristic and so on. The third is the mock-up testing for actual application in the future. As a result, it was found that the water-lubricated thrust bearing was technically applicable to actual equipments.

Inoue, K.; Deguchi, K.; Okude, K.; Fujimoto, R.

2012-11-01

4

Passing Fish Through Hydraulic Turbines  

Microsoft Academic Search

Beginning in 1959, the Walla Walla District, U. S. Army Corps of Engineers, under auspices of the Corps of Engineers' Fisheries Engineering Research Program, has conducted extensive tests on downstream passage of fish through hydraulic turbines, utilizing both model and prototype installations. Purposes of the tests were (1) to establish design criteria for high-head Francis-type turbines that will provide optimum

Frederick K. Cramer; Raymond C. Oligher

1964-01-01

5

Save energy with hydraulic power recovery turbines  

Microsoft Academic Search

The reverse running pump is used as a means of recovering power from process units but lacks the controlability and efficiency of hydraulic power recovery turbines. A comparison of these two devices is presented and also a discussion of why hydraulic turbines can be applied at a lower overall cost.

Franzke

1975-01-01

6

Downhole hydraulic seismic generator  

DOEpatents

A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole.

Gregory, Danny L. (Corrales, NM); Hardee, Harry C. (Albuquerque, NM); Smallwood, David O. (Albuquerque, NM)

1992-01-01

7

Downhole hydraulic seismic generator  

SciTech Connect

A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole. 4 figs.

Gregory, D.L.; Hardee, H.C.; Smallwood, D.O.

1990-12-31

8

Downhole hydraulic seismic generator  

SciTech Connect

A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole. 4 figs.

Gregory, D.L.; Hardee, H.C.; Smallwood, D.O.

1990-01-01

9

Hermetic turbine generator  

DOEpatents

A Rankine cycle turbine drives an electric generator and a feed pump, all on a single shaft, and all enclosed within a hermetically sealed case. The shaft is vertically oriented with the turbine exhaust directed downward and the shaft is supported on hydrodynamic fluid film bearings using the process fluid as lubricant and coolant. The selection of process fluid, type of turbine, operating speed, system power rating, and cycle state points are uniquely coordinated to achieve high turbine efficiency at the temperature levels imposed by the recovery of waste heat from the more prevalent industrial processes.

Meacher, John S. (Ballston Lake, NY); Ruscitto, David E. (Ballston Spa, NY)

1982-01-01

10

Stand alone induction generator with terminal impedance controller and no turbine controls  

Microsoft Academic Search

Induction generators with hydraulic turbines are often used for cogeneration. The same turbine generator configuration can be used for stand-alone generation if an impedance controller is connected to the generator terminals; this configuration requires no hydraulic controls on the turbine. The authors propose an electronic impedance controller to control the voltage and the frequency of a stand-alone induction generator. The

R. Bonert; G. Hoops

1990-01-01

11

Downhole hydraulic seismic generator  

SciTech Connect

This patent describes a downhole seismic source for operation within a borehole to produce seismic energy waves through surrounding earth strata. It includes an elongated housing adapted for lowering into the borehole by a cable means; a hydraulic oscillator means carried by the housing for producing seismic vibrations in the housing; a hydraulic pressure source carried by the housing for providing a flow of high pressure hydraulic fluid, comprising a pump means for recycling the hydraulic fluid and for recharging the downhole seismic source and an electric motor for driving the pump means, the hydraulic pressure source further comprising a low pressure fluid accumulator which receives spent hydraulic fluid from the hydraulic oscillator means and from the clamp valve means and outputs hydraulic fluid to any pump means which outputs a high pressure hydraulic fluid, a heat exchanger means for receiving the high pressure fluid from the pump means and for dissipating heat produced by the pump means in the hydraulic fluid, and a high pressure accumulator for receiving the high pressure hydraulic fluid from the heat exchanger means and for providing the high pressure fluid as an output to an electro-hydraulic servovalve means, whereby the downhole seismic source is recharged for future operation; an electro-hydraulic servovalve means operably connected between the hydraulic pressure source and the hydraulic oscillator means for controlling the flow of high pressure hydraulic fluid from the hydraulic pressure source into the hydraulic oscillator means which thus produces the seismic vibrations; and a clamping means.

Gregory, D.L.; Hardee, H.C.; Smallwood, D.O.

1992-05-19

12

Development of a hydraulic turbine design method  

NASA Astrophysics Data System (ADS)

In this paper a hydraulic turbine parametric design method is presented which is based on the combination of traditional methods and parametric surface modeling techniques. The blade of the turbine runner is described using Bezier surfaces for the definition of the meridional plane as well as the blade angle distribution, and a thickness distribution applied normal to the mean blade surface. In this way, it is possible to define parametrically the whole runner using a relatively small number of design parameters, compared to conventional methods. The above definition is then combined with a commercial CFD software and a stochastic optimization algorithm towards the development of an automated design optimization procedure. The process is demonstrated with the design of a Francis turbine runner.

Kassanos, Ioannis; Anagnostopoulos, John; Papantonis, Dimitris

2013-10-01

13

Turbine hydraulic assessment and optimization in rehabilitation projects  

NASA Astrophysics Data System (ADS)

As turbines age after years of operation, a major rehabilitation is needed to give new life. The owner has two choices: resetting the turbine to the original state or an upgrade with new hydraulic components designed and optimized using state of the art technology. The second solution is by far a more interesting option which can maximize the efficiency gain, increase the turbine capacity and revenues, eliminate cavitation erosion and the needs for repair, reduce the turbine instabilities and smooth unit regulation, and adapt the design to new operation conditions. This paper shows some aspects of the turbine hydraulic assessment and possible solutions to improve existing water passages.

Bornard, L.; Debeissat, F.; Labrecque, Y.; Sabourin, M.; Tomas, L.

2014-12-01

14

Disturbance Control of the Hydraulic Brake in a Wind Turbine  

E-print Network

Disturbance Control of the Hydraulic Brake in a Wind Turbine Frank Jepsen, Anders Søborg brake in a wind turbine. Brake torque is determined by friction coefficient and clamp force; the latter brake is one1 of the two independent brake systems in a wind turbine. As a consequence of the gearing

Yang, Zhenyu

15

Control apparatus for hydraulically driven generator  

SciTech Connect

Apparatus for controlling a hydraulically driven generator for supplying electrical power to power mains. The generator is coupled to a turbine driven by a fluid flow through a duct. The duct has a one-fourth turn butterfly valve controlled by a fluid-actuated operator and the operator receives fluid from the duct by way of a normally closed valve which, when energized, creates water pressure on the operator for opening the butterfly valve. A second, normally open solenoid provides an emergency exit for the water from the operator to relieve the water pressure thereon and thereby close the butterfly valve when certain conditions exist, such as sudden loss of line voltage, overvoltage or deviation in frequency of the line voltage. A differential pressure switch across the turbine rotor also controls the starting of the system to assure proper flow of fluid through the duct before commencing operation of the generator itself.

Beckwith, S.

1985-08-06

16

Superconducting wind turbine generators  

NASA Astrophysics Data System (ADS)

We have examined the potential of 10 MW superconducting direct drive generators to enter the European offshore wind power market and estimated that the production of about 1200 superconducting turbines until 2030 would correspond to 10% of the EU offshore market. The expected properties of future offshore turbines of 8 and 10 MW have been determined from an up-scaling of an existing 5 MW turbine and the necessary properties of the superconducting drive train are discussed. We have found that the absence of the gear box is the main benefit and the reduced weight and size is secondary. However, the main challenge of the superconducting direct drive technology is to prove that the reliability is superior to the alternative drive trains based on gearboxes or permanent magnets. A strategy of successive testing of superconducting direct drive trains in real wind turbines of 10 kW, 100 kW, 1 MW and 10 MW is suggested to secure the accumulation of reliability experience. Finally, the quantities of high temperature superconducting tape needed for a 10 kW and an extreme high field 10 MW generator are found to be 7.5 km and 1500 km, respectively. A more realistic estimate is 200-300 km of tape per 10 MW generator and it is concluded that the present production capacity of coated conductors must be increased by a factor of 36 by 2020, resulting in a ten times lower price of the tape in order to reach a realistic price level for the superconducting drive train.

Abrahamsen, A. B.; Mijatovic, N.; Seiler, E.; Zirngibl, T.; Træholt, C.; Nørgård, P. B.; Pedersen, N. F.; Andersen, N. H.; Østergård, J.

2010-03-01

17

Research of performance prediction to energy on hydraulic turbine  

NASA Astrophysics Data System (ADS)

Refer to the low specific speed Francis turbine blade design principle and double-suction pump structure. Then, design a horizontal double-channel hydraulic turbine Francis. Through adding different guide vane airfoil and and no guide vane airfoil on the hydraulic conductivity components to predict hydraulic turbine energy and using Fluent software to numerical simulation that the operating conditions and point. The results show that the blade pressure surface and suction surface pressure is low when the hydraulic turbine installation is added standard positive curvature of the guide vane and modified positive curvature of guide vane. Therefore, the efficiency of energy recovery is low. However, the pressure of negative curvature guide vane and symmetric guide vane added on hydraulic turbine installations is larger than that of the former ones, and it is conducive to working of runner. With the decreasing of guide vane opening, increasing of inlet angle, flow state gets significantly worse. Then, others obvious phenomena are that the reflux and horizontal flow appeared in blade pressure surface. At the same time, the vortex was formed in Leaf Road, leading to the loss of energy. Through analyzing the distribution of pressure, velocity, flow lines of over-current flow in the the back hydraulic conductivity components in above programs we can known that the hydraulic turbine installation added guide vane is more reasonable than without guide vanes, it is conducive to improve efficiency of energy conversion.

Quan, H.; Li, R. N.; Li, Q. F.; Han, W.; Su, Q. M.

2012-11-01

18

Detection of cavitation vortex in hydraulic turbines using acoustic techniques  

NASA Astrophysics Data System (ADS)

Cavitation phenomena are known for their destructive capacity in hydraulic machineries and are caused by the pressure decrease followed by an implosion when the cavitation bubbles find an adverse pressure gradient. A helical vortex appears in the turbine diffuser cone at partial flow rate operation and can be cavitating in its core. Cavity volumes and vortex frequencies vary with the under-pressure level. If the vortex frequency comes close to one of the eigen frequencies of the turbine, a resonance phenomenon may occur, the unsteady fluctuations can be amplified and lead to important turbine and hydraulic circuit damage. Conventional cavitation vortex detection techniques are based on passive devices (pressure sensors or accelerometers). Limited sensor bandwidths and low frequency response limit the vortex detection and characterization information provided by the passive techniques. In order to go beyond these techniques and develop a new active one that will remove these drawbacks, previous work in the field has shown that techniques based on acoustic signals using adapted signal content to a particular hydraulic situation, can be more robust and accurate. The cavitation vortex effects in the water flow profile downstream hydraulic turbines runner are responsible for signal content modifications. Basic signal techniques use narrow band signals traveling inside the flow from an emitting transducer to a receiving one (active sensors). Emissions of wide band signals in the flow during the apparition and development of the vortex embeds changes in the received signals. Signal processing methods are used to estimate the cavitation apparition and evolution. Tests done in a reduced scale facility showed that due to the increasing flow rate, the signal -- vortex interaction is seen as modifications on the received signal's high order statistics and bandwidth. Wide band acoustic transducers have a higher dynamic range over mechanical elements; the system's reaction time is reduced, resulting in a faster detection of the unwanted effects. The paper will present an example of this new investigation technique on a vortex generator in the test facility that belongs to ICPE- CA.

Candel, I.; Bunea, F.; Dunca, G.; Bucur, D. M.; Ioana, C.; Reeb, B.; Ciocan, G. D.

2014-12-01

19

NEXT GENERATION TURBINE PROGRAM  

SciTech Connect

The Next Generation Turbine (NGT) Program's technological development focused on a study of the feasibility of turbine systems greater than 30 MW that offer improvement over the 1999 state-of-the-art systems. This program targeted goals of 50 percent turndown ratios, 15 percent reduction in generation cost/kW hour, improved service life, reduced emissions, 400 starts/year with 10 minutes to full load, and multiple fuel usage. Improvement in reliability, availability, and maintainability (RAM), while reducing operations, maintenance, and capital costs by 15 percent, was pursued. This program builds on the extensive low emissions stationary gas turbine work being carried out by Pratt & Whitney (P&W) for P&W Power Systems (PWPS), which is a company under the auspices of the United Technologies Corporation (UTC). This study was part of the overall Department of Energy (DOE) NGT Program that extends out to the year 2008. A follow-on plan for further full-scale component hardware testing is conceptualized for years 2002 through 2008 to insure a smooth and efficient transition to the marketplace for advanced turbine design and cycle technology. This program teamed the National Energy Technology Laboratory (NETL), P&W, United Technologies Research Center (UTRC), kraftWork Systems Inc., a subcontractor on-site at UTRC, and Multiphase Power and Processing Technologies (MPPT), an off-site subcontractor. Under the auspices of the NGT Program, a series of analyses were performed to identify the NGT engine system's ability to serve multiple uses. The majority were in conjunction with a coal-fired plant, or used coal as the system fuel. Identified also was the ability of the NGT system to serve as the basis of an advanced performance cycle: the humid air turbine (HAT) cycle. The HAT cycle is also used with coal gasification in an integrated cycle HAT (IGHAT). The NGT systems identified were: (1) Feedwater heating retrofit to an existing coal-fired steam plant, which could supply both heat and peaking power (Block 2 engine); (2) Repowering of an older coal-fired plant (Block 2 engine); (3) Gas-fired HAT cycle (Block 1 and 2 engines); (4) Integrated gasification HAT (Block 1 and 2 engines). Also under Phase I of the NGT Program, a conceptual design of the combustion system has been completed. An integrated approach to cycle optimization for improved combustor turndown capability has been employed. The configuration selected has the potential for achieving single digit NO{sub x}/CO emissions between 40 percent and 100 percent load conditions. A technology maturation plan for the combustion system has been proposed. Also, as a result of Phase I, ceramic vane technology will be incorporated into NGT designs and will require less cooling flow than conventional metallic vanes, thereby improving engine efficiency. A common 50 Hz and 60 Hz power turbine was selected due to the cost savings from eliminating a gearbox. A list of ceramic vane technologies has been identified for which the funding comes from DOE, NASA, the U.S. Air Force, and P&W.

William H. Day

2002-05-03

20

Large wind turbine generators  

NASA Technical Reports Server (NTRS)

The development associated with large wind turbine systems is briefly described. The scope of this activity includes the development of several large wind turbines ranging in size from 100 kW to several megawatt levels. A description of the wind turbine systems, their programmatic status and a summary of their potential costs is included.

Thomas, R. L.; Donovon, R. M.

1978-01-01

21

Application study of magnetic fluid seal in hydraulic turbine  

NASA Astrophysics Data System (ADS)

The waterpower resources of our country are abundant, and the hydroelectric power is developed, but at present the main shaft sealing device of hydraulic turbine is easy to wear and tear and the leakage is great. The magnetic fluid seal has the advantages of no contact, no wear, self-healing, long life and so on. In this paper, the magnetic fluid seal would be used in the main shaft of hydraulic turbine, the sealing structure was built the model, meshed the geometry, applied loads and solved by using MULTIPHYSICS in ANSYS software, the influence of the various sealing structural parameters such as tooth width, height, slot width, sealing gap on the sealing property were analyzed, the magnetic fluid sealing device suitable for large-diameter shaft and sealing water was designed, the sealing problem of the hydraulic turbine main shaft was solved effectively which will bring huge economic benefits.

Yu, Z. Y.; Zhang, W.

2012-11-01

22

30. PLAN AND SECTIONS SHOWING INSTALLATION OF HYDRAULIC TURBINE UNIT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. PLAN AND SECTIONS SHOWING INSTALLATION OF HYDRAULIC TURBINE UNIT FROM KAWEAH NO. 2 REPLACING EXISTING UNIT, SANTA ANA RIVER NO. 3, JUNE 21, 1945. SCE drawing no. 523126-1. - Santa Ana River Hydroelectric System, SAR-3 Powerhouse, San Bernardino National Forest, Redlands, San Bernardino County, CA

23

Failures due to ingested bodies in hydraulic turbines  

Microsoft Academic Search

The ingestion of large bodies in turbines can produce blockage in the runner that generates large, unbalanced forces. Blockage in the distributor can change the amplitude and uniformity of the pressure pulsations. Mechanical damage may also be generated.In all cases, the efficiency of the turbine is reduced and the forces on the runner and the vibration levels in the machine

Eduard Egusquiza; Carme Valero; Aida Estévez; Alfredo Guardo; Miguel Coussirat

24

Effective Lightning Protection For Wind Turbine Generators  

Microsoft Academic Search

A wind turbine generator is the most exposed of all types of generators connected to electric utility systems. Wind turbines are most often erected in hostile lightning environments. Lightning damage to wind turbines is costly in terms of repair and replacement of equipment. Lightning damage is the single largest cause of unplanned downtime in wind turbines, and that downtime is

Bruce Glushakow

2007-01-01

25

Energy recovery using hydraulic turbines in deep underground mines  

Microsoft Academic Search

At present, water for refrigeration purposes free falls in a mine shaft to the desired depth, and is then dissipated by friction and momentum transfer. This process is very costly to the mine owner. By converting the falling water to useful work, to operate a turbine, great savings can be realized. Not only will a turbine generate significant power, but

R. N. Torbin; E. B. Thimons

1983-01-01

26

In-situ robotic interventions in hydraulic turbines  

Microsoft Academic Search

This paper presents the development and implementation of a robotic technology designed to perform in-situ interventions in hydroelectric turbines. A new manipulator was designed with a unique, track-based kinematics well suited to access turbine blades in a confined space. As most work is done on curved surfaces, the robot relies on a curvilinear space model for trajectory generation. Several processes

B. Hazel; J. Co?te?; Y. Laroche; P. Mongenot

2010-01-01

27

Hydrodynamics automatic optimization of runner blades for reaction hydraulic turbines  

NASA Astrophysics Data System (ADS)

The aim of this paper is to optimize the hydrodynamics of the runner blades of hydraulic turbines. The runner presented is an axial Kaplan one, but the methodology is common also to Francis runners. The whole methodology is implemented in the in-house software QTurbo3D. The effect of the runner blades geometry modification upon its hydrodynamics is shown both from energetic and cavitation points of view.

Balint, D.; Câmpian, V.; Nedelcu, D.; Megheles, O.

2012-11-01

28

Hydraulic generator with free-piston engine  

Microsoft Academic Search

A hydraulic generator is disclosed with a free-piston engine and hydropneumatic return cushion and with an associated hydraulic-fluid pumping piston feeding a hydraulic accumulator intended to be charged between two detected levels of pressure. The generator includes a lock device for the free piston at the power-stroke dead center with voluntary control, and servo-control means for this lock device with

P. Bouthers; O. Breting

1983-01-01

29

Effects of turbine's selection on hydraulic transients in the long pressurized water conveyance system  

NASA Astrophysics Data System (ADS)

For a hydropower station with longer water conveyance system, an optimum turbine's selection will be beneficial to its reliable and stable operation. Different optional turbines will result in possible differences of the hydraulic characteristics in the hydromechanical system, and have different effects on the hydraulic transients' analysis and control. Therefore, the premise for turbine's selection is to fully understand the properties of the optional turbines and their effects on the hydraulic transients. After a brief introduction of the simulation models for hydraulic transients' computation and stability analysis, the effects of hydraulic turbine's characteristics at different operating points on the hydro-mechanical system's free vibration analysis were theoretically investigated with the hydraulic impedance analysis of the hydraulic turbine. For a hydropower station with long water conveyance system, based on the detailed hydraulic transients' computation respectively for two different optional turbines, the effects of the turbine's selection on hydraulic transients were analyzed. Furthermore, considering different operating conditions for each turbine and the similar operating conditions for these two turbines, free vibration analysis was comprehensively carried out to reveal the effects of turbine's impedance on system's vibration characteristics. The results indicate that, respectively with two different turbines, most of the controlling parameters under the worst cases have marginal difference, and few shows obvious differences; the turbine's impedances under different operating conditions have less effect on the natural angular frequencies; different turbine's characteristics and different operating points have obvious effects on system's vibration stability; for the similar operating conditions of these two turbines, system's vibration characteristics are basically consistent with each other.

Zhou, J. X.; Hu, M.; Cai, F. L.; Huang, X. T.

2014-12-01

30

Effects of draft tube on the hydraulic performance of a Francis turbine  

NASA Astrophysics Data System (ADS)

The draft tube is an important component of a Francis turbine which influences the hydraulic performance. It is located just under the runner and allowed to decelerate the flow velocity exiting the runner, thereby converting the excess of kinetic energy into static pressure. In this study, we have numerically investigated the hydraulic performance of a Francis turbine on the 15MW hydropower generation with various design parameters (three types of draft tube, thickness of guide vane) through a three-dimensional numerical method with the SST turbulent model. The vortex rope characteristics of the draft tube were confirmed. The results of the vortex flow fields and flow characteristics were graphically depicted with different design parameters and operating conditions.

Jeon, J. H.; Byeon, S. S.; Kim, Y. J.

2013-12-01

31

Dynamics and stability of wind turbine generators  

NASA Astrophysics Data System (ADS)

This paper describes the dynamic and stability properties of wind turbine generators connected to power systems. Both synchronous and induction generators are considered. A comparison is made between wind turbines, steam, and hydro units. The unusual phenomena associated with wind turbines are emphasized. The general control requirements are discussed, as well as various schemes for torsional damping such as speed sensitive stabilizer and blade pitch control. Interaction between adjacent wind turbines in a 'wind farm' is also considered.

Hinrichsen, E. N.; Nolan, P. J.

1982-08-01

32

Microprocessor control of a wind turbine generator  

NASA Technical Reports Server (NTRS)

A microprocessor based system was used to control the unattended operation of a wind turbine generator. The turbine and its microcomputer system are fully described with special emphasis on the wide variety of tasks performed by the microprocessor for the safe and efficient operation of the turbine. The flexibility, cost and reliability of the microprocessor were major factors in its selection.

Gnecco, A. J.; Whitehead, G. T.

1978-01-01

33

Generating Resources Combined Cycle Combustion Turbine  

E-print Network

11/17/2014 1 Generating Resources Combined Cycle Combustion Turbine Utility Scale Solar PV Steven doing recently around two key supply-side resource technologies 1. Combined Cycle Combustion Turbine #12;11/17/2014 4 Combined Cycle Combustion Turbine Background Primary Components Gas-fired combustion

34

Numerical prediction of erosion on guide vanes and in labyrinth seals in hydraulic turbines  

Microsoft Academic Search

Erosion in hydraulic power plants is caused by sand particles in the flow. This is one of the major problems that restricts the lifetime between overhauls of water turbines. Especially those parts of the hydraulic turbine which are exposed to high flow velocities bear a considerable risk of being damaged by erosion processes. Therefore, suitable methods for the prediction of

Reiner Mack; Peter Drtina; Egon Lang

1999-01-01

35

SWIRLING FLOW OPTIMIZATION IN THE SPIRAL CASE AND DISTRIBUTOR OF KAPLAN HYDRAULIC TURBINES  

Microsoft Academic Search

The goal of this paper is to reduce the unsteady blade loadings for the runners of Kaplan hydraulic turbines by using a technique of flow optimization in the ad- duction channel of the turbine: spiral casing, stay and guide vanes. Flow circumferential non-uniformities upstream the runner of Kaplan turbines produce un- wished effects as vibrations, but especially it influences the

Timisoara Branch

36

Performance characteristics of hydraulic turbines and pumps. Proceedings of the Winter annual meeting, Boston, MA, November 13-18, 1983  

Microsoft Academic Search

Various topics are addressed under the headings: four quadrant and two-phase performance of turbines and pumps, cavitation in hydraulic turbines and pumps, pumps as power recovery turbines, and modeling and fluid dynamics in hydraulic turbines and pumps. Individual subjects considered include: representation of pump characteristics for transient analysis, prediction and measurement of the four-quadrant performance of an axial flow pump

G. Jr. Bennett; W. L. Swift

1983-01-01

37

NEXT GENERATION TURBINE SYSTEM STUDY  

SciTech Connect

Rolls-Royce has completed a preliminary design and marketing study under a Department of Energy (DOE) cost shared contract (DE-AC26-00NT40852) to analyze the feasibility of developing a clean, high efficiency, and flexible Next Generation Turbine (NGT) system to meet the power generation market needs of the year 2007 and beyond. Rolls-Royce evaluated the full range of its most advanced commercial aerospace and aeroderivative engines alongside the special technologies necessary to achieve the aggressive efficiency, performance, emissions, economic, and flexibility targets desired by the DOE. Heavy emphasis was placed on evaluating the technical risks and the economic viability of various concept and technology options available. This was necessary to ensure the resulting advanced NGT system would provide extensive public benefits and significant customer benefits without introducing unacceptable levels of technical and operational risk that would impair the market acceptance of the resulting product. Two advanced cycle configurations were identified as offering significant advantages over current combined cycle products available in the market. In addition, balance of plant (BOP) technologies, as well as capabilities to improve the reliability, availability, and maintainability (RAM) of industrial gas turbine engines, have been identified. A customer focused survey and economic analysis of a proposed Rolls-Royce NGT product configuration was also accomplished as a part of this research study. The proposed Rolls-Royce NGT solution could offer customers clean, flexible power generation systems with very high efficiencies, similar to combined cycle plants, but at a much lower specific cost, similar to those of simple cycle plants.

Frank Macri

2002-02-28

38

Anticipatory control of turbine generators  

E-print Network

Kp (12) 20 KrWpKp W -W WpKp 1 S -Wp Fig. 9. Signal flow graph of reheat turbine generator. 21 The typi ca 1 values for the parameter in thi s model ar e as fol 1ows: Rated capacity P = 200 MW r Normal capacity P0 = 100 MW Inertia constant H... = 5 sec Regulation R = 2. 5 Hz/pu MW T =10sec r K =. 3 r 0 = 8. 33 ~ 10 pu MW/Hz T = 20 sec p Kp = 120 Hz/pu MW Using these values (12) is X I ' ' 1 ? . I ? . 04 X 0 . 1 + aL + ap0 X2 4 2 77 X2 6 I 8 (13) XI and X2 are the change...

Messec, Freddie Laurel

1971-01-01

39

Turbine generator pressure relief diaphragm  

SciTech Connect

A steam turbine is described comprising: (a) a turbine housing operable to receive steam and having a relief opening therein surrounded by a turbine flange; (b) a shaft positioned within the housing; (c) a plurality of rows of blades positioned along the longitudinal length of the shaft and extending radially outwardly therefrom; (d) a steam inlet pipe connected with the housing and operable as a conduit to allow the steam entering the housing to pass between the plurality of rows of blades to rotate the shaft; and (e) a pressure relief diaphragm associated with the turbine housing and operable to relieve excess pressure within the turbine housing, including: (i) a safety housing having a mounting flange thereon arranged to mate with the turbine flange so that the safety housing is positioned over the relief opening in the turbine housing; (ii) a first solid, frangible disc covering the relief opening in the turbine housing and having a peripheral portion interposed between the mounting flange on the safety housing and the turbine flange; (iii) a second solid disc positioned in the relief opening in the turbine flange in abutting contact with the first solid disc; (iv) first bolt means for securing the mounting flange on the safety housing to the turbine flange; (v) first spring washer means associated with the first bolt means for maintaining the positional relationship between the mounting flange on the safety housing and the turbine flange; (vi) an annular ring positioned on the first solid disc and above the relief opening in the turbine housing; (vii) second bolt means for securing the second solid disc and the annular ring to the first solid disc; and (viii) second spring washer means associated with the second bolt means for maintaining the positional relationship among the first solid disc, the second solid disc and the annular ring.

Groenendaal, J.C. Jr.; Huang, K.P.

1993-06-29

40

Biomass gasifier gas turbine power generating technology  

Microsoft Academic Search

Integrating gasifiers with gas turbines, aeroderivative gas turbines in particular, makes it possible to achieve high efficiencies and low unit capital costs in modest-scale biomass power generating facilities. Electricity produced with biomass-integrated gasifier\\/gas turbine (BIG\\/GT) power systems would be competitive with electricity produced from coal and nuclear energy under a wide range of circumstances. Biomass also offers major environmental benefits.

R. H. Williams; E. D. Larson

1996-01-01

41

Hydraulic generator with free-piston engine  

SciTech Connect

A hydraulic generator is disclosed with a free-piston engine and hydropneumatic return cushion and with an associated hydraulic-fluid pumping piston feeding a hydraulic accumulator intended to be charged between two detected levels of pressure. The generator includes a lock device for the free piston at the power-stroke dead center with voluntary control, and servo-control means for this lock device with means for detection of the aforementioned two pressure levels, to assure locking the piston in response to detection of the aforementioned highest pressure level and to assure its unlocking in response to detection of the aforementioned lowest pressure level, and thus an automatic intermittent running of said engine.

Bouthers, P.; Breting, O.

1983-11-15

42

Hydraulic optimization of "S" characteristics of the pump-turbine for Xianju pumped storage plant  

NASA Astrophysics Data System (ADS)

The pump-turbine with a rated power capacity of 375MW each at Xianju pumped storage plant is the most powerful one under construction in China. In order to avoid the instability near no-load conditions, the hydraulic design of the pump-turbine has been optimized to improving the "S" characteristic in the development of the model pump-turbine. This paper presents the cause of "S" characteristic of a pump-turbine by CFD simulation of the internal flow. Based on the CFD analysis, the hydraulic design optimization of the pump-turbine was carried out to eliminate the "S" characteristics of the machine at Xianju pumped storage plant and a big step for removing the "S" characteristic of a pump-turbine has been obtained. The model test results demonstrate that the pump-turbine designed for Xianju pumped storage plant can smoothly operate near no-load conditions without an addition of misaligned guide vanes.

Liu, W. C.; Zheng, J. S.; Cheng, J.; Shi, Q. H.

2012-11-01

43

An evaluation of a hubless inducer and a full flow hydraulic turbine driven inducer boost pump  

NASA Technical Reports Server (NTRS)

The purpose of the study was to compare the performance of several configurations of hubless inducers with a hydrodynamically similar conventional inducer and to demonstrate the performance of a full flow hydraulic turbine driven inducer boost pump using these inducers. A boost pump of this type consists of an inducer connected to a hydraulic turbine with a high speed rotor located in between. All the flow passes through the inducer, rotor, and hydraulic turbine, then into the main pump. The rotor, which is attached to the main pump shaft, provides the input power to drive the hydraulic turbine which, in turn, drives the inducer. The inducer, rotating at a lower speed, develops the necessary head to prevent rotor cavitation. The rotor speed is consistent with present main engine liquid hydrogen pump designs and the overall boost pump head rise is sufficient to provide adequate main pump suction head. This system would have the potential for operating at lower liquid hydrogen tank pressures.

Lindley, B. K.; Martinson, A. R.

1971-01-01

44

Reverse engineering of hydraulic turbine runners using coordinate measuring arms and NURBS modeling  

Microsoft Academic Search

This work intends to address the issue of Computer-Aided Design (CAD) model development associated to large complex geometries like hydraulic turbine runners, applying reverse engineering techniques and Non-Uniform Rational B-Splines (NURBS) modeling. A measurement strategy was proposed to reconstruct a Kaplan hydraulic turbine runner. The experimental approach was developed at Coaracy Nunes power plant, pertaining to Eletronorte and located in

Antonio Piratelli-Filho; José Alexander Araújo

45

Challenges in Dynamic Pressure and Stress Predictions at No-Load Operation in Hydraulic Turbines  

NASA Astrophysics Data System (ADS)

Some of the potentially most damaging continuous operating conditions for hydraulic turbines are the no-load (NL) conditions. At NL conditions the flow passes through the turbine without power generation, but with non-negligible flow rate, and therefore all the potential energy in the flow has to be dissipated. This takes place through a mechanism where the runner channels are partially pumping, thus generating large scale unsteady vortex structures which, by their nature, break down into smaller and smaller vortices until energy dissipation occurs at the smallest scales. This type of flow, dominated by its turbulent character, is inherently difficult to simulate by means of numerical methods since turbulence model and numerical dissipation have a major influence. The resulting dynamic loads on the runner are largely of stochastic nature, exciting a broad band of frequencies and thus, almost always interact with at least one deformation mode. The presented investigations are aimed at predicting the effect of the unsteady NL pressure loads on the fatigue life of a Francis turbine runner. A combination of computational fluid dynamics (CFD) and finite element analysis (FEA) methods has been employed. The results from transient CFD simulations are presented. Comparison of the results with prototype strain gauge measurements at no load conditions shows that the stochastic nature and the approximate range of the dynamic stresses can be predicted.

Nennemann, B.; Morissette, J. F.; Chamberland-Lauzon, J.; Monette, C.; Braun, O.; Melot, M.; Coutu, A.; Nicolle, J.; Giroux, A. M.

2014-12-01

46

Novel Repair Technique for Life-Extension of Hydraulic Turbine Components in Hydroelectric Power Stations  

Microsoft Academic Search

A significant number of hydraulic turbines operated in Japan were installed in the first half of the 20th century. Today, aging degradation and flaws are observed in these turbine equipments. So far, Japanese engineers have applied NDI technology of Ultrasonic Testing (UT) to detect the flaws, and after empirical evaluation of the remaining life they decided an adequate moment to

Yoichi Hiramatsu; Jun Ishii; Kazuhiro Funato

2008-01-01

47

NEXT GENERATION GAS TURBINE SYSTEMS STUDY  

SciTech Connect

Under sponsorship of the U.S. Department of Energy's National Energy Technology Laboratory, Siemens Westinghouse Power Corporation has conducted a study of Next Generation Gas Turbine Systems that embraces the goals of the DOE's High Efficiency Engines and Turbines and Vision 21 programs. The Siemens Westinghouse Next Generation Gas Turbine (NGGT) Systems program was a 24-month study looking at the feasibility of a NGGT for the emerging deregulated distributed generation market. Initial efforts focused on a modular gas turbine using an innovative blend of proven technologies from the Siemens Westinghouse W501 series of gas turbines and new enabling technologies to serve a wide variety of applications. The flexibility to serve both 50-Hz and 60-Hz applications, use a wide range of fuels and be configured for peaking, intermediate and base load duty cycles was the ultimate goal. As the study progressed the emphasis shifted from a flexible gas turbine system of a specific size to a broader gas turbine technology focus. This shift in direction allowed for greater placement of technology among both the existing fleet and new engine designs, regardless of size, and will ultimately provide for greater public benefit. This report describes the study efforts and provides the resultant conclusions and recommendations for future technology development in collaboration with the DOE.

Benjamin C. Wiant; Ihor S. Diakunchak; Dennis A. Horazak; Harry T. Morehead

2003-03-01

48

Experimental Study on Abrasive Waterjet Polishing of Hydraulic Turbine Blades  

NASA Astrophysics Data System (ADS)

In this paper, an experimental investigation is implemented on the abrasive waterjet polishing technique to evaluate its capability in polishing of surfaces and edges of hydraulic turbine blades. For this, the properties of this method are studied and the main parameters affecting its performance are determined. Then, an experimental test-rig is designed, manufactured and tested to be used in this study. This test-rig can be used to polish linear and planar areas on the surface of the desired workpieces. Considering the number of parameters and their levels, the Taguchi method is used to design the preliminary experiments. All experiments are then implemented according to the Taguchi L18 orthogonal array. The signal-to-noise ratios obtained from the results of these experiments are used to determine the importance of the controlled polishing parameters on the final quality of the polished surface. The evaluations on these ratios reveal that the nozzle angle and the nozzle diameter have the most important impact on the results. The outcomes of these experiments can be used as a basis to design a more precise set of experiments in which the optimal values of each parameter can be estimated.

Khakpour, H.; Birglenl, L.; Tahan, A.; Paquet, F.

2014-12-01

49

Work of the Leningrad Metal Factory Industrial Association toward modernizing hydraulic turbines at existing hydroelectric plants  

Microsoft Academic Search

Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a At the present time there are tested, reliable solutions for modernization of different hydraulic turbine assemblies, which\\u000a substantially improve their operating characteristics.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a The hydraulic turbine factories may not be able to systematically carry out orders for fabrication of parts intended to modernize\\u000a turbine assemblies, since the existing production facilities are almost fully utilized by the planned manufacture

V. M. Malyshev

1978-01-01

50

Wave Generation Experiments Using a Cycloidal Turbine  

NASA Astrophysics Data System (ADS)

We investigate the wave generation performance of a cycloidal turbine for the purpose of converting wave energy to shaft power. Cycloidal turbines consist of one or more hydrofoils that rotate around a central shaft and can be pitched during rotation. In the present investigation, a two-dimensional wave channel of 45cm width, 4.5m length and a water depth of 30 cm is used. It features a flap wave maker at one end, and a beach at the other end. A two blade Cycloidal turbine model is placed in the center of the wave channel and the generated waves in both up-wave and down-wave directions are measured using wave gauges. We compare the results to inviscid potential flow simulations that show negligible waves traveling up-wave, and a single harmonic wave traveling down-wave making the Cycloidal turbine an ideal wave energy converter if synchronized to the incoming wave.

Siegel, Stefan; McLaughlin, Thomas

2010-11-01

51

Variable speed generator technology options for wind turbine generators  

NASA Technical Reports Server (NTRS)

The electrical system options for variable speed operation of a wind turbine generator are treated in this paper. The key operating characteristics of each system are discussed and the major advantages and disadvantages of each are identified

Lipo, T. A.

1995-01-01

52

Wind tunnel experiments to prove a hydraulic passive torque control concept for variable speed wind turbines  

NASA Astrophysics Data System (ADS)

In this paper the results are presented of experiments to prove an innovative concept for passive torque control of variable speed wind turbines using fluid power technology. It is demonstrated that by correctly configuring the hydraulic drive train, the wind turbine rotor operates at or near maximum aerodynamic efficiency for below rated wind speeds. The experiments with a small horizontal-axis wind turbine rotor, coupled to a hydraulic circuit, were conducted at the Open Jet Facility of the Delft University of Technology. In theory, the placement of a nozzle at the end of the hydraulic circuit causes the pressure and hence the rotor torque to increase quadratically with flow speed and hence rotation speed. The rotor torque is limited by a pressure relief valve. Results from the experiments proved the functionality of this passive speed control concept. By selecting the correct nozzle outlet area the rotor operates at or near the optimum tip speed ratio.

Diepeveen, N. F. B.; Jarquin-Laguna, A.

2014-12-01

53

Hydraulic turbines: hydroelectric and tidal power systems. January, 1973-September, 1981 (citations from the BHRA Fluid Engineering data base). Report for Jan 73-Sep 81  

SciTech Connect

The hydrodynamics of adjustable blade hydraulic turbines are discussed as it applies to hydroelectric and tidal power generation. The adjustable blade concept is presented in terms of cavitation minimization as well as vibrational induced stresses on the blades. (Contains 91 citations fully indexed and including a title list.)

Not Available

1981-09-01

54

Broad band sound from wind turbine generators  

NASA Technical Reports Server (NTRS)

Brief descriptions are given of the various types of large wind turbines and their sound characteristics. Candidate sources of broadband sound are identified and are rank ordered for a large upwind configuration wind turbine generator for which data are available. The rotor is noted to be the main source of broadband sound which arises from inflow turbulence and from the interactions of the turbulent boundary layer on the blade with its trailing edge. Sound is radiated about equally in all directions but the refraction effects of the wind produce an elongated contour pattern in the downwind direction.

Hubbard, H. H.; Shepherd, K. P.; Grosveld, F. W.

1981-01-01

55

Infrasound emission generated by wind turbines  

NASA Astrophysics Data System (ADS)

Aerodynamic noise emissions from the continuously growing number of wind turbines in Germany are creating increasing problems for infrasound recording systems. Such systems are equipped with highly sensitive micro pressure sensors, which are accurately measuring acoustic signals in a frequency range inaudible to humans. At infrasound station IGADE, north of Bremen, a constantly increasing background noise has been observed throughout the years since its installation in 2005. The spectral peaks are reflecting well the blade passing harmonics, which vary with prevailing wind speeds. Overall, a decrease is noted for the infrasound array's detection capability. This aspect is particularly important for the other two sites of the German infrasound stations I26DE in the Bavarian Forest and I27DE in Antarctica, because plans for installing wind turbines near these locations are being under discussion. These stations are part of the International Monitoring System (IMS) verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), and have to meet stringent specifications with respect to infrasonic background noise. Therefore data obtained during a field experiment with mobile micro-barometer stations for measuring the infrasonic pressure level of a single horizontal-axis wind turbine have been revisited. The results of this experiment successfully validate a theoretical model which estimates the generated sound pressure level of wind turbines and makes it possible to specify the minimum allowable distance between wind turbines and infrasound stations for undisturbed recording. Since the theoretical model also takes wind turbine design parameters into account, suitable locations for planned infrasound stations outside the determined disturbance range can be found, which will be presented; and vice versa, the model calculations' results for fixing the minimum distance for wind turbines planned for installation in the vicinity of an existing infrasound array.

Ceranna, Lars; Pilger, Christoph

2014-05-01

56

Designing Micro Wind Turbines for Portable Power Generation Francois Hogan  

E-print Network

is to design a small wind turbine with the capability of charging the batteries of portable devicesDesigning Micro Wind Turbines for Portable Power Generation Francois Hogan Department of Mechanical such as cellular phones. Why should we use wind turbines when we have power supplies? These micro turbines would

Barthelat, Francois

57

Generator Power Measurements for Turbine Performance Testing at Bureau of Reclamation Powerplants  

Microsoft Academic Search

To achieve low uncertainty in a hydroelectric turbine performance test, the measured parameters should be obtained in accordance with the American Society of Mechanical Engineers (ASME) Power Test Code for Hydraulic Turbines and Pump-Turbines (PTC-18) or the International Electrotechnical Commission (IEC) International Code for the Field Acceptance Tests of Hydraulic Turbines (IEC 60041). When the results of past runner replacement

James DeHaan; David Hulse

58

Numerical Simulations of Vortex Shedding in Hydraulic Turbines  

NASA Technical Reports Server (NTRS)

Turbomachines for rocket propulsion applications operate with many different working fluids and flow conditions. Oxidizer boost turbines often operate in liquid oxygen, resulting in an incompressible flow field. Vortex shedding from airfoils in this flow environment can have adverse effects on both turbine performance and durability. In this study the effects of vortex shedding in a low-pressure oxidizer turbine are investigated. Benchmark results are also presented for vortex shedding behind a circular cylinder. The predicted results are compared with available experimental data.

Dorney, Daniel; Marcu, Bogdan

2004-01-01

59

Research on Darrieus-type hydraulic turbine for extra-low head hydropower utilization  

NASA Astrophysics Data System (ADS)

A Darrieus-type turbine has been investigated for extra-low head hydropower utilization. In the present paper, authors'research on Darrieus-type hydraulic turbine is briefly reviewed. The working principle of Darrieus turbine is explained with advantage of its simple structure, at first. Then the fluid-dynamic difference between rotating and linear motions of a blade in a uniform flow is clarified with guiding principle of high performance design of Darrieus turbine. Cavitation problem is also described. Next, effects of duct-casing, consisting of an intake, runner section and draft tube, are discussed and a simplified structure of Darrieus turbine is shown by installing the inlet nozzle. Finally, in the practical use, an adjustment of inlet nozzle section by lowering the inlet nozzle height is proposed when flow rate is varied temporally and seasonally.

Furukawa, A.; Watanabe, S.; Okuma, K.

2012-11-01

60

Dual entry radial turbine gas generator  

SciTech Connect

This patent describes a high efficiency, single spool gas turbine gas generator comprising: (a) compressor means for providing an overall pressure ratio of greater than about 15:1, the compressor means including: (i) a first stage, double-entry centrifugal air compressor having a pair of entrances and a common exit, (ii) a second stage, centrifugal air compressor positioned adjacent to the first stage compressor, the second compressor stage having an entrance that is flow-connected to the first stage common exit and also having a second stage exit, and (iii) a shaft assembly for mechanically interconnecting the first and the second stage for rotation at the same angular speed; (b) combustor means operatively connected to the second stage exit for receiving the compressed air and combusting fuel using the compressed air to generate combustion gases; and (c) a single stage radial inflow turbine having an inlet and an outlet, the turbine being operatively connected directly to the shaft assembly drive and also being flow connected to the combustor means for receiving at the turbine inlet, and partially expanding, the combustion gases.

Mowill, R.J.

1987-02-10

61

Study on stress characteristics of Francis hydraulic turbine runner based on two-way FSI  

NASA Astrophysics Data System (ADS)

In recent years, cracking phenomenon occurs in many large-sized turbines both nationally and internationally, which has threatened the stable operation of hydraulic turbines. Consequently, Stress characteristics calculation and analysis of a Francis hydraulic turbine runner by application of fluid-structure interaction (FSI) technology become significantly important. In order to introduce two-way coupling technology to hydraulic machinery, two-way FSI technology is applied in this article to calculate and analyze stress characteristics. Through coordinate system transformation, the continuity equations and Navier-Stokes equations in the Cartesian coordinates system are firstly transformed to ALE coordinates system. The fluid field control equations are then constructed and discrete equations can be obtained by using flow-condition-based interpolation (FBIC-C). The structure static mechanics equations used are established in rotation coordinate system, and modeled with the finite method. Two-way coupling is computed by using iteration method. The fluid equations and structure equations are iterated until coupling coefficients converge. According to structure result, the maximum stress, displacement as well as its location can be found. As a result, the most easily wear position can be discovered which provides valuable basis for optimized design and stable operation of Francis hydraulic turbines. After comparing the results with that of one-way coupling, it is discovered that displacements is the key factors which affects the results of one-way and two-way coupling.

Zhu, W. R.; Xiao, R. F.; Yang, W.; Liu, J.; Wang, F. J.

2012-11-01

62

Experiences with the hydraulic design of the high specific speed Francis turbine  

NASA Astrophysics Data System (ADS)

The high specific speed Francis turbine is still suitable alternative for refurbishment of older hydro power plants with lower heads and worse cavitation conditions. In the paper the design process of such kind of turbine together with the results comparison of homological model tests performed in hydraulic laboratory of ?KD Blansko Engineering is introduced. The turbine runner was designed using the optimization algorithm and considering the high specific speed hydraulic profile. It means that hydraulic profiles of the spiral case, the distributor and the draft tube were used from a Kaplan turbine. The optimization was done as the automatic cycle and was based on a simplex optimization method as well as on a genetic algorithm. The number of blades is shown as the parameter which changes the resulting specific speed of the turbine between ns=425 to 455 together with the cavitation characteristics. Minimizing of cavitation on the blade surface as well as on the inlet edge of the runner blade was taken into account during the design process. The results of CFD analyses as well as the model tests are mentioned in the paper.

Obrovsky, J.; Zouhar, J.

2014-12-01

63

Matching wind turbine generators with wind regime in Egypt  

Microsoft Academic Search

This paper presents a novel method of matching wind turbine generators to a site using turbine performance index (TPI) in conjunction with minimum deviation ratio (DR) between rated speed of wind turbine generator (WTG) and optimal speed and resulting in minimum cost of energy (COE). The methodology allows yielding higher energy production at higher capacity factor and minimum cost of

Ahmed R. Abul’Wafa

2011-01-01

64

Optimal motion generation for hydraulic robots  

Microsoft Academic Search

this document, the term "hydraulic machine" or "hydraulic robot" will refer to a typicalhydraulic machine or robot with the above characteristics. The testbed used for all the work in this documentis a CAT 325 HEX similar to that in Fig 1.2. Motivation

Murali Krishna

1998-01-01

65

Wind Turbine Generator System Safety and Function Test Report for the Entegrity EW50 Wind Turbine  

SciTech Connect

This report summarizes the results of a safety and function test that NREL conducted on the Entegrity EW50 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.

Smith, J.; Huskey, A.; Jager, D.; Hur, J.

2012-11-01

66

Wind Turbine Generator System Safety and Function Test Report for the Ventera VT10 Wind Turbine  

SciTech Connect

This report summarizes the results of a safety and function test that NREL conducted on the Ventera VT10 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.

Smith, J.; Huskey, A.; Jager, D.; Hur, J.

2012-11-01

67

Understanding the unbalanced-voltage problem in wind turbine generation  

Microsoft Academic Search

Most wind turbines are equipped with line-connected induction generators. Induction generators are very attractive as wind turbine generators due to their low cost, ruggedness, and the need for little or no maintenance. At constant frequency, the induction generator operates in a small range of speeds and, therefore, it operates with a small range of slips with respect to synchronous speed.

E. Muljadi; D. Yildirim; T. Batan; C. P. Butterfield

1999-01-01

68

Development of the helical reaction hydraulic turbine. Final technical report, July 1, 1996--June 30, 1998  

SciTech Connect

The present report contains the final results obtained during July 1996--July 1998. This report should be considered in association with the Annual Progress Report submitted in July 1997 due to the fact that not all of the intermediate results reflected in the Progress Report have been included in the Final Report. The aim of the project was to build a helical hydraulic turbine prototype and demonstrate its suitability and advantages as a novel apparatus to harness hydropower from ultra low-head rivers and other free water streams such as ocean currents or rivers without dams. The research objectives of the project are: Design, optimization and selection of the hydro foil section for the helical turbine; Design of the turbine for demonstration project; Construction and testing of the turbine module; Assessing test results and determining scale-up feasibility. The research conducted under this project has substantially exceeded the original goals including designing, constructing and testing of a scaled-up triple-helix turbine, as well as developing recommendations for application of the turbine for direct water pumping in irrigation systems and for future use in wind farms. Measurements collected during two years of turbine testing are kept in the PI files.

Gorlov, A.

1998-08-01

69

Hydraulic torque on the guide vane within the slight opening of pump turbine in turbine operating mode  

NASA Astrophysics Data System (ADS)

In a pumped storage power station, the units produce vibration and noise at times when the guide vanes rotate into the slight opening region during the turbine operating mode. According to this phenomenon, the simulation of transient flow in the units during the motion of the guide vane is carried out to investigate the variation of flow state in the process of startup and shutdown in turbine mode. The changing rate of hydraulic torque on a single guide vane is introduced to quantitatively represent the varying acuteness of the flow in the guide vanes and the possibility of the noise induced by the instable flow. The correlation between the frequency of noise and water head is summarized. The research indicates that the repeating reversal of fluid after load rejection is the hydraulic phenomenon which is the cause of the distributor vibration and noises within the slight opening, which is in accordance with the data recorded during the operation of the station. The effect of guide vanes closing law on the flow state in guide vanes and hydraulic torque on a single guide vane is analyzed.

Fan, H. G.; Yang, H. X.; Li, F. C.; Chen, N. X.

2014-12-01

70

Wind Turbine Contingency Control Through Generator De-Rating  

NASA Technical Reports Server (NTRS)

Maximizing turbine up-time and reducing maintenance costs are key technology drivers for wind turbine operators. Components within wind turbines are subject to considerable stresses due to unpredictable environmental conditions resulting from rapidly changing local dynamics. In that context, systems health management has the aim to assess the state-of-health of components within a wind turbine, to estimate remaining life, and to aid in autonomous decision-making to minimize damage to the turbine. Advanced contingency control is one way to enable autonomous decision-making by providing the mechanism to enable safe and efficient turbine operation. The work reported herein explores the integration of condition monitoring of wind turbines with contingency control to balance the trade-offs between maintaining system health and energy capture. The contingency control involves de-rating the generator operating point to achieve reduced loads on the wind turbine. Results are demonstrated using a high fidelity simulator of a utility-scale wind turbine.

Frost, Susan; Goebel, Kai; Balas, Mark

2013-01-01

71

Problems assciated with the operating reliability of heavy-duty hydraulic turbines  

Microsoft Academic Search

Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a The study and codification of the operating experience gained with heavy-duty rotary-blade and radial-axial hydraulic turbines\\u000a made it possible to obtain quantitative estimates of the reliability characteristics of basis subassemblies and components\\u000a of the equipment and to ascertain the character of the failure distribution as a function of turbine operation. The estimates\\u000a obtained make it possible to make

G. A. Vil'ner

1976-01-01

72

Low frequency noise from MW wind turbines --mechanisms of generation  

E-print Network

Low frequency noise from MW wind turbines -- mechanisms of generation and its modeling Helge 3.6MW turbine 12 3.2 Noise as function of wind speed 12 3.3 Noise as function of rotor" " Risø-R-1637(EN) 4 #12;Summary A considerable research on low frequency noise from wind turbine rotors

73

A new wind turbine generation system based on matrix converter  

Microsoft Academic Search

At a given wind velocity, the mechanical power available from a wind turbine is a function of its shaft speed. To maximize the power captured from the wind, the shaft speed has to be controlled. In low-cost wind energy conversion systems, the turbine shaft speed is not regulated and a squirrel-cage induction generator is used to convert the turbine mechanical

S. M. Barakati; M. Kazerani; X. Chen

2005-01-01

74

Selection of the parameters of hydraulic turbines when reconstructing operating hydroelectric stations  

Microsoft Academic Search

the use of the energy of the stream has worsened, since the weighted average efficiency with respect to generation was 5-10% below the maximum possible for the give type of turbines. Along with a decrease of the efficiency of using the stream and a shift of the operation of the turbines into the zone of lower efficiency values and increased

I. P. Ivanchenko; A. I. Nikiforov; V. I. Platov

1989-01-01

75

Model 0A wind turbine generator FMEA  

NASA Technical Reports Server (NTRS)

The results of Failure Modes and Effects Analysis (FMEA) conducted for the Wind Turbine Generators are presented. The FMEA was performed for the functional modes of each system, subsystem, or component. The single-point failures were eliminated for most of the systems. The blade system was the only exception. The qualitative probability of a blade separating was estimated at level D-remote. Many changes were made to the hardware as a result of this analysis. The most significant change was the addition of the safety system. Operational experience and need to improve machine availability have resulted in subsequent changes to the various systems which are also reflected in this FMEA.

Klein, William E.; Lalli, Vincent R.

1989-01-01

76

Control of large wind turbine generators connected to utility networks  

NASA Technical Reports Server (NTRS)

This is an investigation of the control requirements for variable pitch wind turbine generators connected to electric power systems. The requirements include operation in very small as well as very large power systems. Control systems are developed for wind turbines with synchronous, induction, and doubly fed generators. Simulation results are presented. It is shown how wind turbines and power system controls can be integrated. A clear distinction is made between fast control of turbine torque, which is a peculiarity of wind turbines, and slow control of electric power, which is a traditional power system requirement.

Hinrichsen, E. N.

1983-01-01

77

10. INTERIOR, MAIN BUILDING, LOOKING SOUTH, SHOWING TWO TURBINE GENERATOR ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. INTERIOR, MAIN BUILDING, LOOKING SOUTH, SHOWING TWO TURBINE GENERATOR SETS (FOREGROUND) AND AN AIR COMPRESSOR (BACKGROUND) - Central Power Station, Puget Sound Naval Shipyard, Bremerton, Kitsap County, WA

78

Design optimization of axial flow hydraulic turbine runner: Part II - multi-objective constrained optimization method  

Microsoft Academic Search

This paper is concerned with the design optimization of axial flow hydraulic turbine runner blade geometry. In order to obtain a better design plan with good performance, a new comprehensive performance optimization procedure has been presented by combining a multi-variable multi-objective constrained optimization model with a Q3D inverse computation and a performance prediction procedure. With careful analysis of the inverse

Guoyi Peng; Shuliang Cao; Masaru Ishizuka; Shinji Hayama

2002-01-01

79

Development of a measurement system able to determine the ow velocity eld on models of hydraulic turbines  

E-print Network

turbines Christian Landry Motivations & Objectives The project was driven by the need to improve the measurement of velocity elds and pressures in a hydraulic turbine. The development of a new probing system sequential measurement of pressure di erences. - Power supply with electricity and compressed air

Diggavi, Suhas

80

Miniature Gas-Turbine Power Generator  

NASA Technical Reports Server (NTRS)

A proposed microelectromechanical system (MEMS) containing a closed- Brayton-cycle turbine would serve as a prototype of electric-power generators for special applications in which high energy densities are required and in which, heretofore, batteries have been used. The system would have a volume of about 6 cm3 and would operate with a thermal efficiency >30 percent, generating up to 50 W of electrical power. The energy density of the proposed system would be about 10 times that of the best battery-based systems now available, and, as such, would be comparable to that of a fuel cell. The working gas for the turbine would be Xe containing small quantities of CO2, O2, and H2O as gaseous lubricants. The gas would be contained in an enclosed circulation system, within which the pressure would typically range between 5 and 50 atm (between 0.5 and 5 MPa). The heat for the Brayton cycle could be supplied by any of a number of sources, including a solar concentrator or a combustor burning a hydrocarbon or other fuel. The system would include novel heat-transfer and heat-management components. The turbine would be connected to an electric power generator/starter motor. The system would include a main rotor shaft with gas bearings; the bearing surfaces would be made of a ceramic material coated with nanocrystalline diamond. The shaft could withstand speed of 400,000 rpm or perhaps more, with bearing-wear rates less than 10(exp -)4 those of silicon bearings and 0.05 to 0.1 those of SiC bearings, and with a coefficient of friction about 0.1 that of Si or SiC bearings. The components of the system would be fabricated by a combination of (1) three-dimensional xray lithography and (2) highly precise injection molding of diamond-compatible metals and ceramic materials. The materials and fabrication techniques would be suitable for mass production. The disadvantages of the proposed system are that unlike a battery-based system, it could generate a perceptible amount of sound, and, if it were to burn fuel, then it would also generate exhaust, similarly to other combustion-based power sources.

Wiberg, Dean; Vargo, Stephen; White, Victor; Shcheglov, Kirill

2003-01-01

81

Wind Turbine Generator System Power Performance Test Report for the ARE442 Wind Turbine  

SciTech Connect

This report summarizes the results of a power performance test that NREL conducted on the ARE 442 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the ARE 442 is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.

van Dam, J.; Jager, D.

2010-02-01

82

Fatigue Analysis of the Piston Rod in a Kaplan Turbine Based on Crack Propagation under Unsteady Hydraulic Loads  

NASA Astrophysics Data System (ADS)

As an important component of the blade-control system in Kaplan turbines, piston rods are subjected to fluctuating forces transferred by the turbines blades from hydraulic pressure oscillations. Damage due to unsteady hydraulic loads might generate unexpected down time and high repair cost. In one running hydropower plant, the fracture failure of the piston rod was found twice at the same location. With the transient dynamic analysis, the retainer ring structure of the piston rod existed a relative high stress concentration. This predicted position of the stress concentration agreed well with the actual fracture position in the plant. However, the local strain approach was not able to explain why this position broke frequently. Since traditional structural fatigue analyses use a local stress strain approach to assess structural integrity, do not consider the effect of flaws which can significantly degrade structural life. Using linear elastic fracture mechanism (LEFM) approaches that include the effect of flaws is becoming common practice in many industries. In this research, a case involving a small semi-ellipse crack was taken into account at the stress concentration area, crack growth progress was calculated by FEM. The relationship between crack length and remaining life was obtained. The crack propagation path approximately agreed with the actual fracture section. The results showed that presence of the crack had significantly changed the local stress and strain distributions of the piston rod compared with non-flaw assumption.

Liu, X.; Luo, Y. Y.; Wang, Z. W.

2014-12-01

83

Method to select instrumentation for hydraulic turbines in retrofitting process  

Microsoft Academic Search

Almost 83% of the brazilin electric power generation is provided by hydroelectric power stations, most of them built in the 60's or 70's. The increase in the electric energy demand forces the power plants to increase their availability. That increase may be possible through maintenance policy improvement. Another alternative is the hydro generator retrofitting aiming at the extension of operational

Daniel Silva; Fernando Carazas; Gilberto Souza

2009-01-01

84

Review of failures and condition monitoring in wind turbine generators  

Microsoft Academic Search

Increasing wind power generation quantity in power systems needs obviously reliable operation. Therefore, accurate condition monitoring and fault diagnosis are almost mandatory. This paper aims to report recent works on condition monitoring and fault diagnosis for wind turbine generators. Wind turbines are subjected to different sort of failures, thus before stating condition monitoring and fault diagnosis methods it is necessary

Z. Daneshi-Far; G. A. Capolino; H. Henao

2010-01-01

85

Wind Turbine Generator Condition-Monitoring Using Temperature Trend Analysis  

Microsoft Academic Search

Condition monitoring can greatly reduce the maintenance cost for a wind turbine. In this paper, a new condition-monitoring method based on the nonlinear state estimate technique for a wind turbine generator is proposed. The technique is used to construct the normal behavior model of the electrical generator temperature. A new and improved memory matrix construction method is adopted to achieve

Peng Guo; David Infield; Xiyun Yang

2012-01-01

86

Performance characteristics of aerodynamically optimum turbines for wind energy generators  

NASA Technical Reports Server (NTRS)

This paper presents a brief discussion of the aerodynamic methodology for wind energy generator turbines, an approach to the design of aerodynamically optimum wind turbines covering a broad range of design parameters, some insight on the effect on performance of nonoptimum blade shapes which may represent lower fabrication costs, the annual wind turbine energy for a family of optimum wind turbines, and areas of needed research. On the basis of the investigation, it is concluded that optimum wind turbines show high performance over a wide range of design velocity ratios; that structural requirements impose constraints on blade geometry; that variable pitch wind turbines provide excellent power regulation and that annual energy output is insensitive to design rpm and solidity of optimum wind turbines.

Rohrbach, C.; Worobel, R.

1975-01-01

87

Hydraulic Turbines: The Pelton Turbine. Technical Terminology Bulletin. Terminotech, Vol. 2, No. 3.  

ERIC Educational Resources Information Center

This issue of a bulletin of technological terminology is devoted to the Pelton turbine. A brief narrative on the subject is presented in both French and English. An English-French dictionary of terms comprises the bulk of the document. Explanatory illustrations are appended. (JB)

General Electric Co. of Canada, Ltd., Montreal, Quebec.

88

Hydraulic Turbines: The Francis Turbine. Technical Terminology Bulletin. Terminotech, Vol. 2, No. 2.  

ERIC Educational Resources Information Center

This issue of a bulletin of technological terminology is devoted to the Francis turbine. A brief narrative on the subject is presented in both French and English. An English-French dictionary of terms comprises the bulk of the document. An explanatory illustration is appended. (JB)

General Electric Co. of Canada, Ltd., Montreal, Quebec.

89

On-Shore Central Hydraulic Power Generation for Wind and Tidal Energy  

NASA Technical Reports Server (NTRS)

Tidal energy, offshore wind energy, and onshore wind energy can be converted to electricity at a central ground location by means of converting their respective energies into high-pressure hydraulic flows that are transmitted to a system of generators by high-pressure pipelines. The high-pressure flows are then efficiently converted to electricity by a central power plant, and the low-pressure outlet flow is returned. The Department of Energy (DOE) is presently supporting a project led by Sunlight Photonics to demonstrate a 15 kilowatt tidal hydraulic power generation system in the laboratory and possibly later submerged in the ocean. All gears and submerged electronics are completely eliminated.A second portion of this DOE project involves sizing and costing a 15 megawatt tidal energy system for a commercial tidal energy plant. For this task, Atlantis Resources Corporation's 18-m diameter demonstrated tidal blades are rated to operate in a nominal 2.6 m/sec tidal flow to produce approximately one megawatt per set of tidal blades. Fifteen units would be submerged in a deep tidal area, such as in Maine's Western Passage. All would be connected to a high-pressure (20 megapascals, 2900 pounds per square inch) line that is 35 cm ID. The high-pressure HEPG fluid flow is transported 500-m to on-shore hydraulic generators. HEPG is an environmentally-friendly, biodegradable, water-miscible fluid. Hydraulic adaptations to ORPC's cross-flow turbines are also discussed.For 15 megawatt of wind energy that is onshore or offshore, a gearless, high efficiency, radial piston pump can replace each set of top-mounted gear-generators. The fluid is then pumped to a central, easily serviceable generator location. Total hydraulic/electrical efficiency is 0.81 at full rated wind or tidal velocities and increases to 0.86 at 1/3 rated velocities.

Jones, Jack A.; Bruce, Allan; Lim, Steven; Murray, Luke; Armstrong, Richard; Kimball, Richard; Cook-Chenault, Kimberly; DeGennaro, Sean

2012-01-01

90

On-Shore Central Hydraulic Power Generation for Wind and Tidal Energy  

NASA Technical Reports Server (NTRS)

Tidal energy, offshore wind energy, and onshore wind energy can be converted to electricity at a central ground location by means of converting their respective energies into high-pressure hydraulic flows that are transmitted to a system of generators by high-pressure pipelines. The high-pressure flows are then efficiently converted to electricity by a central power plant, and the low-pressure outlet flow is returned. The Department of Energy (DOE) is presently supporting a project led by Sunlight Photonics to demonstrate a 15 kW tidal hydraulic power generation system in the laboratory and possibly later submerged in the ocean. All gears and submerged electronics are completely eliminated. A second portion of this DOE project involves sizing and costing a 15 MW tidal energy system for a commercial tidal energy plant. For this task, Atlantis Resources Corporation s 18-m diameter demonstrated tidal blades are rated to operate in a nominal 2.6 m/sec tidal flow to produce approximately one MW per set of tidal blades. Fifteen units would be submerged in a deep tidal area, such as in Maine s Western Passage. All would be connected to a high-pressure (20 MPa, 2900 psi) line that is 35 cm ID. The high-pressure HEPG fluid flow is transported 500-m to on-shore hydraulic generators. HEPG is an environmentally-friendly, biodegradable, watermiscible fluid. Hydraulic adaptations to ORPC s cross-flow turbines are also discussed. For 15 MW of wind energy that is onshore or offshore, a gearless, high efficiency, radial piston pump can replace each set of top-mounted gear-generators. The fluid is then pumped to a central, easily serviceable generator location. Total hydraulic/electrical efficiency is 0.81 at full rated wind or tidal velocities and increases to 0.86 at 1/3 rated velocities.

Jones, Jack A.; Bruce, Allan; Lim, Steven; Murray, Luke; Armstrong, Richard; Kimbrall, Richard; Cook-Chenault, Kimberly; DeGennaro, Sean

2012-01-01

91

Novel Repair Technique for Life-Extension of Hydraulic Turbine Components in Hydroelectric Power Stations  

NASA Astrophysics Data System (ADS)

A significant number of hydraulic turbines operated in Japan were installed in the first half of the 20th century. Today, aging degradation and flaws are observed in these turbine equipments. So far, Japanese engineers have applied NDI technology of Ultrasonic Testing (UT) to detect the flaws, and after empirical evaluation of the remaining life they decided an adequate moment to replace the equipments. Since the replacement requires a large-scale field site works and high-cost, one of the solutions for life-extension of the equipments is introduction of repair services. We have been working in order to enhance the accuracy of results during the detection of flaws and flaws dimensioning, in particular focusing on the techniques of Tip-echo, TOFD and Phased-Array UT, accompanied by the conventional UT. These NDI methods made possible to recognize the entire image of surface and embedded flaws with complicated geometry. Then, we have developed an evaluation system of these flaws based on the theory of crack propagation, of the logic of crack growth driven by the stress-intensity factor of the crack tip front. The sophisticated evaluation system is constituted by a hand-made software and database of stress-intensity factor. Based on these elemental technologies, we propose a technique of repair welding to provide a life-extension of hydraulic turbine components.

Hiramatsu, Yoichi; Ishii, Jun; Funato, Kazuhiro

92

Design optimization of axial flow hydraulic turbine runner: Part II - multi-objective constrained optimization method  

NASA Astrophysics Data System (ADS)

This paper is concerned with the design optimization of axial flow hydraulic turbine runner blade geometry. In order to obtain a better design plan with good performance, a new comprehensive performance optimization procedure has been presented by combining a multi-variable multi-objective constrained optimization model with a Q3D inverse computation and a performance prediction procedure. With careful analysis of the inverse design of axial hydraulic turbine runner, the total hydraulic loss and the cavitation coefficient are taken as optimization objectives and a comprehensive objective function is defined using the weight factors. Parameters of a newly proposed blade bound circulation distribution function and parameters describing positions of blade leading and training edges in the meridional flow passage are taken as optimization variables.The optimization procedure has been applied to the design optimization of a Kaplan runner with specific speed of 440 kW. Numerical results show that the performance of designed runner is successfully improved through optimization computation. The optimization model is found to be validated and it has the feature of good convergence. With the multi-objective optimization model, it is possible to control the performance of designed runner by adjusting the value of weight factors defining the comprehensive objective function. Copyright

Peng, Guoyi; Cao, Shuliang; Ishizuka, Masaru; Hayama, Shinji

2002-06-01

93

Cavitation wear in hydraulic turbines at the Bratsk hydroelectric power plant  

Microsoft Academic Search

Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a A considerable cavitation wear of the runner blades at the Bratsk hydroelectric power plant occurred as the result of operating\\u000a the hydraulic turbines under conditions falling outside the design range and due to distortion of the blade profile caused\\u000a by electrode surfacing on a large scale carried out during repairs.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a The most effective method of reducing cavitation

I. S. Glukhov

1975-01-01

94

A methodology for assessment of wind turbine noise generation  

Microsoft Academic Search

An investigation of the sources of impulsive noise generated by the operation of the Mod 1 2 MW wind turbine was performed to establish criteria for assessing the noise-producing potential of other large wind turbines. Unsteady loading of the rotors was determined to be the cause of the sound pressure, which was generally below 100 Hz. Complaints originated from people

N. D. Kelley; R. R. Hemphill; H. E. McKenna

1982-01-01

95

Methods of attenuating wind turbine ac generator output variations  

NASA Technical Reports Server (NTRS)

Wind speed variation, tower blockage and structural and inertial factors produce unsteady torque in wind turbines. Methods for modifying the turbine torque so that steady torque is delivered to the coupled ac generator are discussed. The method that may evolve will be influenced by the power use that develops and the trade-offs of cost, weight and complexity.

Gold, H.

1978-01-01

96

Washington University Can the Sound Generated by Modern Wind Turbines  

E-print Network

blurring tachycardia (rapid heart rate) irritability 76% problems with concentration and memory 93% panicWashington University Can the Sound Generated by Modern Wind Turbines Affect the Health of Those turbine noise (at 200 m) is as loud as your refrigerator heard from the living room". #12;Washington

Salt, Alec N.

97

Using neural networks to estimate wind turbine power generation  

Microsoft Academic Search

This paper uses data collected at Central and South West Services Fort Davis wind farm (USA) to develop a neural network based prediction of power produced by each turbine. The power generated by electric wind turbines changes rapidly because of the continuous fluctuation of wind speed and direction. It is important for the power industry to have the capability to

Shuhui Li; Donald C. Wunsch; Edgar A. O'Hair; Michael G. Giesselmann

2001-01-01

98

Durability Challenges for Next Generation of Gas Turbine Engine Materials  

NASA Technical Reports Server (NTRS)

Aggressive fuel burn and carbon dioxide emission reduction goals for future gas turbine engines will require higher overall pressure ratio, and a significant increase in turbine inlet temperature. These goals can be achieved by increasing temperature capability of turbine engine hot section materials and decreasing weight of fan section of the engine. NASA is currently developing several advanced hot section materials for increasing temperature capability of future gas turbine engines. The materials of interest include ceramic matrix composites with 1482 - 1648 C temperature capability, advanced disk alloys with 815 C capability, and low conductivity thermal barrier coatings with erosion resistance. The presentation will provide an overview of durability challenges with emphasis on the environmental factors affecting durability for the next generation of gas turbine engine materials. The environmental factors include gaseous atmosphere in gas turbine engines, molten salt and glass deposits from airborne contaminants, impact from foreign object damage, and erosion from ingestion of small particles.

Misra, Ajay K.

2012-01-01

99

A Comparative Study of Modular Axial Flux Podded Generators for Marine Current Turbines  

E-print Network

A Comparative Study of Modular Axial Flux Podded Generators for Marine Current Turbines Sofiane turbines (MCTs). Due to the submarine environment, maintenance operations are very hard, very costly current turbine, axial flux permanent magnet generator, design, optimization. Nomenclature MCT = Marine

Brest, Université de

100

9. PENSTOCK RECEIVER AND ISOLATION VALVE, WITH #4 GENERATOR TURBINE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. PENSTOCK RECEIVER AND ISOLATION VALVE, WITH #4 GENERATOR TURBINE SHUTOFF VALVE IN FOREGROUND. VIEW TO SOUTHEAST. - Santa Ana River Hydroelectric System, SAR-1 Powerhouse, Redlands, San Bernardino County, CA

101

17. TOP OF TURBINE LOOKING NORTHWEST. SHAFT TO GENERATOR IN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. TOP OF TURBINE LOOKING NORTHWEST. SHAFT TO GENERATOR IN CENTER. - Potomac Power Plant, On West Virginia Shore of Potomac River, about 1 mile upriver from confluence with Shenandoah River, Harpers Ferry, Jefferson County, WV

102

Development of the Electromagnetic Induction Type Micro Air Turbine Generator Using MEMS and Multilayer Ceramic Technology  

Microsoft Academic Search

The miniaturized electromagnetic induction type air turbine generator is described. The micro air turbine generator rotated by the compressed air and generating electricity was fabricated by the combination of MEMS and multilayer ceramic technology. The micro generator consisted of an air turbine and a magnetic circuit. The turbine part consisted of 7 silicon layers fabricated by the MEMS technology. The

A. Iiduka; K. Ishigaki; Y. Takikawa; T. Ohse; K. Saito; F. Uchikoba

2011-01-01

103

Wind Turbine Generator System Acoustic Noise Test Report for the Gaia Wind 11kW Wind Turbine  

Microsoft Academic Search

This report details the acoustic noise test conducted on the Gaia-Wind 11-kW wind turbine at the National Wind Technology Center. The test turbine is a two- bladed, downwind wind turbine with a rated power of 11 kW. The test turbine was tested in accordance with the International Electrotechnical Commission standard, IEC 61400-11 Ed 2.1 2006-11 Wind Turbine Generator Systems --

Huskey

2011-01-01

104

Wind Turbine Generator System Acoustic Noise Test Report for the Gaia Wind 11-kW Wind Turbine  

SciTech Connect

This report details the acoustic noise test conducted on the Gaia-Wind 11-kW wind turbine at the National Wind Technology Center. The test turbine is a two- bladed, downwind wind turbine with a rated power of 11 kW. The test turbine was tested in accordance with the International Electrotechnical Commission standard, IEC 61400-11 Ed 2.1 2006-11 Wind Turbine Generator Systems -- Part 11 Acoustic Noise Measurement Techniques.

Huskey, A.

2011-11-01

105

Bulb Turbine Development for Hydro Power Stations  

Microsoft Academic Search

SYNOPSIS—Bulb turbines are gaining increasing importance in the generation of power from low-head schemes all over the world. Because of hydraulic advantages on the one hand and increased feasibility on the other hand they are frequently applied instead of the vertical Kaplan turbines.The following paper deals with the most essential hydraulic differences between a horizontal bulb-turbine and a vertical Kaplan-turbine

F. Strohmer; P. Spitaler

1980-01-01

106

A Permanent Magnet Generator for Small Scale Wind Turbines  

Microsoft Academic Search

This paper describes the development of a permanent magnet generator for small scale wind turbines. The generator has been designed for ease of manufacture so that it can be made by small mechanical engineering companies with limited electrical engineering knowledge. The generator has also been designed to have no cogging torque so that it can be used with all horizontal

J. R. Bumby; N. Stannard; R. Martin

2007-01-01

107

Phenomenon of magnetic force in permanent magnet wind turbine generators  

Microsoft Academic Search

This study presents the investigation on the magnetic force phenomenon in permanent magnet (PM) wind turbine generators. Owing to the presence of PMs, the inherent and ever-existing magnetic force between the stator and rotor becomes one of the most critical phenomena in these generators. Whether it is during the assembly process throughout the manufacturing stages or when the generator is

Y. K. Chin; P. Kanninen; P. Maki-Ontto; R. Sakki; H. Lendenmann

2009-01-01

108

NEXT GENERATION GAS TURBINE (NGGT) SYSTEMS STUDY  

SciTech Connect

Building upon the 1999 AD Little Study, an expanded market analysis was performed by GE Power Systems in 2001 to quantify the potential demand for an NGGT product. This analysis concluded that improvements to the US energy situation might be best served in the near/mid term (2002-2009) by a ''Technology-Focused'' program rather than a specific ''Product-Focused'' program. Within this new program focus, GEPS performed a parametric screening study of options in the three broad candidate categories of gas turbines: aero-derivative, heavy duty, and a potential hybrid combining components of the other two categories. GEPS's goal was to determine the best candidate systems that could achieve the DOE PRDA expectations and GEPS's internal design criteria in the period specified for initial product introduction, circa 2005. Performance feasibility studies were conducted on candidate systems selected in the screening task, and critical technology areas were identified where further development would be required to meet the program goals. DOE PRDA operating parameters were found to be achievable by 2005 through evolutionary technology. As a result, the study was re-directed toward technology enhancements for interim product introductions and advanced/revolutionary technology for potential NGGT product configurations. Candidate technologies were identified, both evolutionary and revolutionary, with a potential for possible development products via growth step improvements. Benefits were analyzed from two perspectives: (1) What would be the attributes of the top candidate system assuming the relevant technologies were developed and available for an NGGT market opportunity in 2009/2010; and (2) What would be the expected level of public benefit, assuming relevant technologies were incorporated into existing new and current field products as they became available. Candidate systems incorporating these technologies were assessed as to how they could serve multiple applications, both in terms of incorporation of technology into current products, as well as to an NGGT product. In summary, potential program costs are shown for development of the candidate systems along with the importance of future DOE enabling participation. Three main conclusions have been established via this study: (1) Rapid recent changes within the power generation regulatory environment and the resulting ''bubble'' of gas turbine orders has altered the timing and relative significance associated with the conclusions of the ADL study upon which the original DOE NGGT solicitation was based. (2) Assuming that the relevant technologies were developed and available for an NGGT market opportunity circa 2010, the top candidate system that meets or exceeds the DOE PRDA requirements was determined to be a hybrid aero-derivative/heavy duty concept. (3) An investment by DOE of approximately $23MM/year to develop NGGT technologies near/mid term for validation and migration into a reasonable fraction of the installed base of GE F-class products could be leveraged into $1.2B Public Benefit, with greatest benefits resulting from RAM improvements. In addition to the monetary Public Benefit, there is also significant benefit in terms of reduced energy consumption, and reduced power plant land usage.

Unknown

2001-12-05

109

Design optimization of axial flow hydraulic turbine runner: Part I - an improved Q3D inverse method  

Microsoft Academic Search

With the aim of constructing a comprehensive design optimization procedure of axial flow hydraulic turbine, an improved quasi-three-dimensional inverse method has been proposed from the viewpoint of system and a set of rotational flow governing equations as well as a blade geometry design equation has been derived. The computation domain is firstly taken from the inlet of guide vane to

Guoyi Peng; Shuliang Cao; Masaru Ishizuka; Shinji Hayama

2002-01-01

110

Design and Performance Study of an Ocean Current Turbine Generator  

NASA Astrophysics Data System (ADS)

The relatively constant flow of the ocean currents carries large amounts of energy that can be captured and converted to a usable form. In this paper, design and performance simulation of a horizontal axial ocean current turbine (OCT) are studied. Also, study on varying the turbine duct housing design parameters and a series of simulation analyses were performed. Our model simulations with and without the turbine duct housing design were compared with existing literature results and very good agreements were obtained. The results also showed that unducted ocean current turbine power output is proportional to the cube of the current speed. Therefore, if we can increase the flow rate, the ocean current turbine generator performance is expected to be greatly enhanced. By adding the turbine duct housing, under the current velocity of 1 and 2 m/s, parametric studies including the duct housing type, duct entrance area, tilt angle, and duct length-to-diameter ratio are performed. After obtaining the optimized set of design values for our current design, a complete system analysis of the ocean current turbine generator was performed to provide future design guidelines.

Chiang, Hsiao-Wei D.; Lin, Chen-Yin; Hsu, Chih-Neng

2013-09-01

111

ERCOT's Dynamic Model of Wind Turbine Generators: Preprint  

SciTech Connect

By the end of 2003, the total installed wind farm capacity in the Electric Reliability Council of Texas (ERCOT) system was approximately 1 gigawatt (GW) and the total in the United States was about 5 GW. As the number of wind turbines installed throughout the United States increases, there is a greater need for dynamic wind turbine generator models that can properly model entire power systems for different types of analysis. This paper describes the ERCOT dynamic models and simulations of a simple network with different types of wind turbine models currently available.

Muljadi, E.; Butterfield, C. P.; Conto, J.; Donoho, K.

2005-08-01

112

Hydraulics.  

ERIC Educational Resources Information Center

This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

Decker, Robert L.; Kirby, Klane

113

A Study of Generator System Selection for Large Wind Turbine Generator System  

NASA Astrophysics Data System (ADS)

This paper focuses on selection of wind turbine generation systems that include generators, converters and gears. We study three systems: permanent magnet generator (PMG) system, doubly-fed generator (DFG) system and synchronous generator (SYG) system in terms of the system efficiencies and running costs. The system efficiencies and running costs are calculated with considering relation between wind power and wind condition. According to these results, the 1-step gear PMG system is the best choice to large wind turbine system.

Kimura, Mamoru; Ide, Kazumasa; Nishihama, Kazuo; Futami, Motoo; Ichinose, Masaya; Fujigaki, Tetsuo; Iizuka, Motonobu; Imaie, Kazuhiro; Yagi, Yasuomi; Tamura, Jyunji

114

Pitch-controlled variable-speed wind turbine generation  

Microsoft Academic Search

This paper covers the operation of variable-speed wind turbines with pitch control. The system the authors considered is controlled to generate maximum energy while minimizing loads. The maximization of energy was only carried out on a static basis and only drive train loads were considered as a constraint. In low to medium wind speeds, the generator and the power converter

Eduard Muljadi; C. P. Butterfield

2001-01-01

115

9. VIEW OF FRANCIS TURBINE, GENERATOR DRIVE SHAFT. NOTE ORIGINAL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. VIEW OF FRANCIS TURBINE, GENERATOR DRIVE SHAFT. NOTE ORIGINAL EXCITER AND GENERATOR RHEOSTATS ATOP CONTROL PANEL AT REAR. CONTROL PANEL IS ORIGINAL EXCEPT FOR HORIZONTAL TOP PANEL WITH CLOCK AT LEFT AND SYNCHROSCOPE AT RIGHT, LOOKING EAST - Centerville Hydroelectric System, Powerhouse, Butte Creek, Centerville, Butte County, CA

116

Integration of wind turbine, SOFC and microturbine in distributed generation  

Microsoft Academic Search

This paper reports the study of dynamic behaviour of an integrated distributed generation (DG) system comprising wind turbines (WTs), solid-oxide fuel cell (SOFC) and microturbine (MT) under variable loading profile. WTs coupled to permanent magnet generators (PMGs) are combined with the SOFC and the MT to meet the total load demand. The fluctuations in the output of the WTs due

A. K. Saha; S. Chowdhury; C. T. Gaunt

2009-01-01

117

Bridging the gap between metallurgy and fatigue reliability of hydraulic turbine runners  

NASA Astrophysics Data System (ADS)

The failure of hydraulic turbine runners is a very rare event. Hence, in order to assess the reliability of these components, one cannot rely on statistical models based on the number of failures in a given population. However, as there is a limited number of degradation mechanisms involved, it is possible to use physically-based reliability models. Such models are more complicated but have the advantage of being able to account for physical parameters in the prediction of the evolution of runner degradation. They can therefore propose solutions to help improve reliability. With the use of such models, the effect of materials properties on runner reliability can easily be illustrated. This paper will present a brief review of the Kitagawa-Takahashi diagram that links the damage tolerance approach, based on fracture mechanics, to the stress or strain-life approaches. This diagram is at the centre of the reliability model used in this study. Using simplified response spectra obtained from on-site runner stress measurements, the paper will show how fatigue reliability is impacted by materials fatigue properties, namely fatigue crack propagation behaviour and fatigue limit obtained on S-N curves. It will also present a review of the most important microstructural features of 13%Cr- 4%Ni stainless steels used for runner manufacturing and will review how they influence fatigue properties in an effort to bridge the gap between metallurgy and turbine runners reliability.

Thibault, D.; Gagnon, M.; Godin, S.

2014-12-01

118

Metallurgical and fatigue assessments of welds in cast welded hydraulic turbine runners  

NASA Astrophysics Data System (ADS)

Decades of hydraulic turbine operation around the world have shown one undeniable fact; welded turbine runners can be prone to fatigue cracking, especially in the vicinity of welds. In this regard, three factors are essential to consider in runner fatigue assessments: (1) the runner's design, which can induce stress concentrations in the fillets, (2) the casting process, which inherently creates defects such as shrinkage cavities and (3) the welding process, which induces significant residual stresses as well as a heat affected zone in the cast pieces near the interface with the filler metal. This study focuses on the latter, the welding process, with emphasis on the influence of the heat affected zone on the runner's fatigue behavior. In a recently concluded study by a large research consortium in Montreal, the microstructure and fatigue crack propagation properties of a CA6NM runner weld heat affected zone were thoroughly investigated to find if this zone deteriorates the runner's resistance to fatigue cracking. The main results showed that this zone's intrinsic fatigue crack propagation resistance is only slightly lower than the unaffected base metal because of its somewhat finer martensitic microstructure leading to a less tortuous crack path. However, it was also confirmed that weld-induced residual stresses represent the dominant influencing factor regarding fatigue crack propagation, though post-weld heat treatments are usually very effective in reducing such residual stresses. This paper aims to further confirm, through a case study, that the weld-induced heat affected zone does not compromise the reliability of welded turbine runners when its fatigue crack propagation properties are considered in fatigue damage models.

Trudel, A.; Sabourin, M.

2014-03-01

119

Advanced Wind Turbine Program Next Generation Turbine Development Project: June 17, 1997--April 30, 2005  

SciTech Connect

This document reports the technical results of the Next Generation Turbine Development Project conducted by GE Wind Energy LLC. This project is jointly funded by GE and the U.S. Department of Energy's National Renewable Energy Laboratory.The goal of this project is for DOE to assist the U.S. wind industry in exploring new concepts and applications of cutting-edge technology in pursuit of the specific objective of developing a wind turbine that can generate electricity at a levelized cost of energy of $0.025/kWh at sites with an average wind speed of 15 mph (at 10 m height).

GE Wind Energy, LLC

2006-05-01

120

Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid  

E-print Network

Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault Wind Turbines with Induction Generator during Grid Fault by Sigrid M. Bolik Institute of Energy turbine technology has undergone rapid developments. Growth in size and the optimization of wind turbines

Hansen, René Rydhof

121

Hydraulic impulse generator and frequency sweep mechanism for borehole applications  

DOEpatents

This invention discloses a valve that generates a hydraulic negative pressure pulse and a frequency modulator for the creation of a powerful, broadband swept impulse seismic signal at the drill bit during drilling operations. The signal can be received at monitoring points on the surface or underground locations using geophones. The time required for the seismic signal to travel from the source to the receiver directly and via reflections is used to calculate seismic velocity and other formation properties near the source and between the source and receiver. This information can be used for vertical seismic profiling of formations drilled, to check the location of the bit, or to detect the presence of abnormal pore pressure ahead of the bit. The hydraulic negative pressure pulse can also be used to enhance drilling and production of wells.

Kolle, Jack J.; Marvin, Mark H.; Theimer, Kenneth J.

2006-11-21

122

Preliminary design of a 100 kW turbine generator  

NASA Technical Reports Server (NTRS)

The National Science Foundation and the Lewis Research Center have engaged jointly in a Wind Energy Program which includes the design and erection of a 100 kW wind turbine generator. The machine consists primarily of a rotor turbine, transmission, shaft, alternator, and tower. The rotor, measuring 125 feet in diameter and consisting of two variable pitch blades operates at 40 rpm and generates 100 kW of electrical power at 18 mph wind velocity. The entire assembly is placed on top of a tower 100 feet above ground level.

Puthoff, R. L.; Sirocky, P. J.

1974-01-01

123

The 100 kW experimental wind turbine generator project  

NASA Technical Reports Server (NTRS)

The Energy Research and Development Administration and the NASA Lewis Research Center engaged jointly in a Wind Energy Program which included the design and erection of a 100 kW wind turbine generator. This test machine consists of a rotor turbine, transmission, shaft, alternator, and tower. The rotor, measuring 125 feet in diameter and consisting of two variable pitch blades, operates at 40 rpm and generates 100 kW of electrical power at a wind velocity of 18 mph. The entire assembly is placed on top of a tower 100 feet above ground level. The machine was scheduled to be ready for operation in August, 1975.

Puthoff, R. L.; Sirocky, P.

1975-01-01

124

Calculation of guaranteed mean power from wind turbine generators  

NASA Technical Reports Server (NTRS)

A method for calculating the 'guaranteed mean' power output of a wind turbine generator is proposed. The term 'mean power' refers to the average power generated at specified wind speeds during short-term tests. Correlation of anemometers, the method of bins for analyzing non-steady data, the PROP Code for predicting turbine power, and statistical analysis of deviations in test data from theory are discussed. Guaranteed mean power density for the Clayton Mod-OA system was found to be 8 watts per square meter less than theoretical power density at all power levels, with a confidence level of 0.999. This amounts to 4 percent of rated power.

Spera, D. A.

1981-01-01

125

Hydraulics.  

ERIC Educational Resources Information Center

These instructional materials provide an orientation to hydraulics for use at the postsecondary level. The first of 12 sections presents an introduction to hydraulics, including discussion of principles of liquids, definitions, liquid flow, the two types of hydraulic fluids, pressure gauges, and strainers and filters. The second section identifies…

Engelbrecht, Nancy; And Others

126

The impact of inlet angle and outlet angle of guide vane on pump in reversal based hydraulic turbine performance  

NASA Astrophysics Data System (ADS)

In this paper, in order to research the impact of inlet angle and outlet angle of guide vane on hydraulic turbine performance, a centrifugal pump in reversal is adopted as turbine. A numerical simulation method is adopted for researching outer performance and flow field of turbine. The results show: inlet angle has a crucial role to turbine, to the same flow, there is a noticeable decline for the efficiency and head of turbine with the inlet angle increases. At the best efficiency point(EFP),to a same inlet angle, when the inlet angle greater than inlet angle, velocity circulation in guide vane outlet decreases, which lead the efficiency of turbine to reduce, Contrarily, the efficiency rises. With the increase of inlet angle and outlet angle, the EFP moves to the big flow area and the uniformity of pressure distribution becomes worse. The paper indicates that the inlet angle and outlet angle have great impact on the turbine performance, and the best combination exists for the inlet angle and outlet angle of the guide vane.

Shi, F. X.; Yang, J. H.; Wang, X. H.; Zhang, R. H.; Li, C. E.

2012-11-01

127

Optical fiber instrumentation of a high power generator and turbine  

NASA Astrophysics Data System (ADS)

The instrumentation of a high power generator and its complementary systems including the turbine bearings is presented and discussed. The generator consists of a 175MW hydroelectric generator installed in the Salto Osório power plant in the southern region of Brazil. Results show good agreement with the already existing instrumentation and demonstrate the technology potential for a full optical fiber sensing system to monitor these large machines.

da Silva, Erlon Vagner; Dreyer, Uilian José; de Morais Sousa, Kleiton; Babinski, Valderi Junot; Somenzi, Jonas; Mezzadri, Felipe; de Lourenço Junior, Ivo; Martelli, Cicero; Cardozo da Silva, Jean Carlos

2013-05-01

128

The effect of mass forces on heat transfer in turbine rotor blades and on hydraulic resistance in cooling channels  

NASA Astrophysics Data System (ADS)

The results of an investigation of local heat transfer between gas and turbine blades are given in the paper. The method of unsteady heat regime of thin wall is used to determine local heat flows. The heat transfer coefficients obtained both for rotating and fixed blades are compared. The effect of non-isothermal flow in rotating rotor systems on heat transfer and hydraulic resistance is analyzed. The qualitative coincidence of heat transfer coefficients and hydraulic resistance in rotating radial and fixed vertical ducts is acknowledged.

Pochuev, V. P.; Tsarlin, M. E.; Shcherbakov, V. F.

129

Methods and apparatus for cooling wind turbine generators  

DOEpatents

A wind turbine generator includes a stator having a core and a plurality of stator windings circumferentially spaced about a generator longitudinal axis. A rotor is rotatable about the generator longitudinal axis, and the rotor includes a plurality of magnetic elements coupled to the rotor and cooperating with the stator windings. The magnetic elements are configured to generate a magnetic field and the stator windings are configured to interact with the magnetic field to generate a voltage in the stator windings. A heat pipe assembly thermally engaging one of the stator and the rotor to dissipate heat generated in the stator or rotor.

Salamah, Samir A. (Niskayuna, NY); Gadre, Aniruddha Dattatraya (Rexford, NY); Garg, Jivtesh (Schenectady, NY); Bagepalli, Bharat Sampathkumaran (Niskayuna, NY); Jansen, Patrick Lee (Alplaus, NY); Carl, Jr., Ralph James (Clifton Park, NY)

2008-10-28

130

Method of installation of large capacity gas-turbine powered electrical generating machinery  

Microsoft Academic Search

A method is disclosed for installing into a machinery hall a gas turbine unit comprising a gas generator unit and a power turbine unit and forming a portion of a large capacity, gas-turbine powered electrical generating apparatus. The method is particularly intended for electric generating equipment having a capacity of at least 60 MW. To install the gas generator of

1977-01-01

131

Comparison of Water Turbine Characteristics using Different Blades in Darrieus Water Turbines used for Tidal Current Generations  

NASA Astrophysics Data System (ADS)

The use of renewable energies has been focused on for preserving environments and coping with the shortage of future energy supplies. In oceans, a tide reverses its current direction every six hours, and the current velocity changes into a sine wave after a period of time. Tidal current generation uses a generator to produce energy, changing the kinetic energy of current into a turning force by setting a water turbine in the tidal current. Therefore, it is considered to be very advantageous to use a water turbine that can always revolve in a fixed direction without any influence from tidal current directions. Water turbines with these characteristics are known as Darrieus water turbines. The Darrieus water turbines were modified for water from turbines originally developed for windmills. Darrieus water turbines have a difficulty in starting, but these days Darrieus water turbines have been developed with spiral blades, which make it easy to get the turbines started. However, there are very few reports regarding Darrieus water turbines with spiral blades, and therefore their characteristics are unknown. From the above points of view, this study devises and investigates spiral blade-Darrieus water turbines to clarify their characteristics through hydrographic experiments, and at the same time, it compares the characteristics of spiral-blade Darrieus water turbines with those of straight-blade ones.

Shiono, Mitsuhiro; Suzuki, Katsuyuki; Kiho, Seiji

132

Wind turbine generator with improved operating subassemblies  

DOEpatents

A wind turbine includes a yaw spring return assembly to return the nacelle from a position to which it has been rotated by yawing forces, thus preventing excessive twisting of the power cables and control cables. It also includes negative coning restrainers to limit the bending of the flexible arms of the rotor towards the tower, and stop means on the rotor shaft to orient the blades in a vertical position during periods when the unit is upwind when the wind commences. A pendulum pitch control mechanism is improved by orienting the pivot axis for the pendulum arm at an angle to the longitudinal axis of its support arm, and excessive creep is of the synthetic resin flexible beam support for the blades is prevented by a restraining cable which limits the extent of pivoting of the pendulum during normal operation but which will permit further pivoting under abnormal conditions to cause the rotor to stall.

Cheney, Jr., Marvin C. (24 Stonepost Rd., Glastonbury, CT 06033)

1985-01-01

133

Dynamic modeling of doubly fed induction generator wind turbines  

Microsoft Academic Search

It is now recognized that many large wind farms will employ doubly fed induction generator (DFIG) variable speed wind turbines. A number of such wind farms are already in operation and more are planned or under construction. With the rising penetration of wind power into electricity networks, increasingly comprehensive studies are required to identify the interaction between the wind farm(s)

Janaka B. Ekanayake; Lee Holdsworth; XueGuang Wu; Nicholas Jenkins

2003-01-01

134

Control systems of wind turbine generators: an Italian experience  

Microsoft Academic Search

The control system of a wind turbine plays a crucial role in determining its dynamic performances in all the possible operating conditions, along the generator start-up and shut-down maneuvers, as well as during the production phase. In particular the regulation of blade pitch and nacelle alignment to the wind direction permit to maximize the power production or to limit the

S. Corsi; M. Pozzi

2003-01-01

135

Individual channel analysis of induction generator-based wind turbines  

Microsoft Academic Search

Wind penetration into electricity grids has been significant over the last decades. The need of comprehensive studies to identify the interactions between wind farms with the power system has been recognised. In line with this, the individual channel analysis of induction generator-based wind turbines is presented in this paper. Individual channel analysis and design (ICAD) is a frequency domain framework

Carlos E. Ugalde-Loo; Janaka B. Ekanayake

2011-01-01

136

Computational intelligence for control of wind turbine generators  

Microsoft Academic Search

This paper summarizes past and ongoing research in the area of the application of computational intelligence (CI) for control of wind turbine generators (WTGs). Several intelligent design approaches and control strategies, including optimal design of WTG controllers using particle swarm optimization (PSO) and mean-variance optimization (MVO) algorithms and adaptive critic design-based coordinated optimal adaptive control for wind plants and shunt

Wei Qiao; Jiaqi Liang; Ganesh K. Venayagamoorthy; Ronald Harley

2011-01-01

137

Single module pressurized fuel cell turbine generator system  

DOEpatents

A pressurized fuel cell system (10), operates within a common pressure vessel (12) where the system contains fuel cells (22), a turbine (26) and a generator (98) where preferably, associated oxidant inlet valve (52), fuel inlet valve (56) and fuel cell exhaust valve (42) are outside the pressure vessel.

George, Raymond A. (Pittsburgh, PA); Veyo, Stephen E. (Murrysville, PA); Dederer, Jeffrey T. (Valencia, PA)

2001-01-01

138

Site matching of wind turbine generators: a case study  

Microsoft Academic Search

Site matching of wind turbine generators is investigated based on the appropriate selection of statistical models and means of wind speed data. The wind speed means are computed using arithmetic mean, root mean square and cubic mean cuberoot. Wind speed frequency distributions are modelled using Weibull and Rayleigh probability density functions. Wind speed data of an existing wind power station,

S. H. Jangamshetti; V. G. Rau

1999-01-01

139

Rotor Speed Stability Analysis of Constant Speed Wind Turbine Generators  

Microsoft Academic Search

This paper presents an analysis of rotor speed stability of a constant speed wind turbine generator with active stall control. To analyze the rotor speed stability, a 3-phase short circuit fault on a sample system with a constant speed WTG has been simulated using DIgSILENT software package. From the simulation results, it has been shown that the operating point of

M. G. Kanabar; C. V. Dobariya; S. A. Khaparde

2006-01-01

140

Development of an axial microturbine for a portable gas turbine generator  

Microsoft Academic Search

A miniature gas turbine is under development with the aim of generating electrical energy from fuel. This system consists of a compressor, combustion chamber, turbine and generator. The turbine is a single-stage axial impulse turbine (Laval turbine) with a rotor diameter of 10 mm, made of stainless steel using die-sinking electro-discharge machining. It has been tested with compressed air to

Jan Peirs; Dominiek Reynaerts; Filip Verplaetsen

2003-01-01

141

An experimental 100 kilowatt wind turbine generator  

NASA Technical Reports Server (NTRS)

Experimental generator consists of two blades mounted on 100 foot tower, driving transmission train and electric generator mounted on top of tower. Machine generates 100 kW of electricity at wind speeds from 18 to 60 miles per hour. Yaw control mechanism automatically orients machine into wind.

Thomas, R. L.; Puthoff, R. L.; Savino, J. M.; Johnson, W. R.

1975-01-01

142

Doubly fed induction generator systems for wind turbines  

Microsoft Academic Search

This article shows that adjustable speed generators for wind turbines are necessary when output power becomes higher than 1 MW. The doubly fed induction generator (DFIG) system presented in this article offers many advantages to reduce cost and has the potential to be built economically at power levels above 1.5 MW, e.g., for off-shore applications. A dynamic model of the

S. Muller; M. Deicke; R. W. De Doncker

2002-01-01

143

Control of Next Generation Aircraft and Wind Turbines  

NASA Technical Reports Server (NTRS)

The first part of this talk will describe some of the exciting new next generation aircraft that NASA is proposing for the future. These aircraft are being designed to reduce aircraft fuel consumption and environmental impact. Reducing the aircraft weight is one approach that will be used to achieve these goals. A new control framework will be presented that enables lighter, more flexible aircraft to maintain aircraft handling qualities, while preventing the aircraft from exceeding structural load limits. The second part of the talk will give an overview of utility-scale wind turbines and their control. Results of collaboration with Dr. Balas will be presented, including new theory to adaptively control the turbine in the presence of structural modes, with the focus on the application of this theory to a high-fidelity simulation of a wind turbine.

Frost, Susan

2010-01-01

144

Method of Electric Power Compensation for Wind Power Generation Using Biomass Gas Turbine Generator and Flywheel  

Microsoft Academic Search

The power generation using natural energy contains electric power fluctuation. Therefore, in order to put such power generation system to practical use, compensation system power fluctuation is necessary. In this paper, we propose a power compensation method using biomass gas turbine generator and flywheel energy storage equipment. In order to realize high quality natural energy power generation system considering wind

M. Hara; N. Yamamura; M. Ishida; Y. Kamada; T. Maeda; M. Wakita

2007-01-01

145

Degradation of Phosphate Ester Hydraulic Fluid in Power Station Turbines Investigated by a Three-Magnet Unilateral Magnet Array  

PubMed Central

A three-magnet array unilateral NMR sensor with a homogeneous sensitive spot was employed for assessing aging of the turbine oils used in two different power stations. The Carr-Purcell-Meiboom-Gill (CPMG) sequence and Inversion Recovery-prepared CPMG were employed for measuring the 1H-NMR transverse and longitudinal relaxation times of turbine oils with different service status. Two signal components with different lifetimes were obtained by processing the transverse relaxation curves with a numeric program based on the Inverse Laplace Transformation. The long lifetime components of the transverse relaxation time T2eff and longitudinal relaxation time T1 were chosen to monitor the hydraulic fluid aging. The results demonstrate that an increase of the service time of the turbine oils clearly results in a decrease of T2eff,long and T1,long. This indicates that the T2eff,long and T1,long relaxation times, obtained from the unilateral magnetic resonance measurements, can be applied as indices for degradation of the hydraulic fluid in power station turbines. PMID:24736132

Guo, Pan; He, Wei; García-Naranjo, Juan C.

2014-01-01

146

Degradation of phosphate ester hydraulic fluid in power station turbines investigated by a three-magnet unilateral magnet array.  

PubMed

A three-magnet array unilateral NMR sensor with a homogeneous sensitive spot was employed for assessing aging of the turbine oils used in two different power stations. The Carr-Purcell-Meiboom-Gill (CPMG) sequence and Inversion Recovery-prepared CPMG were employed for measuring the ¹H-NMR transverse and longitudinal relaxation times of turbine oils with different service status. Two signal components with different lifetimes were obtained by processing the transverse relaxation curves with a numeric program based on the Inverse Laplace Transformation. The long lifetime components of the transverse relaxation time T?eff and longitudinal relaxation time T? were chosen to monitor the hydraulic fluid aging. The results demonstrate that an increase of the service time of the turbine oils clearly results in a decrease of T?eff,long and T?,long. This indicates that the T?eff,long and T?,long relaxation times, obtained from the unilateral magnetic resonance measurements, can be applied as indices for degradation of the hydraulic fluid in power station turbines. PMID:24736132

Guo, Pan; He, Wei; García-Naranjo, Juan C

2014-01-01

147

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations  

E-print Network

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic of multi-megawatt turbines requires a new generation of modeling capability to assess individual turbine. Key Result The work is generating several models, including actuator line models of several wind

148

Development of Trouble Diagnosis Technology of 50W Grade Small Wind Turbine Generator  

Microsoft Academic Search

Establishment of an early trouble diagnosis system is demanded to prevent damage of wind turbine generator. Therefore, AE signal occurring by the damage of a wind blade was detected with the AE sensor which installed to the body of wind turbine generator and a pole. In this study, length of a blade of a small wind turbine generator was changed

Masashige Takaoka; Kazuki Inohata; Takuma Miyake; Daisuke Tashima; Masahisa Otsubo; Toshio Bouno

2008-01-01

149

Optimization of a Small Passive Wind Turbine Generator with Multiobjective Genetic Algorithms  

E-print Network

Optimization of a Small Passive Wind Turbine Generator with Multiobjective Genetic Algorithms A Algorithms (MOGAs) are used for the design of a small wind turbine generator (WTG) coupled to a DC bus improved by optimizing the generator characteristics associated with the wind turbine in relation

Paris-Sud XI, Université de

150

A Systemic Design Methodology of PM Generators for Fixed-Pitch Marine Current Turbines  

E-print Network

A Systemic Design Methodology of PM Generators for Fixed-Pitch Marine Current Turbines Sofiane of permanent magnet (PM) generator associated with fixed-pitch turbine for tidal energy generation. The main problem with marine current turbines systems are the maintenance requirements of the drive

Paris-Sud XI, Université de

151

Hybrid Power Generation System Using Offshore-Wind Turbine and Tidal Turbine for Power Fluctuation Compensation (HOT-PC)  

Microsoft Academic Search

Hybrid power generation system using Offshore-wind turbine and Tidal turbine for Power fluctuation Compensation (HOT-PC) is an autonomous power system. Electric power is generated from both offshore wind and tidal and is distributed over the load system. Power quality problems such as frequency fluctuations and voltage sags, which arise due to a fault or a pulsed load, can cause interruptions

Mohammad Lutfur Rahman; Shunsuke Oka; Yasuyuki Shirai

2010-01-01

152

Exposure of aircraft maintenance technicians to organophosphates from hydraulic fluids and turbine oils: a pilot study.  

PubMed

Hydraulic fluids and turbine oils contain organophosphates like tricresyl phosphate isomers, triphenyl phosphate and tributyl phosphate from very small up to high percentages. The aim of this pilot study was to determine if aircraft maintenance technicians are exposed to relevant amounts of organophosphates. Dialkyl and diaryl phosphate metabolites of seven organophosphates were quantified in pre- and post-shift spot urine samples of technicians (N=5) by GC-MS/MS after solid phase extraction and derivatization. Pre- and post shift values of tributyl phosphate metabolites (dibutyl phosphate (DBP): median pre-shift: 12.5 ?g/L, post-shift: 23.5 ?g/L) and triphenyl phosphate metabolites (diphenyl phosphate (DPP): median pre-shift: 2.9 ?g/L, post-shift: 3.5 ?g/L) were statistically higher than in a control group from the general population (median DBP: <0.25 ?g/L, median DPP: 0.5 ?g/L). No tricresyl phosphate metabolites were detected. The aircraft maintenance technicians were occupationally exposed to tributyl and triphenyl phosphate but not to tricresyl phosphate, tri-(2-chloroethyl)- and tri-(2-chloropropyl)-phosphate. Further studies are necessary to collect information on sources, routes of uptake and varying exposures during different work tasks, evaluate possible health effects and to set up appropriate protective measures. PMID:23597959

Schindler, Birgit Karin; Koslitz, Stephan; Weiss, Tobias; Broding, Horst Christoph; Brüning, Thomas; Bünger, Jürgen

2014-01-01

153

Optimization of robotic welding procedures for maintenance repair of hydraulic turbines  

SciTech Connect

A six axes super-compact robot is used for field repair of cavitation damages found on the discharge ring of hydraulic turbines. Optimization of overlay welding procedures to minimize surface distortion and reduce tearing forces on anchors in concrete, were studied through experimentation and FEM modelling. Planned experimentation has been used to develop optimum pulsed GMAW schedules of stainless steel overlays in 2G position. Best welding sequence was resolved through over lay welding of free plates. Each overlay consisted in one or two layers which were welded in the longitudinal and/or transverse direction of the rectangular plate. A bidirectional welding mode, a longitudinal layer followed by a transverse layer position and no cooling between the two layers, were found to be most effective in reducing distortion. The optimized 2G welding procedure was applied to a simulated field repair. Plate was anchored on a massive iron bracket with a set of instrumented bolts, to understand how normal tearing forces in anchors evolve. Preliminary results on FEM modelling of lateral force on anchors indicate good correlation with experiments, for an elementary design.

Lamarche, L.; Galopin, M. [Ecole Technologie Superieure, Montreal, Quebec (Canada); Simoneau, R.; Lassoeur, P. [Hydro-Quebec, Montreal, Quebec (Canada)

1996-12-31

154

Hydraulics.  

ERIC Educational Resources Information Center

Designed for use in courses where students are expected to become proficient in the area of hydraulics, including diesel engine mechanic programs, this curriculum guide is comprised of fourteen units of instruction. Unit titles include (1) Introduction, (2) Fundamentals of Hydraulics, (3) Reservoirs, (4) Lines, Fittings, and Couplers, (5) Seals,…

Decker, Robert L.

155

Power fluctuations smoothing and regulations in wind turbine generator systems  

NASA Astrophysics Data System (ADS)

Wind is one of the most popular renewable energy sources and it has the potential to become the biggest energy source in future. Since the wind does not always blow constantly, the output wind power is not constant which may make some problem for the power grid. According to the grid code which is set by independent system operator, ISO, wind turbine generator systems need to follow some standards such as the predetermined acceptable power fluctuations. In order to smooth the output powers, the energy storage system and some power electronics modules are employed. The utilized power electronics modules in the wind turbine system can pursue many different goals, such as maintaining the voltage stability, frequency stability, providing the available and predetermined output active and reactive power. On the other side, the energy storage system can help achieving some of these goals but its main job is to store the extra energy when not needed and release the stored energy when needed. The energy storage system can be designed in different sizes, material and also combination of different energy storage systems (hybrid designs). Combination of power electronics devises and also energy storage system helps the wind turbine systems to smooth the output power according to the provided standards. In addition prediction of wind speed may improve the performance of wind turbine generator systems. In this research study all these three topics are studied and the obtained results are written in 10 papers which 7 of them are published and three of them are under process.

Babazadehrokni, Hamed

156

Multilayer magnetic circuit for millimeter scale MEMS air turbine generator  

NASA Astrophysics Data System (ADS)

The multilayer magnetic circuit for the millimeter scale MEMS (Micro Electrical Mechanical System) air turbine generator is proposed in this paper. The dimensions of the fabricated air turbine generator were 3.6 mm, 3.4 mm and 3.5 mm, length, width and height, respectively. The air turbine was fabricated by the MEMS technology. Multilayer magnetic circuits were fabricated by the green sheet process. The achieved output voltage and output power of the generator were 6.2mV and 1.92?VA respectively. Moreover, the optimization of the ceramic magnetic circuit for the generator was performed to improve the output power. In this experiment, the horseshoe shape circuit and step-wise shape circuit were compared on the output power by the spindle machine. When two kinds magnetic circuit were compared, the output power of the step-wise shape circuit was higher than that of the horseshoe shape circuit. The output voltage and the output power of the step-wise shape circuit were 28mV and 1.53 mVA when load resistance of 0.512 ? was connected.

Takato, M.; Kaneko, M.; Nishi, T.; Saito, K.; Uchikoba, F.

2013-12-01

157

Design with constructal theory: Steam generators, turbines and heat exchangers  

NASA Astrophysics Data System (ADS)

This dissertation shows that the architecture of steam generators, steam turbines and heat exchangers for power plants can be predicted on the basis of the constructal law. According to constructal theory, the flow architecture emerges such that it provides progressively greater access to its currents. Each chapter shows how constructal theory guides the generation of designs in pursuit of higher performance. Chapter two shows the tube diameters, the number of riser tubes, the water circulation rate and the rate of steam production are determined by maximizing the heat transfer rate from hot gases to riser tubes and minimizing the global flow resistance under the fixed volume constraint. Chapter three shows how the optimal spacing between adjacent tubes, the number of tubes for the downcomer and the riser and the location of the flow reversal for the continuous steam generator are determined by the intersection of asymptotes method, and by minimizing the flow resistance under the fixed volume constraints. Chapter four shows that the mass inventory for steam turbines can be distributed between high pressure and low pressure turbines such that the global performance of the power plant is maximal under the total mass constraint. Chapter five presents the more general configuration of a two-stream heat exchanger with forced convection of the hot side and natural circulation on the cold side. Chapter six demonstrates that segmenting a tube with condensation on the outer surface leads to a smaller thermal resistance, and generates design criteria for the performance of multi-tube designs.

Kim, Yong Sung

158

Site matching of wind turbine generators: A case study  

SciTech Connect

Site matching of wind turbine generators is investigated based on appropriate selection of statistical models and means of wind speed data. The wind speed means are computed using arithmetic mean, root mean square and cubic mean cuberoot. Wind Speed frequency distributions are modeled using Weibull and Rayleigh probability density functions. Wind speed data of an existing wind power station, located at Kappadagudda, Karnataka, India, is used for computational purposes. The analytically obtained capacity factors are validated by comparing with the actual capacity factors obtained at Kappadagudda. It is observed that the capacity factors computed from the Weibull statistical model using cubic mean of wind speed data fairly match the actual capacity factors obtained from Kappadagudda wind power station. Various commercially available wind turbine generators are used for site matching study. The model described in the paper is useful for planning of wind power stations as it can be applied for accurate assessment of wind power potential at a site.

Jangamshetti, S.H.; Rau, V.G.

1999-12-01

159

Advanced Combustion Systems for Next Generation Gas Turbines  

SciTech Connect

Next generation turbine power plants will require high efficiency gas turbines with higher pressure ratios and turbine inlet temperatures than currently available. These increases in gas turbine cycle conditions will tend to increase NOx emissions. As the desire for higher efficiency drives pressure ratios and turbine inlet temperatures ever higher, gas turbines equipped with both lean premixed combustors and selective catalytic reduction after treatment eventually will be unable to meet the new emission goals of sub-3 ppm NOx. New gas turbine combustors are needed with lower emissions than the current state-of-the-art lean premixed combustors. In this program an advanced combustion system for the next generation of gas turbines is being developed with the goal of reducing combustor NOx emissions by 50% below the state-of-the-art. Dry Low NOx (DLN) technology is the current leader in NOx emission technology, guaranteeing 9 ppm NOx emissions for heavy duty F class gas turbines. This development program is directed at exploring advanced concepts which hold promise for meeting the low emissions targets. The trapped vortex combustor is an advanced concept in combustor design. It has been studied widely for aircraft engine applications because it has demonstrated the ability to maintain a stable flame over a wide range of fuel flow rates. Additionally, it has shown significantly lower NOx emission than a typical aircraft engine combustor and with low CO at the same time. The rapid CO burnout and low NOx production of this combustor made it a strong candidate for investigation. Incremental improvements to the DLN technology have not brought the dramatic improvements that are targeted in this program. A revolutionary combustor design is being explored because it captures many of the critical features needed to significantly reduce emissions. Experimental measurements of the combustor performance at atmospheric conditions were completed in the first phase of the program. Emissions measurements were obtained over a variety of operating conditions. A kinetics model is formulated to describe the emissions performance. The model is a tool for determining the conditions for low emission performance. The flow field was also modeled using CFD. A first prototype was developed for low emission performance on natural gas. The design utilized the tools anchored to the atmospheric prototype performance. The 1/6 scale combustor was designed for low emission performance in GE's FA+e gas turbine. A second prototype was developed to evaluate changes in the design approach. The prototype was developed at a 1/10 scale for low emission performance in GE's FA+e gas turbine. The performance of the first two prototypes gave a strong indication of the best design approach. Review of the emission results led to the development of a 3rd prototype to further reduce the combustor emissions. The original plan to produce a scaled-up prototype was pushed out beyond the scope of the current program. The 3rd prototype was designed at 1/10 scale and targeted further reductions in the full-speed full-load emissions.

Joel Haynes; Jonathan Janssen; Craig Russell; Marcus Huffman

2006-01-01

160

Flicker study on variable speed wind turbines with doubly fed induction generators  

Microsoft Academic Search

Grid connected wind turbines may produce flicker during continuous operation. This paper presents a simulation model of a MW-level variable speed wind turbine with a doubly fed induction generator developed in the simulation tool of PSCAD\\/EMTDC. Flicker emission of variable speed wind turbines with doubly fed induction generators is investigated during continuous operation, and the dependence of flicker emission on

Tao Sun; Zhe Chen; F. Blaabjerg

2005-01-01

161

Design optimization of axial flow hydraulic turbine runner: Part I - an improved Q3D inverse method  

NASA Astrophysics Data System (ADS)

With the aim of constructing a comprehensive design optimization procedure of axial flow hydraulic turbine, an improved quasi-three-dimensional inverse method has been proposed from the viewpoint of system and a set of rotational flow governing equations as well as a blade geometry design equation has been derived. The computation domain is firstly taken from the inlet of guide vane to the far outlet of runner blade in the inverse method and flows in different regions are solved simultaneously. So the influence of wicket gate parameters on the runner blade design can be considered and the difficulty to define the flow condition at the runner blade inlet is surmounted. As a pre-computation of initial blade design on S2m surface is newly adopted, the iteration of S1 and S2m surfaces has been reduced greatly and the convergence of inverse computation has been improved. The present model has been applied to the inverse computation of a Kaplan turbine runner. Experimental results and the direct flow analysis have proved the validation of inverse computation. Numerical investigations show that a proper enlargement of guide vane distribution diameter is advantageous to improve the performance of axial hydraulic turbine runner. Copyright

Peng, Guoyi; Cao, Shuliang; Ishizuka, Masaru; Hayama, Shinji

2002-06-01

162

Exposure to airborne organophosphates originating from hydraulic and turbine oils among aviation technicians and loaders.  

PubMed

This study describes the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils, among ground personnel within the aviation industry. The OPs tri-n-butyl phosphate (TnBP), dibutyl phenyl phosphate (DBPP), triphenyl phosphate (TPP) and tricresyl phosphate (TCP) have been emphasized due to their use in such oils. Oil aerosol/vapor and total volatile organic compounds (tVOCs) in air were also determined. In total, 228 and 182 OPs and oil aerosol/vapor samples from technician and loader work tasks during work on 42 and 21 aircrafts, respectively, were collected in pairs. In general, the measured exposure levels were below the limit of quantification (LOQ) for 84%/98% (oil aerosol) and 82%/90% (TCP) of the samples collected during technician/loader work tasks. The air concentration ranges for all samples related to technician work were

Solbu, Kasper; Daae, Hanne Line; Thorud, Syvert; Ellingsen, Dag Gunnar; Lundanes, Elsa; Molander, Paal

2010-12-01

163

Axial flux, modular, permanent-magnet generator with a toroidal winding for wind turbine applications  

Microsoft Academic Search

Permanent-magnet generators have been used for wind turbines for many years. Many small wind turbine manufacturers use direct-drive permanent-magnet generators. For wind turbine generators, the design philosophy must cover the following characteristics: low cost; light weight; low speed; high torque; and variable speed generation. The generator is easy to manufacture and the design can be scaled up for a larger

E. Muljadi; C. P. Butterfield; Yih-Huei Wan

1998-01-01

164

A hybrid generation system using variable speed wind turbines and diesel units  

Microsoft Academic Search

The paper presents a study of a power system consisting of wind turbines and diesel generation units. In the study, a direct drive modular permanent magnet generator is used for the wind turbine and a normal permanent magnet generator is used for the diesel generation unit. Both types of generation units are connected to the load via power electronic converters

Z. Chen; Y. Hu

2003-01-01

165

IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 27, NO. 1, FEBRUARY 2012 465 Dynamics of Type-3 Wind Turbine Generator Models  

E-print Network

, singular systems, small disturbance analysis, switching deadlock, wind turbine generator modeling. I Turbine Generator Models Ian A. Hiskens, Fellow, IEEE Abstract--The influence of wind turbine generators. INTRODUCTION THE dynamic behavior of wind turbine generators (WTGs) is quite different to that of synchronous

Hiskens, Ian A.

166

Numerical simulation of thermal-hydraulic generators running in a single regime  

NASA Astrophysics Data System (ADS)

The paper presents the basis for the design of thermal-hydraulic generators running in a single regime. The thermal-hydraulic generators in a single regime running represent an absolute novelty worldwide (a pioneer invention). Based on the methodology concerning this subject, the design calculus for an experimental model was developed.

Chioreanu, Nicolae; Mitran, Tudor; Rus, Alexandru; Beles, Horia

2014-06-01

167

Method for predicting impulsive noise generated by wind turbine rotors  

NASA Technical Reports Server (NTRS)

Large wind turbines can generate both broad band and impulsive noises. These noises can be controlled by proper choice of rotor design parameters such as rotor location with respect to the supporting tower, tower geometry and tip speed. A method was developed to calculate the impulsive noise generated when the wind turbine blade experiences air forces that are periodic functions of the rotational frequency. This phenomenon can occur when the blades operate in the wake of the support tower and the nonuniform velocity field near the ground due to wind shear. Results from this method were compared with measured sound spectra taken at locations of one to two rotor diameters from the DOE/NASA Mod-1 wind turbine. The calculated spectra generally agreed with the measured data in both the amplitude of the predominant harmonics and the roll of rate with frequency. Measured sound pressure levels far from the Mod-1 (15 rotor diameters), however, were higher than predicted. Simultaneous measurements in the near and far field indicated that the propagation effects could enhance the sound levels by more than 10 dB above that expected by spherical dispersion. These propagation effects are believed to be due to terrain and atmospheric characteristics of the Mod-1 site.

Viterna, L. A.

1982-01-01

168

Apparatus and methods of reheating gas turbine cooling steam and high pressure steam turbine exhaust in a combined cycle power generating system  

DOEpatents

In a combined cycle system having a multi-pressure heat recovery steam generator, a gas turbine and steam turbine, steam for cooling gas turbine components is supplied from the intermediate pressure section of the heat recovery steam generator supplemented by a portion of the steam exhausting from the HP section of the steam turbine, steam from the gas turbine cooling cycle and the exhaust from the HP section of the steam turbine are combined for flow through a reheat section of the HRSG. The reheated steam is supplied to the IP section inlet of the steam turbine. Thus, where gas turbine cooling steam temperature is lower than optimum, a net improvement in performance is achieved by flowing the cooling steam exhausting from the gas turbine and the exhaust steam from the high pressure section of the steam turbine in series through the reheater of the HRSG for applying steam at optimum temperature to the IP section of the steam turbine.

Tomlinson, Leroy Omar (Niskayuna, NY); Smith, Raub Warfield (Ballston Lake, NY)

2002-01-01

169

Hydraulics  

NSDL National Science Digital Library

These interactive learning objects, created by instructors from Fox Valley Technical College and other colleges in the Wisconsin Technical College program, focus on concepts that cover a broad-based electromechanical program. Here visitors will find learning objects in Hydraulics with over 25 lessons in Actuators, Relief Valves, Basic Concepts, and Directional Control Valves.

170

Superconducting light generator for large offshore wind turbines  

NASA Astrophysics Data System (ADS)

Offshore wind market demands higher power rate and reliable turbines in order to optimize capital and operational cost. These requests are difficult to overcome with conventional generator technologies due to a significant weight and cost increase with the scaling up. Thus superconducting materials appears as a prominent solution for wind generators, based on their capacity to held high current densities with very small losses, which permits to efficiently replace copper conductors mainly in the rotor field coils. However the state-of-the-art superconducting generator concepts still seem to be expensive and technically challenging for the marine environment. This paper describes a 10 MW class novel direct drive superconducting generator, based on MgB2 wires and a modular cryogen free cooling system, which has been specifically designed for the offshore wind industry needs.

Sanz, S.; Arlaban, T.; Manzanas, R.; Tropeano, M.; Funke, R.; Ková?, P.; Yang, Y.; Neumann, H.; Mondesert, B.

2014-05-01

171

Overall control strategy of variable speed doubly-fed induction generator wind turbine  

Microsoft Academic Search

The variable speed doubly-fed induction generator wind turbine is today the most widely used concept. The paper presents an overall control system of the variable speed DFIG wind turbine, with focus on the control strategies and algorithms applied at each hierarchical control level of the wind turbine. The present control method is designed for normal continuous operations. The strongest feature

Anca D. Hansen; Florin Iov; Poul Sørensen; Frede Blaabjerg

2004-01-01

172

Performance of a 3 kW wind turbine generator with variable pitch control system  

Microsoft Academic Search

A prototype 3kW horizontal upwind type wind turbine generator of 4m in diameter has been designed and examined under real wind conditions. The machine was designed based on the concept that even small wind turbines should have a variable pitch control system just as large wind turbines, especially in Japan where typhoons occur at least once a year. A characteristic

Baku M. Nagai; Kazumasa Ameku; Jitendro Nath Roy

2009-01-01

173

Normalized power curves as a tool for identification of optimum wind turbine generator parameters  

Microsoft Academic Search

This paper presents a novel method of matching wind turbine generators to a site using normalized power and capacity factor curves. The site matching is based on identifying optimum turbine speed parameters from turbine performance index curve, which is obtained from the normalized curves, so as to yield higher energy production at higher capacity factor. The wind speeds are parameterized

Suresh H. Jangamshetti; V. Guruprasada Rau

2001-01-01

174

Normalized Power Curves as a Tool for Identification of Optimum Wind Turbine Generator Parameters  

Microsoft Academic Search

This paper presents a novel method of matching wind turbine generators to a site using normalized power and capacity factor curves. The site matching is based on identifying optimum turbine speed parameters from the turbine performance index curve, which is obtained from the normalized curves, so as to yield higher energy production at a higher capacity factor. The wind speeds

V. G. Rau; S. H. Jangamshetti

2001-01-01

175

Variable speed wind turbine generator with zero-sequence filter  

DOEpatents

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility. 14 figs.

Muljadi, E.

1998-08-25

176

Variable speed wind turbine generator with zero-sequence filter  

DOEpatents

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

Muljadi, Eduard (Golden, CO)

1998-01-01

177

Variable Speed Wind Turbine Generator with Zero-sequence Filter  

DOEpatents

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

Muljadi, Eduard (Golden, CO)

1998-08-25

178

Vibration of a utility turbine generator unit under seismic loading  

SciTech Connect

PG and E has an on-line, vibration diagnostic system monitoring a 330MW cross-compound unit in Pittsburg, California. On 17 October 1989 the unit continuously operated during a Richter 7.2 earthquake (the Loma Prieta quake) whose epicenter was within 100 miles of the plant. The unit remained on-line and the monitoring system recorded the induced overall vibration of the shaft in each of the bearings for the turbines, generators, and feed pumps. This paper reports that the vibration responses along the trains were not uniform, nor did the peak response appear to be related to the nominal vibration level.

Branagan, L. (Pacific Gas and Electric Co., San Ramon, CA (United States))

1991-01-01

179

Microfabricated rankine cycle steam turbine for power generation and methods of making the same  

NASA Technical Reports Server (NTRS)

In accordance with the present invention, an integrated micro steam turbine power plant on-a-chip has been provided. The integrated micro steam turbine power plant on-a-chip of the present invention comprises a miniature electric power generation system fabricated using silicon microfabrication technology and lithographic patterning. The present invention converts heat to electricity by implementing a thermodynamic power cycle on a chip. The steam turbine power plant on-a-chip generally comprises a turbine, a pump, an electric generator, an evaporator, and a condenser. The turbine is formed by a rotatable, disk-shaped rotor having a plurality of rotor blades disposed thereon and a plurality of stator blades. The plurality of stator blades are interdigitated with the plurality of rotor blades to form the turbine. The generator is driven by the turbine and converts mechanical energy into electrical energy.

Frechette, Luc (Inventor); Muller, Norbert (Inventor); Lee, Changgu (Inventor)

2009-01-01

180

Output power smoothing of wind turbine generation system for the 2MW permanent magnet synchronous generators  

Microsoft Academic Search

Effective utilization of renewable energies such as wind energy is expected in place of the fossil fuel. The speed of wind is not remained constant and windmill output power is proportional to the cube of wind speed. In order to wind speed deviation, the output power of wind turbine generators (WTGs) is fluctuated. To reduce the fluctuation, different methods are

Abdul Motin Howlader; Naomitsu Urasaki; Tomonobu Senjyu; Akie Uehara; Atsushi Yona; A. Y. Saber

2010-01-01

181

The Darrieus wind turbine for electrical power generation  

NASA Astrophysics Data System (ADS)

Aspects of wind as an energy source and the momentum theory of wind turbines are briefly examined. Types of Darrieus wind turbine are described; attention is given to a turbine with airfoil blades curved in troposkein form, and a turbine with straight blades of fixed or variable pitch. The Darrieus vertical-axis wind turbine is then considered with regard to aerodynamics, annual energy output, structures, control systems, and energy storage. Brief reviews of selected Darrieus wind turbine projects are given, including those at Magdalen Islands, Canada, Sandia Laboratories, Reading University, and Australia and New Zealand.

Robinson, M. L.

1981-06-01

182

Turbine generator evaluation for the Eesti-Energia Estonia and Baltic power plants. Export trade information  

SciTech Connect

The report evaluates the feasibility of 200 MW turbines and generators modernization in two Estonian power plants in order to improve performance and/or availability. This is Volume 1 and it includes the following: (1) scope; (2) evaluation approach; (3) summary of major recommendations; (4) performance tests descriptions; (5) current technology -- component description; (6) recommended studies; (7) recommendations; (8) district heating; (9) description of turbine K-200-130; (10) turbine evaluation results; (11) generator; (12) estimation of modernization costs.

NONE

1995-12-01

183

Repair of Kaplan turbine shaft sealing based on evaluation of hydraulic conditions  

NASA Astrophysics Data System (ADS)

This paper has been written to call attention to a potential danger what may occur in Kaplan turbine refurbishments. In Tiszalök hydropower plant, Hungary, the shaft sealing of the refurbished turbine was damaged. In searching for the reasons it was assumed that due to increased internal velocities in the turbine, the pressure at the hub clearance became lower than the atmospheric pressure, and therefore the sealing, which always operated satisfactorily before the refurbishment, had uncertain water supply, dry-running occurred, and after some time the sealing was burnt. First the flow conditions in the turbine and the pressure at the hub clearance were calculated by a one-dimensional flow model. Later this was refined by a two-dimensional approach. The above conclusion was also justified by the data acquisition system and by observing the operation of the small dewatering pump. When the turbine operated at a larger discharge than a certain limit value, then the dewatering pump remained standstill, indicating that no water passed through the shaft sealing. External water supply was then applied, and after this the turbine operated all right.

Lakatos, K.; Szamosi, Z.; Bereczkei, S.

2012-11-01

184

Stabilization of Wind Turbine Generator System by STATCOM  

NASA Astrophysics Data System (ADS)

Recently voltage-source or current-source inverter based various FACTS devices have been used for flexible power flow control, secure loading, damping of power system oscillation and even for the stabilization of wind energy generation. In this paper, we propose the static synchronous compensator (STATCOM) based on voltage source converter (VSC) PWM technique to stabilize grid connected wind generator system. A simple control strategy of STATCOM is adopted where only measurement of rms voltage at the wind generator terminal is needed. Fuzzy logic controller rather than conventional PI controller is proposed as the control methodology of STATCOM. Multi-mass shaft model of wind turbine generator system (WTGS) is also considered as shaft modeling has a big influence on the transient performance of WTGS. Transient performance of STATCOM connected WTGS is compared also with that of pitch controlled WTGS. Both symmetrical and unsymmetrical faults are analyzed. Moreover, the steady state performance of STATCOM connected WTGS is analyzed. It is reported that STATCOM can reduce the voltage fluctuation significantly. Finally STATCOM is applied to a wind park model with multiple wind generators. Comprehensive results are presented to assess the performance of STATCOM connected WTGS, where the simulations have been done by PSCAD/EMTDC.

Muyeen, S. M.; Mannan, Mohammad Abdul; Ali, Mohd. Hasan; Takahashi, Rion; Murata, Toshiaki; Tamura, Junji

185

A doubly-fed permanent magnet generator for wind turbines  

E-print Network

Optimum extraction of energy from a wind turbine requires that turbine speed vary with wind speed. Existing solutions to produce constant-frequency electrical output under windspeed variations are undesirable due to ...

Thomas, Andrew J. (Andrew Joseph), 1981-

2004-01-01

186

A methodology for assessment of wind turbine noise generation  

NASA Astrophysics Data System (ADS)

An investigation of the sources of impulsive noise generated by the operation of the Mod 1 2 MW wind turbine was performed to establish criteria for assessing the noise-producing potential of other large wind turbines. Unsteady loading of the rotors was determined to be the cause of the sound pressure, which was generally below 100 Hz. Complaints originated from people in dwellings with a room with a window facing the machine. Indoor monitoring revealed pressure traces in the 31.5 Hz band with energy densities exceeding background by about 30 dB. It was concluded that the sound pressure was conveyed by the walls acting as a diaphragm. The induced vibration coupled with human body fundamental modes to produce a feeling of whole-body vibration. Spectral analyses were made of the vibration fields of the Mod 2, a 17 m Darrieus, and a Mod OA to allow comparison with the nuisance points of the Mod 1. Sound pressure levels were found at certain frequencies which would eliminate the occurrence of acoustic pollution.

Kelley, N. D.; Hemphill, R. R.; McKenna, H. E.

1982-05-01

187

A novel control of a small wind turbine driven generator based on neural networks  

Microsoft Academic Search

This paper presents a novel control strategy of turbine directly driven permanent magnet synchronous generator (PMSG) for a small wind generation system. Compared to the traditional techniques, this new method has following advantages: 1) the proposed neural networks provides a fast and accurate estimation of actual wind velocity without anemometer; 2) the maximum mechanical power of small wind turbine can

K. L. Shi; H. Li

2004-01-01

188

Design Study of 10 kW Superconducting Generator for Wind Turbine Applications  

Microsoft Academic Search

We have performed a design study of a 10 kW superconducting slow rotating generator suitable for demonstration in a small scale wind turbine, where the drive train only consists of the turbine blades connected directly to the generator. The flux density in the superconducting rotor is chosen as B = 1 Tesla to be similar to the performance of permanent

A. B. Abrahamsen; N. Mijatovic; E. Seiler; M. P. Sorensen; M. Koch; P. B. Norgard; N. F. Pedersen; C. Traeholt; N. H. Andersen; J. Ostergard

2009-01-01

189

RENOVATION OF TURBINE CONTROL SYSTEM USING PLC-BASED FOR SMALL HYDROELECTRIC POWER GENERATION  

Microsoft Academic Search

This paper presents the development of PLC-based turbine control system for small hydroelectric power generation with Kaplan turbine type. The proposed system is a pilot project of modernization of power plant control system prepared for supplantation of worn electronic equipment or analog technology. The proposed system is implemented for Mae-Ngat hydro- power plant, under responsibility of the Electricity Generating Authority

Tanabodee Duangsoithong; Chanapan Kongnam

190

Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 5  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. There are four volumes. This volume contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. Detail drawings of several assemblies and subassemblies are given. This is the fifth book of volume 4.

1984-01-01

191

Dynamic equivalence to induction generators and wind turbines for power system stability analysis  

Microsoft Academic Search

With increasing installation capacity and energy production, wind power plays more important role in power systems. In transient stability analysis, detailed modeling to each induction generator and wind turbine will introduce lots of calculation effort, which necessitates dynamic equivalence to induction generators and wind turbines in the same wind farm, or wind farms closely located. In this paper, weighted equivalence

Shenghu Li; Zhengkai Liu; Xinjie Hao; Shusen Jia

2010-01-01

192

Output power leveling of wind generation system using inertia of wind turbine  

Microsoft Academic Search

Wind energy is a significant and powerful natural resource that is safe, clean, and abundant. However, wind energy has a drawback of having only 1\\/800 density as compared to that of water energy, and it is not constant and wind turbine output is proportional to the cube of wind speed, which causes the generated power of wind turbine generator (WTG)

Tomonobu Senjyu; Yasutaka Ochi; Yasuaki Kikunaga; Motoki Tokudome; Endusa Billy Muhando; Atsushi Yona; Toshihisa Funabashi

2008-01-01

193

Wind turbine generator interaction with diesel generators on an isolated power system  

NASA Technical Reports Server (NTRS)

The results of a dynamic interaction investigation to characterize any disturbances caused by interfacing the Mod 0A wind turbine (150 kW configuration) with the Block Island utility diesel generator grid are reported. The tests were run when only two diesel generators were on line, and attention was given to power, frequency, and voltage time profiles. The interconnected system was examined in the start-up and synchronization phase, normal shutdown and cut-out of the wind turbine, during fixed pitch generation, and during variable pitch operation. Governors were installed on the diesel generators to accommodate the presence of wind-derived electricity. The blade pitch control was set to maintain power at 150 kW or below. Power and voltage transients were insignificant during start-up and shutdown, and frequency aberrations were within the range caused by load fluctuations. It is concluded that wind turbine generation can be successfully implemented by an isolated utility, even with a significant penetration to the total grid output.

Scott, G. W.; Wilreker, V. F.; Shaltens, R. K.

1983-01-01

194

Removal of Dioxin Contamination for Gas Turbine Generator Set Repair  

SciTech Connect

Decontamination projects are typically undertaken in the interest of reducing disposal costs. This goal can be achieved because decontamination concentrates the contaminant into a smaller volume or changes its form so that a lower cost disposal technology becomes available. Less frequently, decontamination adds value back to the fouled structure or contaminated piece of equipment. This removal of dioxins from a gas turbine generator set is one of the latter cases. A multi-million dollar piece of equipment could have been destined for the scrap pile. Instead, an innovative, non-destructive decontamination technology, developed under EPA and DOE demonstration programs has was employed so that the set could repaired and put back into service. The TechXtractchemical decontamination technology reduced surface dioxin / furan concentrations from as high as 24,000 ng / m2 to less than 25 ng / m2 and below detection limits.

Fay, W. S.; Borah, R.E.

2003-02-25

195

Influence of Hydraulic Design on Stability and on Pressure Pulsations in Francis Turbines at Overload, Part Load and Deep Part Load based on Numerical Simulations and Experimental Model Test Results  

NASA Astrophysics Data System (ADS)

Francis turbines have been running more and more frequently in part load conditions, in order to satisfy the new market requirements for more dynamic and flexible energy generation, ancillary services and grid regulation. The turbines should be able to be operated for longer durations with flows below the optimum point, going from part load to deep part load and even speed-no-load. These operating conditions are characterised by important unsteady flow phenomena taking place at the draft tube cone and in the runner channels, in the respective cases of part load and deep part load. The current expectations are that new Francis turbines present appropriate hydraulic stability and moderate pressure pulsations at overload, part load, deep part load and speed-no-load with high efficiency levels at normal operating range. This study presents series of investigations performed by Voith Hydro with the objective to improve the hydraulic stability of Francis turbines at overload, part load and deep part load, reduce pressure pulsations and enlarge the know-how about the transient fluid flow through the turbine at these challenging conditions. Model test measurements showed that distinct runner designs were able to influence the pressure pulsation level in the machine. Extensive experimental investigations focused on the runner deflector geometry, on runner features and how they could reduce the pressure oscillation level. The impact of design variants and machine configurations on the vortex rope at the draft tube cone at overload and part load and on the runner channel vortex at deep part load were experimentally observed and evaluated based on the measured pressure pulsation amplitudes. Numerical investigations were employed for improving the understanding of such dynamic fluid flow effects. As example for the design and experimental investigations, model test observations and pressure pulsation curves for Francis machines in mid specific speed range, around nqopt = 50 min?1 are reported, analysed and commented here. The analysis of experimental results allowed the identification of designs and configurations, which can improve the machine stability.

Magnoli, M. V.; Maiwald, M.

2014-12-01

196

Synchronization of wind turbine generators against an infinite bus under gusting wind conditions  

NASA Technical Reports Server (NTRS)

Studies of synchronizing a wind turbine generator against an infinite bus are performed on a digital computer. In the digital simulation, wind gusts of different magnitudes and durations are hypothesized. Prior to the synchronization, differences of the frequency and phase position between voltages of the alternator and the bus are also included in the simulation. Solutions for rotor speed, generator power angle, electromagnetic torque, wind turbine torque, wind turbine blade pitch angle, and armature current are simulated and presented graphically. The ERDA-NASA 100-kW wind turbine is used as a case study. The results so obtained will thus have immediate applications.

Hwang, H. H.; Gilbert, L. J.

1978-01-01

197

Structural optimisation of permanent magnet direct drive generators for 5MW wind turbines   

E-print Network

This thesis focuses on permanent magnet "direct drive" electrical generators for wind turbines with large power output. A variety of such generator topologies is reviewed, tested and optimised in an attempt to increase ...

Zavvos, Aristeidis

2013-11-28

198

Stresa, Italy, 26-28 April 2006 A SILICON-BASED MICRO GAS TURBINE ENGINE FOR POWER GENERATION  

E-print Network

gas turbine engine consists of a micro combustor, a turbine and a centrifugal compressor and a piezoelectric converter, as illustrated in Fig. 1 [6]. The micro gas turbine engine is composed of a centrifugalStresa, Italy, 26-28 April 2006 A SILICON-BASED MICRO GAS TURBINE ENGINE FOR POWER GENERATION X. C

Paris-Sud XI, Université de

199

Operational-Condition-Independent Criteria Dedicated to Monitoring Wind Turbine Generators: Preprint  

SciTech Connect

To date the existing wind turbine condition monitoring technologies and commercially available systems have not been fully accepted for improving wind turbine availability and reducing their operation and maintenance costs. One of the main reasons is that wind turbines are subject to constantly varying loads and operate at variable rotational speeds. As a consequence, the influences of turbine faults and the effects of varying load and speed are coupled together in wind turbine condition monitoring signals. So, there is an urgent need to either introduce some operational condition de-coupling procedures into the current wind turbine condition monitoring techniques or develop a new operational condition independent wind turbine condition monitoring technique to maintain high turbine availability and achieve the expected economic benefits from wind. The purpose of this paper is to develop such a technique. In the paper, three operational condition independent criteria are developed dedicated for monitoring the operation and health condition of wind turbine generators. All proposed criteria have been tested through both simulated and practical experiments. The experiments have shown that these criteria provide a solution for detecting both mechanical and electrical faults occurring in wind turbine generators.

Yang, W.; Sheng, S.; Court, R.

2012-08-01

200

Sound measurements of the MOD-2 wind turbine generator  

NASA Astrophysics Data System (ADS)

Sound measurements were made for the MOD-2 wind turbine generator for wind conditions of 7.6 to 13.4 m/sec and for output power ratings of about 1 to 2 NW. Both broad band and narrow band data wre obtained for a range of distances and azimuth angles from the machine. The rotor sound spectra are random in character and peak in the frequency ranges 30 to 50 Hz and 800 to 1300 Hz. Both peaks are predictable from experience with helicopter rotors and propellers. Results suggest that the lower frequency peak is due to the effects of inflow turbulence and the higher frequency peak is due to the interactions of the turbulent boundary layers with the trailing edges of the blades. The boundary layer related sound is the dominant component in the audible frequency range and determines the detectability of the machine. It could be detected at a distance of 1350 m in the upwind direction where the background noise was 30 dB (A) and at distances in excess of 2100 m in the downwind direction. Discrete frequency sound components associated with the power generation equipment are measurable in the direction normal to the axis of rotation but are not believed to be significant for detection or community response.

Hubbard, H. H.; Shepherd, K. P.; Grosveld, F. W.

1981-07-01

201

Sound measurements of the MOD-2 wind turbine generator  

NASA Technical Reports Server (NTRS)

Sound measurements were made for the MOD-2 wind turbine generator for wind conditions of 7.6 to 13.4 m/sec and for output power ratings of about 1 to 2 NW. Both broad band and narrow band data wre obtained for a range of distances and azimuth angles from the machine. The rotor sound spectra are random in character and peak in the frequency ranges 30 to 50 Hz and 800 to 1300 Hz. Both peaks are predictable from experience with helicopter rotors and propellers. Results suggest that the lower frequency peak is due to the effects of inflow turbulence and the higher frequency peak is due to the interactions of the turbulent boundary layers with the trailing edges of the blades. The boundary layer related sound is the dominant component in the audible frequency range and determines the detectability of the machine. It could be detected at a distance of 1350 m in the upwind direction where the background noise was 30 dB (A) and at distances in excess of 2100 m in the downwind direction. Discrete frequency sound components associated with the power generation equipment are measurable in the direction normal to the axis of rotation but are not believed to be significant for detection or community response.

Hubbard, H. H.; Shepherd, K. P.; Grosveld, F. W.

1981-01-01

202

Wind Turbine Generator System Acoustic Noise Test Report for the ARE 442 Wind Turbine  

Microsoft Academic Search

This test was conducted on the ARE 442 as part of the U.S. Department of Energy's (DOE's) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of this

A. Huskey; J. van Dam

2010-01-01

203

Wind Turbine Generator System Duration Test Report for the Mariah Power Windspire Wind Turbine  

Microsoft Academic Search

This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of the first round of this project. Duration testing is

A. Huskey; A. Bowen; D. Jager

2010-01-01

204

Wind Turbine Generator System Duration Test Report for the ARE 442 Wind Turbine  

Microsoft Academic Search

This test is being conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, four turbines are being tested at the NWTC as a part of this project. Duration testing is one of up

J. van Dam; D. Baker; D. Jager

2010-01-01

205

Wind Turbine Generator System Duration Test Report for the Mariah Power Windspire Wind Turbine  

SciTech Connect

This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of the first round of this project. Duration testing is one of up to five tests that may be performed on the turbines. Other tests include power performance, safety and function, noise, and power quality tests. NWTC testing results provide manufacturers with reports that may be used to meet part of small wind turbine certification requirements. This duration test report focuses on the Mariah Power Windspire wind turbine.

Huskey, A.; Bowen, A.; Jager, D.

2010-05-01

206

Wind Turbine Generator System Duration Test Report for the ARE 442 Wind Turbine  

SciTech Connect

This test is being conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, four turbines are being tested at the NWTC as a part of this project. Duration testing is one of up to 5 tests that may be performed on the turbines, including power performance, safety and function, noise, and power quality tests. The results of the testing provide manufacturers with reports that may be used for small wind turbine certification. The test equipment includes a grid connected ARE 442 wind turbine mounted on a 30.5 meter (100 ft) lattice tower manufactured by Abundant Renewable Energy. The system was installed by the NWTC Site Operations group with guidance and assistance from Abundant Renewable Energy.

van Dam, J.; Baker, D.; Jager, D.

2010-05-01

207

Doubly fed induction generator wind turbines with fuzzy controller: a survey.  

PubMed

Wind energy is one of the extraordinary sources of renewable energy due to its clean character and free availability. With the increasing wind power penetration, the wind farms are directly influencing the power systems. The majority of wind farms are using variable speed wind turbines equipped with doubly fed induction generators (DFIG) due to their advantages over other wind turbine generators (WTGs). Therefore, the analysis of wind power dynamics with the DFIG wind turbines has become a very important research issue, especially during transient faults. This paper presents fuzzy logic control of doubly fed induction generator (DFIG) wind turbine in a sample power system. Fuzzy logic controller is applied to rotor side converter for active power control and voltage regulation of wind turbine. PMID:25028677

Sathiyanarayanan, J S; Kumar, A Senthil

2014-01-01

208

Doubly Fed Induction Generator Wind Turbines with Fuzzy Controller: A Survey  

PubMed Central

Wind energy is one of the extraordinary sources of renewable energy due to its clean character and free availability. With the increasing wind power penetration, the wind farms are directly influencing the power systems. The majority of wind farms are using variable speed wind turbines equipped with doubly fed induction generators (DFIG) due to their advantages over other wind turbine generators (WTGs). Therefore, the analysis of wind power dynamics with the DFIG wind turbines has become a very important research issue, especially during transient faults. This paper presents fuzzy logic control of doubly fed induction generator (DFIG) wind turbine in a sample power system. Fuzzy logic controller is applied to rotor side converter for active power control and voltage regulation of wind turbine. PMID:25028677

Sathiyanarayanan, J. S.; Senthil Kumar, A.

2014-01-01

209

Turbine set with a generator feeding a network of constant frequency  

SciTech Connect

In a turbine set with an axial flow which is traversed by water and which is coupled to a generator feeding a network of constant frequency, the flow turbine is a propeller turbine with nonadjustable blades. The stator winding of the generator is connected to the network by means of a frequency-controllable converter, in particular a direct converter. The speed of rotation of the turbine set is controllable continuously according to the power to be delivered. In the case of an asynchronous design of the generator, it is advisable to provide the stator with a waterproof jacket on the inside and to flange it into the turbine tube, since the rotor with its cage winding is swept by water.

Spirk, F.

1983-01-11

210

Modern challenges for flow investigations in model hydraulic turbines on classical test rig  

NASA Astrophysics Data System (ADS)

The BulbT project involved several investigations of flow phenomena in different parts of a model bulb turbine installed on the test rig of Laval University Laboratory. The aim is to create a comprehensive data base in order to increase the knowledge of the flow phenomena in this type of turbines and to validate or improve numerical flow simulation strategies. This validation being based on a kinematic comparison between experimental and numerical data, the project had to overcome challenges to facilitate the use of the experimental data for that purpose. Many parameters were checked, such as the test bench repeatability, the intrusiveness of a priori non-intrusive methods, the geometry of the runner and draft tube. This paper illustrates how some of those problematic were solved.

Deschênes, C.; Houde, S.; Aeschlimann, V.; Fraser, R.; Ciocan, G. D.

2014-12-01

211

Prediction of pressure fluctuation of a hydraulic turbine at no-load condition  

NASA Astrophysics Data System (ADS)

In order to study characteristics of pressure fluctuation of a turbine during the starting period, a turbine with guide vanes device at no-load condition was investigated using RNG k-epsilon turbulence model. The inner flow distribution and pressure fluctuation characteristics were analyzed. Results show that the pressure fluctuations in the region between the runner and guide vanes are different around the runner inlet. The dominant frequency of pressure fluctuation in the vaneless space close to the casing outlet is the blade passing frequency, while the dominant frequency at the rest region is the twice of the blade passing frequency. The increase of amplitude of pressure fluctuation close to the casing outlet can be attribute to the large scale stall at suction side of the runner inlet.

Chen, T. J.; Wu, X. J.; Liu, J. T.; Wu, Y. L.

2015-01-01

212

Effect of tip clearance on performance of small axial hydraulic turbine  

NASA Technical Reports Server (NTRS)

The first two stages of a six stage liquid oxygen turbine were tested in water. One and two stage performance was determined for one shrouded and two unshrouded blade end configurations over ranges of clearance and blade-jet speed ratio. First stage, two stage, and second stage efficiencies are included as well as the effect of clearance on mass flow for two stage operation.

Boynton, J. L.; Rohlik, H. E.

1976-01-01

213

A direct drive permanent magnet generator design for a tidal current turbine(SeaGen)  

Microsoft Academic Search

In this study, the feasibility of a direct-drive per- manent magnet generator for a tidal turbine power take-off system, namely MCT's SeaGen -the world's first full scale commercial tidal turbine- has been investigated. The investigated PM generator topology is called C-GEN which is an air-cored axial-flux generator developed in the University of Edinburgh. The C-GEN is prior to conventional PM

Ozan Keysan; Alasdair S. McDonald; Markus Mueller

2011-01-01

214

Biomass & Natural Gas Based Hydrogen Fuel For Gas Turbine (Power Generation)  

EPA Science Inventory

Significant progress has been made by major power generation equipment manufacturers in the development of market applications for hydrogen fuel use in gas turbines in recent years. Development of a new application using gas turbines for significant reduction of power plant CO2 e...

215

An Experimental Study on the Darrieus-Savonius Turbine for the Tidal Current Power Generation  

Microsoft Academic Search

The Darrieus turbine is popular for tidal current power generation in Japan. It is simple in structure with straight wings rotating around a vertical axis, so that it has no directionality against the motion of tidal flow which changes its direction twice a day. However, there is one defect in the Darrieus turbine; its small starting torque. Once it stops,

Yusaku Kyozuka

2008-01-01

216

Wind Turbines Condition Monitoring and Fault Diagnosis Using Generator Current Amplitude  

E-print Network

detection in a Doubly-Fed Induction Generator (DFIG) based wind turbine for stationary and nonstationary cases. Index Terms--Wind turbine, DFIG, fault detection, diagnosis, amplitude modulation, Hilbert and maintaining older system, becomes more costly and challenging with obsolescence of key components. DFIG

Paris-Sud XI, Université de

217

Model Development and Field Testing of a Heavy-Duty Gas-Turbine Generator  

Microsoft Academic Search

This paper presents a detailed account of model development for a heavy-duty gas-turbine generator, based on field testing. Some salient points are discussed. These include a more elegant way of modeling the ambient temperature and frequency dependence of the turbine power output, the deadband in the governor response and the importance of modeling the excitation system limiters for system studies.

Pouyan Pourbeik; Fhedzisani Modau

2008-01-01

218

Mechanism of formation of dynamic loads acting on the main elements of turbine—Generator units  

Microsoft Academic Search

The dynamic properties of turbine--generator units are the main factor on which depend the operating reliability and life of hydropower equipment. At hydroelectric stations operation of the units is often accompanied by increased vibrations, and cracks form in the run~r blades of the turbines with the course of time. Other breaks of equipment components having a fatigue nature are also

V. I. Grigor’ev

1997-01-01

219

Failure Envelope Generation Using Modified Failure Criteria for Wind Turbine Blade and Validation for FRP Laminates  

Microsoft Academic Search

Wind energy is a non polluting cost-effective renewable energy source. Wind power technology in India has grown significantly in the last decade. Capacity of wind turbines has been increased significantly and at the same time, the cost of generating power from wind has come down. The blades used in the wind turbine are of composite material with aerodynamic profile, twisted

J. Selwin Rajadurai; G. Thanigaiyarasu

2009-01-01

220

Condition Monitoring of Generators & Other Subassemblies in Wind Turbine Drive Trains  

Microsoft Academic Search

Offshore wind turbines, incorporating electrical generators and converters, operate in locations where accessibility can lead to long mean times to repair. Condition-based maintenance is therefore essential if cost-effective availability targets are to be reached. As yet the condition monitoring techniques appropriate for offshore wind turbines have not been resolved. Reliability studies have shown that the majority of failure modes in

M. R. Wilkinson; F. Spinato; P. J. Tavner

2007-01-01

221

Thermal-hydraulic characteristics of a combustion engineering system 80 steam generator. Volume 2: Appendix A  

Microsoft Academic Search

The steady state thermal hydraulic characteristics on the secondary side of a combustion engineering system 80 steam generator are presented. Details of the CALIPSOS model with accompanying assumptions, operating parameters, and transport correlations are identified. Comprehensive graphical and numerical results are presented to facilitate the desired comparison with other steam generators analyzed by the same flow distribution code. Bibtex entry

R. W. Fanselau; J. G. Thakkar; J. W. Hiestand; D. S. Cassell

1980-01-01

222

BIOMASS GASIFICATION AND POWER GENERATION USING ADVANCED GAS TURBINE SYSTEMS  

SciTech Connect

A multidisciplined team led by the United Technologies Research Center (UTRC) and consisting of Pratt & Whitney Power Systems (PWPS), the University of North Dakota Energy & Environmental Research Center (EERC), KraftWork Systems, Inc. (kWS), and the Connecticut Resource Recovery Authority (CRRA) has evaluated a variety of gasified biomass fuels, integrated into advanced gas turbine-based power systems. The team has concluded that a biomass integrated gasification combined-cycle (BIGCC) plant with an overall integrated system efficiency of 45% (HHV) at emission levels of less than half of New Source Performance Standards (NSPS) is technically and economically feasible. The higher process efficiency in itself reduces consumption of premium fuels currently used for power generation including those from foreign sources. In addition, the advanced gasification process can be used to generate fuels and chemicals, such as low-cost hydrogen and syngas for chemical synthesis, as well as baseload power. The conceptual design of the plant consists of an air-blown circulating fluidized-bed Advanced Transport Gasifier and a PWPS FT8 TwinPac{trademark} aeroderivative gas turbine operated in combined cycle to produce {approx}80 MWe. This system uses advanced technology commercial products in combination with components in advanced development or demonstration stages, thereby maximizing the opportunity for early implementation. The biofueled power system was found to have a levelized cost of electricity competitive with other new power system alternatives including larger scale natural gas combined cycles. The key elements are: (1) An Advanced Transport Gasifier (ATG) circulating fluid-bed gasifier having wide fuel flexibility and high gasification efficiency; (2) An FT8 TwinPac{trademark}-based combined cycle of approximately 80 MWe; (3) Sustainable biomass primary fuel source at low cost and potentially widespread availability-refuse-derived fuel (RDF); (4) An overall integrated system that exceeds the U.S. Department of Energy (DOE) goal of 40% (HHV) efficiency at emission levels well below the DOE suggested limits; and (5) An advanced biofueled power system whose levelized cost of electricity can be competitive with other new power system alternatives.

David Liscinsky

2002-10-20

223

New generation of hydraulic pedotransfer functions for Europe  

PubMed Central

A range of continental-scale soil datasets exists in Europe with different spatial representation and based on different principles. We developed comprehensive pedotransfer functions (PTFs) for applications principally on spatial datasets with continental coverage. The PTF development included the prediction of soil water retention at various matric potentials and prediction of parameters to characterize soil moisture retention and the hydraulic conductivity curve (MRC and HCC) of European soils. We developed PTFs with a hierarchical approach, determined by the input requirements. The PTFs were derived by using three statistical methods: (i) linear regression where there were quantitative input variables, (ii) a regression tree for qualitative, quantitative and mixed types of information and (iii) mean statistics of developer-defined soil groups (class PTF) when only qualitative input parameters were available. Data of the recently established European Hydropedological Data Inventory (EU-HYDI), which holds the most comprehensive geographical and thematic coverage of hydro-pedological data in Europe, were used to train and test the PTFs. The applied modelling techniques and the EU-HYDI allowed the development of hydraulic PTFs that are more reliable and applicable for a greater variety of input parameters than those previously available for Europe. Therefore the new set of PTFs offers tailored advanced tools for a wide range of applications in the continent. PMID:25866465

Tóth, B; Weynants, M; Nemes, A; Makó, A; Bilas, G; Tóth, G

2015-01-01

224

Development of an axial microturbine for a portable gas turbine generator  

NASA Astrophysics Data System (ADS)

A miniature gas turbine is under development with the aim of generating electrical energy from fuel. This system consists of a compressor, combustion chamber, turbine and generator. The turbine is a single-stage axial impulse turbine (Laval turbine) with a rotor diameter of 10 mm, made of stainless steel using die-sinking electro-discharge machining. It has been tested with compressed air to speeds up to 160 000 rpm and generates a maximum mechanical power of 28 W with an efficiency of 18.4%. When coupled to a small generator, it generates 16 W of electrical power, which corresponds to an efficiency for the total system of 10.5%. The power density is mainly limited by the maximal speed of the ball bearings. The main losses are the blade profile losses and the exit losses. Higher speeds can considerably reduce the exit losses and therefore increase efficiency and power density. An improved turbine has been tested at temperatures up to 360 °C and generates up to 44 W of electrical energy with a total efficiency of 16%. A 20 mm diameter centrifugal compressor matching the pressure and flow characteristics of the turbine has been designed and is currently under construction.

Peirs, Jan; Reynaerts, Dominiek; Verplaetsen, Filip

2003-07-01

225

Synchronization of the ERDA-NASA 100 LkW wind turbine generator with large utility networks  

NASA Technical Reports Server (NTRS)

The synchronizing of a wind turbine generator against an infinite bus under random conditions is studied. With a digital computer, complete solutions for rotor speed, generator power angle, electromagnetic torque, wind turbine torque, wind turbine blade pitch angle, and armature current are obtained and presented by graphs.

Hwang, H. H.; Gilbert, L. J.

1977-01-01

226

Parallel operation of wind turbine, fuel cell, and diesel generation sources  

Microsoft Academic Search

We investigated a small isolated hybrid power system that used a parallel combination of dispatchable and nondispatchable power generation sources. The nondispatchable generation came from a nature-dependent wind turbine, and the dispatchable generations were a fuel cell and a diesel generator. On the load side, the nondispatchable portion was the village load, and the dispatchable portion was the energy storage,

E. Muljadi; C. Wang; M. H. Nehrir

2004-01-01

227

Increasing power generation in horizontal axis wind turbines using optimized flow control  

NASA Astrophysics Data System (ADS)

In order to effectively realize future goals for wind energy, the efficiency of wind turbines must increase beyond existing technology. One direct method for achieving increased efficiency is by improving the individual power generation characteristics of horizontal axis wind turbines. The potential for additional improvement by traditional approaches is diminishing rapidly however. As a result, a research program was undertaken to assess the potential of using distributed flow control to increase power generation. The overall objective was the development of validated aerodynamic simulations and flow control approaches to improve wind turbine power generation characteristics. BEM analysis was conducted for a general set of wind turbine models encompassing last, current, and next generation designs. This analysis indicated that rotor lift control applied in Region II of the turbine power curve would produce a notable increase in annual power generated. This was achieved by optimizing induction factors along the rotor blade for maximum power generation. In order to demonstrate this approach and other advanced concepts, the University of Notre Dame established the Laboratory for Enhanced Wind Energy Design (eWiND). This initiative includes a fully instrumented meteorological tower and two pitch-controlled wind turbines. The wind turbines are representative in their design and operation to larger multi-megawatt turbines, but of a scale that allows rotors to be easily instrumented and replaced to explore new design concepts. Baseline data detailing typical site conditions and turbine operation is presented. To realize optimized performance, lift control systems were designed and evaluated in CFD simulations coupled with shape optimization tools. These were integrated into a systematic design methodology involving BEM simulations, CFD simulations and shape optimization, and selected experimental validation. To refine and illustrate the proposed design methodology, a complete design cycle was performed for the turbine model incorporated in the wind energy lab. Enhanced power generation was obtained through passive trailing edge shaping aimed at reaching lift and lift-to-drag goals predicted to optimize performance. These targets were determined by BEM analysis to improve power generation characteristics and annual energy production (AEP) for the wind turbine. A preliminary design was validated in wind tunnel experiments on a 2D rotor section in preparation for testing in the full atmospheric environment of the eWiND Laboratory. These tests were performed for the full-scale geometry and atmospheric conditions. Upon making additional improvements to the shape optimization tools, a series of trailing edge additions were designed to optimize power generation. The trailing edge additions were predicted to increase the AEP by up to 4.2% at the White Field site. The pieces were rapid-prototyped and installed on the wind turbine in March, 2014. Field tests are ongoing.

Cooney, John A., Jr.

228

A market and engineering study of a 3-kilowatt class gas turbine generator  

E-print Network

Market and engineering studies were performed for the world's only commercially available 3 kW class gas turbine generator, the IHI Aerospace Dynajet. The objectives of the market study were to determine the competitive ...

Monroe, Mark A. (Mark Alan)

2003-01-01

229

On Impedance Spectroscopy Contribution to Failure Diagnosis in Wind Turbine Generators  

E-print Network

-fed induction generator, failure diagnosis, impedance spectroscopy. Nomenclature WT = Wind Turbine; DFIG rotor end- rings and harmonic degrading. In particular, DFIG-based WT failure diagnosis seems to become

Boyer, Edmond

230

Axial-flux modular permanent-magnet generator with a toroidal winding for wind-turbine applications  

Microsoft Academic Search

Permanent-magnet (PM) generators have been used for wind turbines for many years. Many small wind-turbine manufacturers use direct-drive PM generators. For wind turbine-generators, the design philosophy must cover the following characteristics: low cost, light weight, low speed, high torque and variable-speed generation. The generator is easy to manufacture and the design can be scaled up for a larger size without

Eduard Muljadi; C. P. Butterfield; Yih-Huie Wan

1999-01-01

231

An Experimental Study on the Darrieus-Savonius Turbine for the Tidal Current Power Generation  

NASA Astrophysics Data System (ADS)

The Darrieus turbine is popular for tidal current power generation in Japan. It is simple in structure with straight wings rotating around a vertical axis, so that it has no directionality against the motion of tidal flow which changes its direction twice a day. However, there is one defect in the Darrieus turbine; its small starting torque. Once it stops, a Darrieus turbine is hard to re-start until a fairly fast current is exerted on it. To improve the starting torque of the Darrieus turbine used for tidal power generation, a hybrid turbine, composed of a Darrieus turbine and a Savonius rotor is proposed. Hydrodynamic characteristics of a semi-circular section used for the Savonius bucket were measured in a wind tunnel. The torque of a two bucket Savonius rotor was measured in a circulating water channel, where four different configurations of the bucket were compared. A combined Darrieus and Savonius turbine was tested in the circulating water channel, where the effect of the attaching angle between Darrieus wing and Savonius rotor was studied. Finally, power generation experiments using a 48 pole electric generator were conducted in a towing tank and the power coefficients were compared with the results of experiments obtained in the circulating water channel.

Kyozuka, Yusaku

232

Predictive control of a chaotic permanent magnet synchronous generator in a wind turbine system  

NASA Astrophysics Data System (ADS)

This paper investigates how to address the chaos problem in a permanent magnet synchronous generator (PMSG) in a wind turbine system. Predictive control approach is proposed to suppress chaotic behavior and make operating stable; the advantage of this method is that it can only be applied to one state of the wind turbine system. The use of the genetic algorithms to estimate the optimal parameter values of the wind turbine leads to maximization of the power generation. Moreover, some simulation results are included to visualize the effectiveness and robustness of the proposed method. Project supported by the CMEP-TASSILI Project (Grant No. 14MDU920).

Manal, Messadi; Adel, Mellit; Karim, Kemih; Malek, Ghanes

2015-01-01

233

Analyzing the requirements for mass production of small wind turbine generators  

Microsoft Academic Search

Mass producibility of small wind turbine generators to give manufacturers design and cost data for profitable production operations is discussed. A 15 kW wind turbine generator for production in annual volumes from 1,000 to 50,000 units is discussed. Methodology to cost the systems effectively is explained. The process estimate sequence followed is outlined with emphasis on the process estimate sheets

T. Anuskiewicz; J. Asmussen; O. Frankenfield

1981-01-01

234

Probabilistic computation of wind farm power generation based on wind turbine dynamic  

Microsoft Academic Search

This paper addresses the problem of predicting a wind farm's power generation when no or few statistical data is available. The study is based on a time-series wind speed model and on a simple dynamic model of a doubly-fed induction generator wind turbine including cut-off and cut-in behaviours. The wind turbine is modeled as a stochastic hybrid system with three

Herman Bayem; Yannick Phulpin; Philippe Dessante; Julien Bect

235

Modeling and Simulation of Grid-connected Superconducting Wind Turbine Generators  

Microsoft Academic Search

Superconducting machines have been proposed to solve the problem of upscaling wind turbine generators. In order to design such machines, since prototyping would be very expensive, it is crucial to be able to simulate the interactions between them and the external systems. Within this framework, this thesis addresses the problem of modeling and simulating grid-connected superconducting wind turbine generators.\\u000a\\u000aThe

L. Queval

2013-01-01

236

Superconducting generators for large off shore wind turbines   

E-print Network

This thesis describes four novel superconducting machine concepts, in the pursuit of finding a suitable design for large offshore wind turbines. The designs should be reliable, modular and light-weight. The main novelty ...

Keysan, Ozan

2014-06-30

237

Laboratory implementation of variable-speed wind turbine generation  

SciTech Connect

To improve the performance of wind turbines, various control schemes such as variable speed operation have been proposed. Testing of these control algorithms on a full scale system is very expensive. To test these systems simulation, we developed programs and small scale laboratory experiments. We used this system to verify a control method that attempts to keep the turbine operating at its peak power coefficient. Both the simulations and the experiments verified the principle of operation of this control scheme.

Zinger, D.S. [Northern Illinois University, DeKalb, IL (United States)] [Northern Illinois University, DeKalb, IL (United States); Miller, A.A. [Univ. of Idaho, Moscow, ID (United States)] [Univ. of Idaho, Moscow, ID (United States); Muljadi, E.; Butterfield, C.P.; Robinson, M.C. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States)

1996-07-01

238

CFD Analysis for the Performance of Cross-Flow Hydraulic Turbine with the Variation of Blade Angle  

Microsoft Academic Search

The purpose of this study is both to further optimize the structure of cross-flow turbine and to improve the turbine performance. Optimization of the turbine structure has been made by the analysis of the turbine performance with the variation of the blade angle using a commercial CFD code. The results show that inlet and outlet angles of the runner blade

Y. D. Choi; J.. I. Lim; C. G. Kim; Y. T. Kim; Y. H. Lee

2009-01-01

239

Numerical prediction for effects of guide vane blade numbers on hydraulic turbine performance  

NASA Astrophysics Data System (ADS)

Using unstructured hybrid grid technique and SIMPLEC algorithm,a general three-dimensional simulation based on Reynolds Navier- stocks in multiple reference frames and the RNG k-? turbulence model, is presented for the reversal centrifugal pump (PAT) with a guide vane. Four different schemes are designed by a change of the number of guide vane blade of PAT. The inner flow field in every scheme is simulated, accordingly, the external characteristic and static pressure distribution in flow field in PAT is obtained. The results obtained show that the efficiency can be improved by adding a guide vane for the PAT, besides, the high efficiency area is wider than before. Guide blade numbers changed, external characteristics of turbine changed, and the external characteristic changed. The optimal value is existent for the guide vane blade number, which has a great impact on the distribution of pressure in runner inlet.

Shi, F. X.; Yang, J. H.; Wang, X. H.; Li, C. E.

2013-12-01

240

From experience with the operation of adjustable-blade hydraulic turbines  

Microsoft Academic Search

Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a It is necessary to perform systematic work to improve the qualifications of operating and repair personnel at hydroelectric\\u000a plants.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a The most critical repair work should be performed with the participation of specialists from the manufacturing plants.\\u000a \\u000a \\u000a \\u000a \\u000a 3. \\u000a \\u000a Operating personnel at hydroelectric plants should develop an inventory with determination of the condition of rotor blades\\u000a in adjustable-blade turbines

M. I. Gal'perin; V. V. Balagurov

1980-01-01

241

Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component  

E-print Network

Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component Ensemble on the homopolar component of the generator stator current and attempts to highlight the use of the Ensemble detection of the generator health degeneration, facilitating a proactive response, minimizing downtime

Paris-Sud XI, Université de

242

EEMD-based wind turbine bearing failure detection using the generator stator current homopolar component  

E-print Network

EEMD-based wind turbine bearing failure detection using the generator stator current homopolar detection techniques based on the homopolar component of the generator stator current and attempts. This allows for early detection of the generator health degeneration, facilitating a proactive response

Boyer, Edmond

243

Control design and dynamic performance analysis of a wind turbine-induction generator unit  

Microsoft Academic Search

This paper presents the modeling and control design for a wind energy conversion scheme using induction generators. The scheme consists of a three-phase induction generator driven by a horizontal axis wind turbine and interfaced to the utility through a double overhead transmission line. A static VAr compensator was connected at the induction generator terminals to regulate its voltage. The mechanical

Ezzeldin S. Abdin; Wilson Xu

2000-01-01

244

Energy yield of two generator systems for small wind turbine application  

Microsoft Academic Search

This paper presents the design of an axial flux permanent magnet (AFPM) generator and comparison of cost and energy yield of this generator with an automotive alternator which was adapted for small wind turbine application. The designed AFPM generator is a double-sided (TORUS) machine with air gap winding having 3 coils per pole and one stator disk sandwiched between two

S. O. Ani; H. Polinder; J. A. Ferreira

2011-01-01

245

Slip power recovery induction generators for large vertical axis wind turbines  

Microsoft Academic Search

Simulation results are presented for the performance of a slip power recovery induction generator coupled to a vertical-axis wind turbine. The suitability of this type of generator for wind-driven applications is discussed. A qualitative comparison with two other alternatives is made, highlighting the basic features of the generator configuration studied. Quantitative simulation analysis showed that it is possible to reduce

H. L. Nakra; B. Dube

1988-01-01

246

Comparative Assessment of Direct Drive High Temperature Superconducting Generators in Multi-Megawatt Class Wind Turbines  

SciTech Connect

This paper summarizes the work completed under the CRADA between NREL and American Superconductor (AMSC). The CRADA combined NREL and AMSC resources to benchmark high temperature superconducting direct drive (HTSDD) generator technology by integrating the technologies into a conceptual wind turbine design, and comparing the design to geared drive and permanent magnet direct drive (PMDD) wind turbine configurations. Analysis was accomplished by upgrading the NREL Wind Turbine Design Cost and Scaling Model to represent geared and PMDD turbines at machine ratings up to 10 MW and then comparing cost and mass figures of AMSC's HTSDD wind turbine designs to theoretical geared and PMDD turbine designs at 3.1, 6, and 10 MW sizes. Based on the cost and performance data supplied by AMSC, HTSDD technology has good potential to compete successfully as an alternative technology to PMDD and geared technology turbines in the multi megawatt classes. In addition, data suggests the economics of HTSDD turbines improve with increasing size, although several uncertainties remain for all machines in the 6 to 10 MW class.

Maples, B.; Hand, M.; Musial, W.

2010-10-01

247

Closed-cycle gas turbines for power generation and LNG vaporization  

NASA Astrophysics Data System (ADS)

Cooling by LNG (liquefied nitrogen gas) in closed-cycle gas turbines results in double the electrical output of water cooled turbines. A circuit scheme of the LNG turbine is presented with the temperatures and pressures of the cycle. The turbine inlet temperature is limited to 720 C. Pressure level control and bypass control are the two basic types of control applied. The power station has an output of 4 x 100 MW, with four heaters arranged in series. The basic design of the heater, turbine, compressor, recuperator, and vaporizer is given. A cost comparison is made between the closed cycle gas turbine and steam turbine power stations with open rack vaporizer, submerged combustion vaporizer, or both. Using an LNG terminal with a closed-cycle gas turbine for the generation of electric power and LNG vaporization would mean a potential world-wide saving of 2,350 MW thermal power or 4.2 x 10(6) kg of LNG/day by 1985.

Weber, D.

1980-09-01

248

New-generation gas turbine helping brewery lighten energy costs  

SciTech Connect

In nearly any manufacturing industry, the loss of electrical power can have a severe impact on the manufacturing process. The case of Labatt's Ontario Breweries in particular, the loss of electrical service puts a crimp in the brewmaster's art by forcing the company to dump large quantities of it's Labatt's Blue. To solve the problem, the company has installed a gas-turbine-drive cogeneration system to guard against brownout. The new 501-KB7 was developed from the well-established 501-KB5 turbine. It has improved power output over the 501-KB7 design, up from 4025 to 5225 kw, a higher 13.5:1 pressure ratio, and a 32% increased in airflow (20.4 kg/s). The Labatt's installation which became operational in 1993 reduced the Breweries energy cost because of 501-KB7 turbine's higher energy output. 3 figs.

Brezonick, M.

1994-10-01

249

Thermal-Hydraulic Study of Integrated Steam Generator in PWR  

Microsoft Academic Search

One of the safety aspects of innovative reactor concepts is the integration of steam generators (SGs) into the reactor vessel in the case of the pressurized water reactor (PWR). All of the reactor system components including the pressurizer are within the reactor vessel in the SG integrated PWR.The simple heat transfer code was developed for the parametric study of the

Masahiro OSAKABE

1989-01-01

250

Candidate wind turbine generator site: annual data summary, January 1981-December 1981  

SciTech Connect

Summarized hourly meteorological data for 34 candidate and wind turbine generator sites for calendar year 1981 are presented. These data are collected for the purpose of evaluating the wind energy potential at these sites and are used to assist in selection of potential sites for installation and testing of large wind turbines in electric utility systems. For each site, wind speed, direction, and distribution data are given in eight tables. Use of information from these tables, with information about specific wind turbines, should allow the user to estimate the potential for wind energy production at each site.

Sandusky, W.F.; Buck, J.W.; Renne, D.S.; Hadley, D.L.; Abbey, O.B.

1982-07-01

251

Large wind turbines: A utility option for the generation of electricity  

NASA Technical Reports Server (NTRS)

The wind resource is such that wind energy generation has the potential to save 6-7 quads of energy nationally. Thus, the Federal Government is sponsoring and encouraging the development of cost effective and reliable wind turbines. One element of the Federal Wind Energy Programs, Large Horizontal Axis Wind Turbine Development, is managed by the NASA Lewis Research Center for the Department of Energy. There are several ongoing wind system development projects oriented primarily toward utility application within this program element. In addition, a comprehensive technology program supporting the wind turbine development projects is being conducted. An overview is presented of the NASA activities with emphasis on application of large wind turbines for generation of electricity by utility systems.

Robbins, W. H.; Thomas, R. L.; Baldwin, D. H.

1980-01-01

252

Thermal analysis of a simple-cycle gas turbine in biogas power generation  

SciTech Connect

This paper investigates the technical feasibility of utilizing small simple-cycle gas turbines (25 kW to 125 kW) for biogas power generation through thermal analysis. A computer code, GTPower, was developed to evaluate the performance of small simple-cycle gas turbines specifically for biogas combustion. The 125 KW Solar Gas Turbine (Tital series) has been selected as the base case gas turbine for biogas combustion. After its design parameters and typical operating conditions were entered into GTPower for analysis, GTPower outputted expected values for the thermal efficiency and specific work. For a sensitivity analysis, the GTPower Model outputted the thermal efficiency and specific work. For a sensitivity analysis, the GTPower Model outputted the thermal efficiency and specific work profiles for various operating conditions encountered in biogas combustion. These results will assist future research projects in determining the type of combustion device most suitable for biogas power generation.

Yomogida, D.E. [California Energy Commission, Sacramento, CA (United States); Thinh, Ngo Dinh [California State Univ., Sacramento, CA (United States)

1995-09-01

253

Return on capital and earned carbon credit by hybrid solar Photovoltaic—wind turbine generators  

Microsoft Academic Search

This paper presents a methodology to optimise a hybrid solar Photovoltaic—wind turbine generator for the villages situated\\u000a in the remote areas, especially coastal regions of India. Owing to good insolation and wind density, the hybrid system composed\\u000a of 6 photovoltaic (PV) modules, one wind turbine and 3 batteries are sufficient to fulfil all the necessary power demand without\\u000a interruption for

Prabhakant; Basant Agrawal; G. N. Tiwari

2010-01-01

254

On Adapting a Small PM Wind Generator for a Multiblade, High Solidity Wind Turbine  

Microsoft Academic Search

This paper explores the design space that exists between multiblade, high-solidity water-pumping turbines and modern high-speed two and three-bladed horizontal axis wind turbines (HAWTs). In particular, it compares the features and performance of a small 12-bladed, high-solidity HAWT to that of a modern three-bladed HAWT. It also outlines a procedure for adapting a small PM wind generator, intended for high-speed

M. A. Khan; P. Pillay; K. D. Visser

2005-01-01

255

Probabilistic Computation of Wind Farm Power Generation Based on Wind Turbine Dynamic Modeling  

Microsoft Academic Search

This paper addresses the problem of predicting a wind farm's power generation when no or few statistical data is available. The study is based on a time-series wind speed model and on a simple dynamic model of a DFIG wind turbine including cut-off and cut-in behaviours. The wind turbine is modeled as a stochastic hybrid system with three operation modes.

Herman Bayem; Yannick Phulpin; Philippe Dessante; Julien Bect

2008-01-01

256

Evaluation of a wind turbine electric power generator  

NASA Technical Reports Server (NTRS)

A technical assessment of the aerodynamic performance of the wind wheel turbine (WWT) is reported. The potential of the WWT in utilizing wind as an alternate power source was evaluated. Scaling parameters were developed to predict the aerodynamic performance of WWT prototype sized to produce 3, 9, 30, and 100 kw outputs in a 6.7 m/sec wind.

Swim, W. B.

1981-01-01

257

Control of wind turbine generators connected to power systems  

NASA Technical Reports Server (NTRS)

A unique simulation model based on a Mode-O wind turbine is developed for simulating both speed and power control. An analytical representation for a wind turbine that employs blade pitch angle feedback control is presented, and a mathematical model is formulated. For Mode-O serving as a practical case study, results of a computer simulation of the model as applied to the problems of synchronization and dynamic stability are provided. It is shown that the speed and output of a wind turbine can be satisfactorily controlled within reasonable limits by employing the existing blade pitch control system under specified conditions. For power control, an additional excitation control is required so that the terminal voltage, output power factor, and armature current can be held within narrow limits. As a result, the variation of torque angle is limited even if speed control is not implemented simultaneously with power control. Design features of the ERDA/NASA 100-kW Mode-O wind turbine are included.

Hwang, H. H.; Mozeico, H. V.; Gilbert, L. J.

1978-01-01

258

Application of Magnetic Energy Recovery Switch (MERS) to Improve Output Power of Wind Turbine Generators  

NASA Astrophysics Data System (ADS)

The experimental results of an innovative power conversion technology using magnetic energy recovery switch (MERS) in a wind turbine system with a synchronous generator to improve the output power and the efficiency are presented. The MERS can compensate for the reactance voltage of the generator. The output voltage of the system increases and the excitation power of the generator can be significantly reduced. The data indicate a great potential of the new power conversion technology to make the actual wind turbine system compact and to improve the efficiency.

Takaku, Taku; Homma, Gen; Isobe, Takanori; Kato, Shuhei; Igarashi, Seiki; Uchida, Yoshiyuki; Shimada, Ryuichi

259

Mod-5A Wind Turbine Generator Program Design Report. Volume 4: Drawings and Specifications, Book 1  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. Volume 4 contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. This is the first of five books of volume four. It contains structural design criteria, generator step-up transformer specs, specs for design, fabrication and testing of the system, specs for the ground control enclosure, systems specs, slip ring specs, and control system specs.

1984-01-01

260

Statistical Safety Evaluation of BWR Turbine Trip Scenario Using Coupled Neutron Kinetics and Thermal Hydraulics Analysis Code SKETCH-INS/TRACE5.0  

NASA Astrophysics Data System (ADS)

The Best Estimate Plus Uncertainty (BEPU) method has been prepared for the regulatory cross-check analysis at Japan Nuclear Energy Safety Organization (JNES) on base of the three-dimensional neutron-kinetics/thermal- hydraulics coupled code SKETCH-INS/TRACE5.0. In the preparation, TRACE5.0 is verified against the large-scale thermal-hydraulic tests carried out with NUPEC facility. These tests were focused on the pressure drop of steam-liquid two phase flow and void fraction distribution. From the comparison of the experimental data with other codes (RELAP5/MOD3.3 and TRAC-BF1), TRACE5.0 was judged better than other codes. It was confirmed that TRACE5.0 has high reliability for thermal hydraulics behavior and are used as a best-estimate code for the statistical safety evaluation. Next, the coupled code SKETCH-INS/TRACE5.0 was applied to turbine trip tests performed at the Peach Bottom-2 BWR4 Plant. The turbine trip event shows the rapid power peak due to the voids collapse with the pressure increase. The analyzed peak value of core power is better simulated than the previous version SKETCH-INS/TRAC-BF1. And the statistical safety evaluation using SKETCH-INS/TRACE5.0 was applied to the loss of load transient for examining the influence of the choice of sampling method.

Ichikawa, Ryoko; Masuhara, Yasuhiro; Kasahara, Fumio

261

Operating experience feedback report -- turbine-generator overspeed protection systems: Commercial power reactors. Volume 11  

SciTech Connect

This report presents the results of the US Nuclear Regulatory Commission`s Office for Analysis and Evaluation of Operational Data (AEOD) review of operating experience of main turbine-generator overspeed and overspeed protection systems. It includes an indepth examination of the turbine overspeed event which occurred on November 9, 1991, at the Salem Unit 2 Nuclear Power Plant. It also provides information concerning actions taken by other utilities and the turbine manufacturers as a result of the Salem overspeed event. AEOD`s study reviewed operating procedures and plant practices. It noted differences between turbine manufacturer designs and recommendations for operations, maintenance, and testing, and also identified significant variations in the manner that individual plants maintain and test their turbine overspeed protection systems. AEOD`s study provides insight into the shortcomings in the design, operation, maintenance, testing, and human factors associated with turbine overspeed protection systems. Operating experience indicates that the frequency of turbine overspeed events is higher than previously thought and that the bases for demonstrating compliance with NRC`s General Design Criterion (GDC) 4, Environmental and dynamic effects design bases, may be nonconservative with respect to the assumed frequency.

Ornstein, H.L.

1995-04-01

262

Impact of Increased Penetration of DFIG-Based Wind Turbine Generators on Transient and Small Signal Stability of Power Systems  

Microsoft Academic Search

The targeted and current development of wind energy in various countries around the world reveals that wind power is the fastest growing power generation technology. Among the several wind generation technologies, variable speed wind turbines utilizing doubly fed induction generators (DFIGs) are gaining momentum in the power industry. With the increase in penetration of these wind turbines, the power system

Durga Gautam; Vijay Vittal; Terry Harbour

2009-01-01

263

An Experimental Study of Lightning Overvoltages in Wind Turbine Generation Systems Using a Reduced-Size Model  

Microsoft Academic Search

Wind turbine generation systems are built at locations where few tall structures are found nearby so as to obtain good wind conditions, and thus, they are often struck by lightning. To promote wind power generation, lightning-protection methodologies for such wind turbine generation systems have to be established. This paper presents the result of an experimental study of lightning overvoltages in

Kazuo Yamamoto; Taku Noda; Shigeru Yokoyama; Akihiro Ametani

2006-01-01

264

Nonlinear control for variable-speed wind turbines with permanent magnet generators  

Microsoft Academic Search

This paper proposed a nonlinear control algorithm for a variable-speed wind turbine without wind speed measurement. The measured permanent magnet generator output current, terminal voltage and shaft speed are used to estimate the electromagnetic torque of the permanent magnet generator by using Kalman filter. Then the wind speed is estimated by Newton-Raphson method after obtaining the estimated power of the

Jianzhong Zhang; Ming Cheng; Zhe Chen

2007-01-01

265

Review of modeling methods in electromagnetic and thermal design of permanent magnet generators for wind turbines  

Microsoft Academic Search

The rapidly developing wind power industry demands high power generators. Direct driven permanent magnet synchronous generator (PMSG), which has the advantages of high drive train efficiency and high reliability, is promising in wind turbine applications, especially offshore. It is known, that direct driven PMSG is heavier than its geared counterparts, which increases the cost and may bring up engineering challenges.

Z. Zhang; A. Matveev; S. Ovrebo; R. Nilssen; A. Nysveen

2011-01-01

266

SLOTLESS, TOROIDAL WOUND, AXIALLY- MAGNETIZED PERMANENT MAGNET GENERATOR FOR SMALL WIND TURBINE SYSTEMS  

Microsoft Academic Search

A toroidal wound three phase axially-magnetized, disc type, permanent magnet generator is presented in this paper. For a novel wind turbine application the generator must have a low reluctance torque and need to be direct-driven to reduce mechanical losses in the application. For this purpose the stator winding is wound around a slotless ring core. The rotor disc has 18

S. E. Skaar; O. Krovel; R. Nilssen; H. Erstad

267

EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE GENERATORS  

E-print Network

of these systems is that the induction generators require reactive power from the grid or capacitor banks to meetEFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE GENERATORS Hari Sharma* Trevor Pryor* Syed Islam** *Murdoch University Energy Research Institute (MUERI

268

Executive summary: Mod-1 wind turbine generator analysis and design report  

NASA Technical Reports Server (NTRS)

Activities leading to the detail design of a wind turbine generator having a nominal rating of 1.8 megawatts are reported. Topics covered include (1) system description; (2) structural dynamics; (3) stability analysis; (4) mechanical subassemblies design; (5) power generation subsystem; and (6) control and instrumentation subsystem.

1979-01-01

269

Study of downward communication receiver in rotary steerable drilling tool based on turbine generator  

Microsoft Academic Search

For the existence issues of underground information receiving at drilling, such as the installation space in the drill collar, installation location, and connections to the measurement circuit, etc., turbine generator as detection devices was proposed to achieve downward information received. The instruction encoding was built, and the effective downhole control instruction was generated by the use of drilling fluid pump

Huo Aiqing; He Yuyao; Wang Yuelong; Tang Nan; Cheng Weibin

2010-01-01

270

Use of power electronic converters in wind turbines and photovoltaic generators  

Microsoft Academic Search

In this paper, a brief review is presented of common electrical generation schemes for wind turbines (WTs) and photovoltaics (PVs). Attention is mainly focused on the power converter interfaces used for the grid connected operation of the renewable generators. The WT soft starting arrangements are described and the most common variable speed operation configurations are presented and discussed. The fundamental

S. A. Papathanassiou; G. A. Vokas; M. P. Papadopoulos

1995-01-01

271

Optimal design of the direct-driven high power permanent magnet generator turbine by wind  

Microsoft Academic Search

In this paper, an optimal design method of a high power permanent magnet synchronous generator (PMSG) turbine by wind is proposed. The expression of the cogging torque was studied based on the Fourier analysis. A method of permanent magnet shifting to reduce cogging torque was presented. In this paper a prototype for 5MW generator was built and a comparative study

Ting Liu; Shoudao Huang; Jian Gao

2011-01-01

272

Performance analysis of a miniature turbine generator for intracorporeal energy harvesting.  

PubMed

Replacement intervals of implantable medical devices are commonly dictated by battery life. Therefore, intracorporeal energy harvesting has the potential to reduce the number of surgical interventions by extending the life cycle of active devices. Given the accumulated experience with intravascular devices such as stents, heart valves, and cardiac assist devices, the idea to harvest a small fraction of the hydraulic energy available in the cardiovascular circulation is revisited. The aim of this article is to explore the technical feasibility of harvesting 1?mW electric power using a miniature hydrodynamic turbine powered by about 1% of the cardiac output flow in a peripheral artery. To this end, numerical modelling of the fluid mechanics and experimental verification of the overall performance of a 1:1 scale friction turbine are performed in vitro. The numerical flow model is validated for a range of turbine configurations and flow conditions (up to 250?mL/min) in terms of hydromechanic efficiency; up to 15% could be achieved with the nonoptimized configurations of the study. Although this article does not entail the clinical feasibility of intravascular turbines in terms of hemocompatibility and impact on the circulatory system, the numerical model does provide first estimates of the mechanical shear forces relevant to blood trauma and platelet activation. It is concluded that the time-integrated shear stress exposure is significantly lower than in cardiac assist devices due to lower flow velocities and predominantly laminar flow. PMID:24646095

Pfenniger, Alois; Vogel, Rolf; Koch, Volker M; Jonsson, Magnus

2014-05-01

273

Hydraulic resistance and convective heat transfer within independent power generation micro sources (IPM) channels  

NASA Astrophysics Data System (ADS)

The introduction of new structural materials and technologies contributes to the efficiency increase for the compact IPMs used in various branches of engineering. Use of a driving high-temperature (TIT600K), regenerative (the regeneration ratio is E>85%) micro gas turbine engine ?GTE, major components which are made of structural ceramics, allows not only to maintain the effective efficiency at ?e=26-30%, but, also, sharply reduce the material consumption rate for the micro source as a whole. Application of the laser prototyping technique to manufacture the air heater, which is a part of ?GTE, increases the IPM compactness. Miniaturization of the air heater, manufactured by the structural ceramics laser fusion, can significantly reduce the hydraulic diameter (dh<=1.0 mm) of the channels, designed to transport the working media inside it. Reducing dh leads to a significant increase in the hydraulic resistance of the micro channels. The associated increase in the energy consumption for ?GTE's own needs is compensated by increasing the TIT, E, and heat transfer coefficients in micro channels, and by eliminating the need in cooling for high temperature IPM components.

V, Sudarev A.; V, Sudarev B.; A, Suryaninov A.

2012-05-01

274

Application of multi-objective controller to optimal tuning of PID gains for a hydraulic turbine regulating system using adaptive grid particle swam optimization.  

PubMed

A hydraulic turbine regulating system (HTRS) is one of the most important components of hydropower plant, which plays a key role in maintaining safety, stability and economical operation of hydro-electrical installations. At present, the conventional PID controller is widely applied in the HTRS system for its practicability and robustness, and the primary problem with respect to this control law is how to optimally tune the parameters, i.e. the determination of PID controller gains for satisfactory performance. In this paper, a kind of multi-objective evolutionary algorithms, named adaptive grid particle swarm optimization (AGPSO) is applied to solve the PID gains tuning problem of the HTRS system. This newly AGPSO optimized method, which differs from a traditional one-single objective optimization method, is designed to take care of settling time and overshoot level simultaneously, in which a set of non-inferior alternatives solutions (i.e. Pareto solution) is generated. Furthermore, a fuzzy-based membership value assignment method is employed to choose the best compromise solution from the obtained Pareto set. An illustrative example associated with the best compromise solution for parameter tuning of the nonlinear HTRS system is introduced to verify the feasibility and the effectiveness of the proposed AGPSO-based optimization approach, as compared with two another prominent multi-objective algorithms, i.e. Non-dominated Sorting Genetic Algorithm II (NSGAII) and Strength Pareto Evolutionary Algorithm II (SPEAII), for the quality and diversity of obtained Pareto solutions set. Consequently, simulation results show that this AGPSO optimized approach outperforms than compared methods with higher efficiency and better quality no matter whether the HTRS system works under unload or load conditions. PMID:25481821

Chen, Zhihuan; Yuan, Yanbin; Yuan, Xiaohui; Huang, Yuehua; Li, Xianshan; Li, Wenwu

2014-12-01

275

Parallel Operation of Wind Turbine, Fuel Cell, and Diesel Generation Sources: Preprint  

Microsoft Academic Search

We investigated a small isolated hybrid power system that used a parallel combination of dispatchable and non-dispatchable power generation sources. The non-dispatchable generation came from a nature-dependent wind turbine, and the dispatchable generations were a fuel cell and a diesel generator. On the load side, the non-dispatchable portion was the village load, and the dispatchable portion was the energy storage,

E. Muljadi; C. Wang; M. H. Nehrir

2004-01-01

276

Wind Turbine Generator Physics: Gear Boxes and Blades  

NSDL National Science Digital Library

This module, produced by the Wind Technician TV project from Highland Community College, introduces students to the gear boxes and blades of wind turbines. The module consists of four lessons: gear box solids and liquids, blades- force analysis, gear box heat transfer and gearbox force and stress analysis. The lessons include audio and animated visuals as well as interactive simulations. Each lesson includes a PDF document with the lesson's text and images. Skill check activities are also included.

277

Biphase turbine for reverse osmosis desalination. Final report  

SciTech Connect

A new hydraulic reaction turbine was designed to recover the power available in the high-pressure waste-brine stream of reverse osmosis desalination systems. A reaction turbine sized for reverse-osmosis systems producing 600 gph was built and tested. The turbine performed well driving either a variable-speed pump or an electrical generator. Measured turbine efficiency (shaft power divided by available power) was 63%, compared with a prediction of 67%. The turbine can be built with larger capacity to reduce the size, weight and power consumption of reverse osmosis desalination systems. Efficiency of larger units is predicted to lie in the range of 65 to 70%.

Limburg, P.L.

1982-12-01

278

Simulation of Turbine Tone Noise Generation Using a Turbomachinery Aerodynamics Solver  

NASA Technical Reports Server (NTRS)

As turbofan engine bypass ratios continue to increase, the contribution of the turbine to the engine noise signature is receiving more attention. Understanding the relative importance of the various turbine noise generation mechanisms and the characteristics of the turbine acoustic transmission loss are essential ingredients in developing robust reduced-order models for predicting the turbine noise signature. A computationally based investigation has been undertaken to help guide the development of a turbine noise prediction capability that does not rely on empiricism. As proof-of-concept for this approach, two highly detailed numerical simulations of the unsteady flow field inside the first stage of a modern high-pressure turbine were carried out. The simulations were computed using TURBO, which is an unsteady Reynolds-Averaged Navier-Stokes code capable of multi-stage simulations. Spectral and modal analysis of the unsteady pressure data from the numerical simulation of the turbine stage show a circumferential modal distribution that is consistent with the Tyler-Sofrin rule. Within the high-pressure turbine, the interaction of velocity, pressure and temperature fluctuations with the downstream blade rows are all possible tone noise source mechanisms. We have taken the initial step in determining the source strength hierarchy by artificially reducing the level of temperature fluctuations in the turbine flowfield. This was accomplished by changing the vane cooling flow temperature in order to mitigate the vane thermal wake in the second of the two simulations. The results indicated that, despite a dramatic change in the vane cooling flow, the computed modal levels changed very little indicating that the contribution of temperature fluctuations to the overall pressure field is rather small compared with the viscous and potential field interaction mechanisms.

VanZante, Dale; Envia, Edmane

2010-01-01

279

Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 4  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator are documented. There are four volumes. This volume contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. This volume contains 5 books of which this is the fourth, providing drawings 47A380128 through 47A387125. In addition to the parts listing and where-used list, the logic design of the controller software and the code listing of the controller software are provided. Also given are the aerodynamic profile coordinates.

1984-01-01

280

Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 2  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. There are four volumes. This volume contains the drawings and specifications that were developed in preparation for building the MOD-5A wind turbine generator. This is the second book of volume four. Some of the items it contains are specs for the emergency shutdown panel, specs for the simulator software, simulator hardware specs, site operator terminal requirements, control data system requirements, software project management plan, elastomeric teeter bearing requirement specs, specs for the controls electronic cabinet, and specs for bolt pretensioning.

1984-01-01

281

Measurements and observations of noise from a 4.2 megawatt (WTS-4) wind turbine generator  

NASA Astrophysics Data System (ADS)

Noise measurements and calculations are being made for large wind turbine generators to develop a data base for use in designing and siting such systems for community acceptance. As part of this program, measurements were made on the WTS-4 wind turbine generator during its acceptance runs. This paper presents the results of these exploratory measurements for power output conditions in the range 1.0 to 4.2 MW. Data include noise levels, spectra, radiation patterns, effects of distance, and the associated perception thresholds for use in the further development of acceptance criteria for this type of machine.

Shepherd, K. P.; Hubbard, H. H.

1983-05-01

282

Measurements and observations of noise from a 4.2 megawatt (WTS-4) wind turbine generator  

NASA Technical Reports Server (NTRS)

Noise measurements and calculations are being made for large wind turbine generators to develop a data base for use in designing and siting such systems for community acceptance. As part of this program, measurements were made on the WTS-4 wind turbine generator during its acceptance runs. This paper presents the results of these exploratory measurements for power output conditions in the range 1.0 to 4.2 MW. Data include noise levels, spectra, radiation patterns, effects of distance, and the associated perception thresholds for use in the further development of acceptance criteria for this type of machine.

Shepherd, K. P.; Hubbard, H. H.

1983-01-01

283

Representation of Type 4 wind turbine generator for steady state short-circuit calculations  

NASA Astrophysics Data System (ADS)

Various technical impacts are associated to the interconnection of wind turbine generators to the grid. Among them, the increase of short-circuit levels along with its effect on the settings of protecting relays has long acted as an important inhibiting factor for the interconnection of new wind power plants to the grid. This is especially true at the medium voltage level where networks operate close to their short-circuit design value [1]. As renewable energies are progressively replacing traditional power generation sources, short-circuit studies need to adequately assess the impact of newly interconnected wind power plants on the fault level of the network. For planning and design purposes, short-circuit studies are usually performed using steady-state short-circuit programs. Unfortunately, very few have developed models of wind turbine generators that accurately estimate their fault contribution in the phase domain. In particular, no commercial fault-flow analysis program specifically addresses the modeling of inverter-based wind turbine generators which behavior is based on the inverter's characteristics rather than the generator's. The main contribution of this research work is the development of a simplified and yet accurate model of full-scale converter based wind turbine generator, also called Type 4 wind turbine generator, for steady-state short-circuit calculations. The model reproduces the real behavior of the Type 4 wind turbine generator under fault conditions by correctly accounting for the effect of the full-scale converter. The data used for the model is easily accessible to planning engineers. An additional contribution of this research work is the development of a short-circuit algorithm adapted to support the proposed model of Type 4 wind-turbine generator. Short-circuit algorithm based on modified-augmented-nodal analysis (MANA) is solved iteratively to accommodate the proposed model. The algorithm is successfully implemented in CYME 7.0, a commercial distribution system analysis program, to perform short-circuit calculations in multiphase complex unbalanced systems. Detailed study of the behavior of Type 4 wind turbine generator using electromagnetic type programs like EMTP-RV has assessed that the proposed model closely reproduces the real behavior of the wind turbine generator under steady-state fault conditions. The proposed model is then implemented in CYME 7.0 and validated for different fault scenarios using the Fortis Alberta 25 kV distribution system as benchmark. The fault contribution obtained from the proposed model is compared against the one obtained from the previous model implemented in CYME 7.0. The validation test cases show that the proposed model estimates the fault contribution of the wind turbine generator with better precision than the former models. Besides, the performance and robustness of the short-circuit algorithm developed allow handling unbalanced networks with inverter interfaced wind turbine generators as it is based on the MANA formulation.

Kamara, Wouleye

284

New high voltage insulation system for air-cooled turbine generators  

Microsoft Academic Search

For competitive power generation all over the world, air-cooled turbine generators tend to be used with large capacity up to a few hundred MVA, while hydrogen-cooling was adopted ten years ago. At the same time, the customers require compact, cost-effective generators. To meet such a new trend of power market, Mitsubishi Electric has developed a new high-voltage global impregnation insulation

N. Urakawa; S. Takada; M. Tsukiji; W. Bito; A. Yamada; T. Umemoto

1999-01-01

285

National Renewable Energy Laboratory program on lightning risk and wind turbine generator protection  

SciTech Connect

In the early development of wind turbine generators (WTG) in the United States, wind farms were primarily located in California where lightning activity is the lowest in the United States. As such, lightning protection for wind turbines was not considered to be a major issue for designers or wind farm operators. However, wind turbine installations are expanding into the Midwest, Southwest and other regions of the United States where lightning activity is significantly more intense and lightning damage to wind turbines is more common. There is a growing need, therefore, to better understand lightning activity on wind farms and to improve wind turbine lightning protection systems. In support of the U.S. Department of Energy/Electric Power Research Institute (DOE/EPRI) Utility Wind Turbine Verification Program (TVP), the National Renewable Energy Laboratory (NREL) has recently begun to take steps to determine the extent of damage due to lightning and the effectiveness of various lightning protection techniques for wind power plants. Working through the TVP program, NREL will also perform outreach and education to (1) help manufacturers to provide equipment that is adequately designed to survive lightning, (2) make sure that operators are aware of effective safety procedures, and (3) help site designers and wind farm developers take the risk of lightning into account as effectively as possible.

Muljadi, E. [National Renewable Energy Lab., Golden, CO (United States); McNiff, B. [McNiff Light Industry, Blue Hill, ME (United States)

1997-12-31

286

Next Generation Engineered Materials for Ultra Supercritical Steam Turbines  

SciTech Connect

To reduce the effect of global warming on our climate, the levels of CO{sub 2} emissions should be reduced. One way to do this is to increase the efficiency of electricity production from fossil fuels. This will in turn reduce the amount of CO{sub 2} emissions for a given power output. Using US practice for efficiency calculations, then a move from a typical US plant running at 37% efficiency to a 760 C /38.5 MPa (1400 F/5580 psi) plant running at 48% efficiency would reduce CO2 emissions by 170kg/MW.hr or 25%. This report presents a literature review and roadmap for the materials development required to produce a 760 C (1400 F) / 38.5MPa (5580 psi) steam turbine without use of cooling steam to reduce the material temperature. The report reviews the materials solutions available for operation in components exposed to temperatures in the range of 600 to 760 C, i.e. above the current range of operating conditions for today's turbines. A roadmap of the timescale and approximate cost for carrying out the required development is also included. The nano-structured austenitic alloy CF8C+ was investigated during the program, and the mechanical behavior of this alloy is presented and discussed as an illustration of the potential benefits available from nano-control of the material structure.

Douglas Arrell

2006-05-31

287

Control system for grid generation of a switched reluctance generator driven by a variable speed wind turbine  

Microsoft Academic Search

This paper presents a novel control system for the operation of a grid connected switched reluctance generator driven by a variable speed wind turbine. The SRG is connected to a power converter which is controlled to drive the wind energy conversion system (WECS) to the point of maximum aerodynamics efficiency using closed loop control of the power output. A second

Roberto CARDENAS; R. Pena; M. Perez; G. Asher; J. Clare; P. Wheeler

2004-01-01

288

Fundamental characteristics of test facility for micro hydroelectric power generation system  

Microsoft Academic Search

This paper proposes a test facility for micro hydraulic generation system. Micro hydraulic generation system is very difficult to exam their characteristics including hydraulic turbine because water flow in various conditions is necessary but it is very difficult to realize in laboratory. In this paper water flow is realized using general purpose pump that can add pressure to water flow

T. Sakurai; H. Funato; S. Ogasawara

2009-01-01

289

Counter-Rotatable Fan Gas Turbine Engine with Axial Flow Positive Displacement Worm Gas Generator  

NASA Technical Reports Server (NTRS)

A counter-rotatable fan turbine engine includes a counter-rotatable fan section, a worm gas generator, and a low pressure turbine to power the counter-rotatable fan section. The low pressure turbine maybe counter-rotatable or have a single direction of rotation in which case it powers the counter-rotatable fan section through a gearbox. The gas generator has inner and outer bodies having offset inner and outer axes extending through first, second, and third sections of a core assembly. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes and extending radially outwardly and inwardly respectively. The helical blades have first, second, and third twist slopes in the first, second, and third sections respectively. A combustor section extends through at least a portion of the second section.

Giffin, Rollin George (Inventor); Murrow, Kurt David (Inventor); Fakunle, Oladapo (Inventor)

2014-01-01

290

Mod-5A wind turbine generator program design report. Volume 3: Final design and system description, book 1  

NASA Astrophysics Data System (ADS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. Volume 3, book 1 describes the performance and characteristics of the MOD-5A wind turbine generator in its final configuration. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation is described in detail.

1984-08-01

291

Modelling and Control of a Variable Speed Wind Energy Conversion Turbine driven Synchronous Generator Connected to the Grid  

Microsoft Academic Search

This paper presents the modelling and control design for a wind energy conversion scheme using synchronous generator. The wind turbine is coupled to a synchronous generator connected to grid trough a static converter. The objective of the proposed control strategy is to maximize energy captured from the wind turbine. The adapting control law used for extracting maximum power from the

O. HASNAOUI; I. B. SALEM; M. F. MIMOUNI; R. DHIFAOUI

2006-01-01

292

Proposal and Development of Radial Air-gap Coreless Generator Suitable for Small Wind Turbine using in Urban Area  

Microsoft Academic Search

Independent distributed generations using small wind turbines are widely spread as increasing of wind power generation. Installation of small wind turbines in densely-populated urban area is not only useful from the viewpoint of digging up wind power source in weak-wind area but also for enlightenment of renewable energy due to closing power supplies to consumptions. From the point of view,

Toshiyuki Takahashi; Yoh Yasuda; Shingo Ohmoto; Takehisa Hara

2007-01-01

293

Mod-5A wind turbine generator program design report. Volume 3: Final design and system description, book 1  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. Volume 3, book 1 describes the performance and characteristics of the MOD-5A wind turbine generator in its final configuration. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation is described in detail.

1984-01-01

294

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 1: Executive summary  

NASA Technical Reports Server (NTRS)

Primary results are summarized for a three-part study involving the effects of connecting a MOD-OA wind turbine generator to an isolated diesel power system. The MOD-OA installation considered was the third of four experimental nominal 200 kW wind turbines connected to various utilities under the Federal Wind Energy Program and was characterized by the highest wind energy penetration levels of four sites. The study analyses address: fuel displacement, dynamic interaction, and three modes of reactive power control. These analyses all have as their basis the results of the data acquisition program conducted on Block Island, Rhode Island.

Wilreker, V. F.; Stiller, P. H.; Scott, G. W.; Kruse, V. J.; Smith, R. F.

1984-01-01

295

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 1: Executive summary  

NASA Astrophysics Data System (ADS)

Primary results are summarized for a three-part study involving the effects of connecting a MOD-OA wind turbine generator to an isolated diesel power system. The MOD-OA installation considered was the third of four experimental nominal 200 kW wind turbines connected to various utilities under the Federal Wind Energy Program and was characterized by the highest wind energy penetration levels of four sites. The study analyses address: fuel displacement, dynamic interaction, and three modes of reactive power control. These analyses all have as their basis the results of the data acquisition program conducted on Block Island, Rhode Island.

Wilreker, V. F.; Stiller, P. H.; Scott, G. W.; Kruse, V. J.; Smith, R. F.

1984-02-01

296

Wind turbine generators using superconducting coils and bulks  

NASA Astrophysics Data System (ADS)

Wind power generation has been expected as a promising clean energy source in the world. Recently, generation capacity produced by wind power generators has been growing with increasing size of windmills. However, huge nacelles result in extreme load for towers supporting them. We have focused on a wind power generator using superconducting wires and superconducting bulks to solve the problem. Large currents may flow through superconducting wires with zero DC resistance. Superconducting bulks are magnetic shielding materials. These enable reduction of size and weight of nacelles. In addition, large generators using these materials can generate an output power of 10 MW with very large power densities. This paper describes calculation of generated magnetic field and power generation characteristics using three-dimensional finite element method (FEM) analysis of the generators using high temperature superconducting coils and bulks.

Ohsaki, H.; Terao, Y.; Sekino, M.

2010-06-01

297

Lightning accommodation systems for wind turbine generator safety  

NASA Technical Reports Server (NTRS)

The wind turbine safety program identifies the naturally occurring lightning phenomenon as a hazard with the potential to cause loss of program objectives, injure personnel, damage system instrumentation, structure or support equipment and facilities. Several candidate methods of lightning accommodation for each blade were designed, analyzed, and tested by submitting sample blade sections to simulated lightning. Lightning accommodation systems for composite blades were individually developed. Their effectiveness was evaluated by submitting the systems to simulated lightning strikes. The test data were analyzed and system designs were reviewed on the basis of the analysis. This activity is directed at defining design and procedural constraints, requirements for safety devices and warning methods, special procedures, protective equipment and personnel training.

Bankaitis, H.

1981-01-01

298

Safe Harbor Kaplan Turbines Design of Setting and Cavitation Limit as Developed at the Holtwood Hydraulic Laboratory  

Microsoft Academic Search

The Safe Harbor plant is the first large development in this country to use the Kaplan type of turbine. This paper describes the problems of design and operation which were comprehensively studied by means of model and field tests, with particular regard to the power limits of the turbines as established from a study of cavitation.

L. M. Davis; G. W. Spaulding

1933-01-01

299

Mod-1 wind turbine generator analysis and design report, volume 1  

NASA Technical Reports Server (NTRS)

The activities leading to the completion of detail design of the MOD-1 wind turbine generator are described. Emphasis is placed on the description of the design as it finally evolved. However, the steps through which the design progressed are also traced in order to understand the major design decisions.

1979-01-01

300

Synchronization of the DOE/NASA 100-kilowatt wind turbine generator with a large utility network  

NASA Technical Reports Server (NTRS)

The DOE/NASA 100 kilowatt wind turbine generator system was synchronized with a large utility network. The system equipments and procedures associated with the synchronization process were described. Time history traces of typical synchronizations were presented indicating that power and current transients resulting from the synchronizing procedure are limited to acceptable magnitudes.

Gilbert, L. J.

1977-01-01

301

Ridethrough of wind turbines with doubly-fed induction generator during a voltage dip  

Microsoft Academic Search

In this paper, a solution is described that makes it possible for wind turbines using doubly-fed induction generators to stay connected to the grid during grid faults. The key of the solution is to limit the high current in the rotor in order to protect the converter and to provide a bypass for this current via a set of resistors

Johan Morren; Sjoerd W. H. de Haan

2005-01-01

302

Prediction of Wind Turbine Noise Generation and Propagation based on an Acoustic Analogy  

Microsoft Academic Search

The acoustical field behind a complete three dimensional wind turbine is considered numerically. Noise generated by the spatial velocity variation, force exerted by the blade on the fluid, and blade acceleration is taken into account. The sources are extracted from a detailed, instantaneous flow field which is computed using Large Eddy Simulations (LES). The propagation of the sound is calculated

Drago? Moroianu; Laszlo Fuchs

303

Partial discharges in stator winding insulation of turbine generators — A case study and remedies  

Microsoft Academic Search

Development of partial discharge (PD) detection methods by A\\/D conversion has acquired very important place in diagnosis for healthiness assessment of dielectric insulation of stator windings in turbine generators (TG). Evaluation of acquired digital spectrum for characteristics of PDs of the machine is the critical aspect in PD analysis. This paper describes the method of detecting PDs in (TG) high

P. G. S. Kumar; J. Amarnath; B. P. Singh

2011-01-01

304

Direct Power Control of Doubly-Fed Generator Based Wind Turbine Converters to Improve Low Voltage  

E-print Network

Control (DPC) is discussed for Low Voltage Ride Through (LVRT) of DFIG based wind turbine converters power integration state that doubly fed induction generator (DFIG) controllers should be capable and maintaining dc bus voltage, then the DFIG will stay online during the disturbance. A fast acting controller

Kimball, Jonathan W.

305

FEM study on permanent magnet synchronous generators for small wind turbines  

Microsoft Academic Search

Permanent magnet synchronous generators (PMSGs) have a bright prospect in the small wind turbine applications. Finite element method (FEM) is a powerful tool to study and design PMSGs, as reported in this paper. First, FEM is employed to study the PMSG's output voltage. Valuable conclusions have been drawn regarding of the PMSG's performance and manufacture cost. Second, a FEM model,

Zhenhong Guo; Liuchen Chang

2005-01-01

306

Modeling and simulation of an induction drive with application to a small wind turbine generator  

Microsoft Academic Search

Among renewable energies the solution of utilizing wind energy conversion systems is now in a growing trend. A valid choice for operation of such systems may be the use of the induction machine. This study presents modeling and simulation of a stand-alone induction drive with application to a small wind turbine generator system. The model of the induction machine is

L. Tamas; Z. Szekely

2008-01-01

307

Pinson C2E wind turbine generator failure analysis and corrective design modification  

Microsoft Academic Search

On December 4, 1978 wind speeds at the Rocky Flats Small Wind Systems Test Center reached 42 m\\/s. Two failures were observed on the Pinson C2E wind turbine generator during a routine inspection of all wind machines following this windstorm. One failure was fatigue cracks which formed on plates welded to the rotor shaft. The second failure was a number

M. J. Carr; V. K. Grotsky; J. H. Sexton

1980-01-01

308

The generation of electricity by gas turbines using the catalytic combustion of low-Btu gases  

Microsoft Academic Search

Various systems for the generation of electricity by gas turbines using catalytic combustion of low-Btu gases have been investigated. Parametric studies of three configurations that are deemed to be practically feasible have been completed. It is shown that thermodynamic efficiency of these systems may be quite high. The system design has been made to comply with generally accepted limitations on

O. P. Frederiksen; B. Qvale

1989-01-01

309

Status of Evaluating the Fatigue of Large Steam Turbine-Generators Caused by Electrical Disturbances  

Microsoft Academic Search

The torsional fatigue impact of different and successive electrical transients on the shafts of nearby turbine-generators is explained and quantitatively compared for various fault conditions and system switching operations. The basis for evaluating fatigue is explained and the many contributory factors are discussed. Results of measurements of the damping of shaft torsional oscillations are presented. The operating principle of the

John Joyce; Dietrich Lambrecht

1980-01-01

310

A new monitoring system for wind turbines with doubly-fed induction generators  

Microsoft Academic Search

For modern large wind farms, it is interesting to design an efficient diagnosis system oriented to wind turbine generators based on doubly-fed induction machine (DFIM). Intensive research efforts have been focused on the signature analysis to predict or to detect electrical and mechanical faults in induction machines. Different signals can be used such as voltages, currents or stray flux. In

A. Yazidi; G. A. Capolino; F. Filippetti; D. Casadei

2006-01-01

311

Optimization of heat recovery steam generators for combined cycle gas turbine power plants  

Microsoft Academic Search

The heat recovery steam generator (HRSG) is one of the few components of combined cycle gas turbine power plants tailored for each specific application. Any change in its design would directly affect all the variables of the cycle and therefore the availability of tools for its optimization is of the greatest relevance. This paper presents a method for the optimization

Manuel Valdés; José L. Rapún

2001-01-01

312

MOD-1 Wind Turbine Generator Analysis and Design Report, Volume 2  

NASA Technical Reports Server (NTRS)

The MOD-1 detail design is appended. The supporting analyses presented include a parametric system trade study, a verification of the computer codes used for rotor loads analysis, a metal blade study, and a definition of the design loads at each principal wind turbine generator interface for critical loading conditions. Shipping and assembly requirements, composite blade development, and electrical stability are also discussed.

1979-01-01

313

Economic index for selection of wind turbine generator at a site  

Microsoft Academic Search

In this paper a new methodology to select a wind turbine generator from the view point of performance and economic considerations is presented. Weibull probability density function is used to analyze the wind data and the performance analysis is based on computing the capacity factors. The economic considerations involve computation of cost of energy based on the energy yield, capital

Sangamesh S. Doddamani; Suresh H. Jangamshetti

2008-01-01

314

The Future of Combustion Turbine Technology for Industrial and Utility Power Generation  

E-print Network

Low capital cost and ample low-cost natural gas supplies will make natural gas-fired combustion turbine systems the power generation technology of choice over the next decade. Against the background of earlier use by electric utilities, this paper...

Karp, A. D.; Simbeck, D. R.

315

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 2: Data analysis  

NASA Astrophysics Data System (ADS)

Assessing the performance of a MOD-OA horizontal axis wind turbine connected to an isolated diesel utility, a comprehensive data measurement program was conducted on the Block Island Power Company installation on Block Island, Rhode Island. The detailed results of that program focusing on three principal areas of (1) fuel displacement (savings), (2) dynamic interaction between the diesel utility and the wind turbine, (3) effects of three models of wind turbine reactive power control are presented. The approximate two month duration of the data acquisition program conducted in the winter months (February into April 1982) revealed performance during periods of highest wind energy penetration and hence severity of operation. Even under such conditions fuel savings were significant resulting in a fuel reduction of 6.7% while the MOD-OA was generating 10.7% of the total electrical energy. Also, electrical disturbance and interactive effects were of an acceptable level.

Wilreker, V. F.; Stiller, P. H.; Scott, G. W.; Kruse, V. J.; Smith, R. F.

1984-02-01

316

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 2: Data analysis  

NASA Technical Reports Server (NTRS)

Assessing the performance of a MOD-OA horizontal axis wind turbine connected to an isolated diesel utility, a comprehensive data measurement program was conducted on the Block Island Power Company installation on Block Island, Rhode Island. The detailed results of that program focusing on three principal areas of (1) fuel displacement (savings), (2) dynamic interaction between the diesel utility and the wind turbine, (3) effects of three models of wind turbine reactive power control are presented. The approximate two month duration of the data acquisition program conducted in the winter months (February into April 1982) revealed performance during periods of highest wind energy penetration and hence severity of operation. Even under such conditions fuel savings were significant resulting in a fuel reduction of 6.7% while the MOD-OA was generating 10.7% of the total electrical energy. Also, electrical disturbance and interactive effects were of an acceptable level.

Wilreker, V. F.; Stiller, P. H.; Scott, G. W.; Kruse, V. J.; Smith, R. F.

1984-01-01

317

554 IEEE JOURNAL OF OCEANIC ENGINEERING, VOL. 37, NO. 3, JULY 2012 Generator Systems for Marine Current Turbine  

E-print Network

turbine. DFIG Doubly-fed induction generator. PMSG Permanent magnet synchronous generator. MPPT Maximum from a DFIG- and PMSG-based MCT. To high- light differences between the considered technologies, a vari

Paris-Sud XI, Université de

318

Turbine Drive Gas Generator for Zero Emission Power Plants  

Microsoft Academic Search

The Vision 21 Program seeks technology development that can reduce energy costs, reduce or eliminate atmospheric pollutants from power plants, provide choices of alternative fuels, and increase the efficiency of generating systems. Clean Energy Systems is developing a gas generator to replace the traditional boiler in steam driven power systems. The gas generator offers the prospects of lower electrical costs,

Stephen E. Doyle; Roger E. Anderson

2001-01-01

319

Case History of Reapplication of a 2500 KW Steam Turbine/Gear Drive Generator  

E-print Network

with the main oil pump driven off the gear box. Turbine Due to the steam inlet conditions, 575 psig at 750 degrees F, the first concern was the material of construction. It was decided that the material of the steam chest needed to be carbon steel. Cast iron...CASE HISTORY OF REAPPLICATION OF A 2500 KW STEAM TURBINE/GEAR DRIVE GENERATOR SAMUEL V. SMITH Manager, Technical Sales and ~ervice Revak Turbomachinery SerVlces La Porte, Texas Abstract In today' s equipment market more and more...

Smith, S.

320

Advances in Thermal Spray Coatings for Gas Turbines and Energy Generation: A Review  

NASA Astrophysics Data System (ADS)

Functional coatings are widely used in energy generation equipment in industries such as renewables, oil and gas, propulsion engines, and gas turbines. Intelligent thermal spray processing is vital in many of these areas for efficient manufacturing. Advanced thermal spray coating applications include thermal management, wear, oxidation, corrosion resistance, sealing systems, vibration and sound absorbance, and component repair. This paper reviews the current status of materials, equipment, processing, and properties' aspects for key coatings in the energy industry, especially the developments in large-scale gas turbines. In addition to the most recent industrial advances in thermal spray technologies, future technical needs are also highlighted.

Hardwicke, Canan U.; Lau, Yuk-Chiu

2013-06-01

321

Output Power Control of Wind Turbine Generator by Pitch Angle Control using Minimum Variance Control  

NASA Astrophysics Data System (ADS)

In recent years, there have been problems such as exhaustion of fossil fuels, e. g., coal and oil, and environmental pollution resulting from consumption. Effective utilization of renewable energies such as wind energy is expected instead of the fossil fuel. Wind energy is not constant and windmill output is proportional to the cube of wind speed, which cause the generated power of wind turbine generators (WTGs) to fluctuate. In order to reduce fluctuating components, there is a method to control pitch angle of blades of the windmill. In this paper, output power leveling of wind turbine generator by pitch angle control using an adaptive control is proposed. A self-tuning regulator is used in adaptive control. The control input is determined by the minimum variance control. It is possible to compensate control input to alleviate generating power fluctuation with using proposed controller. The simulation results with using actual detailed model for wind power system show effectiveness of the proposed controller.

Senjyu, Tomonobu; Sakamoto, Ryosei; Urasaki, Naomitsu; Higa, Hiroki; Uezato, Katsumi; Funabashi, Toshihisa

322

Modeling a high output marine steam generator feedwater control system which uses parallel turbine-driven feed pumps  

NASA Astrophysics Data System (ADS)

Parallel turbine-driven feedwater pumps are needed when ships travel at high speed. In order to study marine steam generator feedwater control systems which use parallel turbine-driven feed pumps, a mathematical model of marine steam generator feedwater control system was developed which includes mathematical models of two steam generators and parallel turbine-driven feed pumps as well as mathematical models of feedwater pipes and feed regulating valves. The operating condition points of the parallel turbine-driven feed pumps were calculated by the Chebyshev curve fit method. A water level controller for the steam generator and a rotary speed controller for the turbine-driven feed pumps were also included in the model. The accuracy of the mathematical models and their controllers was verified by comparing their results with those from a simulator.

Qiu, Zhi-Qiang; Zou, Hai; Sun, Jian-Hua

2008-09-01

323

Imbalance Fault Detection of Direct-Drive Wind Turbines Using Generator Current Signals  

Microsoft Academic Search

Imbalance faults constitute a significant portion of all faults in wind turbine generators (WTGs). WTG imbalance fault detection using generator current measurements has advantages over traditional vibration-based methods in terms of cost, implementation, and system reliability. However, there are challenges in using current signals for imbalance fault detection due to low signal-to-noise ratio of the useful information in current signals

Xiang Gong; Wei Qiao

2012-01-01

324

Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines  

Microsoft Academic Search

In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic

Allan Chertok; David Hablanian; Paul McTaggart; DOE Project Officer

2004-01-01

325

Robust Predictive Control of Variable-Speed Wind Turbine Generator by Self-Tuning Regulator  

Microsoft Academic Search

The parameter variation problem in controller design for wind turbine generator (WTG) systems due to wind speed fluctuations is addressed in this paper. The wind speed is generated by an auto-regressive and moving average (ARMA) model while drive-train components are modelled as a two- mass system described by non-linear equations for accurate dynamic performance assessment. The control of the unit

E. B. Muhando; T. Senjyu; N. Urasaki; A. Yona; T. Funabashi

2007-01-01

326

Air-cooled large turbine generator with multiple-pitched ventilation ducts  

Microsoft Academic Search

On the air-cooled turbine generators, windage loss is the substantial factor of generator losses. One solution for the windage loss reduction is to minimize the amount of coolant air with the multiple-pitched ventilation ducts in the stator core. However, non-uniform duct distribution leads to the circulating currents in the stator bar strands which increase coil losses and cause significant distribution

Masafumi Fujita; Yasuo Kabata; Tadashi Tokumasu; Mikio Kakiuchi; Hidekazu Shiomi; Susumu Nagano

2005-01-01

327

A three-dimensional algebraic grid generation scheme for gas turbine combustors with inclined slots  

NASA Technical Reports Server (NTRS)

A 3D algebraic grid generation scheme is presented for generating the grid points inside gas turbine combustors with inclined slots. The scheme is based on the 2D transfinite interpolation method. Since the scheme is a 2D approach, it is very efficient and can easily be extended to gas turbine combustors with either dilution hole or slot configurations. To demonstrate the feasibility and the usefulness of the technique, a numerical study of the quick-quench/lean-combustion (QQ/LC) zones of a staged turbine combustor is given. Preliminary results illustrate some of the major features of the flow and temperature fields in the QQ/LC zones. Formation of co- and counter-rotating bulk flow and shape temperature fields can be observed clearly, and the resulting patterns are consistent with experimental observations typical of the confined slanted jet-in-cross flow. Numerical solutions show the method to be an efficient and reliable tool for generating computational grids for analyzing gas turbine combustors with slanted slots.

Yang, S. L.; Cline, M. C.; Chen, R.; Chang, Y. L.

1993-01-01

328

Accumulative fatigue life expenditure of turbine/generator shafts following worst-case system disturbances  

SciTech Connect

The paper reviews phenomena which influence accumulative fatigue life expenditure of turbine/generator exciter shafts following severe disturbances on the electrical supply. Fatigue models for estimating cumulative fatigue of Machine shafts are discussed. The importance of allowing for mean stress and of simulating steam and electrical damping is examined for both worst-case 3-phase fault clearance and bad synchronising. The effect of auto-reclosure on fatigue life expenditure of shafts is also considered. The effect of variation of stress concentration factor (or shaft diameter) on cumulative fatigue is illustrated as is the effectiveness of torque limiting shearing couplings in protecting shaft systems from damage following a severe switching event. The effect of machine disconnection following a severe electrical disturbance is examined. Shaft torsional monitors for estimating fatigue life expenditure of shafts are also discussed. It is concluded that fatigue life expenditure at shaft couplings following worst-case 3-phase fault clearance may be up to double that corresponding to worst-case synchronising although peak shaft torques are only marginally higher. Cumulative fatigue will quite often be higher at couplings along the shaft than at the turbine/generator coupling on account of electrical damping although peak torque is generally highest at the turbine/generator coupling and reduces progressively along the turbine shaft.

Hammons, T.J.

1982-07-01

329

Vertical-axis wind turbine modeling and performance with axial-flux permanent magnet synchronous generator for battery charging applications  

Microsoft Academic Search

The modeling and simulation of a 1kW vertical-axis direct drive topology wind turbine are implemented. An axial flux permanent magnet synchronous generator with multi-pole is directly connected to the wind turbine shaft. The wind turbine system is controlled to operate at constant tip-speed ratio and hence maximizing the power extracted from the wind. For battery charging applications, a modified version

Ahmad M. Eid; Mazen Abdel-Salam; M. Tharwat Abdel-Rahman

2006-01-01

330

LPV Control for the Full Region Operation of a Wind Turbine Integrated with Synchronous Generator  

PubMed Central

Wind turbine conversion systems require feedback control to achieve reliable wind turbine operation and stable current supply. A robust linear parameter varying (LPV) controller is proposed to reduce the structural loads and improve the power extraction of a horizontal axis wind turbine operating in both the partial load and the full load regions. The LPV model is derived from the wind turbine state space models extracted by FAST (fatigue, aerodynamics, structural, and turbulence) code linearization at different operating points. In order to assure a smooth transition between the two regions, appropriate frequency-dependent varying scaling parametric weighting functions are designed in the LPV control structure. The solution of a set of linear matrix inequalities (LMIs) leads to the LPV controller. A synchronous generator model is connected with the closed LPV control loop for examining the electrical subsystem performance obtained by an inner speed control loop. Simulation results of a 1.5?MW horizontal axis wind turbine model on the FAST platform illustrates the benefit of the LPV control and demonstrates the advantages of this proposed LPV controller, when compared with a traditional gain scheduling PI control and prior LPV control configurations. Enhanced structural load mitigation, improved power extraction, and good current performance were obtained from the proposed LPV control.

Grigoriadis, Karolos M.; Nyanteh, Yaw D.

2015-01-01

331

LPV Control for the Full Region Operation of a Wind Turbine Integrated with Synchronous Generator.  

PubMed

Wind turbine conversion systems require feedback control to achieve reliable wind turbine operation and stable current supply. A robust linear parameter varying (LPV) controller is proposed to reduce the structural loads and improve the power extraction of a horizontal axis wind turbine operating in both the partial load and the full load regions. The LPV model is derived from the wind turbine state space models extracted by FAST (fatigue, aerodynamics, structural, and turbulence) code linearization at different operating points. In order to assure a smooth transition between the two regions, appropriate frequency-dependent varying scaling parametric weighting functions are designed in the LPV control structure. The solution of a set of linear matrix inequalities (LMIs) leads to the LPV controller. A synchronous generator model is connected with the closed LPV control loop for examining the electrical subsystem performance obtained by an inner speed control loop. Simulation results of a 1.5?MW horizontal axis wind turbine model on the FAST platform illustrates the benefit of the LPV control and demonstrates the advantages of this proposed LPV controller, when compared with a traditional gain scheduling PI control and prior LPV control configurations. Enhanced structural load mitigation, improved power extraction, and good current performance were obtained from the proposed LPV control. PMID:25884036

Cao, Guoyan; Grigoriadis, Karolos M; Nyanteh, Yaw D

2015-01-01

332

Advanced Seal Technology Role in Meeting Next Generation Turbine Engine Goals  

NASA Technical Reports Server (NTRS)

Cycle studies have shown the benefits of increasing engine pressure ratios and cycle temperatures to decrease engine weight and improve performance in next generation turbine engines. Advanced seals have been identified as critical in meeting engine goals for specific fuel consumption, thrust-to-weight, emissions, durability and operating costs. NASA and the industry are identifying and developing engine and sealing technologies that will result in dramatic improvements and address the goals for engines entering service in the 2005-2007 time frame. This paper provides an overview of advanced seal technology requirements and highlights the results of a preliminary design effort to implement advanced seals into a regional aircraft turbine engine. This study examines in great detail the benefits of applying advanced seals in the high pressure turbine region of the engine. Low leakage film-riding seals can cut in half the estimated 4% cycle air currently used to purge the high pressure turbine cavities. These savings can be applied in one of several ways. Holding rotor inlet temperature (RIT) constant the engine specific fuel consumption can be reduced 0.9%, or thrust could be increased 2.5%, or mission fuel burn could be reduced 1.3%. Alternatively, RIT could be lowered 20 'F resulting in a 50% increase in turbine blade life reducing overall regional aircraft maintenance and fuel bum direct operating costs by nearly 1%. Thermal, structural, secondary-air systems, safety (seal failure and effect), and emissions analyses have shown the proposed design is feasible.

Steinetz, Bruce M.; Hendricks, Robert C.; Munson, John

1999-01-01

333

Design and construction of a thermophotovoltaic generator using turbine combustion gas  

SciTech Connect

This US Naval Academy project involves the development of a prototype thermophotovoltaic (TPV) generator that uses a General Electric T-58 helicopter gas turbine as the heat source. The goals of this project were to demonstrate the viability of using TPV and external combustion gases to generate electricity, and develop a system which could also be used for materials testing. The generator was modularly designed so that different materials could be tested at a later date. The combustion gas was tapped from the T-58`s combustor through one of the two igniter ports and extracted through a silicon carbide matrix ceramic composite tube into a similarly constructed ceramic composite radiant emitter. The ceramic radiant emitters is heated by the combustion gas via convection, and then serves the TPV generator by radiating the heat outwards where it can be absorbed by thermophotovoltaic cells and converted directly into electricity. The gas turbine and generator module are monitored by a data acquisition system that performs both data collection and control functions. This paper details the design of the TPV generator. It also gives results of initial tests with the gas turbine.

Erickson, T.A.; Lindler, K.W.; Harper, M.J. [Naval Academy, Annapolis, MD (United States). Dept. of Naval Architecture, Ocean, and Marine Engineering

1997-07-01

334

An optimal design of coreless direct-drive axial flux permanent magnet generator for wind turbine  

NASA Astrophysics Data System (ADS)

Different types of generators are currently being used in wind power technology. The commonly used are induction generator (IG), doubly-fed induction generator (DFIG), electrically excited synchronous generator (EESG) and permanent magnet synchronous generator (PMSG). However, the use of PMSG is rapidly increasing because of advantages such as higher power density, better controllability and higher reliability. This paper presents an innovative design of a low-speed modular, direct-drive axial flux permanent magnet (AFPM) generator with coreless stator and rotor for a wind turbine power generation system that is developed using mathematical and analytical methods. This innovative design is implemented in MATLAB / Simulink environment using dynamic modelling techniques. The main focus of this research is to improve efficiency of the wind power generation system by investigating electromagnetic and structural features of AFPM generator during its operation in wind turbine. The design is validated by comparing its performance with standard models of existing wind power generators. The comparison results demonstrate that the proposed model for the wind power generator exhibits number of advantages such as improved efficiency with variable speed operation, higher energy yield, lighter weight and better wind power utilization.

Ahmed, D.; Ahmad, A.

2013-06-01

335

Power train analysis for the DOE/NASA 100-kW wind turbine generator  

NASA Technical Reports Server (NTRS)

Progress in explaining variations of power experienced in the on-line operation of a 100 kW experimental wind turbine-generator is reported. Data are presented that show the oscillations tend to be characteristic of a wind-driven synchronous generator because of low torsional damping in the power train, resonances of its large structure, and excitation by unsteady and nonuniform wind flow. The report includes dynamic analysis of the drive-train torsion, the generator, passive driveline damping, and active pitch control as well as correlation with experimental recordings. The analysis assumes one machine on an infinite bus with constant generator-field excitation.

Seidel, R. C.; Gold, H.; Wenzel, L. M.

1978-01-01

336

Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines  

SciTech Connect

In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic model was created and the modular PMG design was compared to an illustrative non-modular design. The resulting projections show that the modular design can achieve significant reductions in size, weight, and manufacturing cost without compromising efficiency. Reducing generator size and weight can also lower the size and weight of other wind turbine components and hence their manufacturing cost.

Chertok, Allan; Hablanian, David; McTaggart, Paul; DOE Project Officer - Keith Bennett

2004-11-16

337

A microfabricated ElectroQuasiStatic induction turbine-generator  

E-print Network

An ElectroQuasiStatic (EQS) induction machine has been fabricated and has generated net electric power. A maximum power output of 192 [mu]W at 235 krpm has been measured under driven excitation of the six phases. Self ...

Steyn, J. Lodewyk (Jasper Lodewyk), 1976-

2005-01-01

338

Evolution of air-cooled turbine generator design  

Microsoft Academic Search

Recent market trends have seen air-cooled generators fulfilling application needs over an increasing range of power output ratings. While GE continues to provide and to further develop an extensive line of hydrogen-cooled generators, significant investment in the air-cooled product line has further enhanced the reliability and performance of the overall product structure. Concurrent with this demand for increased performance and

E. Jarczynski; T. Wetzel; J. Fealey

2003-01-01

339

Optimized working conditions for a thermoelectric generator as a topping cycle for gas turbines  

NASA Astrophysics Data System (ADS)

This paper presents a model for a theoretical maximum efficiency of a thermoelectric generator integrated with a Brayton-cycle engine. The thermoelectric cycle is presented in two configurations as a topping cycle and a preheating topping cycle. For the topping cycle configuration, the thermoelectric generator receives heat from a high-temperature heat source and produces electrical work before rejecting heat to a Brayton cycle. For the preheating topping cycle, the rejected heat from the thermoelectric generator partially heats the compressed working fluid of the Brayton cycle before a secondary heater delivers heat to the working fluid directly from the heat source. The thermoelectric topping cycle efficiency increases as the temperature difference between the hot- and cold-side increases; however, this limits the heat transfer possible to the Brayton cycle, which in turn reduces power generation from the Brayton cycle. This model identifies the optimum operating parameters of the thermoelectric and Brayton cycles to obtain the maximum thermal efficiency of the combined cycle. In both configurations, efficiency gains are larger at low-temperature Brayton cycles. Although a thermoelectric generator (TEG) topping cycle enhances efficiency for a low temperature turbine, efficiency cannot exceed a high temperature gas turbine. Using a TEG topping cycle is limited to cases when space or price for a high temperature turbine cannot be justified. A design to achieve the preheating thermoelectric topping cycle is also presented.

Brady Knowles, C.; Lee, Hohyun

2012-10-01

340

Hydraulic waste energy recovery, Phase 2  

SciTech Connect

The energy required for booster station operation is supplied by the electrical utility company and has an associated cost. Energy removed by pressure reducing valves in the system is lost or wasted. The objective of this project is to capture the wasted hydraulic energy with in-line turbines. In this application, the in-line turbines act as pressure reducing valves while removing energy from the water distribution system and converting it to electrical energy. The North Service Center pumping station was selected for the pilot program due to the availability of a wide range in pressure drop and flow, which are necessary for hydraulic energy recovery. The research performed during this project resulted in documentation of technical, economic, installation, and operational information necessary for local government officials to make an informed judgement as it relates to in-line turbine generation.

Not Available

1992-02-01

341

Revenue Maximization of Electricity Generation for a Wind Turbine Integrated with a Compressed Air Energy Storage System  

E-print Network

controller is developed for a Compressed Air Energy Storage (CAES) system integrated with a wind turbine availability of wind energy more reliable, predictable and less disruptive to the electric grid. MoreoverRevenue Maximization of Electricity Generation for a Wind Turbine Integrated with a Compressed Air

Li, Perry Y.

342

Investigation of vortex generators for augmentation of wind turbine power performance  

SciTech Connect

This study focuses on the use of vortex generators (VGs) for performance augmentation of the stall-regulated AWT-26 wind turbine. The goal was to design a VG array which would increase annual energy production (AEP) by increasing power output at moderate wind speeds, without adversely affecting the loads or stall-regulation performance of the turbine. Wind tunnel experiments were conducted at the University of Washington to evaluate the effect of VGs on the AWT-26 blade, which is lofted from National Renewable Energy Laboratory (NREL) S-series airfoils. Based on wind-tunnel results and analysis, a VG array was designed and then tested on the AWT-26 prototype, designated P1. Performance and loads data were measured for P1, both with and without VGs installed. the turbine performance with VGs met most of the design requirements; power output was increased at moderate wind speeds with a negligible effect on peak power. However, VG drag penalties caused a loss in power output for low wind speeds, such that performance with VGs resulted in a net decrease in AEP for sites having annual average wind speeds up to 8.5 m/s. While the present work did not lead to improved AEP for the AWT-2 turbine, it does provide insight into performance augmentation of wind turbines with VGs. The safe design of a VG array for a stall-regulated turbine has been demonstrated, and several issues involving optimal performance with VGs have been identified and addressed. 15 refs., 34 figs., 10 tabs.

Griffin, D.A. [Lynette (R.) and Associates, Seattle, WA (United States)

1996-12-01

343

Permanent magnet axial flux disc generator for small wind turbines  

Microsoft Academic Search

In the paper a permanent magnet axial flux disc generator (AFPMG) with fractional slot pitch winding for small wind energy applications is proposed. Its main features are high specific power, very low torque ripple and a quasi-sinusoidal output voltage. A preliminary design can be carried out by a simplified analytical procedure. Afterwards, an automated sequence of magnetostatic FEM analyses on

Mauro Andriollo; Manuel De Bortoli; Giovanni Martinelli; Augusto Morini; Andrea Tortella

2008-01-01

344

RELAP5/MOD3 Analysis of Transient Steam-Generator Behavior During Turbine Trip Test of a Prototype Fast Breeder Reactor MONJU  

SciTech Connect

In order to develop a thermal-hydraulic model of the steam-generator (SG) to simulate transient phenomena in the sodium cooled fast breeder reactor (FBR) MONJU, Japan Nuclear Energy Safety Organization (JNES) verified the SG model using the RELAP5/MOD3 code against the results of the turbine trip test at a 40% power load of MONJU. The modeling by using RELAP5 was considered to explain the significant observed behaviors of the pressure and the temperature of the EV steam outlet, and the temperature of water supply distributing piping till 600 seconds after the turbine trip. The analysis results of these behaviors showed good agreement with the test results based on results of parameter study as the blow efficiency (release coef.) and heat transferred from the helical coil region to the down-comer (temperature heating down-comer tubes). It was found that the RELAP5/MOD3 code with a two-fluids model can predict well the physical situation: the gas-phase of steam generated by the decompression boiling moves upward in the down-comer tubes accompanied by the enthalpy increase of the water supply chambers; and that the pressure change of a 'shoulder' like shape is induced by the mass balance between the steam mass generated in the down-comer tubes and the steam mass blown from the SG. The applicability of RELAP5/MOD3 to SG modeling was confirmed by simulating the actual FBR system. (authors)

Yoshihisa Shindo; Hiroshi Endo; Tomoko Ishizu; Kazuo Haga [Japan Nuclear Energy Safety Organization (Japan)

2006-07-01

345

Electromagnetic design analysis and performance improvement of axial field permanent magnet generator for small wind turbine  

NASA Astrophysics Data System (ADS)

Axial field permanent magnet (AFPM) generators are widely applied for the small wind turbine. The output power of conventional AFPM generator, AFER-NS (Axial Field External Rotor-Non Slotted) generator, is limited by the large reluctance by the long air-gap flux paths. In this paper, the novel structure of AFPM generator, AFIR-S (Axial Field Inner Rotor-Slotted) generator, is suggested to improve the output characteristics. The electromagnetic design analysis and the design improvement of the suggested AFIR-S generator are studied. Firstly, the electromagnetic design analysis was done to increase the power density. Secondly, the design optimizations of the rotor pole-arc ratio and skew angle to increase the output power and to reduce the cogging torque. Finally, the output performances of AFER-NS and AFIR-S generator are compared with each other.

Jung, Tae-Uk

2012-04-01

346

A Parametric Study of the Thermal-Hydraulic Response of Supercritical Light Water Reactors During Loss-of-Feedwater and Turbine-Trip Events  

SciTech Connect

The Idaho National Engineering and Environmental Laboratory in investigating the feasibility of supercritical light water reactors for low-cost electric power production through a Nuclear Energy Research Initiative Project sponsored by the United State Department of Energy. The project is evaluating a variety of technical issues related to the fuel and reactor design, material corrosion, and safety characteristics. This paper presents the results of parametric calculations using the RELAP5 computer code to characterize the thermal-hydraulic response of supercritical reactors to transients initiated by loss-of-feedwater and turbine-trip events. The purpose of the calculations was to aid in the design of the safety systems by determining the time available for the safety systems to respond and their required capacities.

Cliff B. Davis; Jacopo Buongiorno; Philip E. MacDonald

2003-09-01

347

Removable bearing arrangement for a wind turbine generator  

DOEpatents

A wind generator having removable change-out bearings includes a rotor and a stator, locking bolts configured to lock the rotor and stator, a removable bearing sub-assembly having at least one shrunk-on bearing installed, and removable mounting bolts configured to engage the bearing sub-assembly and to allow the removable bearing sub-assembly to be removed when the removable mounting bolts are removed.

Bagepalli, Bharat Sampathkumaran; Jansen, Patrick Lee; Gadre, Aniruddha Dattatraya

2010-06-15

348

Method for changing removable bearing for a wind turbine generator  

DOEpatents

A wind generator having removable change-out bearings includes a rotor and a stator, locking bolts configured to lock the rotor and stator, a removable bearing sub-assembly having at least one shrunk-on bearing installed, and removable mounting bolts configured to engage the bearing sub-assembly and to allow the removable bearing sub-assembly to be removed when the removable mounting bolts are removed.

Bagepalli, Bharat Sampathkumaran (Niskayuna, NY); Jansen, Patrick Lee (Scotia, NY); Gadre, Aniruddha Dattatraya (Rexford, NY)

2008-04-22

349

Preliminary analysis of performance and loads data from the 2-megawatt mod-1 wind turbine generator  

NASA Technical Reports Server (NTRS)

Preliminary test data on output power versus wind speed, rotor blade loads, system dynamic behavior, and start-stop characteristics on the Mod-1 wind turbine generator are presented. These data were analyzed statistically and are compared with design predictions of system performance and loads. To date, the Mod-1 wind turbine generator has produced up to 1.5 MW of power, with a measured power versus wind speed curve which agrees closely with design. Blade loads were measured at wind speeds up to 14 m/s and also during rapid shutdowns. Peak transient loads during the most severe shutdowns are less than the design limit loads. On the inboard blade sections, fatigue loads are approximately equal to the design cyclic loads. On the outboard blade sections, however, measured cyclic loads are significantly larger than design values, but they do not appear to exceed fatigue allowable loads as yet.

Spera, D. A.; Viterna, L. A.; Richards, T. R.; Neustadter, H. E.

1979-01-01

350

Investigation of Shaft Voltage in Wind Turbine Systems with Induction Generators  

NASA Astrophysics Data System (ADS)

This paper presents the analysis of shaft voltage in different configurations of a doubly fed induction generator (DFIG) and an induction generator (IG) with a back-to-back inverter in wind turbine applications. Detailed high frequency model of the proposed systems have been developed based on existing capacitive couplings in IG & DFIG structures and common mode voltage sources. In this research work, several arrangements of DFIG based wind energy conversion systems (WES) are investigated in case of shaft voltage calculation and its mitigation techniques. Placements of an LC line filter in different locations and its effects on shaft voltage elimination are studied via Mathematical analysis and simulations. A pulse width modulation (PWM) technique and a back-to-back inverter with a bidirectional buck converter have been presented to eliminate the shaft voltage in a DFIG wind turbine.

Adabi, Jafar; Zare, Firuz

351

A composite algorithm for flow rate reduction and stable body trajectory generation in a hydraulic actuated quadruped robot with kinematic redundancy  

Microsoft Academic Search

A hydraulic actuator has a various merits. It has a small size and a high power-to-weight ratio. So it is able to generate high torque in small size actuator. These features of hydraulic actuator are very useful for a walking robot. However, the hydraulic actuator needs a hydraulic power-pack which supplies pressure and flow. Usually, a big and heavy power-pack

Taeju Kim; Byung-Ju Yi

2011-01-01

352

Wind Turbine Generator System Power Quality Test Report for the Gaia Wind 11kW Wind Turbine  

Microsoft Academic Search

This report details the power quality test on the Gaia Wind 11-kW Wind Turbine as part of the U.S. Department of Energy's Independent Testing Project. In total five turbines are being tested as part of the project. Power quality testing is one of up to five test that may be performed on the turbines including power performance, safety and function,

A. Curtis; V. Gevorgian

2011-01-01

353

Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 3  

NASA Astrophysics Data System (ADS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. This volume contains the drawings and specifications developed for the final design. This volume is divided into 5 books of which this is the third, containing drawings 47A380074 through 47A380126. A full breakdown parts listing is provided as well as a where used list.

1984-08-01

354

Comparison of measured and calculated sound pressure levels around a large horizontal axis wind turbine generator  

NASA Astrophysics Data System (ADS)

Results are reported from a large number of simultaneous acoustic measurements around a large horizontal axis downwind configuration wind turbine generator. In addition, comparisons are made between measurements and calculations of both the discrete frequency rotational harmonics and the broad band noise components. Sound pressure time histories and noise radiation patterns as well as narrow band and broadband noise spectra are presented for a range of operating conditions. The data are useful for purposes of environmental impact assessment.

Shepherd, Kevin P.; Willshire, William L., Jr.; Hubbard, Harvey H.

1989-03-01

355

Comparison of measured and calculated sound pressure levels around a large horizontal axis wind turbine generator  

NASA Technical Reports Server (NTRS)

Results are reported from a large number of simultaneous acoustic measurements around a large horizontal axis downwind configuration wind turbine generator. In addition, comparisons are made between measurements and calculations of both the discrete frequency rotational harmonics and the broad band noise components. Sound pressure time histories and noise radiation patterns as well as narrow band and broadband noise spectra are presented for a range of operating conditions. The data are useful for purposes of environmental impact assessment.

Shepherd, Kevin P.; Willshire, William L., Jr.; Hubbard, Harvey H.

1989-01-01

356

Direct and Quadrature-Axis Equivalent Circuits for Solid-Rotor Turbine Generators  

Microsoft Academic Search

Direct- and quadrature-axis equivalent circuits are developed for solid-rotor turbine generators. The equivalent circuits model, in considerable detail, important current-carrying paths in the rotor in addition to the excitation winding. Impedance equations are formulated so that a valid representation can be obtained over a wide range of frequencies. Operational solution of the equivalent circuits provides a powerful means for accurate

William Jackson; Robert Winchester

1969-01-01

357

Mod-5A wind turbine generator program design report. Volume 4: Drawings and specifications, book 3  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. This volume contains the drawings and specifications developed for the final design. This volume is divided into 5 books of which this is the third, containing drawings 47A380074 through 47A380126. A full breakdown parts listing is provided as well as a where used list.

1984-01-01

358

Wind Turbine Generator System Power Quality Test Report for the Gaia Wind 11-kW Wind Turbine  

SciTech Connect

This report details the power quality test on the Gaia Wind 11-kW Wind Turbine as part of the U.S. Department of Energy's Independent Testing Project. In total five turbines are being tested as part of the project. Power quality testing is one of up to five test that may be performed on the turbines including power performance, safety and function, noise, and duration tests. The results of the testing provide manufacturers with reports that may be used for small wind turbine certification.

Curtis, A.; Gevorgian, V.

2011-07-01

359

The internal flow pattern analysis of a tidal power turbine operating on bidirectional generation-pumping  

NASA Astrophysics Data System (ADS)

Using tidal energy can reduce environment pollution, save conventional energy and improve energy structure, hence it presents great advantage and is developing potential. Influenced by flood tide and low tide, a fully functional tidal power station needs to experience six operating modes, including bidirectional generation, pumping and sluice; the internal unsteady flow pattern and dynamic characters are very complicated. Based on a bidirectional tidal generator unit, three-dimensional unsteady flows in the flow path were calculated for four typical operating conditions with the pressure pulsation characteristics analyzed. According to the numerical results, the internal flow characteristics in the flow path were discussed. The influence of gravity to the hydraulic performance and flow characteristics were analysed. The results provide a theoretical analysis method of the hydraulic optimization design of the same type unit as well as a direction for stable operation and optimal scheduling of existing tidal power unit.

Y Luo, Y.; Xiao, Y. X.; Wang, Z. W.

2013-12-01

360

New trends in the monitoring and diagnosis of turbine-generator set operation  

SciTech Connect

This paper describes current trends in monitoring, with special emphasis on the use of expert systems for the treatment of variables, and underlines the advantages offered by these relatively recent systems with respect to the conventional supervision systems still used in many Plants to determine unit status. Monitoring of rotating machinery has traditionally been based on surveillance of vibrations, sometimes backed by some other variable, such as bearing temperature. At present several Spanish companies are studying the possibility of developing a monitoring and diagnosis system for turbine-generator sets using thermodynamic and electrical variables, such as pressures, temperatures, flows, levels, valve positions, power intensities, etc., the aim of which is to provide a prompt diagnosis of faults and recommend operating or maintenance corrective actions. The most frequent faults found in turbine-generator sets include wear and cracking in the blades, valve stem seizure, erosion of valve seats, play in the labyrinth seals, etc. In summary, the monitoring of turbine-generator set operation may be improved, as regards malfunction prevention and analysis, if the new techniques that have emerged in recent years are applied, increasing the reliability of the overall man-machine unit and limiting human intervention to those areas in which it is truly necessary.

Marcelles, I.; Aguado, M.T. [Tecnatom, S.A., Madrid (Spain)

1994-12-31

361

Algebraic grid generation for coolant passages of turbine blades with serpentine channels and pin fins  

NASA Technical Reports Server (NTRS)

In order to study numerically details of the flow and heat transfer within coolant passages of turbine blades, a method must first be developed to generate grid systems within the very complicated geometries involved. In this study, a grid generation package was developed that is capable of generating the required grid systems. The package developed is based on an algebraic grid generation technique that permits the user considerable control over how grid points are to be distributed in a very explicit way. These controls include orthogonality of grid lines next to boundary surfaces and ability to cluster about arbitrary points, lines, and surfaces. This paper describes that grid generation package and shows how it can be used to generate grid systems within complicated-shaped coolant passages via an example.

Shih, T. I.-P.; Roelke, R. J.; Steinthorsson, E.

1991-01-01

362

Integration of permanent magnet synchronous generator wind turbines into power grid  

NASA Astrophysics Data System (ADS)

The world is seeing an ever-increasing demand for electrical energy. The future growth of electrical power generation needs to be a mix of technologies including fossil fuels, hydro, nuclear, wind, and solar. The federal and state energy agencies have taken several proactive steps to increase the share of renewable energy in the total generated electrical power. In 2005, 11.1% of the total 1060 GW electricity generation capacity was from Renewable Energy Sources (RES) in the US. The power capacity portfolio included 9.2% from hydroelectric, 0.87% from wind, and 0.7% from biomass. Other renewable power capacity included 2.8 GW of geothermal, 0.4 GW of solar thermal, and 0.2 GW of solar PV. Although the share of renewable energy sources is small compared with the total power capacity, they are experiencing a high and steady growth. The US is leading the world in wind energy growth with a 27% increase in 2006 and a projected 26% increase in 2007, according to the American Wind Energy Association (AWEA). The US Department of Energy benchmarked a goal to meet 5% of the nation's energy need by launching the Wind Powering America (WPA) program. Although renewable energy sources have many benefits, their utilization in the electrical grid does not come without cost. The higher penetration of RES has introduced many technical and non-technical challenges, including power quality, reliability, safety and protection, load management, grid interconnections and control, new regulations, and grid operation economics. RES such as wind and PV are also intermittent in nature. The energy from these sources is available as long as there is wind or sunlight. However, these are energies that are abundant in the world and the power generated from these sources is pollution free. Due to high price of foundation of wind farms, employing variable speed wind turbines to maximize the extracted energy from blowing wind is more beneficial. On the other hand, since wind power is intermittent, integrating energy storage systems with wind farms has attracted a lot of attention. These two subjects are addressed in this dissertation in detail. Permanent Magnet Synchronous Generators (PMSG) are used in variable speed wind turbines. In this thesis, the dynamic of the PMSG is investigated and a power electronic converter is designed to integrate the wind turbine to the grid. The risks of PMSG wind turbines such as low voltage ride through and short circuits, are assessed and the methods of mitigating the risks are discussed. In the second section of the thesis, various methods of smoothing wind turbine output power are explained and compared. Two novel methods of output power smoothing are analyzed: Rotor inertia and Super capacitors. The advantages and disadvantages of each method are explained and the dynamic model of each method is developed. The performance of the system is evaluated by simulating the wind turbine system in each method. The concepts of the methods of smoothing wind power can be implemented in other types of wind turbines such as Doubly Fed Induction Generator (DFIG) wind turbines.

Abedini, Asghar

363

Process characteristics of pretreatment system under H 2 S circumstance for bio-gas micro gas turbine power generation  

Microsoft Academic Search

As distributed generation becomes more reliable and economically feasible, it is expected that a higher application of the\\u000a distributed generation such as Micro Gas Turbine Power system would be interconnected to the existing grids. This paper describes\\u000a the results for the mechanical and environmental tests of pretreatment system for Livestock bio-energy Micro Gas Turbine (MGT)\\u000a Combined Heat & power. It

Kwang-Beom Hur; Sang-Kyu Rhim; Jung-Keuk Park; Jae-Hoon Kim

2010-01-01

364

Vibrator systems for generating elastic waves in the Earth. [hydraulic system  

Microsoft Academic Search

Oscillating fluid flow in and out of a hydraulic cylinder is controlled by an electromechanical or electrohydraulic actuator which drives the hydraulic piston rod. Conduits connect the hydraulic cylinder to one or more seismic vibrators consisting of closed expandable chambers (14', 14'') supporting a reaction mass and attached to a base plate resting on the ground.

Silverman

1976-01-01

365

Wind Turbine Generator System Duration Test Report for the Gaia-Wind 11 kW Wind Turbine  

Microsoft Academic Search

This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Renewable Energy Laboratory's (NRELs) National Wind Technology Center (NWTC) as a part of

A. Huskey; A. Bowen; D. Jager

2010-01-01

366

Low-frequency noise and air vibration generated by a simple cycle gas turbine installation  

NASA Astrophysics Data System (ADS)

Standard noise regulations, measurement techniques, and acoustic treatments can fail to address energy emitted by certain problem gas turbine installations in the form of low-frequency noise and air vibrations. Survey and treatment of the entire acoustic environment is necessary to diagnose and solve these annoyance problems. The presence of ground-borne vibrations, infrasound, and noise in the lower octave bands complicates environmental noise assessment and limits mitigation options. Variability in the perception, effects, and annoyance level of low-frequency noise and air vibrations prevents this relatively common problem from being well understood by industry. Particular attention must be paid to propagation paths when the dynamic range of air-borne and ground-borne vibrations overlaps. This paper is the case study of a 2002 analysis, by ATCO Noise Management, of an installation consisting of 3-120 MW combustion generator turbines causing such low-frequency noise and air vibrations.

Giesbrecht, Chris; Hertil, Salem

2005-04-01

367

Employing static excitation control and tie line reactance to stabilize wind turbine generators  

NASA Technical Reports Server (NTRS)

An analytical representation of a wind turbine generator is presented which employs blade pitch angle feedback control. A mathematical model was formulated. With the functioning MOD-0 wind turbine serving as a practical case study, results of computer simulations of the model as applied to the problem of dynamic stability at rated load are also presented. The effect of the tower shadow was included in the input to the system. Different configurations of the drive train, and optimal values of the tie line reactance were used in the simulations. Computer results revealed that a static excitation control system coupled with optimal values of the tie line reactance would effectively reduce oscillations of the power output, without the use of a slip clutch.

Hwang, H. H.; Mozeico, H. V.; Guo, T.

1978-01-01

368

Prediction of broadband noise from large horizontal axis wind turbine generators  

NASA Technical Reports Server (NTRS)

A method is presented for predicting the broadband noise spectra of large horizontal axis wind turbine generators. It includes contributions from such noise sources as the inflow turbulence to the rotor, the interactions between the turbulent boundary layers on the blade surfaces with their trailing edges and the wake due to a blunt trailing edge. The method is partly empirical and is based on acoustic measurements of large wind turbines and airfoil models. The predicted frequency spectra are compared with measured data from several machines including the MOD-OA, the MOD-2, the WTS-4 and the U.S. Wind-power Inc. machine. Also included is a broadband noise prediction for the proposed MOD-5B. The significance of the effects of machine size, power output, trailing edge bluntness and distance to the receiver is illustrated. Good agreement is obtained between the predicted and measured far field noise spectra.

Grosveld, F. W.

1984-01-01

369

Prediction of broadband noise from large horizontal axis wind turbine generators  

NASA Astrophysics Data System (ADS)

A method is presented for predicting the broadband noise spectra of large horizontal axis wind turbine generators. It includes contributions from such noise sources as the inflow turbulence to the rotor, the interactions between the turbulent boundary layers on the blade surfaces with their trailing edges and the wake due to a blunt trailing edge. The method is partly empirical and is based on acoustic measurements of large wind turbines and airfoil models. The predicted frequency spectra are compared with measured data from several machines including the MOD-OA, the MOD-2, the WTS-4 and the U.S. Wind-power Inc. machine. Also included is a broadband noise prediction for the proposed MOD-5B. The significance of the effects of machine size, power output, trailing edge bluntness and distance to the receiver is illustrated. Good agreement is obtained between the predicted and measured far field noise spectra.

Grosveld, F. W.

1984-10-01

370

Measurement and prediction of broadband noise from large horizontal axis wind turbine generators  

NASA Astrophysics Data System (ADS)

A method is presented for predicting the broadband noise spectra of large wind turbine generators. It includes contributions from such noise sources as the inflow turbulence to the rotor, the interactions between the turbulent boundary layers on the blade surfaces with their trailing edges and the wake due to a blunt trailing edge. The method is partly empirical and is based on acoustic measurements of large wind turbines and airfoil models. Spectra are predicted for several large machines including the proposed MOD-5B. Measured data are presented for the MOD-2, the WTS-4, the MOD-OA, and the U.S. Windpower Inc. machines. Good agreement is shown between the predicted and measured far field noise spectra.

Grosveld, F. W.; Shepherd, K. P.; Hubbard, H. H.

1995-05-01

371

Measurement and prediction of broadband noise from large horizontal axis wind turbine generators  

NASA Technical Reports Server (NTRS)

A method is presented for predicting the broadband noise spectra of large wind turbine generators. It includes contributions from such noise sources as the inflow turbulence to the rotor, the interactions between the turbulent boundary layers on the blade surfaces with their trailing edges and the wake due to a blunt trailing edge. The method is partly empirical and is based on acoustic measurements of large wind turbines and airfoil models. Spectra are predicted for several large machines including the proposed MOD-5B. Measured data are presented for the MOD-2, the WTS-4, the MOD-OA, and the U.S. Windpower Inc. machines. Good agreement is shown between the predicted and measured far field noise spectra.

Grosveld, F. W.; Shepherd, K. P.; Hubbard, H. H.

1995-01-01

372

Design Study of Coated Conductor Direct Drive Wind Turbine Generator for Small Scale Demonstration  

NASA Astrophysics Data System (ADS)

We have investigated the properties of a superconducting direct drive generator suitable for demonstration in a small scale 11 kW wind turbine. The engineering current density of the superconducting ?eld windings is based on properties of coated conductors wound into coils holding of the order 68 meters of tape. The active mass of the generators has been investigated as function of the number of poles and a 4 pole generator is suggested as a feasible starting point of an in-?eld demonstration of the system reliability. An active mass of m = 421 kg and a usage of 3.45 km of tape will be needed to realize such a generator with a peak ?ux density in the airgap of B0 = 1.5 T.

Abrahamsen, Asger B.; Jensen, Bogi B.

373

Large Eddy Simulation of the meandering of a wind turbine wake with stochastically generated boundary conditions  

NASA Astrophysics Data System (ADS)

Wind turbine wakes are known to be affected by the large atmospheric turbulent scales, which can cause trajectory variations within a wide frequency band. This phenomenon, called meandering, is suspected to be a cause of premature wear on turbines located inside wind farms. This work proposes a method to generate and apply synthetic turbulent velocity series as boundary conditions in a Large Eddy Simulation of an actuator disk in a flow with realistic turbulence characteristics. The stochastic generation method relies on the inverse Short-Time Fourier Transform (STFT) of a random vector field correlated in Fourier space according to the covariance tensor calculated from the homogeneous isotropic spectral tensor. In contrast with a single Fourier transform, the STFT allows the generation of arbitrarily large velocity fields. The generated series are used as boundary values on the inlet as well as on the lateral boundaries of the domain. This allows for sustained turbulent forcing on the whole length of the domain which is especially useful for a small computational domain relative to the size of the dominant turbulent scales.

Muller, Yann-Aël; Masson, Christian; Aubrun, Sandrine

2014-06-01

374

Strategies for Refining IEC 61400-2: Wind Turbine Generator Systems - Part 2: Safety of Small Wind Turbines: Preprint  

Microsoft Academic Search

This paper provides a status of the changes currently being made by IEC Maintenance Team 02 (MT02) to the existing IEC 61400-2 ''Safety of small wind turbines.'' In relation to the work done by IEC MT02, work has been done by NREL and Windward Engineering under the DOE\\/NREL Small Wind Turbine (SWT) Project. Aeroelastic models were built and measurements taken

J. J. D. van Dam; T. L. Forsyth; A. C. Hansen

2001-01-01

375

Development and testing of vortex generators for small horizontal axis wind turbines  

NASA Technical Reports Server (NTRS)

Vortex generators (VGs) for a small (32 ft diameter) horizontal axis wind turbine, the Carter Model 25, have been developed and tested. Arrays of VGs in a counterrotating arrangement were tested on the inbound half-span, outboard half-span, and on the entire blade. VG pairs had their centerlines spaced at a distance of 15% of blade chord, with a spanwise width of 10% of blade chord. Each VG had a length/height ratio of 4, with a height of between 0.5% and 1.0% of the blade chord. Tests were made with roughness strips to determine whether VGs alleviated the sensitivity of some turbines to an accumulation of bugs and dirt on the leading edge. Field test data showed that VGs increased power output up to 20% at wind speeds above 10 m/s with only a small (less than 4%) performance penalty at lower speeds. The VGs on the outboard span of the blade were more effective than those on inner sections. For the case of full span coverage, the energy yearly output increased almost 6% at a site with a mean wind speed of 16 mph. The VGs did reduce the performance loss caused by leading edge roughness. An increase in blade pitch angle has an effect on the power curve similar to the addition of VGs. VGs alleviate the sensitivity of wind turbine rotors to leading edge roughness caused by bugs and drift.

Gyatt, G. W.

1986-01-01

376

Wind Turbine Generator System Duration Test Report for the Gaia-Wind 11 kW Wind Turbine  

SciTech Connect

This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Renewable Energy Laboratory's (NRELs) National Wind Technology Center (NWTC) as a part of this project. Duration testing is one of up to five tests that may be performed on the turbines, including power performance, safety and function, noise, and power quality tests. The results of the testing will provide the manufacturers with reports that may be used for small wind turbine certification. The test equipment includes a Gaia-Wind 11 kW wind turbine mounted on an 18 m monopole tower. Gaia-Wind Ltd. manufactured the turbine in Denmark, although the company is based in Scotland. The system was installed by the NWTC Site Operations group with guidance and assistance from Gaia-Wind.

Huskey, A.; Bowen, A.; Jager, D.

2010-09-01

377

Baseload wind energy: modeling the competition between gas turbines and compressed air energy storage for supplemental generation  

Microsoft Academic Search

The economic viability of producing baseload wind energy was explored using a cost-optimization model to simulate two competing systems: wind energy supplemented by simple- and combined cycle natural gas turbines (“wind+gas”), and wind energy supplemented by compressed air energy storage (“wind+CAES”). Pure combined cycle natural gas turbines (“gas”) were used as a proxy for conventional baseload generation. Long-distance electric transmission

Jeffery B. Greenblatt; Samir Succar; David C. Denkenberger; Robert H. Williams; Robert H. Socolow

2007-01-01

378

Industrial gas turbine combustion performance test of DME to use as an alternative fuel for power generation  

Microsoft Academic Search

DME (dimethyl ether, CH3OCH3) is both a good alternative fuel for transportation and power generation and an LPG substitute owing to its cleanliness, multi-source productivity and the ease with which it is transported. This study was conducted to verify whether DME is a good fuel for gas turbines and to identify potential problems in fuelling a commercial gas turbine with

Min Chul Lee; Seok Bin Seo; Jae Hwa Chung; Yong Jin Joo; Dal Hong Ahn

2009-01-01

379

The Dynamic Performance of an Isolated Self-Excited Induction Generator Driven by a Variable-Speed Wind Turbine  

Microsoft Academic Search

This paper presents the analysis, design and simulation of wind-powered self-excited induction generator (SEIG). The three -phase SEIG is driven by a variable-speed prime mover (VSPM) such as a wind turbine for the clean alternative renewable energy in rural areas. The VSPM is modeled by as a variable-speed separately-excited DC motor to simulate to the wind turbine. Also, the paper

Mahmoud M. Neam; Fayez F. M. El-Sousy; Mohamed A. Ghazy; Maged A. Abo-Adma

2007-01-01

380

The dynamic performance of an isolated self-excited induction generator driven by a variable-speed wind turbine  

Microsoft Academic Search

This paper presents the analysis, design and simulation or wind-powered self-excited induction generator (SEIG). The three-phase SEIG is driven by a variable-speed prime mover (VSPM) such as a wind turbine for the clean alternative renewable energy in rural areas. The VSPM is modeled by as a variable-speed separately-excited DC motor to simulate to the wind turbine. Also, the paper describes

M. M. Neam; F. F. M. El-Sousy; M. A. Ghazy; M. A. Abo-Adma

2006-01-01

381

FABRICATE AND TEST AN ADVANCED NON-POLLUTING TURBINE DRIVE GAS GENERATOR  

SciTech Connect

In September 2000 the Department of Energy's National Energy Technology Laboratory (DOE/NETL) contracted with Clean Energy Systems, Inc. (CES) of Sacramento, California to design, fabricate, and test a 20 MW{sub t} (10 MW{sub e}) gas generator. Program goals were to demonstrate a non-polluting gas generator at temperatures up to 3000 F at 1500 psi, and to demonstrate resulting drive gas composition, comprising steam and carbon dioxide substantially free of pollutants. Following hardware design and fabrication, testing, originally planned to begin in the summer of 2001, was delayed by unavailability of the contracted test facility. CES designed, fabricated, and tested the proposed gas generator as originally agreed. The CES process for producing near-zero-emissions power from fossil fuels is based on the near-stoichiometric combustion of a clean gaseous fuel with oxygen in the presence of recycled water, to produce a high-temperature, high-pressure turbine drive fluid comprising steam and carbon dioxide. Tests demonstrated igniter operation over the prescribed ranges of pressure and mixture ratios. Ignition was repeatable and reliable through more than 100 ignitions. Injector design ''A'' was operated successfully at both low power ({approx}20% of rated power) and at rated power ({approx}20 MW{sub t}) in more than 95 tests. The uncooled gas generator configuration (no diluent injectors or cooldown chambers installed) produced drive gases at temperatures approaching 3000 F and at pressures greater than 1550 psia. The fully cooled gas generator configuration, with cooldown chambers and injector ''A'', operated consistently at pressures from 1100 to 1540 psia and produced high pressure, steam-rich turbine drive gases at temperatures ranging from {approx}3000 to as low as 600 F. This report includes description of the intended next steps in the gas generator technology demonstration and traces the anticipated pathway to commercialization for the gas generator technology developed in this program.

Eugene Baxter; Roger E. Anderson; Stephen E. Doyle

2003-06-01

382

An online technique for condition monitoring the induction generators used in wind and marine turbines  

NASA Astrophysics Data System (ADS)

Induction generators have been successfully applied to a variety of industries. However, their operation and maintenance in renewable wind and marine energy industries still face challenges due to harsh environments, limited access to site and relevant reliability issues. Hence, further enhancing their condition monitoring is regarded as one of the essential measures for improving their availability. To date, much effort has been made to monitor induction motors, which can be equally applied to monitoring induction generators. However, the achieved techniques still have constrains in particular when dealing with the condition monitoring problems in wind and marine turbine generators. For example, physical measurements of partial discharge, noise and temperature have been widely applied to monitoring induction machinery. They are simple and cost-effective, but unable to be used for fault diagnosis. The spectral analysis of vibration and stator current signals is also a mature technique popularly used in motor/generator condition monitoring practice. However, it often requires sufficient expertise for data interpretation, and significant pre-knowledge about the machines and their components. In particular in renewable wind and marine industries, the condition monitoring results are usually coupled with load variations, which further increases the difficulty of obtaining a reliable condition monitoring result. In view of these issues, a new condition monitoring technique is developed in this paper dedicated for wind and marine turbine generators. It is simple, informative and less load-dependent thus more reliable to deal with the online motor/generator condition monitoring problems under varying loading conditions. The technique has been verified through both simulated and practical experiments. It has been shown that with the aid of the proposed technique, not only the electrical faults but also the shaft unbalance occurring in the generator become detectable despite the external loading conditions. Moreover, the rotor and stator winding faults can be readily discriminated through observing the variation tendencies of the proposed condition monitoring criteria.

Yang, Wenxian; Tavner, P. J.; Court, R.

2013-07-01

383

14 CFR 33.72 - Hydraulic actuating systems.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Hydraulic actuating systems. 33.72 Section 33...Construction; Turbine Aircraft Engines § 33.72 Hydraulic actuating systems. Each hydraulic actuating system must function...

2010-01-01

384

14 CFR 33.72 - Hydraulic actuating systems.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Hydraulic actuating systems. 33.72 Section 33.72 Aeronautics...Turbine Aircraft Engines § 33.72 Hydraulic actuating systems. Each hydraulic actuating system must function properly under...

2012-01-01

385

14 CFR 33.72 - Hydraulic actuating systems.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Hydraulic actuating systems. 33.72 Section 33.72 Aeronautics...Turbine Aircraft Engines § 33.72 Hydraulic actuating systems. Each hydraulic actuating system must function properly under...

2013-01-01

386

14 CFR 33.72 - Hydraulic actuating systems.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Hydraulic actuating systems. 33.72 Section 33.72 Aeronautics...Turbine Aircraft Engines § 33.72 Hydraulic actuating systems. Each hydraulic actuating system must function properly under...

2011-01-01

387

14 CFR 33.72 - Hydraulic actuating systems.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Hydraulic actuating systems. 33.72 Section 33.72 Aeronautics...Turbine Aircraft Engines § 33.72 Hydraulic actuating systems. Each hydraulic actuating system must function properly under...

2014-01-01

388

Model-OA wind turbine generator - Failure modes and effects analysis  

NASA Technical Reports Server (NTRS)

The results failure modes and effects analysis (FMEA) conducted for wind-turbine generators are presented. The FMEA was performed for the functional modes of each system, subsystem, or component. The single-point failures were eliminated for most of the systems. The blade system was the only exception. The qualitative probability of a blade separating was estimated at level D-remote. Many changes were made to the hardware as a result of this analysis. The most significant change was the addition of the safety system. Operational experience and need to improve machine availability have resulted in subsequent changes to the various systems, which are also reflected in this FMEA.

Klein, William E.; Lali, Vincent R.

1990-01-01

389

Opportunities for ice storage to provide ancillary services to power grids incorporating wind turbine generation  

NASA Astrophysics Data System (ADS)

Power generation using wind turbines increases the electrical system balancing, regulation and ramp rate requirements due to the minute to minute variability in wind speed and the difficulty in accurately forecasting wind speeds. The addition of thermal energy storage, such as ice storage, to a building's space cooling equipment increases the operational flexibility of the equipment by allowing the owner to choose when the chiller is run. The ability of the building owner to increase the power demand from the chiller (e.g. make ice) or to decrease the power demand (e.g. melt ice) to provide electrical system ancillary services was evaluated.

Finley, Christopher

390

MOD-0A 200 kW wind turbine generator design and analysis report  

NASA Astrophysics Data System (ADS)

The design, analysis, and initial performance of the MOD-OA 200 kW wind turbine generator at Clayton, NM is documented. The MOD-OA was designed and built to obtain operation and performance data and experience in utility environments. The project requirements, approach, system description, design requirements, design, analysis, system tests, installation, safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the wind turbine are discussed. The design and analysis of the rotor, drive train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electricl system, and control systems are presented. The rotor includes the blades, hub, and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control are discussed. Systems analyses on dynamic loads and fatigue are presented.

Anderson, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.

1980-08-01

391

MOD-0A 200 kW wind turbine generator design and analysis report  

NASA Technical Reports Server (NTRS)

The design, analysis, and initial performance of the MOD-OA 200 kW wind turbine generator at Clayton, NM is documented. The MOD-OA was designed and built to obtain operation and performance data and experience in utility environments. The project requirements, approach, system description, design requirements, design, analysis, system tests, installation, safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the wind turbine are discussed. The design and analysis of the rotor, drive train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electricl system, and control systems are presented. The rotor includes the blades, hub, and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control are discussed. Systems analyses on dynamic loads and fatigue are presented.

Anderson, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.

1980-01-01

392

Closed-cycle gas turbines for power generation and LNG vaporization  

Microsoft Academic Search

Cooling by LNG (liquefied nitrogen gas) in closed-cycle gas turbines results in double the electrical output of water cooled turbines. A circuit scheme of the LNG turbine is presented with the temperatures and pressures of the cycle. The turbine inlet temperature is limited to 720 C. Pressure level control and bypass control are the two basic types of control applied.

D. Weber

1980-01-01

393

The MOD-OA 200 kilowatt wind turbine generator design and analysis report  

NASA Astrophysics Data System (ADS)

The project requirements, approach, system description, design requirements, design, analysis, system tests, installation safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the MOD-OA 200 kw wind turbine generator are discussed. The components, the rotor, driven train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electrical system, and control systems are presented. The rotor includes the blades, hub and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control and Dynamic loads and fatigue are analyzed.

Andersen, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.

1980-08-01

394

EEMD-based wind turbine bearing failure detection using the generator stator current homopolar component  

NASA Astrophysics Data System (ADS)

Failure detection has always been a demanding task in the electrical machines community; it has become more challenging in wind energy conversion systems because sustainability and viability of wind farms are highly dependent on the reduction of the operational and maintenance costs. Indeed the most efficient way of reducing these costs would be to continuously monitor the condition of these systems. This allows for early detection of the generator health degeneration, facilitating a proactive response, minimizing downtime, and maximizing productivity. This paper provides then an assessment of a failure detection techniques based on the homopolar component of the generator stator current and attempts to highlight the use of the ensemble empirical mode decomposition as a tool for failure detection in wind turbine generators for stationary and non-stationary cases.

Amirat, Yassine; Choqueuse, Vincent; Benbouzid, Mohamed

2013-12-01

395

Wind turbine generators having wind assisted cooling systems and cooling methods  

DOEpatents

A wind generator includes: a nacelle; a hub carried by the nacelle and including at least a pair of wind turbine blades; and an electricity producing generator including a stator and a rotor carried by the nacelle. The rotor is connected to the hub and rotatable in response to wind acting on the blades to rotate the rotor relative to the stator to generate electricity. A cooling system is carried by the nacelle and includes at least one ambient air inlet port opening through a surface of the nacelle downstream of the hub and blades, and a duct for flowing air from the inlet port in a generally upstream direction toward the hub and in cooling relation to the stator.

Bagepalli, Bharat (Niskayuna, NY); Barnes, Gary R. (Delanson, NY); Gadre, Aniruddha D. (Rexford, NY); Jansen, Patrick L. (Scotia, NY); Bouchard, Jr., Charles G. (Schenectady, NY); Jarczynski, Emil D. (Scotia, NY); Garg, Jivtesh (Cambridge, MA)

2008-09-23

396

The MOD-OA 200 kilowatt wind turbine generator design and analysis report  

NASA Technical Reports Server (NTRS)

The project requirements, approach, system description, design requirements, design, analysis, system tests, installation safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the MOD-OA 200 kw wind turbine generator are discussed. The components, the rotor, driven train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electrical system, and control systems are presented. The rotor includes the blades, hub and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control and Dynamic loads and fatigue are analyzed.

Andersen, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.; Lipner, M. H.; Schornhorst, J. R.

1980-01-01

397

Proposal and Development of Radial Air-gap Coreless Generator Suitable for Small Wind Turbine using in Urban Area  

NASA Astrophysics Data System (ADS)

Independent distributed generations using small wind turbines are widely spread as increasing of wind power generation. Installation of small wind turbines in densely-populated urban area is not only useful from the viewpoint of digging up wind power source in weak-wind area but also for enlightenment of renewable energy due to closing power supplies to consumptions. From the point of view, the authors proposed “urban wind power generation" using collective system with a number of small vertical wind turbines and have developed a suitable generator for low-speed vertical wind turbines such as Savonius windmill. Standardized on a coreless generator, the proposed generator is designed to let direction of magnetic fluxes radial in order to install the magnets and coils on the outer end of the generator. The change of magnet composition and flux direction gives realization of maximized speed of flux change and output voltage in the limited space. With above composition, the power of the proposed one is independent on the diameter. In this report, we describe evaluated fundamental performance of a prototype of the proposed generator. As the result of the experiments, the maximum output power of 283W was obtained. The obtained starting torque is enough small to begin to rotate at weak wind condition of no more than 1m/s. Therefore, it is clear that the proposed “radial” coreless generator is suitable for self-starting and producing high power at low speed wind.

Takahashi, Toshiyuki; Yasuda, Yoh; Ohmoto, Shingo; Hara, Takehisa

398

Variable speed generator application on the MOD-5A 7.3 mW wind turbine generator  

NASA Astrophysics Data System (ADS)

This paper describes the application of a Scherbiustat type variable speed subsystem in the MOD-5A Wind Turbine Generator. As designed by General Electric Company, Advanced Energy Programs Department, under contract DEN3-153 with NASA Lewis Research Center and DOE, the MOD-5A utilizes the subsystem for both starting assistance in a motoring mode and generation in a controlled airgap torque mode. Reactive power control is also provided. The Scherbiustat type arrangement of a wound rotor machine with a cycloconverter in the rotor circuit was selected after an evaluation of variable speed technologies that followed a system evaluation of drivetrain cost and risk. The paper describes the evaluation factors considered, the results of the evaluations and summarizes operating strategy and performance simulations.

Barton, Robert S.

1995-05-01

399

Short term hydroelectric power system scheduling with wind turbine generators using the multi-pass iteration particle swarm optimization approach  

Microsoft Academic Search

This paper uses multi-pass iteration particle swarm optimization (MIPSO) to solve short term hydroelectric generation scheduling of a power system with wind turbine generators. MIPSO is a new algorithm for solving nonlinear optimal scheduling problems. A new index called iteration best (IB) is incorporated into particle swarm optimization (PSO) to improve solution quality. The concept of multi-pass dynamic programming is

Tsung-Ying Lee

2008-01-01

400

Neural Network Based Modeling of a Large Steam Turbine-Generator Rotor Body Parameters from On-Line Disturbance Data  

E-print Network

Neural Network Based Modeling of a Large Steam Turbine-Generator Rotor Body Parameters from On neural network (ANN) based estimators are later used to model the non-linearities in the estimated identification, large utility generators, rotor body parameters, artificial neural networks. I. INTRODUCTION On

401

Mod-5A wind turbine generator program design report. Volume 2: Conceptual and preliminary design, book 2  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind tunnel generator is documented. There are four volumes. In Volume 2, book 2 the requirements and criteria for the design are presented. The development tests, which determined or characterized many of the materials and components of the wind turbine generator, are described.

1984-01-01

402

ARE660 Wind Generator: Low Wind Speed Technology for Small Turbine Development  

SciTech Connect

This project is for the design of a wind turbine that can generate most or all of the net energy required for homes and small businesses in moderately windy areas. The purpose is to expand the current market for residential wind generators by providing cost effective power in a lower wind regime than current technology has made available, as well as reduce noise and improve reliability and safety. Robert W. Preus’ experience designing and/or maintaining residential wind generators of many configurations helped identify the need for an improved experience of safety for the consumer. Current small wind products have unreliable or no method of stopping the wind generator in fault or high wind conditions. Consumers and their neighbors do not want to hear their wind generators. In addition, with current technology, only sites with unusually high wind speeds provide payback times that are acceptable for the on-grid user. Abundant Renewable Energy’s (ARE) basic original concept for the ARE660 was a combination of a stall controlled variable speed small wind generator and automatic fail safe furling for shutdown. The stall control for a small wind generator is not novel, but has not been developed for a variable speed application with a permanent magnet alternator (PMA). The fail safe furling approach for shutdown has not been used to our knowledge.

Robert W. Preus; DOE Project Officer - Keith Bennett

2008-04-23

403

Performance analysis of a counter-rotating tubular type micro-turbine by experiment and CFD  

NASA Astrophysics Data System (ADS)

Micro hydraulic turbines have a growing interest because of its small and simple structure, as well as a high possibility of using in micro and small hydropower applications. The differential pressure existing in city water pipelines can be used efficiently to generate electricity in a way similar to that of energy being generated through gravitational potential energy in dams. The pressure energy in the city pipelines is often wasted by using pressure reducing valves at the inlet of water cleaning centers. Instead of using the pressure reducing valves, a micro counter-rotating hydraulic turbine can be used to make use of the pressure energy. In the present paper, a counter-rotating tubular type micro-turbine is studied, with the front runner connected to the generator stator and the rear runner connected to the generator rotor. The performance of the turbine is investigated experimentally and numerically. A commercial ANSYS CFD code was used for numerical analysis.

Lee, N. J.; Choi, J. W.; Hwang, Y. H.; Kim, Y. T.; Lee, Y. H.

2012-11-01

404

Dispersion analysis of passive surface-wave noise generated during hydraulic-fracturing operations  

NASA Astrophysics Data System (ADS)

Surface-wave dispersion analysis is useful for estimating near-surface shear-wave velocity models, designing receiver arrays, and suppressing surface waves. Here, we analyze whether passive seismic noise generated during hydraulic-fracturing operations can be used to extract surface-wave dispersion characteristics. Applying seismic interferometry to noise measurements, we extract surface waves by cross-correlating several minutes of passive records; this approach is distinct from previous studies that used hours or days of passive records for cross-correlation. For comparison, we also perform dispersion analysis for an active-source array that has some receivers in common with the passive array. The active and passive data show good agreement in the dispersive character of the fundamental-mode surface-waves. For the higher mode surface waves, however, active and passive data resolve the dispersive properties at different frequency ranges. To demonstrate an application of dispersion analysis, we invert the observed surface-wave dispersion characteristics to determine the near-surface, one-dimensional shear-wave velocity.

Forghani-Arani, Farnoush; Willis, Mark; Snieder, Roel; Haines, Seth S.; Behura, Jyoti; Batzle, Mike; Davidson, Michael

2014-12-01

405

Turbine modeling technique to generate off-design performance data for both single and multistage axial-flow turbines  

NASA Technical Reports Server (NTRS)

This technique is applicable to larger axial flow turbines which may or may not incorporate variable geometry in the first stage stator. A user specified option will also permit the calculation of design point cooling flow levels and the corresponding change in turbine efficiency. The modeling technique was incorporated into a time sharing computer program in order to facilitate its use. Because this report contains a description of the input output data, values of typical inputs, and example cases, it is suitable as a user's manual.

Converse, G. L.

1981-01-01

406

Measured effects of wind turbine generation at the Block Island Power Company  

NASA Technical Reports Server (NTRS)

Data measurements made on the NASA MOD-OA 200-kw wind-turbine generator (WTG) installed on a utility grid form the basis for an overall performance analysis. Fuel displacement/-savings, dynamic interactions, and WTG excitation (reactive-power) control effects are studied. Continuous recording of a large number of electrical and mechanical variables on FM magnetic tape permit evaluation and correlation of phenomena over a bandwidth of at least 20 Hz. Because the wind-power penetration reached peaks of 60 percent, the impact of wind fluctuation and wind-turbine/diesel-utility interaction is evaluated in a worst-case scenario. The speed-governor dynamics of the diesel units exhibited an underdamped response, and the utility operation procedures were not altered to optimize overall WTG/utility performance. Primary findings over the data collection period are: a calculated 6.7-percent reduction in fuel consumption while generating 11 percent of the total electrical energy; acceptable system voltage and frequency fluctuations with WTG connected; and applicability of WTG excitation schemes using voltage, power, or VARS as the controlled variable.

Wilreker, V. F.; Smith, R. F.; Stiller, P. H.; Scot, G. W.; Shaltens, R. K.

1984-01-01

407

Fluid power network for centralized electricity generation in offshore wind farms  

NASA Astrophysics Data System (ADS)

An innovative and completely different wind-energy conversion system is studied where a centralized electricity generation within a wind farm is proposed by means of a hydraulic network. This paper presents the dynamic interaction of two turbines when they are coupled to the same hydraulic network. Due to the stochastic nature of the wind and wake interaction effects between turbines, the operating parameters (i.e. pitch angle, rotor speed) of each turbine are different. Time domain simulations, including the main turbine dynamics and laminar transient flow in pipelines, are used to evaluate the efficiency and rotor speed stability of the hydraulic system. It is shown that a passive control of the rotor speed, as proposed in previous work for a single hydraulic turbine, has strong limitations in terms of performance for more than one turbine coupled to the same hydraulic network. It is concluded that in order to connect several turbines, a passive control strategy of the rotor speed is not sufficient and a hydraulic network with constant pressure is suggested. However, a constant pressure network requires the addition of active control at the hydraulic motors and spear valves, increasing the complexity of the initial concept. Further work needs to be done to incorporate an active control strategy and evaluate the feasibility of the constant pressure hydraulic network.

Jarquin-Laguna, A.

2014-06-01

408

Noise measurements for single and multiple operation of 50 kw wind turbine generators  

NASA Technical Reports Server (NTRS)

The noise characteristics of the U.S. Windpower Inc., 50 kw wind turbine generator were measured at various distances from 30 m to 1100 m and for a range of output power. The generated noise is affected by the aerodynamic wakes of the tower legs at frequencies below about 120 Hz and the blade trailing edge thickness at frequencies of about 2 kHz. Rope strakes and airfoil fairings on the legs did not result in substantial noise reductions. Sharpening the blade trailing edges near the tip was effective in reducing broad band noise near 2 kHz. For multiple machines the sound fields are superposed. A three-fold increase in number of machines (from 1 to 3) results in a predicted increase in he sound pressure level of about 5 dB. The detection threshold for 14 machines operating in a 13 - 20 mph wind is observed to be at approximately 1160 m in the downwind direction.

Hubbard, H. H.; Shepherd, K. P.

1982-01-01

409

Endwall shape modification using vortex generators and fences to improve gas turbine cooling and effectiveness  

NASA Astrophysics Data System (ADS)

The gas turbine is one of the most important parts of the air-breathing jet engine. Hence, improving its efficiency and rendering it operable under high temperatures are constant goals for the aerospace industry. Two types of flow within the gas turbine are of critical relevance: The flow around the first row of stator blades (also known as the nozzle guide vane blade - NGV) and the cooling flow inside the turbine blade cooling channel. The subject of this thesis work was to search for methods that could improve the characteristics of these two types of flows, thus enabling superior engine performance. The innovative aspect of our work was to apply an endwall shape modification previously employed by non-aerospace industries for cooling applications, to the gas turbine cooling flow which is vital to aerospace propulsion. Since the costs of investigating the possible benefits of any idea via extensive experiments could be quite high, we decided to use computational fluid dynamics (CFD) followed by experimentation as our methodology. We decided to analyze the potential benefits of using vortex generators (VGs) as well as the rectangular endwall fence. Since the pin-fins used in cooling flow are circular cylinders, and since the boundary layer flow is mainly characterized by the leading edge diameter of the NGV blade, we modeled both the pin-fins and the NGV blade as vertical circular cylinders. The baseline case consisted of the cylinder(s) being subjected to cross flow and a certain amount of freestream turbulence. The modifications we made on the endwall consisted of rectangular fences. In the case of the cooling flow, we used triangular shaped, common flow up oriented, delta winglet type vortex generators as well as rectangular endwall fences. The channel contained singular cylinders as well as staggered rows of multiple cylinders. For the NGV flow, a rectangular endwall fence and a singular cylinder were utilized. Using extensive CFD modeling and analysis, we confirmed that placing a rectangular endwall fence upstream of the cylinder created additional turbulent mixing in the domain. This led to increased mixing of the cooler flow in the freestream and the hotter flow near the endwall. As a result, we showed that adding a rectangular fence created a 10% mean heat transfer increase downstream of the cylinder. When vortex generators are used, as the flow passes over the sharp edges of the vortex generators, it separates and continues downstream in a rolling, helical pattern. Combined with the effect generated by the orientation of the vortex generators, this flow structure mixes the higher momentum fluid in the freestream with lower momentum fluid in the boundary layer. Similar turbulent mixing behavior is observed over the entire domain, near the cylinders and the side walls. As a result, the heat transfer levels over the wall surfaces are increased and improved cooling is achieved. The improvements in heat transfer are obtained at the expense of acceptable pressure losses across the cooling channel. When the vortex generators are used, the CFD modeling studies showed that overall heat transfer improvements as high as 27% compared to the baseline case are observed inside a domain containing multiple rows of cylinders. A price in the form of 13% pressure loss increase across the channel is paid for the heat transfer benefits. Experiments conducted in the open loop wind tunnel of the Turbomachinery Aero-Heat Transfer Laboratory of the Department of Aerospace Engineering of Penn State University supported the general positive trend of these findings, with a 14% overall increase in heat transfer over the constant heat flux surface when vortex generators are installed, accompanied by an 8% increase in pressure loss. (Abstract shortened by UMI.)

Gokce, Zeki Ozgur

410

Wind Turbine Generator System Power Performance Test Report for the Gaia-Wind 11-kW Wind Turbine  

SciTech Connect

This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. It is a power performance test that the National Renewable Energy Laboratory (NREL) conducted on the Gaia-Wind 11-kW small wind turbine.

Huskey, A.; Bowen, A.; Jager, D.

2009-12-01

411

Development of a High Pressure/High Temperature Down-hole Turbine Generator  

SciTech Connect

As oil & natural gas deposits become more difficult to obtain by conventional means, wells must extend to deeper more heat-intensive environments. The technology of the drilling equipment required to reach these depths has exceeded the availability of electrical power sources needed to operate these tools. Historically, logging while drilling (LWD) and measure while drilling (MWD) devices utilized a wireline to supply power and communication from the operator to the tool. Lithium ion batteries were used in scenarios where a wireline was not an option, as it complicated operations. In current downhole applications, lithium ion battery (LIB) packs are the primary source for electrical power. LIB technology has been proven to supply reliable downhole power at temperatures up to 175 °C. Many of the deeper well s reach ambient temperatures above 200 °C, creating an environment too harsh for current LIB technology. Other downfalls of LIB technology are cost, limitations on charge cycles, disposal issues and possible safety hazards including explosions and fires. Downhole power generation can also be achieved by utilizing drilling fluid flow and converting it to rotational motion. This rotational motion can be harnessed to spin magnets around a series of windings to produce power proportional to the rpm experienced by the driven assembly. These generators are, in most instances, driven by turbine blades or moyno-based drilling fluid pumps. To date, no commercially available downhole power generators are capable of operating at ambient temperatures of 250 °C. A downhole power g enerator capable of operation in a 250 °C and 20,000 psi ambient environment will be an absolute necessity in the future. Dexter Magnetic Technologies’ High-Pressure High-Temperature (HPHT) Downhole Turbine Generator is capable of operating at 250 °C and 20, 000 psi, but has not been tested in an actual drilling application. The technology exists, but to date no company has been willing to test the tool.

Ben Plamp

2008-06-30

412

Transient response to three-phase faults on a wind turbine generator. Ph.D. Thesis - Toledo Univ.  

NASA Technical Reports Server (NTRS)

In order to obtain a measure of its responses to short circuits a large horizontal axis wind turbine generator was modeled and its performance was simulated on a digital computer. Simulation of short circuit faults on the synchronous alternator of a wind turbine generator, without resort to the classical assumptions generally made for that analysis, indicates that maximum clearing times for the system tied to an infinite bus are longer than the typical clearing times for equivalent capacity conventional machines. Also, maximum clearing times are independent of tower shadow and wind shear. Variation of circuit conditions produce the modifications in the transient response predicted by analysis.

Gilbert, L. J.

1978-01-01

413

Mod-5A wind turbine generator program design report. Volume 2: Conceptual and preliminary design, book 1  

NASA Astrophysics Data System (ADS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. There are four volumes. In Volume 2, book 1 the requirements and criteria for the design are presented. The conceptual design studies, which defined a baseline configuration and determined the weights, costs and sizes of each subsystem, are described. The development and optimization of the wind turbine generator are presented through the description of the ten intermediate configurations between the conceptual and final designs. Analyses of the system's load and dynamics are presented.

1984-08-01

414

Mod-5A Wind Turbine Generator Program Design Report. Volume 2: Conceptual and Preliminary Design, Book 1  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. There are four volumes. In Volume 2, book 1 the requirements and criteria for the design are presented. The conceptual design studies, which defined a baseline configuration and determined the weights, costs and sizes of each subsystem, are described. The development and optimization of the wind turbine generator are presented through the description of the ten intermediate configurations between the conceptual and final designs. Analyses of the system's load and dynamics are presented.

1984-01-01

415

Effect of wind turbine generator model and siting on wind power changes out of large WECS arrays  

NASA Technical Reports Server (NTRS)

Methods of reducing the WECS generation change through selection of the wind turbine model for each site, selection of an appropriate siting configuration, and wind array controls are discussed. An analysis of wind generation change from an echelon and a farm for passage of a thunderstorm is presented. Reduction of the wind generation change over ten minutes is shown to reduce the increase in spinning reserve, unloadable generation and load following requirements on unit commitment when significant WECS generation is present and the farm penetration constraint is satisfied. Controls on the blade pitch angle of all wind turbines in an array or a battery control are shown to reduce both the wind generation change out of an array and the effective farm penetration in anticipation of a storm so that the farm penetration constraint may be satisfied.

Schleuter, R. A.; Park, G. L.; Lotfalian, M.; Dorsey, J.; Shayanfar, H.

1981-01-01

416

Hydraulic waste energy recovery, Phase 2. A technical report  

SciTech Connect

The energy required for booster station operation is supplied by the electrical utility company and has an associated cost. Energy removed by pressure reducing valves in the system is lost or wasted. The objective of this project is to capture the wasted hydraulic energy with in-line turbines. In this application, the in-line turbines act as pressure reducing valves while removing energy from the water distribution system and converting it to electrical energy. The North Service Center pumping station was selected for the pilot program due to the availability of a wide range in pressure drop and flow, which are necessary for hydraulic energy recovery. The research performed during this project resulted in documentation of technical, economic, installation, and operational information necessary for local government officials to make an informed judgement as it relates to in-line turbine generation.

Not Available

1992-02-01

417

A modular and cost-effective superconducting generator design for offshore wind turbines  

NASA Astrophysics Data System (ADS)

Superconducting generators have the potential to reduce the tower head mass for large (?10 MW) offshore wind turbines. However, a high temperature superconductor generator should be as reliable as conventional generators for successful entry into the market. Most of the proposed designs use the superconducting synchronous generator concept, which has a higher cost than conventional generators and suffers from reliability issues. In this paper, a novel claw pole type of superconducting machine is presented. The design has a stationary superconducting field winding, which simplifies the design and increases the reliability. The machine can be operated in independent modules; thus even if one of the sections fails, the rest can operate until the next planned maintenance. Another advantage of the design is the very low superconducting wire requirement; a 10 MW, 10 rpm design is presented which uses 13 km of MgB2 wire at 30 K. The outer diameter of the machine is 6.63 m and it weighs 184 tonnes including the structural mass. The design is thought to be a good candidate for entering the renewable energy market, with its low cost and robust structure.

Keysan, Ozan; Mueller, Markus

2015-03-01

418

Operational behavior of a double-fed permanent magnet generator for wind turbines  

E-print Network

Greater efficiency in wind turbine systems is achieved by allowing the rotor to change its rate of rotation as the wind speed changes. The wind turbine system is decoupled from the utility grid and a variable speed operation ...

Reddy, Sivananda Kumjula

2005-01-01

419

Attenuation of upstream-generated low frequency noise by gas turbines  

NASA Technical Reports Server (NTRS)

The acoustic transfer functions of low frequency (below 3500 Hz) noise through aircraft turbines were investigated. Model test results were compared with theoretical predictions in order to assess the validity of the theory. Component tests were conducted on both high pressure and low pressure model turbines. The influence of inlet temperature and turbine speed attenuation was evaluated, while the effects of turbine pressure ratio, blade-row choking, and additional downstream stages were determined. Preliminary identification of pertinent aeroacoustic correlating parameters was made.

Doyle, V. L.; Matta, R. K.

1977-01-01

420

Experience and assessment of the DOE-NASA Mod-1 2000-Kilowatt wind turbine generator at Boone, North Carolina  

NASA Technical Reports Server (NTRS)

The Mod 1 program objectives are defined. The Mod 1 wind turbine is described. In addition to the steel blade operated on the wind turbine, a composite blade was designed and manufactured. During the early phase of the manufacturing cycle of Mod 1A configuration was designed that identified concepts such as partial span control, a soft tower, and upwind teetered rotors that were incorporated in second and third generation industry designs. The Mod 1 electrical system performed as designed, with voltage flicker characteristics within acceptable utility limits. Power output versus wind speed equaled or exceeded design predictions. The wind turbine control system was operated successfully at the site and remotely from the utility dispatcher's office. During wind turbine operations, television interference was experienced by the local residents. As a consequence, operations were restricted. Although not implemented, two potential solutions were identified. In addition to television interference, a few local residents complained bout objectionable sound, particularly the 'thump' as the blade passed behind the tower. To eliminate objections, the sound generation level was reduced by 10 dB by reducing the rotor speed from 35 rpm to 23 rpm. Bolts in the drive train fractured. A solution was identified but not implemented. The public reaction toward the Mod 1 wind turbine program was overwhelmingly favorable.

Collins, J. L.; Shaltenc, R. K.; Poor, R. H.; Barton, R. S.

1982-01-01

421

Low NO{sub x} turbine power generation utilizing low Btu GOB gas. Final report, June--August 1995  

SciTech Connect

Methane, a potent greenhouse gas, is second only to carbon dioxide as a contributor to potential global warming. Methane liberated by coal mines represents one of the most promising under exploited areas for profitably reducing these methane emissions. Furthermore, there is a need for apparatus and processes that reduce the nitrogen oxide (NO{sub x}) emissions from gas turbines in power generation. Consequently, this project aims to demonstrate a technology which utilizes low grade fuel (CMM) in a combustion air stream to reduce NO{sub x} emissions in the operation of a gas turbine. This technology is superior to other existing technologies because it can directly use the varying methane content gases from various streams of the mining operation. The simplicity of the process makes it useful for both new gas turbines and retrofitting existing gas turbines. This report evaluates the feasibility of using gob gas from the 11,000 acre abandoned Gateway Mine near Waynesburg, Pennsylvania as a fuel source for power generation applying low NO{sub x} gas turbine technology at a site which is currently capable of producing low grade GOB gas ({approx_equal} 600 BTU) from abandoned GOB areas.

Ortiz, I.; Anthony, R.V.; Gabrielson, J.; Glickert, R.

1995-08-01

422

Pinson C2E wind turbine generator failure analysis and corrective design modification  

NASA Astrophysics Data System (ADS)

On December 4, 1978 wind speeds at the Rocky Flats Small Wind Systems Test Center reached 42 m/s. Two failures were observed on the Pinson C2E wind turbine generator during a routine inspection of all wind machines following this windstorm. One failure was fatigue cracks which formed on plates welded to the rotor shaft. The second failure was a number of cracks in the skin of all three blades. Although the possibility exists that the high winds of that data contributed to these failures, no conclusive data exist substantiating this theory. In fact, the C2E's feathering mechanism functioned normally during the windstorm, thereby controlling rotor overspeed, a potential cause of damage.

Carr, M. J.; Grotsky, V. K.; Sexton, J.

1980-03-01

423

Development of a High-Pressure/High-Temperature Downhole Turbine Generator  

SciTech Connect

The objective of this project as originally outlined has been to achieve a viable downhole direct current (DC) power source for extreme high pressure, high temperature (HPHT) environments of >25,000 psi and >250 C. The Phase I investigation posed and answered specific questions about the power requirements, mode of delivery and form factor the industry would like to see for downhole turbine generator tool for the HPHT environment, and noted specific components, materials and design features of that commercial system that will require upgrading to meet the HPHT project goals. During the course of Phase I investigation the scope of the project was HPHT downhole DC power. Phase I also investigated the viability of modifying a commercial expanded, without additional cost expected to the project, to include the addition of HT batteries to the power supply platform.

Timothy F. Price

2007-02-01

424

Axial-flux modular permanent-magnet generator with a toroidal winding for wind-turbine applications  

SciTech Connect

Permanent-magnet (PM) generators have been used for wind turbines for many years. Many small wind-turbine manufacturers use direct-drive PM generators. For wind-turbine generators, the design philosophy must cover the following characteristics: low cost, light weight, low speed, high torque, and variable-speed generation. The generator is easy to manufacture and the design can be scaled up for a larger size without major retooling. A modular PM generator with axial flux direction was chosen. The permanent magnet used is NdFeB or ferrite magnet with flux guide to focus flux density in the air gap. Each unit module of the generator may consist of one, two, or more phases. Each generator can be expanded to two or more unit modules. Each unit module is built from simple modular poles. The stator winding is formed like a torus. Thus, the assembly process is simplified and the winding insertion in the slot is less tedious. The authors built a prototype of one unit module and performed preliminary tests in the laboratory. Follow-up tests will be conducted in the laboratory to improve the design.

Muljadi, E.; Butterfield, C.P.; Wan, Y.H.

1999-08-01

425

A new generation of marine turbine that can harness energy from the sea is being developed by Nautricity,  

E-print Network

A new generation of marine turbine that can harness energy from the sea is being developed. There are currently a number of devices, in various stages of development, that aim to capture the energy of waves the most cost-effective developer of tidal energy sites and establish market leadership. It plans to lead

Mottram, Nigel

426

Comparative study on the performance of control systems for doubly fed induction generator (DFIG) wind turbines operating with power regulation  

Microsoft Academic Search

As a result of the increasing wind power penetration on power systems, the wind farms are today required to participate actively in grid operation by an appropriate generation control. This paper presents a comparative study on the performance of three control strategies for DFIG wind turbines. The study focuses on the regulation of the active and reactive power to a

L. M. Fernandez; C. A. Garcia; F. Jurado

2008-01-01

427

State Space Averaging Modeling and Analysis of Disturbance Injection Method of MPPT for Small Wind Turbine Generating Systems  

Microsoft Academic Search

Based on a configuration with low cost and high reliability, disturbance injection method is employed to achieve the maximum power point tracking (MPPT) for the small wind turbine generating systems(SWTGS) in this paper. State space averaging method is used to model the whole system, and its nonlinear and linearization model are given. The choosing principle of two crucial parameters of

Shengtie Wang; Zhiyuan Qi; Tore Undeland

2009-01-01

428

Benefit Evaluation of Wind Turbine Generators in Wind Farms Using Capacity-Factor Analysis and Economic-Cost Methods  

Microsoft Academic Search

Due to the recent price spike of the international oil and the concern of global warming, the development and deployment of renewable energy become one of the most important energy policies around the globe. Currently, there are different capacities and hub heights for commercial wind turbine generators (WTGs). To fully capture wind energy, different wind farms (WFs) should select adequate

Li Wang; Tai-Her Yeh; We-Jen Lee; Zhe Chen

2009-01-01

429

MATERIALS AND FABRICATION METHODS FOR HIGH TEMPERATURE MICRO-MAGNETIC MACHINES FOR MICRO-TURBINE POWER GENERATION  

E-print Network

are also discussed. INTRODUCTION Army concepts such as the Objective Force Warrior will require energy centimeters) turbine engine coupled to an electrical generator running on a hydrocarbon fuel. Such a system into electrical power. One approach is the use of a magnetic induction machine. We have previously reported

430

GETRAN: A generic, modularly structured computer code for simulation of dynamic behavior of aero- and power generation gas turbine engines  

Microsoft Academic Search

The design concept, the theoretical background essential for the development of the modularly structured simulation code GETRAN, and several critical simulation cases are presented in this paper. The code being developed under contract with NASA Lewis Research Center is capable of simulating the nonlinear dynamic behavior of single- and multispool core engines, turbofan engines, and power generation gas turbine engines

M. T. Schobeiri; M. Attia; C. Lippke

1994-01-01

431

Speed Sensor-less Direct Power Control of a Matrix Converter Fed Induction Generator for Variable Speed Wind Turbines  

Microsoft Academic Search

In this paper, the conventional direct torque control (DTC) scheme for induction motor drives is extended to directly control the active power (DPC) delivered to the grid by a wind turbine driven squirrel cage induction generator (SCIG). The SCIG is interfaced to the grid through an AC-AC matrix converter. A constant switching frequency based direct power control scheme with flux

T. Satish; K. K. Mohapatra; N. Mohan

2006-01-01

432

Dynamic behavior analysis of doubly-fed induction generator wind turbines – The influence of rotor and speed controller parameters  

Microsoft Academic Search

This paper analytically investigates the effects of system and controller parameters and operating conditions on the dynamic and transient behavior of wind turbines (WTs) with doubly-fed induction generators (DFIGs) under voltage dips and wind speed fluctuations. Also, it deals with the design considerations regarding rotor and speed controllers. The poorly damped electrical and mechanical modes of the system are identified,

Mohsen Rahimi; Mostafa Parniani

2010-01-01

433

Economical Condensing Turbines?  

E-print Network

Economical Condensing Turbines? by J.E.Dean, P.E. Steam turbines have long been used at utilities and in industry to generate power. There are three basic types of steam turbines: condensing, letdown 1 and extraction/condensing. ? Letdown... turbines reduce the pressure of the incoming steam to one or more pressures and generate power very efficiently, assuming that all the letdown steam has a use. Two caveats: ? Letdown turbines produce power based upon steam requirements and not based upon...

Dean, J. E.

434

Portable Hydraulic Powerpack  

NASA Technical Reports Server (NTRS)

Rechargeable hydraulic powerpack functions as lightweight, compact source of mechanical energy. Self-contained hydraulic powerpack derives energy from solid chemical charge. Combustion of charge initiated by small hammer, and revolving feeder replaces charges expended. Combustion gases cool during expansion in turbine and not too hot for release to atmosphere. Unit has applications driving wheelchairs and operating drills, winches, and other equipment in remote areas. Also replaces electric motors and internal-combustion engines as source of power in explosive atmospheres.

Anderson, L. A.; Henry, R. L.; Fedor, O. H.; Owens, L. J.

1986-01-01

435

MOD-5A wind turbine generator program design report: Volume 1: Executive Summary  

NASA Astrophysics Data System (ADS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator covering work performed between July 1980 and June 1984 is discussed. The report is divided into four volumes: Volume 1 summarizes the entire MOD-5A program, Volume 2 discusses the conceptual and preliminary design phases, Volume 3 describes the final design of the MOD-5A, and Volume 4 contains the drawings and specifications developed for the final design. Volume 1, the Executive Summary, summarizes all phases of the MOD-5A program. The performance and cost of energy generated by the MOD-5A are presented. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation, power generation, and control and instrumentation subsystems - is described briefly. The early phases of the MOD-5A program, during which the design was analyzed and optimized, and new technologies and materials were developed, are discussed. Manufacturing, quality assurance, and safety plans are presented. The volume concludes with an index of volumes 2 and 3.

1984-08-01

436

MOD-5A wind turbine generator program design report: Volume 1: Executive Summary  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator covering work performed between July 1980 and June 1984 is discussed. The report is divided into four volumes: Volume 1 summarizes the entire MOD-5A program, Volume 2 discusses the conceptual and preliminary design phases, Volume 3 describes the final design of the MOD-5A, and Volume 4 contains the drawings and specifications developed for the final design. Volume 1, the Executive Summary, summarizes all phases of the MOD-5A program. The performance and cost of energy generated by the MOD-5A are presented. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation, power generation, and control and instrumentation subsystems - is described briefly. The early phases of the MOD-5A program, during which the design was analyzed and optimized, and new technologies and materials were developed, are discussed. Manufacturing, quality assurance, and safety plans are presented. The volume concludes with an index of volumes 2 and 3.

1984-01-01

437

Evaluation of an Integrated Gas-Cooled Reactor Simulator and Brayton Turbine-Generator  

NASA Technical Reports Server (NTRS)

A closed-loop brayton cycle, powered by a fission reactor, offers an attractive option for generating both planetary and in-space electric power. Non-nuclear testing of this type of system provides the opportunity to safely work out integration and system control challenges for a modest investment. Recognizing this potential, a team at Marshall Space Flight Center has evaluated the viability of integrating and testing an existing gas-cooled reactor simulator and a modified commercially available, off-the-shelf, brayton turbine-generator. Since these two systems were developed independently of one another, this evaluation had to determine if they could operate together at acceptable power levels, temperatures, and pressures. Thermal, fluid, and structural analyses show that this combined system can operate at acceptable power levels and temperatures. In addition, pressure drops across the reactor simulator, although higher than desired, are also viewed as acceptable. Three potential working fluids for the system were evaluated: N2, He/Ar, and He/Xe. Other potential issues, such as electrical breakdown in the generator and the operation of the brayton foil bearings using various gas mixtures, were also investigated.

Hissam, David Andy; Stewart, Eric T.

2006-01-01

438

Economic scales for first-generation biomass-gasifier\\/gas turbine combined cycles fueled from energy plantations  

Microsoft Academic Search

This paper assesses the scales at which commercial, first-generation biomass integrated-gasifier\\/gas turbine combined cycle (BIG\\/GTCC) technology is likely to be most economic when fueled by plantation-derived biomass. First-generation BIG\\/GTCC systems are likely to be commercially offered by vendors beginning around 2000 and will be based on either pressurized or atmospheric-pressure gasification. Both plant configurations are considered here, with estimates of

E. D. Larson; C. I. Marrison

1997-01-01

439

Energy saving of a prototype fishing boat using a small wind turbine generator: Practical installation and measured results  

Microsoft Academic Search

This paper presents field-measurement results of a commercial 400-W wind turbine generator (WTG) installed on a prototype fishing boat to achieve a preliminary study on energy saving of the diesel engine in the fishing boat. The Darrieus-type WTG consisting of three blades made of stainless, a coreless permanent-magnet generator (PMG), and a maximum-power point-tracking (MPPT) controller is employed in this

Li Wang; Shiang-Shong Chen; Chen-Yuan Wei; Kuo-Hua Wang; Jun-De Lee; Cheng-Ching Huang; Wei-Jen Lee

2009-01-01

440

Installation of a 400-W wind turbine generator on a commercial fishing boat to achieve energy saving  

Microsoft Academic Search

This paper presents field-measurement results of a small 400-W wind turbine generator (WTG) installed on a commercial 9.8-ton fishing boat to achieve the goal of energy saving. The Darrieus-type WTG consisting of three stainless blades, a coreless permanent-magnet generator (PMG), and a maximum-power-point-tracking controller is employed in this study. The output of the wind PMG is connected to the battery

Li Wang; Shiang-Shong Chen; Guang-Zhe Zheng; Zhi-Rong Lu; Chia-Tien Hsiung; Cheng-Ching Huang

2010-01-01

441

CAD-based design, analysis and experimental verification of an outrunner permanent magnet synchronous generator for small scale wind turbines  

Microsoft Academic Search

This paper presents the CAD-based design procedure, analysis and experimental verification of a 1 kW out-runner permanent magnet synchronous generator (PMSG) with radial magnetic flux for small-scale wind turbine systems. Firstly, the CAD and mechanical model used in the design procedure of the PMSG are presented. The generator is designed via developed CAD-procedure and design interface in which the basic

D. Uygun; C. Ocak; Y. Cetinceviz; E. Demir; Y. Gungor

2012-01-01

442

GETRAN: A generic, modularly structured computer code for simulation of dynamic behavior of aero- and power generation gas turbine engines  

SciTech Connect

The design concept, the theoretical background essential for the development of the modularly structured simulation code GETRAN, and several critical simulation cases are presented in this paper. The code being developed under contract with NASA Lewis Research Center is capable of simulating the nonlinear dynamic behavior of single- and multispool core engines, turbofan engines, and power generation gas turbine engines under adverse dynamic operating conditions. The modules implemented into GETRAN correspond to components of existing and new-generation aero- and stationary gas turbine engines with arbitrary configuration and arrangement. For precise simulation of turbine and compressor components, row-by-row diabatic and adiabatic calculation procedures are implemented that account for the specific turbine and compressor cascade, blade geometry, and characteristics. The nonlinear, dynamic behavior of the subject engine is calculated solving a number of systems of partial differential equations, which describe the unsteady behavior of each component individually. To identify each differential equation system unambiguously, special attention is paid to the addressing of each component. The code is capable of executing the simulation procedure at four levels, which increase with the degree of complexity of the system and dynamic event. As representative simulations, four different transient cases with single- and multispool thrust and power generation engines were simulated. These transient cases vary from throttling the exit nozzle area, operation with fuel schedule, rotor speed control, to rotating stall and surge.

Schobeiri, M.T.; Attia, M.; Lippke, C. (Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering)

1994-07-01

443

Start-up and Self-sustain Test of 500 W Ultra-Micro Gas Turbine Generator  

NASA Astrophysics Data System (ADS)

This paper provides the performance test for start-up and self-sustaining of 500W ultra-micro gas turbine (UMGT) generator. Each component of UMGT, a centrifugal compressor, a radial turbine, an annular combustor and a shaft is already designed, manufactured and tested to meet design requirements in previous researches. However, they are not tested to work in an integrate system. Currently, integrated test unit with a compressor, a combustor and a turbine, is developed to find the proper condition of start-up and self-sustain. Ignition sequence depending on rotating speed is designed. Performance test for start-up and self-sustain is designed based on the ignition possible condition. An air impingement starter and a hot bulb inginer are applied. LPG is used as main fuel.

Seo, Jeong Min; Park, Jun Young; Seog Choi, Bum

2013-12-01

444

Candidate wind-turbine-generator site summarized meteorological data for December 1976-December 1981. [Program WIND listed  

SciTech Connect

Summarized hourly meteorological data for 16 of the original 17 candidate and wind turbine generator sites collected during the period from December 1976 through December 1981 are presented. The data collection program at some individual sites may not span this entire period, but will be contained within the reporting period. The purpose of providing the summarized data is to document the data collection program and provide data that could be considered representative of long-term meteorological conditions at each site. For each site, data are given in eight tables and a topographic map showing the location of the meteorological tower and turbine, if applicable. Use of information from these tables, along with information about specific wind turbines, should allow the user to estimate the potential for long-term average wind energy production at each site.

Sandusky, W.F.; Renne, D.S.; Hadley, D.L.

1982-09-01

445

The Performance and Wind Tunnel Test of Aerofoils for Small Wind Turbine Generating Systems  

Microsoft Academic Search

The small scale wind turbines have been used as the stand alone power source for years. Particularly these days, there is an increasing demand for the small wind turbines, of the output below 1kW, as monuments and educational materials. It is recommended that wind turbines of a diameter under 1.0m must be the low blade tip speed ratio type, owing

Hideki Tokuyama; Izumi Ushiyama; Kazuichi Seki

2003-01-01

446

Detection of low frequency impulsive noise from large wind turbine generators  

NASA Technical Reports Server (NTRS)

The thresholds of detection of low frequency, impulsive wind turbine sounds in the presence of background noise were examined. Seven wind turbine sounds, six of which were synthesized, were used in conjunction with three background noise conditions; quiet, 35, and 45 dB(A). The results indicate that thresholds of detection are predictable based on assumed characteristics of the auditory system. The synthesized wind turbine sounds were found to adequately represent a real recording.

Shepherd, K. P.

1985-01-01

447

The Effect of Wind Speed at the Top of the Tower on the Performance and Energy Generated from _THERMOSYPHON Solar Turbine  

NASA Astrophysics Data System (ADS)

Energy generated from wind turbine depends to a great extent on the wind speed at its inlet. The use of thermosyphon solar tower is an attempt to increase the air velocity at inlet of the wind turbine and of course to increase its power. The wind speed in a certain location changes always with time and with the height above ground surface. In this work, the effect of wind speed at the top of the tower on the performance as well as on the energy generated from thermosyphon solar turbine was studied theoretically. One location in Egypt was chosen for this study. The calculations were achieved mainly with the solar turbine located at tower bottom. For the purpose of comparison, the energy generated from the solar turbine was compared with that generated from free wind turbine at tower height with the absence of solar tower. It was found that, the wind speed at the top of the tower results in a pressure drop which affects the performance of the thermosyphon solar turbine. This pressure drop increases with the rise in wind speed and will be zero only when the wind speed at the top of the tower reaches zero. It was found also that, there is an increase in friction losses through the tower and a decrease in both temperature difference between inlet and outlet of the tower and in heat losses from tower walls with the rise in wind speed in location. The inlet air velocity to the solar turbine and consequently its specific power were found to be increased with the increase in wind speed at the top of the tower. Therefore, the effect of wind speed at the top of the tower must be taken into account during thermosyphon solar tower calculations. By comparing the performance of solar turbine and the free wind turbine located at tower height with the absence of thermosyphon solar tower, it was found that the mean inlet air velocity to the solar turbine located at tower bottom and consequently its specific power are higher than these values for free wind turbine. The mean inlet air velocity to the solar turbine is found to be 117% of its value for a free wind turbine. The yearly specific energy generated from solar turbine is expected to be 157% of its value for free wind turbine.

El-Haroun, A. A.

2002-01-01

448

Mod-5A wind turbine generator program design report. Volume 3: Final design and system description, book 2  

NASA Astrophysics Data System (ADS)

The design, development and analysis of the 7.3MW MOD-5A wind turbine generator is documented. The report is divided into four volumes: Volume 1 summarizes the entire MOD-5A program, Volume 2 discusses the conceptual and preliminary design phases, Volume 3 describes the final design of the MOD-5A, and Volume 4 contains the drawings and specifications developed for the final design. Volume 3, book 2 describes the performance and characteristics of the MOD-5A wind turbine generator in its final configuration. The subsystem for power generation, control, and instrumentation subsystems is described in detail. The manufacturing and construction plans, and the preparation of a potential site on Oahu, Hawaii, are documented. The quality assurance and safety plan, and analyses of failure modes and effects, and reliability, availability and maintainability are presented.

1984-08-01

449

Mod-5A wind turbine generator program design report. Volume 3: Final design and system description, book 2  

NASA Technical Reports Server (NTRS)

The design, development and analysis of the 7.3MW MOD-5A wind turbine generator is documented. The report is divided into four volumes: Volume 1 summarizes the entire MOD-5A program, Volume 2 discusses the conceptual and preliminary design phases, Volume 3 describes the final design of the MOD-5A, and Volume 4 contains the drawings and specifications developed for the final design. Volume 3, book 2 describes the performance and characteristics of the MOD-5A wind turbine generator in its final configuration. The subsystem for power generation, control, and instrumentation subsystems is described in detail. The manufacturing and construction plans, and the preparation of a potential site on Oahu, Hawaii, are documented. The quality assurance and safety plan, and analyses of failure modes and effects, and reliability, availability and maintainability are presented.

1984-01-01

450

Electronic Simulation of a HydroTurbine with its Penstock, Speed Regulator and Damping Unit  

Microsoft Academic Search

The conception of an electronic-analog-real-time-hydro-turbine simulator is presented as a companion paper to the hydro-generator simulator previously published (1). Penstock, speed regulator and damping unit are accounted for. The system can 1- simulate any Pelton, Francis, Kaplan or Propeller type of hydraulic turbine; 2- take care of the non-linear relationships between power, water flow, speed, water head and gate position

G. Jasmin; A. Leroux; D. Mukhedkar

1983-01-01

451

Electrical power obtained from burning landfill gas into a gas turbine generator: Experience after one year of operation  

SciTech Connect

A typical example of a ``waste to energy'' concept can be found also in the landfill environment. The biogas derived by fermentation process is usually burnt into gas engines. This choice is usually due to the electric efficiency that is normally higher than gas turbine application and to the size that usually, almost in Italian landfill size, does not allow power higher than 1,000 kW. On the other side gas turbine applications, typically based on generator sets greater than 1,000 kW do not require special biogas pre-treatment; require less maintenance and have an extremely higher reliability. The paper describes an application of a gas turbine generator of 4,800 kW outlining the experiences collected after one year of operation. During this period, the system fulfilled the target of a total operating time greater than 8,000 hours. Description is done of the biogas compression system feeding the turbine and also of the subsystem adopted to reach the above mentioned target reliability.

Fabbri, R.; Mignani, N.

1998-07-01

452

The Effect of Wind Speed at the Top of the Tower on the Performance and Energy Generated from _THERMOSYPHON Solar Turbine  

Microsoft Academic Search

Energy generated from wind turbine depends to a great extent on the wind speed at its inlet. The use of thermosyphon solar tower is an attempt to increase the air velocity at inlet of the wind turbine and of course to increase its power. The wind speed in a certain location changes always with time and with the height above

A. A. El-Haroun

2002-01-01

453

Very Low Head Turbine Deployment in Canada  

NASA Astrophysics Data System (ADS)

The Very Low Head (VLH) turbine is a recent turbine technology developed in Europe for low head sites in the 1.4 - 4.2 m range. The VLH turbine is primarily targeted for installation at existing hydraulic structures to provide a low impact, low cost, yet highly efficient solution. Over 35 VLH turbines have been successfully installed in Europe and the first VLH deployment for North America is underway at Wasdell Falls in Ontario, Canada. Deployment opportunities abound in Canada with an estimated 80,000 existing structures within North America for possible low-head hydro development. There are several new considerations and challenges for the deployment of the VLH turbine technology in Canada in adapting to the hydraulic, environmental, electrical and social requirements. Several studies were completed to determine suitable approaches and design modifications to mitigate risk and confirm turbine performance. Diverse types of existing weirs and spillways pose certain hydraulic design challenges. Physical and numerical modelling of the VLH deployment alternatives provided for performance optimization. For this application, studies characterizing the influence of upstream obstacles using water tunnel model testing as well as full-scale prototype flow dynamics testing were completed. A Cold Climate Adaptation Package (CCA) was developed to allow year-round turbine operation in ice covered rivers. The CCA package facilitates turbine extraction and accommodates ice forces, frazil ice, ad-freezing and cold temperatures that are not present at the European sites. The Permanent Magnet Generator (PMG) presents some unique challenges in meeting Canadian utility interconnection requirements. Specific attention to the frequency driver control and protection requirements resulted in a driver design with greater over-voltage capability for the PMG as well as other key attributes. Environmental studies in Europe included fish friendliness testing comprised of multiple in-river live passage tests for a wide variety of fish species. Latest test results indicate fish passage survivability close to 100%. Further fish studies are planned in Canada later this year. Successful deployment must meet societal requirements to gain community acceptance and public approval. Aesthetics considerations include low noise, disguised control buildings and vigilant turbine integration into the low profile existing structures. The resulting design was selected for deployment at existing historic National Park waterway structures. The integration of all of these design elements permits the successful deployment of the VLH turbine in Canada.

Kemp, P.; Williams, C.; Sasseville, Remi; Anderson, N.

2014-12-01

454

Urban energy generation: Influence of micro-wind turbine output on electricity consumption in buildings  

Microsoft Academic Search

Small scale wind turbines installed within the built environment is classified as microgeneration technology. Such turbines may soon become a commercial reality in the UK as a result of both advancements in technology and new financial incentives provided by the government. In addition, microgeneration technologies, especially those with appreciable resource, have the potential to reduce built environment related CO2 emissions

A. S. Bahaj; L. Myers; P. A. B. James

2007-01-01

455

A preliminary analysis of the audible noise of constant speed, horizontal axis wind turbine generators  

NASA Astrophysics Data System (ADS)

A preliminary analytical procedure developed for calculating certain aerodynamic sound levels produced by large, horizontal axis wind turbine generators (WTG's) such as the DOE/NASA Mods- O, OA, 1, and 22. It postulates a noise component due to the (constant) rotation of the blades of the WTG, plus a wake-noise component that increases with the square of the power produced by the WTG. Sounds from machinery, and low frequency impulsive sounds produced by blade interaction with the wake of the support tower are not considered. In order to evaluate the acceptability of the sounds from WTG's, three noise limits were selected: the noise regulations of the states of Minnesota and Illinois and a U.S. EPA guideline for avoiding noise complaints from the public. The impact of WTG noise was evaluated against these three limits by computing acceptability distances. It is concluded that the infrasonic component of WTG sound, occurring at the blade passage rate, is at a very low level compared with existing limits of acceptability for human health. On the other hand, they could be a source of annoyance to people inside light weight structures (such as some residences) at a WTG site.

Keast, D. N.; Potter, R. C.

1980-07-01

456

Conceptual design of a fixed-pitch wind turbine generator system rated at 400 kilowatts  

NASA Technical Reports Server (NTRS)

The design and cost aspects of a fixed pitch, 400 kW Wind Turbine Generator (WTG) concept are presented. Improvements in reliability and cost reductions were achieved with fixed pitch operation and by incorporating recent advances in WTG technology. The specifications for this WTG concept were as follows: (1) A fixed pitch, continuous wooden rotor was to be provided by the Gougeon Bros. Co. (2) An 8 leg hyperboloid tower that showed promise as a low cost structure was to be used. (3) Only commercially available components and parts that could be easily fabricated were to be considered. (4) Design features deemed desirable based on recent NASA research efforts were to be incorporated. Detailed costs and weight estimates were prepared for the second machine and a wind farm of 12 WTG's. The calculated cost of energy for the fixed pitch, twelve unit windfarm is 11.5 cents/kW hr not including the cost of land and access roads. The study shows feasibility of fixed pitch, intermediate power WTG operation.

Pintz, A.; Kasuba, R.; Spring, J.

1984-01-01

457

Wind turbine/generator set having a stator cooling system located between stator frame and active coils  

DOEpatents

A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle via a bearing assembly. The wind rotor hub includes an opening having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity inside the wind rotor hub. The spindle is attached to a turret supported by a tower. Each of the spindle, turret and tower has an interior cavity that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

Bevington, Christopher M.; Bywaters, Garrett L.; Coleman, Clint C.; Costin, Daniel P.; Danforth, William L.; Lynch, Jonathan A.; Rolland, Robert H.

2012-11-13

458

Response measurements for two building structures excited by noise from a large horizontal axis wind turbine generator  

NASA Astrophysics Data System (ADS)

Window and wall acceleration measurements and interior noise measurements ere made for two different building structures during excitation by noise from the WTS-4 horizontal axis wind turbine generator operating in a normal power generation mode. With turbine noise input pulses resulted in acceleration pulses for the wall and window elements of the two tests buildings. Response spectra suggest that natural vibration modes of the structures are excited. Responses of a house trailer were substantially greater than those for a building of sturdier construction. Peak acceleration values correlate well with similar data for houses excited by flyover noise from commercial and military airplanes and helicopters, and sonic booms from supersonic aircraft. Interior noise spectra have peaks at frequencies corresponding to structural vibration modes and room standing waves; and the levels for particular frequencies and locations can be higher than the outside levels.

Hubbard, H. H.; Shepherd, K. P.

1984-11-01

459

Response measurements for two building structures excited by noise from a large horizontal axis wind turbine generator  

NASA Technical Reports Server (NTRS)

Window and wall acceleration measurements and interior noise measurements ere made for two different building structures during excitation by noise from the WTS-4 horizontal axis wind turbine generator operating in a normal power generation mode. With turbine noise input pulses resulted in acceleration pulses for the wall and window elements of the two tests buildings. Response spectra suggest that natural vibration modes of the structures are excited. Responses of a house trailer were substantially greater than those for a building of sturdier construction. Peak acceleration values correlate well with similar data for houses excited by flyover noise from commercial and military airplanes and helicopters, and sonic booms from supersonic aircraft. Interior noise spectra have peaks at frequencies corresponding to structural vibration modes and room standing waves; and the levels for particular frequencies and locations can be higher than the outside levels.

Hubbard, H. H.; Shepherd, K. P.

1984-01-01

460

Detailed design of a 30kW switched reluctance starter\\/generator system for a gas turbine engine application  

Microsoft Academic Search

A new switched reluctance starter\\/generator (SR S\\/G) system has been developed for an aircraft engine application. The system is rated at 30 kW, 270 Vdc, 52 k r\\/min maximum operating speed. The system also provides 17 hp to start the 1400-hp engine. The system consists of an SR machine directly coupled to the gas turbine engine, an inverter converter unit

Caio A. Ferreira; Stephen R. Jones; William S. Heglund; William D. Jones

1995-01-01

461

A New Nine-Level Active NPC (ANPC) Converter for Grid Connection of Large Wind Turbines for Distributed Generation  

Microsoft Academic Search

Wind power is one of the most promising emerging renewable energy technologies for distributed generation (DG). In this paper, a new nine-level active neutral-point-clamped (9L ANPC) converter is proposed for the grid connection of large wind turbines (WTs) to improve the waveform quality of the converter output voltage and current. Therefore, the bulky passive grid fil- ters can be reduced

Jun Li; Subhashish Bhattacharya; Alex Q. Huang

2011-01-01

462

Power fluctuations suppression of stand-alone hybrid generation combining solar photovoltaic\\/wind turbine and fuel cell systems  

Microsoft Academic Search

In this paper a hybrid energy system combining variable speed wind turbine, solar photovoltaic and fuel cell generation systems is presented to supply continuous power to residential power applications as stand-alone loads. The wind and photovoltaic systems are used as main energy sources while the fuel cell is used as secondary or back-up energy source. Three individual dc–dc boost converters

Nabil A. Ahmed; Masafumi Miyatake; A. K. Al-Othman

2008-01-01

463

National Renewable Energy Laboratory program on lightning risk and wind turbine generator protection  

SciTech Connect

This paper will describe the NREL program for addressing lightning protection for wind turbines. A test program will begin this summer at the Central and South West Services Inc. (CSW) wind farm near Fort Davis, Texas, to assess lightning risk, the frequency of lightning strikes on wind turbines compared to risk assessment predictions, and the effectiveness of some protection techniques. A Web page will be assembled to provide resources for designers and operators and feedback for issues as they arise. Also, a database of lightning events (and corresponding damage) will be collected to assist in maturing the understanding of wind turbine lightning protection.

Muljadi, E. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); McNiff, B. [McNiff Light Industry, Blue Hill, ME (United States)] [McNiff Light Industry, Blue Hill, ME (United States)

1997-09-01

464

Potential benefits of a ceramic thermal barrier coating on large power generation gas turbine  

NASA Technical Reports Server (NTRS)

Thermal barrier coating design option offers benefit in terms of reduced electricity costs when used in utility gas turbines. Options considered include: increased firing temperature, increased component life, reduced cooling air requirements, and increased corrosion resistance (resulting in increased tolerance for dirty fuels). Performance and cost data were obtained. Simple, recuperated and combined cycle applications were considered, and distillate and residual fuels were assumed. The results indicate that thermal barrier coatings could produce large electricity cost savings if these coatings permit turbine operation with residual fuels at distillate-rated firing temperatures. The results also show that increased turbine inlet temperature can result in substantial savings in fuel and capital costs.

Clark, J. S.; Nainiger, J. J.

1977-01-01

465

Physical modeling of wind turbine generators in a small scale analog system  

E-print Network

This project represents the physical modeling and experimental test of a Doubly-fed Induction Machine (DFIM), in order to substantially analyze the characteristic behaviors of wind turbines and its use in the micro-grid ...

Wang, Xuntuo

2014-01-01

466

Large wind turbines: A utility option for the generation of electricity  

NASA Technical Reports Server (NTRS)

The economic and technical potential of wind energy in the United States is discussed. Particular attention is given to the status of wind turbine operational experience as well as the environmental posture of the technology.

Robbins, W. H.; Thomas, R. L.; Baldwin, D. H.

1980-01-01

467

Impact of unsteady secondary air flow interaction with main flow on loss generation in axial turbines  

E-print Network

Secondary air, often called purge air, is injected through the endwall gap between stationary vanes and rotating rotors in axial turbines to prevent ingestion of the hot working gas into the endwall cavities. Three-dimensional ...

Clifton, David (David Madison)

2014-01-01

468

On adapting a small PM wind generator for a multi-blade, high solidity wind turbine  

Microsoft Academic Search

Summary form only given. This paper explores the design space that exists between multi-blade, high-solidity water-pumping turbines and modern high-speed 2 and 3-bladed horizontal axis wind turbines (HAWTs). In particular, it compares the features and performance of a small 12-bladed, high solidity HAWT to that of a modern 3-bladed HAWT. It also outlines a procedure for adapting a small PM

M. A. Khan; P. Pillay; K. D. Visser

2005-01-01

469

Using the Biphase Turbine to Generate Useful Energy from Process Streams  

E-print Network

to the deliverable power advantage, the Biphase turbine also provides a means for achieving efficient separation of the gas and liquid phases without the use of large disengagement vessels. Cryogenic Refrigeration To reach the low temperatures sometimes needed... in industry liquid refrigerants are often flashed for cooling. Each flash is a candidate for application of the Biphase turbine. Common cryogenic refriger ants used for this purpose are methane, ethylene, propane and propylene. III1111 FLASH OPERATION CO...

Helgeson, N. L.; Studhalter, W. R.

1981-01-01

470

Optimal Operation Planning of Wind Farm Installed BESS Using Wind Power Forecast Data of Wind Turbine Generators Considering Forecast Error  

NASA Astrophysics Data System (ADS)

In order to solve the problems of global warming and depletion of energy resource, renewable energy systems such as wind generation are getting attention. However, wind power fluctuates due to variation of wind speed, and it is difficult to perfectly forecast wind power. This paper describes a method to use power forecast data of wind turbine generators considering wind power forecast error for optimal operation. The purpose in this paper is to smooth the output power fluctuation of a wind farm and to obtain more beneficial electrical power for selling.

Ogimi, Kazuki; Kamiyama, Shota; Palmer, Michael; Yona, Atsushi; Senju, Tomonobu; Funabashi, Toshihisa

2013-06-01

471

A medium frequency transformer with multiple secondary windings for medium voltage converter based wind turbine power generating systems  

NASA Astrophysics Data System (ADS)

Recent advances in magnetic materials have led to the development of compact and light weight, medium and high frequency transformers, which would be a possible solution to reducing the size and weight of wind turbine power generating systems. This paper presents the overall design and analysis of a Metglas amorphous alloy 2605SA1 based medium frequency transformer to generate the isolated balanced multiple DC supplies for medium voltage converter systems. A comprehensive electromagnetic analysis is conducted on the proposed design based on experimental results. The test stand, data analysis, and test results are discussed.

Islam, Md Rabiul; Guo, Youguang; Zhu, Jianguo

2013-05-01

472

NREL Controllable Grid Interface for Testing MW-Scale Wind Turbine Generators (Poster)  

SciTech Connect

In order to understand the behavior of wind turbines experiencing grid disturbances, it is necessary to perform a series of tests and accurate transient simulation studies. The latest edition of the IEC 61400-21 standard describes methods for such tests that include low voltage ride-through (LVRT), active power set-point control, ramp rate limitations, and reactive power capability tests. The IEC methods are being widely adopted on both national and international levels by wind turbine manufacturers, certification authorities, and utilities. On-site testing of wind turbines might be expensive and time consuming since it requires both test equipment transportation and personnel presence in sometimes remote locations for significant periods of time because such tests need to be conducted at certain wind speed and grid conditions. Changes in turbine control software or design modifications may require redoing of all tests. Significant cost and test-time reduction can be achieved if these tests are conducted in controlled laboratory environments that replicate grid disturbances and simulation of wind turbine interactions with power systems. Such testing capability does not exist in the United States today. An initiative by NREL to design and construct a 7-MVA grid simulator to operate with the existing 2.5 MW and new upcoming 5-MW dynamometer facilities will fulfill this role and bring many potential benefits to the U.S. wind industry with the ultimate goal of reducing wind energy integration costs.

McDade, M.; Gevorgian, V.; Wallen, R.; Erdman, W.

2013-04-01

473

Abstract--A bi-objective optimization model of power and power changes generated by a wind turbine is discussed in this  

E-print Network

1 Abstract--A bi-objective optimization model of power and power changes generated by a wind theory is introduced. Data-mining algorithms were used to identify the model of power generation from prediction, power ramp rate, data mining, wind turbine operation strategy, generator torque, blade pitch

Kusiak, Andrew

474

Elevated Temperature Materials for Power Generation and Propulsion The energy industry is designing higher-efficiency land-based turbines for natural gas-fired  

E-print Network

Elevated Temperature Materials for Power Generation and Propulsion The energy industry is designing higher-efficiency land-based turbines for natural gas-fired power generation systems. The high inlet of thermomechanical fatigue life of the next generation's Ni-base superalloys are being developed to enhance life

Li, Mo

475

Wind Power predictability a risk factor in the design, construction and operation of Wind Generation Turbines  

NASA Astrophysics Data System (ADS)

Summit: The wind power predictability is often a forgotten decision and planning factor for most major wind parks, both onshore and offshore. The results of the predictability are presented after having examined a number of European offshore and offshore parks power predictability by using three(3) mesoscale model IRIE_GFS and IRIE_EC and WRF. Full description: It is well known that the potential wind production is changing with latitude and complexity in terrain, but how big are the changes in the predictability and the economic impacts on a project? The concept of meteorological predictability has hitherto to some degree been neglected as a risk factor in the design, construction and operation of wind power plants. Wind power plants are generally built in places where the wind resources are high, but these are often also sites where the predictability of the wind and other weather parameters is comparatively low. This presentation addresses the question of whether higher predictability can outweigh lower average wind speeds with regard to the overall economy of a wind power project. Low predictability also tends to reduce the value of the energy produced. If it is difficult to forecast the wind on a site, it will also be difficult to predict the power production. This, in turn, leads to increased balance costs and a less reduced carbon emission from the renewable source. By investigating the output from three(3) mesoscale models IRIE and WRF, using ECMWF and GFS as boundary data over a forecasting period of 3 months for 25 offshore and onshore wind parks in Europe, the predictability are mapped. Three operational mesoscale models with two different boundary data have been chosen in order to eliminate the uncertainty with one mesoscale model. All mesoscale models are running in a 10 km horizontal resolution. The model output are converted into "day a head" wind turbine generation forecasts by using a well proven advanced physical wind power model. The power models are using a number of weather parameters like wind speed in different heights, friction velocity and DTHV. The 25 wind sites are scattered around in Europe and contains 4 offshore parks and 21 onshore parks in various terrain complexity. The "day a head" forecasts are compared with production data and predictability for the period February 2010-April 2010 are given in Mean Absolute Errors (MAE) and Root Mean Squared Errors (RMSE). The power predictability results are mapped for each turbine giving a clear picture of the predictability in Europe. . Finally a economic analysis are shown for each wind parks in different regimes of predictability will be compared with regard to the balance costs that result from errors in the wind power prediction. Analysis shows that it may very well be profitable to place wind parks in regions of lower, but more predictable wind ressource. Authors: Ivan Ristic, CTO Weather2Umberlla D.O.O Tomislav Maric, Meteorologist at Global Flow Solutions Vestas Wind Technology R&D Line Gulstad, Manager Global Flow Solutions Vestas Wind Technology R&D Jesper Thiesen, CEO ConWx ApS

Thiesen, J.; Gulstad, L.; Ristic, I.; Maric, T.

2010-09-01

476

Land-use effects on flood generation - considering soil hydraulic measurements in modelling  

NASA Astrophysics Data System (ADS)

The investigation in the catchment of the Mulde (51°0'55" N, 13°15'54" E Saxony, Germany) researches the effect of afforestation measures on the soil hydraulic properties. The concept of a "false chronosequence" was used to quantify the time-dependent dynamical character of the forest impact. Four adjacent plots were identified at a test location with comparable pedological start conditions and a set of tree stands of different age: (1) arable field (initial state); (2) 6-year-old afforestation; (3) 50-year-old afforestation; (4) ancient natural forest ("target" stocking). Water retention curves and unsaturated conductivities were analysed in the lab. In the field, the undisturbed infiltration capacities were measured quantitatively (hood infiltrometer) and qualitatively (brilliant blue tracer). Pronounced differences between all 4 plots were detected. The afforestation causes an increased infiltration and soil water retention potential. Especially the topsoil layers showed a distinct increase in conductivity and portion of coarse/middle pores. The influence of these changes on rainfall-runoff calculations at the test location was analysed in this study.

Wahren, A.; Feger, K.-H.; Schwärzel, K.; Münch, A.

2009-08-01

477

Measurement of aeroacoustic noise generated on wind turbine blades modified by trailing edge brushes  

NASA Astrophysics Data System (ADS)

As wind technology becomes a larger portion of the energy production picture, the problematic interactions between the machines and society will continue to become more pronounced. Of these problems, wind turbine noise is one of the most important to the future of wind turbine development. This study looks at the effect trailing edge brushes mounted on the 2 bladed Controls Advance Research Turbine (CART 2), located at the National Wind Technology Center, have on the overall acoustic and aerodynamic performance of the blades. The use of trailing edge brushes reduced the aeroacoustic noise by 1.0 to 5.0 dB over the baseline blade, depending on wind speed. This acoustic performance comes at a cost to the aerodynamic performance of the blades. The aerodynamic performance indicators, such as turbine power and root bending moments show that increased drag due to the brushes is the main contributor to the reduction in power production. An economic analysis also investigated how to best use noise mitigation devices to optimize acoustic, power performance and loads of a 600 kW baseline turbine, such as the CART 2. The analysis shows that the use of up a noise mitigation device of 4 dB is best used by increasing the rotor diameter and the power rating of the machine, from a 43.3 m diameter, 600 kW machine to a 68.8 m diameter, 886.7 kW machine. This increase resulted in an annual energy production increase of 414% when using a Rayleigh wind distribution with at a mean annual wind speed of 8.5 m/s. This is a reduction of cost of energy from 0.0463 per kWh to 0.0422 kWh. This reduction in energy production costs helps to explain the continuing trend of turbine machine growth in both rotor diameter and power rating.

Asheim, Michael J.

478

Control system design for the MOD-5A 7.3 mW wind turbine generator  

NASA Technical Reports Server (NTRS)

This paper provides descriptions of the requirements analysis, hardware development and software development phases of the Control System design for the MOD-5A 7.3 mW Wind Turbine Generator. The system, designed by General Electric Company, Advanced Energy Programs Department, under contract DEN 3-153 with NASA Lewis Research Center and DOE, provides real time regulation of rotor speed by control of both generator torque and rotor torque. A variable speed generator system is used to provide both airgap torque control and reactive power control. The wind rotor is designed with segmented ailerons which are positioned to control blade torque. The central component of the control system, selected early in the design process, is a programmable controller used for sequencing, alarm monitoring, communication, and real time control. Development of requirements for use of aileron controlled blades and a variable speed generator required an analytical simulation that combined drivetrain, tower and blade elastic modes with wind disturbances and control behavior. An orderly two phase plan was used for controller software development. A microcomputer based turbine simulator was used to facilitate hardware and software integration and test.

Barton, Robert S.; Hosp, Theodore J.; Schanzenbach, George P.

1995-01-01

479

Control of the variable speed generator on the Sandia 34-metre vertical axis wind turbine  

NASA Astrophysics Data System (ADS)

The DOE/Sandia 34-meter VAWT Test Bed is a 500kW variable-speed wind turbine. The turbine is operated between 25 and 38 rpm and has been characterized from a structural and aerodynamic standpoint. A preliminary variable speed control algorithm has been implemented on the Test Bed. This paper describes the initial variable-speed control algorithm developed for the Test Bed and the performance of that algorithm to date. Initial performance comparisons between variable-speed and fixed-speed operation are made as well as some thoughts on the expansion of the operating envelope of the Test Bed.

Ralph, Mark E.

480

Turbine operation, general characteristics  

Microsoft Academic Search

\\u000a Reverse-running centrifugal pumps can be used as turbines for energy recuperation (in [N.6] termed “Hydraulic Power Recovery\\u000a Turbines”, HPRT). Applications are processes where a large amount of fluid energy is dissipated in valves or other throttling\\u000a devices. In some processes dissolved gases separate from the fluid or liquid is flashed into steam during the expansion. Higher\\u000a energy differences are then

Johann Friedrich Gülich

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