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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

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

SciTech Connect

In the present 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 whole loading range. Speed governor dynamics are fully simulated, and the influence of torsional vibrations is studied. The vibration response of the unit to draft tube surges is investigated and the risk of excessive oscillations is evaluated. The approach was developed for diagnosis of excessive vibrations of Kastraki hydro power station in Greece.

Konidaris, D.N. [Public Power Corp. (Greece)] [Public Power Corp. (Greece); Tegopoulos, J.A. [National Technical Univ. of Athens (Greece)] [National Technical Univ. of Athens (Greece)

1997-12-01

4

Small hydraulic turbine drives  

NASA Technical Reports Server (NTRS)

Turbine, driven by the fluid being pumped, requires no external controls, is completely integrated into the flow system, and has bearings which utilize the main fluid for lubrication and cooling. Torque capabilities compare favorably with those developed by positive displacement hydraulic motors.

Rostafinski, W. A.

1970-01-01

5

Hydro turbine transfer functions with hydraulic coupling  

SciTech Connect

This paper deals with the development of transfer functions for hydraulic turbines connected to a common penstock. These turbines tend to be hydraulically coupled. Both the solid mass approximation and the pressure wave modeling approach are applied for the development of diagonal ([Delta]P[sub mi]/[Delta]g[sub i]) and coupling ([Delta]P[sub mi]/[Delta]g[sub j]) transfer functions. This modeling approach is applied to the Stratos hydro power station of PPC. It is shown that the solid mass approach gives relatively simple rational transfer functions that represent accurately the hydraulic coupling between turbines for a wide frequency range.

Vournas, C.D.; Zaharakis, A. (National Technical Univ., Athens (Greece). Electrical Energy Systems Lab.)

1993-09-01

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

Electro-Hydraulic Proportional Synchronous Control System of Ring Gate for Hydraulic Turbine  

Microsoft Academic Search

Based on the analysis of opening and closing control manner for ring gate of hydraulic turbine, the electro-hydraulic proportional control system for ring gate of hydraulic turbine was studied. A new control system, which combines mechanics, hydraulics and electrics, was presented. More particularly, the modules of speed control and multi-cylinder synchronous control for the movement of ring gate was designed.

Juliang Xiao; Guodong Wang; Weike Song

2009-01-01

8

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

9

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

10

DYNAMIC ANALYSIS OF A HYDRAULIC TURBINE UNIT  

Microsoft Academic Search

Dynamic analysis is of great importance not only for understanding the natural characteristics and dynamic response of a rotor-bearing system, but also for supplying knowledge of the fault mechanism. The dynamic analysis of a large-scale waterturbine generator set has rarely been investigated. This article establishes a model of a large water-turbine generator set and presents some research results. This article

Fuzhou Feng; Fulei Chu

2001-01-01

11

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

12

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

13

Liquid hammer and the transient operation of hydraulic turbines  

SciTech Connect

The mathematical study of the flow of incompressible fluids through turbomachines such as pumps and turbine generators is difficult because such machines contain irregular shaped channels with variable curved surfaces and variable cross sections. A nonlinear black box model for such flows has been introduced based on conservation of mass, energy and momentum. The model involves the rotation speed x = x(t) of the turbine rotor, the liquid flow rate y = y(t) through the machine, and the hydraulic pressure head between the inlet and outlet of the machine, all considered as functions of time t. Conservation of mass follows directly from the common assumption that the mass flows across the inlet and the outlet are the same. The model has been used for inflow and for outflow turbine generators to study transient pressure pulses due to liquid hammer effects for fixed or variable speed radial flow turbines following a power failure during operation. The methods can also be used directly to study transient liquid hammer pulses following startup for fixed and variable speed pumps, and the model can also be used to study the response of turbomachines to small periodic disturbances during operation near a rated state. In the present work this latter phenomenon, of forced harmonic oscillations, is illustrated for the radial inflow turbine generator. From a practical standpoint the crucial question is the existence or lack of existence of resonant driving frequencies for which small-amplitude periodic driving mechanisms may lead to large responses. The authors show that such resonant frequencies do not exist.

Smith, D.R. [Univ. of California, San Diego, La Jolla, CA (United States); Kimmel, H.E. [EBARA International Corp., Sparks, NV (United States)

1998-12-31

14

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

15

Steam generators, turbines, and condensers. Volume six  

SciTech Connect

Volume six covers steam generators (How steam is generated, steam generation in a PWR, vertical U-tube steam generators, once-through steam generators, how much steam do steam generators make.), turbines (basic turbine principles, impulse turbines, reaction turbines, turbine stages, turbine arrangements, turbine steam flow, steam admission to turbines, turbine seals and supports, turbine oil system, generators), and condensers (need for condensers, basic condenser principles, condenser arrangements, heat transfer in condensers, air removal from condensers, circulating water system, heat loss to the circulating water system, factors affecting condenser performance, condenser auxiliaries).

Not Available

1986-01-01

16

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

17

Anticipatory control of turbine generators  

E-print Network

ANTICIPATORY CONTROL OF TURBINE GENERATORS A Thesis By FREODIE LAUREL MESSEC Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1971 Major Subject...: Electrical Engineering ANTICIPATORY CONTROL OF TURBINE GENERATORS A Thesis By FREDDIE LAUREL MESSEC Approved as to style and content by: airman o Cosmist e ( yj~ Hea o, epartm / Member em r Member May 1971 ABSTRACT Anticipatory Control...

Messec, Freddie Laurel

2012-06-07

18

The hydraulic design of pump turbine for Xianyou pumped storage power station  

NASA Astrophysics Data System (ADS)

This paper presents the hydraulic design of pump turbines for Xianyou pumped storage power station. The method of improving the hydraulic performance of pump turbine with CFD analysis is given. The results of model test indicate that the final hydraulic design of pump turbine for Xianyou pumped storage power station is of high efficiencies, good

Zheng, J. S.; Liu, W. C.; Fu, Z. Y.; Shi, Q. H.

2012-11-01

19

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

20

3D numerical simulation of transient processes in hydraulic turbines  

Microsoft Academic Search

An approach for numerical simulation of 3D hydraulic turbine flows in transient operating regimes is presented. The method is based on a coupled solution of incompressible RANS equations, runner rotation equation, and water hammer equations. The issue of setting appropriate boundary conditions is considered in detail. As an illustration, the simulation results for runaway process are presented. The evolution of

S. Cherny; D. Chirkov; D. Bannikov; V. Lapin; V. Skorospelov; I. Eshkunova; A. Avdushenko

2010-01-01

21

A Direct Drive Wind Turbine HTS Generator  

Microsoft Academic Search

The wind turbine market is growing rapidly, and there has also been a trend toward ever increasing turbine rating. Most turbines to date has used geared high speed generators, but a history of gearbox reliability problems have turned many turbine manufacturers towards direct drive generators, which are very low speed, high torque, and therefore very large. Superconducting machines offer the

Clive Lewis; Jens Müller

2007-01-01

22

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

23

A Robot for Welding Repair of Hydraulic Turbine Blade  

Microsoft Academic Search

This paper proposed a scheme of using rail-free multifunctional robot in onsite repair of hydraulic turbine blade for large-scale axial-flow and Francis runners. The robot processes such functions as profile detection and measurement, air-gouging cleaning, grinding, welding and so on. The robot's main body is composed of an all-position rail-free mobile platform and a multiple degree-of-freedom (DOF) manipulator. The mobile

Qiang Chen; Zhenguo Sun; Wenzeng Zhang; Zhongcheng Gui

2008-01-01

24

3D numerical simulation of transient processes in hydraulic turbines  

NASA Astrophysics Data System (ADS)

An approach for numerical simulation of 3D hydraulic turbine flows in transient operating regimes is presented. The method is based on a coupled solution of incompressible RANS equations, runner rotation equation, and water hammer equations. The issue of setting appropriate boundary conditions is considered in detail. As an illustration, the simulation results for runaway process are presented. The evolution of vortex structure and its effect on computed runaway traces are analyzed.

Cherny, S.; Chirkov, D.; Bannikov, D.; Lapin, V.; Skorospelov, V.; Eshkunova, I.; Avdushenko, A.

2010-08-01

25

The Overvoltage protection Of wind turbine generators  

Microsoft Academic Search

The paper introduces the related characteristics of wind turbine generators, Such as the wind turbine generator may cause serious over-voltage problems of electromagnetic compatibility for using converter technique and be struck by lightning easily and also result in high maintenance costs. So we analyze several hotspots of the over-voltage protection of wind turbine generators, such as the standard on the

Tianwen Yin; Niansheng Xu; Rongxing Jiang

2009-01-01

26

Dual-speed wind turbine generation  

Microsoft Academic Search

Induction generator has been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator

E. Muljadi; C. P. Butterfield; D. Handman

1996-01-01

27

Dynamics and Stability of Wind Turbine Generators  

Microsoft Academic Search

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

E. N. Hinrichsen; P. J. Nolan

1982-01-01

28

Dynamics and stability of wind turbine generators  

NASA Technical Reports Server (NTRS)

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. Integration between adjacent wind turbines in a wind farm is also considered.

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

1981-01-01

29

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

30

Simulation Model of Hydraulic Turbine Speed Control System and Its Parameters Identification Based on Resilient Adaptive Particle Swarm Optimization Algorithm  

Microsoft Academic Search

A new simulation model of hydraulic turbine speed control system and mathematical models of microcomputer governor is proposed, and to investigate the first and second regulation characteristics of hydraulic turbine speed control system, after hydraulic turbine group connected to the major power systems. Simulation model established and parameters were identified intelligently by using resilient adaptive particle swarm optimization algorithm. The

Bai Ji-zhong; Xie Ai-guo; Yu Xin-hua; Zhou Li-kun

2010-01-01

31

Strain gauge measurement uncertainties on hydraulic turbine runner blade  

NASA Astrophysics Data System (ADS)

Strains experimentally measured with strain gauges can differ from those evaluated using the Finite Element (FE) method. This difference is due mainly to the assumptions and uncertainties inherent to each method. To circumvent this difficulty, we developed a numerical method based on Monte Carlo simulations to evaluate measurement uncertainties produced by the behaviour of a unidirectional welded gauge, its position uncertainty and its integration effect. This numerical method uses the displacement fields of the studied part evaluated by an FE analysis. The paper presents a study case using in situ data measured on a hydraulic turbine runner. The FE analysis of the turbine runner blade was computed, and our numerical method used to evaluate uncertainties on strains measured at five locations with welded strain gauges. Then, measured strains and their uncertainty ranges are compared to the estimated strains. The uncertainty ranges obtained extended from 74 ?epsilon to 165 ?epsilon. Furthermore, the biases observed between the median of the uncertainty ranges and the FE strains varied from -36 to 36 ?epsilon. Note that strain gauge measurement uncertainties depend mainly on displacement fields and gauge geometry.

Arpin-Pont, J.; Gagnon, M.; Tahan, S. A.; Coutu, A.; Thibault, D.

2012-11-01

32

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

33

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

34

Variable speed generator technology options for wind turbine generators  

NASA Astrophysics Data System (ADS)

The electrical system options for variable speed operation of a wind turbine generator were considered. Systems considered for large wind turbine generators were: (1) dc generator with line commutated inverted bridge; (2) synchronous generator with thyristor rectifier and inverter; (3) doubly fed induction generator with dc current link rectifier and inverter; (4) doubly fed induction generator with dc voltage link rectifier and inverter; and (5) doubly fed induction generator and cycloconverter. Those systems considered for smaller wind turbine generators were: (1) dc generator with copper based dc voltage link; (2) induction generator with dc voltage link; (3) induction generator with cycloconverter; (4) induction generator with high frequency link converter; and (5) permanent magnet generator configuration. The key operating characteristics of each system are discussed and the major advantages and disadvantages of each are identified.

Lipo, T. A.

1984-06-01

35

Hydraulic development of high specific-speed pump-turbines by means of an inverse design method, numerical flow-simulation (CFD) and model testing  

NASA Astrophysics Data System (ADS)

In recent years an increased interest in pump-turbines has been recognized in the market. The rapid availability of pumped storage schemes and the benefits to the power system by peak lopping, providing reserve and rapid response for frequency control are becoming of growing advantage. In that context it is requested to develop pump-turbines that reliably stand dynamic operation modes, fast changes of the discharge rate by adjusting the variable diffuser vanes as well as fast changes from pump to turbine operation. Within the present study various flow patterns linked to the operation of a pump-turbine system are discussed. In that context pump and turbine mode are presented separately and different load cases at both operation modes are shown. In order to achieve modern, competitive pump-turbine designs it is further explained which design challenges should be considered during the geometry definition of a pump-turbine impeller. Within the present study a runner-blade profile for a low head pump-turbine has been developed. For the initial hydraulic runner-blade design, an inverse design method has been applied. Within this design procedure, a first blade geometry is generated by imposing the pressure loading-distribution and by means of an inverse 3D potential-flow-solution. The hydraulic behavior of both, pump-mode and turbine-mode is then evaluated by solving the full 3D Navier-Stokes equations in combination with a robust turbulence model. Based on this initial design the blade profile has been further optimized and redesigned considering various hydraulic pump-turbine requirements. Finally, the progress in hydraulic design is demonstrated by model test results which show a significant improvement in hydraulic performance compared to an existing reference design.

Kerschberger, P.; Gehrer, A.

2010-08-01

36

Washington University Can the Sound Generated by Modern Wind Turbines  

E-print Network

Windmills:Sound from Windmills: Wind Turbine SyndromeWind Turbine Syndrome Dr. Nina Pierpont, MD, 2009 (selfWashington University Can the Sound Generated by Modern Wind Turbines Affect the Health of Those turbines haveWind turbines have been getting biggerbeen getting bigger and bigger....and bigger.... Lars

Salt, Alec N.

37

Fault tolerant generator systems for wind turbines  

Microsoft Academic Search

The objective of this paper is to review the possibilities of applying fault tolerance in generator systems for wind turbines based on what has been presented in the literature. In order to make generator systems fault tolerant in a suitable way, it is necessary to gain insight into the probability of different failures, so that suitable measures can be taken.

H. Polinder; H. Lendenmann; R. Chin; W. M. Arshad

2009-01-01

38

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

39

10 MW Class Superconductor Wind Turbine Generators  

Microsoft Academic Search

High temperature superconductor (HTS) technology enables generators with one third the weight and one half the losses of conventional machines. These technologies enable a significant reduction in the size and weight of 10 MW-class generators for direct-drive wind turbine systems and reduce the cost of clean energy relative to conventional copper and perma- nent-magnet-based generators and gearboxes. With compact and

Gregory Snitchler; Bruce Gamble; Christopher King; Peter Winn

2011-01-01

40

Machined blocks ease job of separating generator rotor from Francis-type turbine  

SciTech Connect

The Bureau of Reclamation has designed a new method of separating the generator rotor from a hydraulic turbine. Before disassembly, workers measure the distance from the top of the discharge ring to the bottom of the turbine runner, at 10 to 12 locations around the discharge ring. Mechanics then machine steel blocks to the exact measurement for each location. Workers then use the generator's braking system to jack up the generator, and then set the steel blocks in place on the discharge ring. The generator is then lowered onto the jacking block, which supports the rotor. The turbine runner barely touches the steel blocks. The coupling bolts are then removed and the rotor lifted out. Since the elevation of the turbine runner is not significantly changed, reassembly is a matter of setting the rotor in place. This method has saved manhours of labor and has increased worker safety by decreasing workers' handling of heavy equipment.

Anderson, B. (Bureau of Reclamation, Hungry Horse, MT (United States))

1991-06-01

41

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

42

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

43

Effect of water compressibility on nonstationary characteristics of hydraulic turbines  

NASA Astrophysics Data System (ADS)

We have investigated the effect of water compressibility on the nonstationary characteristics of turbines connected with the ability of the liquid to execute natural hydroacoustic vibrations in the setting of hydroelectric units. We have constructed a model of the setting up of forced hydroacoustic vibrations in the water conduit due to the precession of the vortex core running off the turbine. The conditions for the possibility that low-frequency hydroacoustic natural vibrations will arise have been considered.

Kurzin, V. B.

2013-09-01

44

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

45

Parameter Identification of Hydraulic Turbine Governing System based on Prony Method  

Microsoft Academic Search

A scheme for identifying hydraulic turbine governing system based on Prony method is proposed. Considering the application of Prony method in identifying system transfer function, parameters can be identified through the analysis of the system eigenvalues and residues. The proposed scheme was verified via simulation in Matlab and Simulink. Identification results show that such method has the advantage of fast

Shaokang Zhang; Xingyuan Li

2010-01-01

46

Operation of a third generation wind turbine  

SciTech Connect

A modern wind turbine was installed on May 26, 1982, at the USDA Conservation and Production Research Laboratory, Bushland, Texas. This wind machine was used to provide electrical energy for irrigation pumping and other agricultural loads. The wind turbine purchased for this research is an Enertech Model 44, manufactured by Enertech Corporation, Norwich, Vermont. The horizontal-axis wind turbine has a 13.4 m diameter, three-bladed, fixed-pitch rotor on a 24.4-m tower. The blades are laminated epoxy-wood, and are attached to a steel hub. A 25-kW induction generator provides 240 V, 60 Hz, single-phase electrical power. The wind turbine operated 64 percent of the time, while being available to operate over 94 percent of the time. The unit had a net energy production of over 80,000 kWh in an average windspeed of 5.9 m/s at a height of 10 m in a 16-month period. The blade pitch was originally offset two degrees from design to maintain power production within the limitations of the gearbox, generator, and brakes. A maximum output of 23.2 kW averaged over a 15-second period indicated that with a new brake, the system was capable of handling more power. After a new brake was installed, the blade pitch was changed to one degree from design. The maximum power output measured after the pitch change was 29.3 kW. Modified blade tip brakes were installed on the wind turbine on July 7, 1983. These tip brakes increased power production at lower windspeeds while reducing power at higher windspeeds.

Vosper, F.C.; Clark, R.N.

1983-12-01

47

Dynamic simulation of dual-speed wind turbine generation  

Microsoft Academic Search

Induction generators have been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness, and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator

E. Muljadi; C. P. Butterfield

1996-01-01

48

Turbine electric generator with solar heating and space cooling  

Microsoft Academic Search

A ther,pdynamic unit is described comprised of a pair of vessels which alternately generate and condense vapor are connected in a sealed system to drive a turbine with the vessel generating vapor having an outlet nozzle directed to the turbine and with the turbine exhaust being connected to the vessel condensing the vapor. Thermal control shutters and particular thermal radiation

Adler

1980-01-01

49

Flow Characteristics in an Augmentation Channel of a Direct Drive Turbine for Wave Power Generation  

Microsoft Academic Search

Cross flow turbine also known as Banki turbine, is a hydraulic turbine that may be classified as an impulse turbine. At present it has gained interest in small and low head establishments because of its simple structure, cost effectiveness and low maintenance. Therefore, the present paper expands on this idea and aims at implementing the Direct Drive Turbine (DDT) for

Deepak Prasad; Mohammed Asid Zullah; Young-Do Choi; Young-Ho Lee

2010-01-01

50

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

51

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

52

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

53

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

54

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

55

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

56

Torsional vibration analysis of turbine-generator-blade coupled system  

Microsoft Academic Search

Turbine-generator sets are major components of electricity generating power plants. Pretwisted turbine blades, fixed on a rotating shaft by means of mounting disks, vibrate in both tangential and axial directions. The tangential component of blade vibrations is coupled with torsional vibrations of the shaft. This problem of a coupled shaft-blade torsional vibration in turbine-generator sets requires an equivalent reduction modeling

O. Matsushita; Namura; T. K. Yoshida; R. Kaneko; A. Okabe

1989-01-01

57

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

58

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.

59

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.

60

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

61

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

62

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

63

4. INTERIOR VIEW OF GENERATING ROOM, SHOWING PENSTOCKS, TURBINES AND ...  

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

4. INTERIOR VIEW OF GENERATING ROOM, SHOWING PENSTOCKS, TURBINES AND GENERATORS, LOOKING SOUTHEAST. MOVABLE CRANE ON BEAM IS AT UPPER RIGHT REAR - Enloe Dam, Power House, On Similkameen River, Oroville, Okanogan County, WA

64

The General Electric MOD-1 wind turbine generator program  

NASA Technical Reports Server (NTRS)

The design, fabrication, installation and checkout of MOD-1, a megawatt class wind turbine generator which generates utility grade electrical power, is described. A MOD-1/MOD-1A tradeoff study is discussed.

Poor, R. H.; Hobbs, R. B.

1979-01-01

65

Overview of and trends in wind turbine generator systems  

Microsoft Academic Search

This paper gives an overview of wind turbine generator systems and describes some trends. Around 1998, many wind turbine manufacturers changed from constant speed systems to variable speed with doubly-fed induction generators. Since around 2005, they have come with a number of alternative generators systems, mainly to comply with grid requirements as grid-fault ride-through. Most alternatives have brushless generators and

Henk Polinder

2011-01-01

66

Numerical simulation of pulsation processes in hydraulic turbine based on 3D model of cavitating flow  

NASA Astrophysics Data System (ADS)

A new approach was proposed for simulation of unsteady cavitating flow in the flow passage of a hydraulic power plant. 1D hydro-acoustics equations are solved in the penstock domain. 3D equations of turbulent flow of isothermal compressible liquid-vapor mixture are solved in the turbine domain. Cavitation is described by a transfer equation for liquid phase with a source term which is responsible for evaporation and condensation. The developed method was applied for simulation of pulsations in pressure, discharge, and total energy propagating along the flow conduit of the hydraulic power plant. Simulation results are in qualitative and quantitative agreement with experiment. The influence of key physical and numerical parameters like discharge, cavitation number, penstock length, time step, and vapor density on simulation results was studied.

Panov, L. V.; Chirkov, D. V.; Cherny, S. G.; Pylev, I. M.

2014-01-01

67

Managing turbine-generator outages by computer  

SciTech Connect

This article describes software being developed to address the need for computerized planning and documentation programs that can help manage outages. Downsized power-utility companies and the growing demand for independent, competitive engineering and maintenance services have created a need for a computer-assisted planning and technical-direction program for turbine-generator outages. To meet this need, a software tool is now under development that can run on a desktop or laptop personal computer to assist utility personnel and technical directors in outage planning. Total Outage Planning Software (TOPS), which runs on Windows, takes advantage of the mass data storage available with compact-disc technology by archiving the complete outage documentation on CD. Previous outage records can then be indexed, searched, and viewed on a computer with the click of a mouse. Critical-path schedules, parts lists, parts order tracking, work instructions and procedures, custom data sheets, and progress reports can be generated by computer on-site during an outage.

Reinhart, E.R. [Reinhart and Associates, Inc., Austin, TX (United States)

1997-09-01

68

Recent experience of IFFM PAS in the design process of lowhead propeller hydraulic turbines for Small Hydro  

NASA Astrophysics Data System (ADS)

The paper contains the short description of the design process of the axial flow turbines for Small Hydro. The crucial elements of the process are: ARDES programme for 1D inverse problem (containing the statistic information of the well performed hydraulic units, applying the lifting aerofoil theory); determination of universal hill diagram and optimization of the runner blades geometry by utilization of the 3D CFD codes. As the result of design process with utilization of both design steps, the generated runner blades geometry (1D inverse problem) and some computational results of 3D CFD solver have been presented. As the conclusion some crucial remarks of the designed process have been brought forward.

Kaniecki, M.; Krzemianowski, Z.

2010-08-01

69

Representing wind turbine electrical generating systems in fundamental frequency simulations  

Microsoft Academic Search

Increasing numbers of wind turbines are being erected. In the near future, they may start to influence the dynamics of electrical power systems by interacting with conventional generation equipment and with loads. The impact of wind turbines on the dynamics of electrical power systems therefore becomes an important subject, studied by means of power system dynamics simulations. Various types of

J. G. Slootweg; H. Polinder; W. L. Kling

2003-01-01

70

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

71

Experimental comparison of cavitation erosion rates of different steels used in hydraulic turbines  

NASA Astrophysics Data System (ADS)

The prediction of cavitation erosion rates has an important role in order to evaluate the exact life of components in fluid machineries. Hydro-Québec has studied this phenomenon for several years, in particular in hydraulic turbine runners, to try to understand the different degradation mechanisms related to this phenomenon. This paper presents part of this work. In this study, we carried out experimental erosion tests to compare different steels used in actual hydraulic turbine runners (carbon steels, austenitic and martensitic stainless steels) to high strength steels in terms of cavitation erosion resistance. The results for these different classes of steels are presented. The tests have been performed in a cavitating liquid jet apparatus according to the ASTM G134-95 standard to simulate the flow conditions. The mass loss has been followed during the exposure time. The maximum depth of erosion, the mean depth of erosion, and the mean depth erosion rate are determined. As a result we found that ASTM-A514 high strength steels present excellent cavitation erosion resistance properties. The cavitation eroded surface is followed by optical profilometry technique. Determination of mechanical properties and examinations of the eroded surfaces of the samples have also been carried out in order to identify the erosion mechanisms involved in the degradation of these kinds of materials.

Tôn-Thât, L.

2010-08-01

72

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

73

46 CFR 112.50-3 - Hydraulic starting.  

Code of Federal Regulations, 2012 CFR

...SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic starting. A hydraulic starting system must meet the...

2012-10-01

74

46 CFR 112.50-3 - Hydraulic starting.  

Code of Federal Regulations, 2011 CFR

...SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic starting. A hydraulic starting system must meet the...

2011-10-01

75

46 CFR 112.50-3 - Hydraulic starting.  

Code of Federal Regulations, 2013 CFR

...SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic starting. A hydraulic starting system must meet the...

2013-10-01

76

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

77

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

78

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

79

Radar signature control of wind turbine generators  

Microsoft Academic Search

Many of the prime locations for wind farms in the UK are on exposed landscapes close to regional airports. However, planning permission for such installations is often being denied because the moving blades of the wind turbines interfere with the operation of airport radar systems. Airport surveillance radars track the position and speed of aircraft in their surrounding airspace using

A. Tennant; B. Chambers

2005-01-01

80

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

81

Voltaic turbine - A paradigm shift proposed in generating electricity  

NASA Astrophysics Data System (ADS)

Sustainable demand for electric power results in a warehouse that naturally favors development of wind turbines that are significantly quieter and more efficient for generating electricity than today's fleet. Achieving this will require a revolutionary new concept, in particular "Magneto Voltaic Power plant" that generate electricity with the help of repulsive force which cause the turbine blades to rotate. The magneto voltaic power plant triggered the original development of wind turbines raising its energy and output power. This paper outlines the main issues involved in replacing the wind source to that of the repulsive force. It's shown that implementation of repulsive force generates electric power at a feasible cost and this would clearly be the enabling technology for generating electricity of the future.

V, Meera

2013-12-01

82

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 April 2008 #12;Author: Helge Aagaard Madsen Risø-R-1637(EN) April 2008 Title: Low frequency noise from the mechanisms of generation of low frequency noise (LFN) for upwind rotors has been investigated. A 3.6 MW

83

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

84

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

85

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

86

Using the Biphase Turbine to Generate Useful Energy from Process Streams  

E-print Network

devices' (steam or hydraulic turbines for example) have been demonstrated in its application to geothermal energy conversion. Its development and application to other areas such as waste-heat recovery, desalination, solar cooling, and now, two phase...

Helgeson, N. L.; Studhalter, W. R.

1981-01-01

87

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.

88

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 in wind turbine generators for stationary and non stationary cases. Keyword: Wind turbine, induction on the installed equipment because they are hardly accessible or even inaccessible [1]. 1.1. Wind turbine failure

Boyer, Edmond

89

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

90

Electrical generation using a vertical-axis wind turbine  

SciTech Connect

Traditionally, windmills have been of the propeller or multiblade types, both of which have their rotational axis parallel to the flow of the wind. A vertical-axis wind turbine has its rotational axis perpendicular to the flow of wind and requires no orientation to keep the rotor in the windstream. The vertical-axis wind turbine operates on the same principle as an airfoil and produces lift and drag as any airfoil. A newly designed 100-kW vertical-axis wind turbine has been operated for one year at the USDA Conservation and Production Research Laboratory, Bushland, TX. The turbine has an induction generator and supplies power to a sprinkler irrigation system with excess power being sold to the electric utility. The turbine begins producing power at 5.5 m/s windspeed and reaches its rated output of 100-kW at 15 m/s. The unit has obtained a peak efficiency of 48% at a windspeed of 8 m/s or 81% of theoretical maximum. Using 17 years of windspeed data from the National Weather Service, the annual energy output is estimated at 200,000 kWh. The unit has experienced several operational problems during its initial testing. Guy cables were enlarged to provide greater stiffness to reduce blade stress levels, lightning shorted the main contactor, and the brake system required a complete redesign and modification. The turbine was operational about 60% of the time.

Clark, R.N.

1982-12-01

91

Coordinate Control of Wind Turbine and Battery in Wind Turbine Generator System  

NASA Astrophysics Data System (ADS)

Battery is installed for with wind power generator to level the output power fluctuations, since output power fluctuations of wind power generator are large. However, if large battery is installed in wind turbine generator, the capital cost for wind power system will increase. Hence, the smallest size of battery should be preferable to save the capital cost. In this paper, we propose a methodology for controlling combined system output power and storage energy capacity of battery system. The system consists of wind turbine generator and battery energy storage system. The generated power fluctuation in low and high frequency range are smoothed by pitch angle control and battery charge or discharge. This coordinated control reduces the rated battery capacity and windmill blade stress. In our proposed method, we apply H? control theory to achieve good response and robustness. The effectiveness of the proposed control system is simulated.

Senjyu, Tomonobu; Kikunaga, Yasuaki; Tokudome, Motoki; Uehara, Akie; Yona, Atsushi; Funabashi, Toshihisa

92

Pressure probe with five embedded flush-mounted sensors: unsteady pressure and velocity measurements in hydraulic turbine model  

NASA Astrophysics Data System (ADS)

The unsteady five-hole Pitot tube, with embedded flush-mounted sensors, provides one of the most advanced experimental techniques in fluid mechanics stemming from Pitot tube. This instrument enables the measurement of both unsteady pressures and instantaneous three-dimensional velocity vectors. The present paper focuses on the methodology and use of this type of probe in hydraulic turbines. Different fluctuating phenomena can be monitored, providing reliable estimates regarding amplitude and frequency. The probe is particularly advantageous for applications when the flow exhibits large angular fluctuation. In such cases, even the mean values must be validated using unsteady measurements. The calibration method and the validation of the unsteady measurements are presented through three different hydraulic turbine models.

Duquesne, Pierre; Ciocan, Gabriel Dan; Aeschlimann, Vincent; Bombenger, Antoine; Deschênes, Claire

2012-12-01

93

Pressure probe with five embedded flush-mounted sensors: unsteady pressure and velocity measurements in hydraulic turbine model  

NASA Astrophysics Data System (ADS)

The unsteady five-hole Pitot tube, with embedded flush-mounted sensors, provides one of the most advanced experimental techniques in fluid mechanics stemming from Pitot tube. This instrument enables the measurement of both unsteady pressures and instantaneous three-dimensional velocity vectors. The present paper focuses on the methodology and use of this type of probe in hydraulic turbines. Different fluctuating phenomena can be monitored, providing reliable estimates regarding amplitude and frequency. The probe is particularly advantageous for applications when the flow exhibits large angular fluctuation. In such cases, even the mean values must be validated using unsteady measurements. The calibration method and the validation of the unsteady measurements are presented through three different hydraulic turbine models.

Duquesne, Pierre; Ciocan, Gabriel Dan; Aeschlimann, Vincent; Bombenger, Antoine; Deschênes, Claire

2013-01-01

94

Modeling and Control of Micro-Turbine Based Distributed Generation System  

Microsoft Academic Search

Micro turbine generation is currently attracting lot of attention to meet users need in the distributed generation market due to the deregulation of electric power utilities, advancement in technology, environmental concerns. In this paper modeling of micro-turbine distributed generation system has been implemented and a new converter controller for a simulation of dynamic model of a micro-turbine generation system (MTG)

Ashwani Kumar; K. S. Sandhu; S. P. Jain; P. Sharath Kumar

95

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

96

11. VIEW NORTHEAST OF HYDROELECTRIC GENERATING FACILITY SHOWING TURBINE FIT ...  

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

11. VIEW NORTHEAST OF HYDROELECTRIC GENERATING FACILITY SHOWING TURBINE FIT WITH INTAKE TRASH RACK AT WATER LINE AND SWITCH GEAR ON TOP - Middle Creek Hydroelectric Dam, On Middle Creek, West of U.S. Route 15, 3 miles South of Selinsgrove, Selinsgrove, Snyder County, PA

97

Signature management of radar returns from wind turbine generators  

Microsoft Academic Search

The large radar cross section of wind turbine generator (WTG) blades combined with high tip speeds can produce significant Doppler returns when illuminated by a radar. Normally, an air traffic control radar system will filter out large returns from stationary targets, but the Doppler shifts introduced by the WTG blades are interpreted as moving aircraft that can confuse radar operators

A. Tennant; B. Chambers

2006-01-01

98

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

99

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

100

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

101

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

102

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

103

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

104

Testing Small Wind Turbine Generators: Design of a Driving Dynamometer Stephen Rehmeyer Pepe  

E-print Network

Testing Small Wind Turbine Generators: Design of a Driving Dynamometer by Stephen Rehmeyer Pepe Sc, Berkeley Spring 2007 #12;Testing Small Wind Turbine Generators: Design of a Driving Dynamometer Copyright c 2007 by Stephen Rehmeyer Pepe #12;Abstract Testing Small Wind Turbine Generators: Design of a Driving

Kammen, Daniel M.

105

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 Empirical Mode Decomposition (EEMD) as a tool for failure detection in wind turbine generators for stationary and non stationary cases. Index Terms-Wind turbine, induction generator, bearing failure, ensemble

Paris-Sud XI, Université de

106

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

107

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

108

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

109

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

110

Examination of wind turbine generator models response to disturbances  

Microsoft Academic Search

The paper discusses wind turbine generator (WTG) dynamic models intended for power system stability simulations. Presented are results of an examination performed for models of different variable-speed pitch-regulated WTGs. Subject to examination were models' dynamic response to grid-side and wind-side disturbances and models' sensitivity to parameter values. Discussed are phenomena observed in simulations and related concerns in regard to the

M. Y. Borodulin

2009-01-01

111

MICRO-TURBO CHARGER FOR A PALMTOP GAS TURBINE GENERATOR  

Microsoft Academic Search

Micro-turbo chargers were manufactured and operated to test the compressor of a palmtop gas turbine generator at low temperature (< 100 °C). Impellers are 10 mm in diameter and have 3-dimensional blades machined using a 5-axis NC milling machine. The performance of the compressor were measured at 50 % (435,000 rpm) and 60 % (530,000 rpm) of the rated rotational

Shuji Tanaka; Kousuke Isomura; Shin-ichi Togo; Kousuke Hikichi; Satoshi Goto; Masayoshi Esashi

112

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

113

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

114

Wind Turbines Condition Monitoring and Fault Diagnosis Using Generator Current Amplitude  

E-print Network

Wind Turbines Condition Monitoring and Fault Diagnosis Using Generator Current Amplitude in the research of renewable energy sources. In order to make wind turbines as competitive as the classical detection in a Doubly-Fed Induction Generator (DFIG) based wind turbine for stationary and nonstationary

Paris-Sud XI, Université de

115

Dynamic modelling of a wind turbine with doubly fed induction generator  

Microsoft Academic Search

As a result of increasing environmental concern, more and more electricity is generated from renewable sources. One way of generating electricity from renewable sources is to use wind turbines. A tendency to erect more and more wind turbines can be observed. As a result of this, in the near future wind turbines may start to influence the behaviour of electrical

J. G. Slootweg; H. Polinder; W. L. Kling

2001-01-01

116

Preliminary design and viability consideration of external, shroud-based stators in wind turbine generators  

E-print Network

Horizontal-axis wind turbine designs often included gearboxes or large direct-drive generators to compensate for the low peripheral speeds of the turbine hub. To take advantage of high blade tip speeds, an alternative ...

Shoemaker-Trejo, Nathaniel (Nathaniel Joseph)

2012-01-01

117

Self-excited induction generator for variable-speed wind turbine generation  

SciTech Connect

When an induction generator is connected to a utility bus, the voltage and frequency at the terminal of the generator are the same as the voltage and frequency of the utility. The reactive power needed by the induction generator is supplied by the utility and the real power is returned to the utility. The rotor speed varies within a very limited range, and the reactive power requirement must be transported through a long line feeder, thus creating additional transmission losses. The energy captured by a wind turbine can be increased if the rotor speed can be adjusted to follow wind speed variations. For small applications such as battery charging or water pumping, a stand alone operation can be implemented without the need to maintain the output frequency output of the generator. A self- excited induction generator is a good candidate for a stand alone operation where the wind turbine is operated at variable speed. Thus the performance of the wind turbine can be unproved. In this paper, we examine a self-excited induction generator operated in a stand alone mode. A potential application for battery charging is given. The output power of the generator will be controlled to improve the performance of the wind turbine.

Muljadi, E.; Gregory, B. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Broad, D. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Electrical Engineering] [Colorado State Univ., Fort Collins, CO (United States). Dept. of Electrical Engineering

1996-10-01

118

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

119

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

120

Comparative study on fault responses of synchronous generators and wind turbine generators using transient stability index based on  

E-print Network

Comparative study on fault responses of synchronous generators and wind turbine generators using voltage sag and the slip on fault responses with the TSI between synchronous generators and wind turbine Wales, Australian Defence Force Academy, ACT 2600, Australia a r t i c l e i n f o Article history

Pota, Himanshu Roy

121

On Impedance Spectroscopy Contribution to Failure Diagnosis in Wind Turbine Generators  

E-print Network

On Impedance Spectroscopy Contribution to Failure Diagnosis in Wind Turbine Generators Mohamed Becherif1 , El Houssin El Bouchikhi2 and Mohamed Benbouzid2 Abstract ­ Wind turbines proliferation of six 1.5-MW wind turbines connected to a 25-kV distribution system that exports power to a 120-kV grid

Boyer, Edmond

122

Development of a New Procedure for Reliability Modeling of Wind Turbine Generators  

Microsoft Academic Search

A method for determining the impact of wind generation on system reliability is developed. This method combines the effects of wind turbine forced outage rates and varying power output due to wind speed variations. Since individual wind turbines on a windfarm all have an output related to wind speed, each turbine's output cannot be assumed to be independent random variables.

Paul Giorsetto; Kent F. Utsurogi

1983-01-01

123

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

E-print Network

EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE), Curtin University of Technology, WA Abstract: Variable speed wind turbine generators provide analysis and control of variable speed wind turbine system for transient studies are discussed

124

Non-Stationary Spectral Estimation for Wind Turbine Induction Generator Faults Detection  

E-print Network

and performance and reduce wind turbine operating and maintenance costs. They are one of the huge issues that faceNon-Stationary Spectral Estimation for Wind Turbine Induction Generator Faults Detection El Houssin- rine current turbine farms implies to minimize and predict maintenance operations. In direct

Paris-Sud XI, Université de

125

Control strategy of a variable speed wind turbine with multipole permanent magnet synchronous generator  

Microsoft Academic Search

Summary: The paper presents a control strategy of a variable speed wind turbine with multipole permanent magnet syn- chronous generator (PMSG) and full scale IGBT power converter. A comprehensive dynamical model of the wind turbine and its control strategy is implemented in the power system simulation tool DIgSILENT. The con- trol strategy comprises both the wind turbine control itself and

Gabriele Michalke; Anca D. Hansen; Thomas Hartkopf

126

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

E-print Network

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... it to diesel fuel, naphtha and a high grade of wax. The plant requires a steam turbine generator set to produce electrical power for its base load operation. This paper covers the history of how the turbine, gear and generator were selected, along...

Smith, S.

127

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

128

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

129

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

130

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

131

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

E-print Network

Roter Blades Turbine NGV Exhaust Nozzle Fig. 2 Implementation of the micro gas turbine engineStresa, Italy, 26-28 April 2006 A SILICON-BASED MICRO GAS TURBINE ENGINE FOR POWER GENERATION X. C in developing a micro power generation system based on gas turbine engine and piezoelectric converter. The micro

Paris-Sud XI, Université de

132

Short-Circuit Current of Wind Turbines With Doubly Fed Induction Generator  

Microsoft Academic Search

The short-circuit current contribution of wind turbines has not received much attention so far. This paper considers the short-circuit behavior, especially the short-circuit current of wind turbines with a doubly fed induction generator. Mostly, these wind turbines have a crowbar to protect the power electronic converter that is connected to the rotor windings of the induction generator. First, the maximum

Johan Morren; Sjoerd W. H. de Haan

2007-01-01

133

Optimized Permanent Magnet Generator Topologies for Direct-Drive Wind Turbines  

Microsoft Academic Search

The thesis deals with the issue of cost reduction in direct-drive generators for wind turbines. Today, the combination gearbox-medium-speed (1000-2000 rpm) induction generator largely dominates the market of MW-scale wind turbines. This is due to the lower costs of the gearbox option compared to the costs of gearless systems. Nevertheless, there is an acute interest among researchers and wind turbine

M. R. J. Dubois

2004-01-01

134

Derivation of a complete transfer function for a wind turbine generator system by experiments  

Microsoft Academic Search

In this paper, an effort is made to derive a complete transfer function of a variable-speed wind turbine generator (WTG) system. This transfer function is important for designing a sensorless speed controller and performing its stability. The proposed WTG system includes a wind turbine, a permanent magnet synchronous generator (PMSG), and a switch mode rectifier (SMR) for implementing a maximum

A. J. Mahdi; W. H. Tang; Q. H. Wu

2011-01-01

135

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

136

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

137

Turbine  

SciTech Connect

A turbine suitable for a gas turbine engine is provided with a bearing support member which is interconnected with the turbine casing by means of an annular array of aerofoil guide vanes. The whole assembly of support member and aerofoil guide vanes is maintained in a state of tension. The degree of tension in the assembly is controlled so as to be substantially constant throughout the normal operating cycle of the turbine.

Coplin, J.F.; Hadaway, E.S.

1984-01-31

138

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

139

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

140

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

141

Practical Calculation Method of Circulating Current Loss for Large Turbine Generator Designs  

NASA Astrophysics Data System (ADS)

In this paper, the authors describe a practical calculation method of armature strand current distributions and circulating current losses for large turbine generators. A chain of analysis is made up of automatic mesh generation, a quasi three-dimensional linkage flux calculation and an armature strand network calculation. The calculated total armature coil losses for a 200MVA class turbine generator shows good agreement with detailed calculation results obtained by full three-dimensional magnetic field analysis.

Ide, Kazumasa; Takahashi, Kazuhiko; Hattori, Ken'Ichi; Motoi, Naganori; Furukawa, Katsuya; Watanaba, Takashi

142

Background and system description of the Mod 1 wind turbine generator  

Microsoft Academic Search

The Mod-1 wind turbine considered is a large utility-class machine, operating in the high wind regime, which has the potential for generation of utility grade power at costs competitive with other alternative energy sources. A Mod-1 wind turbine generator (WTG) description is presented, taking into account the two variable-pitch steel blades of the rotor, the drive train, power generation\\/control, the

E. H. Ernst

1978-01-01

143

Investigation of self-excited induction generators for wind turbine applications  

Microsoft Academic Search

To realize a reliable system, a wind turbine must be connected to the utility grid. The squirrel-cage induction generator is a common choice for wind applications. An AC\\/DC\\/AC converter is used as an interface to connect the wind turbine to the utility grid to adjust the generated voltage to the utility grid voltage. Moreover, it can allow the generator to

Mohamed Orabi; M. Z. Youssef; P. K. Jain

2004-01-01

144

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

145

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

146

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

Microsoft Academic Search

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

B. Maples; M. Hand; W. Musial

2010-01-01

147

A Model-Based Control Strategy for Wind Turbines with Asynchronous Generator  

Microsoft Academic Search

In this paper a model based control methodology is described with reference to a wind turbine for production of alternative energy. The mathematical model of a 600 kW wind turbine is taken into account assuming a well defined profile of the rotor blades. A set of reference angular speeds of the asynchronous generator and a set of reference pitch angles

F. Alonge; F. D'Ippolito; T. Cangemi; A. Magazzu; M. Maniscalchi

2007-01-01

148

Modeling of the wind turbine with a doubly fed induction generator for grid integration studies  

Microsoft Academic Search

Due to its many advantages such as the improved power quality, high energy efficiency and controllability, etc. the variable speed wind turbine using a doubly fed induction generator (DFIG) is becoming a popular concept and thus the modeling of the DFIG based wind turbine becomes an interesting research topic. Fundamental frequency models have been presented but these models are often

Yazhou Lei; Alan Mullane; Gordon Lightbody; Robert Yacamini

2006-01-01

149

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

150

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

151

Evolution of Westinghouse heavy-duty power generation and industrial combustion turbines  

SciTech Connect

This paper reviews the evolution of heavy-duty power generation and industrial combustion turbines in the United States from a Westinghouse Electric Corporation perspective. Westinghouse combustion turbine genealogy began in March of 1943 when the first wholly American designed and manufactured jet engine went on test in Philadelphia, and continues today in Orlando, Florida, with the 230 MW, 501G combustion turbine. In this paper, advances in thermodynamics, materials, cooling, and unit size will be described. Many basic design features such as two-bearing rotor, cold-end drive, can-annular internal combustors, CURVIC{sup 2} clutched turbine disks, and tangential exhaust struts have endured successfully for over 40 years. Progress in turbine technology includes the clean coal technology and advanced turbine systems initiatives of the US Department of Energy.

Scalzo, A.J.; Bannister, R.L. [Westinghouse Electric Corp., Orlando, FL (United States). Power Generation Business Unit; DeCorso, M.; Howard, G.S.

1996-04-01

152

Floating axis wind turbines for offshore power generation—a conceptual study  

NASA Astrophysics Data System (ADS)

The cost of energy produced by offshore wind turbines is considered to be higher than land based ones because of the difficulties in construction, operation and maintenance on offshore sites. To solve the problem, we propose a concept of a wind turbine that is specially designed for an offshore environment. In the proposed concept, a floater of revolutionary shape supports the load of the wind turbine axis. The floater rotates with the turbine and the turbine axis tilts to balance the turbine thrust, buoyancy and gravity. The tilt angle is passively adjustable to wind force. The angle is 30° at rated power. The simplicity of the system leads to further cost reduction of offshore power generation.

Akimoto, Hiromichi; Tanaka, Kenji; Uzawa, Kiyoshi

2011-10-01

153

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

154

Integration of steam injection and inlet air cooling for a gas turbine generation system  

Microsoft Academic Search

The temperature of exhaust gases from simple cycle gas turbine generation sets (GENSETs) is usually very high (around 500 °C), and a heat recovery steam generator (HRSG) is often used to recover the energy from the exhaust gases and generate steam. The generated steams can be either used for many useful processes (heating, drying, separation etc.) or used back in

F. J. Wang; J. S. Chiou

2004-01-01

155

Development of Micromachine Gas Turbine for Portable Power Generation  

Microsoft Academic Search

Micromachine gas turbine with centrifugal impellers of 10mm diameter fabricated by 5-axis micro-milling is under development at Tohoku University, in conjunction with Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI), Tohoku-Gakuin University, and Sankyo Seiki Mfg. Co., Ltd. The development is currently at the stage of proving the feasibility of the gas turbine cycle by component tests. Micro-combustors have been developed for

Kousuke Isomura; Shuji Tanaka; Shinichi Togo; Hideki Kanebako; Motohide Murayama; Nobuyoshi Saji; Fumihiro Sato; Masayoshi Esashi

2004-01-01

156

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

157

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.

158

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

159

Pitch Angle Control of Wind Turbine Generator Using Less Conservative Robust Control  

NASA Astrophysics Data System (ADS)

In this paper, the pitch angle control design problem of wind turbine generator is considered. Dynamic characteristics of wind turbine system vary according to the wind speed and also the generator speed. But it is required to maintain the generator speed at the optimal one in spite of such variations. For this purpose, the pitch angle control of wind turbine which includes the robust stability is used. However, the conventional standard H? control provides conservative performance, so the control performance is inferior to conventional controllers such as gain scheduling PI controls. In this paper, a result of a pitch angle control of wind turbine generator by using the less conservative robust control is shown. Obtained control performances are verified based on the dynamic simulator “Bladed” and it is confirmed that the obtained controller provides acceptable control performances by a fixed parameter controller. And the performances are almost the same as the results by the gain scheduling PI control.

Takaai, Hitoshi; Chida, Yuichi; Sakurai, Kimi; Isobe, Takashi

160

Pitch-control for wind turbine generator based on Action Dependent Heuristic Dynamic Programming  

Microsoft Academic Search

Pitch-control is a main method to maintain the output power stable when wind speed above the rated in Large and medium-sized variable pitch wind turbine generator. Because wind turbine generator is a complex nonlinear system of multi-interference and strong coupling, traditional pitch controller can not satisfactorily solve the problems of low convergence speed and large steady-state error. A new type

Lianyou An; Bilian Liao; Shaojian Song; Xiaofeng Lin

2011-01-01

161

Coordinated robust nonlinear boiler-turbine-generator control systems via approximate dynamic feedback linearization  

Microsoft Academic Search

A coordinated robust nonlinear control scheme for a boiler-turbine-generator system is usually difficult to build using nonlinear methods based on the exact static-state feedback linearization (EFL) due to the deficiency of accurate parameter information. This paper presents a novel coordinated robust nonlinear control scheme for a boiler-turbine-generator system, in which, the approximate dynamic feedback linearization is established by constructing a

T. Yu; K. W. Chan; J. P. Tong; B. Zhou; D. H. Li

2010-01-01

162

Dynamic modeling and analysis of an isolated self excited induction generator driven by a wind turbine  

Microsoft Academic Search

This paper presents modeling, simulation and transient analysis of three phase self-excited induction generator (SEIG) driven by a wind turbine. Three phase self-excited induction generator is driven by a variable-speed prime mover such as a wind turbine for the clean alternative renewable energy in rural areas. Transients of machine self-excitation under three phase balanced load conditions are simulated using a

N. S. Jayalakshmi; D. N. Gaonkar

2012-01-01

163

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

164

Comparison of direct-drive and geared generator concepts for wind turbines  

Microsoft Academic Search

The objective of this paper is to compare five different generator systems for wind turbines, namely the doubly-fed induction generator with three-stage gearbox (DFIG3G), the direct-drive synchronous generator with electrical excitation (DDSG), the direct-drive permanent-megnet generator (DDPMG), the permanent-magnet generator with single stage gearbox (PMG1G), and the doubly-fed induction generator with single-stage gearbox (DFIG1G). The comparison is based on cost

Henk Polinder; Frank F. A. van der Pijl; Gert-Jan de Vilder; Peter J. Tavner

2006-01-01

165

A Silicon-Based Micro Gas Turbine Engine for Power Generation  

E-print Network

This paper reports on our research in developing a micro power generation system based on gas turbine engine and piezoelectric converter. The micro gas turbine engine consists of a micro combustor, a turbine and a centrifugal compressor. Comprehensive simulation has been implemented to optimal the component design. We have successfully demonstrated a silicon-based micro combustor, which consists of seven layers of silicon structures. A hairpin-shaped design is applied to the fuel/air recirculation channel. The micro combustor can sustain a stable combustion with an exit temperature as high as 1600 K. We have also successfully developed a micro turbine device, which is equipped with enhanced micro air-bearings and driven by compressed air. A rotation speed of 15,000 rpm has been demonstrated during lab test. In this paper, we will introduce our research results major in the development of micro combustor and micro turbine test device.

Shan, X -C; Maeda, R; Sun, Y F; Wu, M; Hua, J S

2007-01-01

166

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

167

Parameter estimation of doubly fed induction generator driven by wind turbine  

Microsoft Academic Search

In order to reduce the environmental consequences of electric power generation, there has been a growing interest in the use of renewable resources for generating electricity. One way of generating electricity from renewable sources is to use wind turbines that convert the kinetic energy contained in the flowing air into electrical energy. As wind power is integrated in large scale

Sahar Pirooz Azad; Joseph Euzebe Tate

2011-01-01

168

Protection of Large Steam Turbine-Generator Units on TVA System  

Microsoft Academic Search

This paper describes the relay protection applied by TVA to large steam turbine-generator units, including the main power transformer and its connections. The basic philosophy underlying relay applications is given, and the interrelations between generator protective relays and those on the station equipment and connecting transmission lines are included. The relation of protection to generator types is shown, and the

M. S. Merritt; J. A. Akerman; R. C. Price; L. E. Owen

1965-01-01

169

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

170

Inverter supplied voltage control system for an isolated induction generator driven by a wind turbine  

Microsoft Academic Search

This paper deals with a technique to control the voltage generated from an isolated three-phase induction generator excited by an inverter and a single DC capacitor for use in a remote area power supply. The speed of the wind turbine that drives the induction generator could be regulated or unregulated. During the voltage build up process there is a variation

D. Seyoum; M. F. Rahman; C. Grantham

2003-01-01

171

Investigation of self-excited induction generators for wind turbine applications  

Microsoft Academic Search

The use of squirrel-cage induction machines in wind generation is widely accepted as a generator of choice. The squirrel-cage induction machine is simple, reliable, cheap, lightweight, and requires very little maintenance. Generally, the induction generator is connected to the utility at constant frequency and operates at practically constant speed (small range of slip). The wind turbine operates in optimum efficiency

Eduard Muljadi; Jesus Sallan; M. Sanz; Charles P. Butterfield

1999-01-01

172

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

173

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

174

Condition based monitoring, diagnosis and maintenance on operating equipments of a hydraulic generator unit  

NASA Astrophysics Data System (ADS)

According to performance characteristics of operating equipments in a hydraulic generator unit (HGU), the relative techniques on condition monitoring and fault diagnosis (CMFD) are introduced in this paper, especially the key technologies are emphasized, such as equipment monitoring, expert system (ES), intelligent diagnosis and condition based maintenance (CBM). Meanwhile, according to the instructor on CBM proposed by State electric power corporation, based on integrated mode, the main steps on implementation of CBM are discussed in this paper.

Liu, X. T.; Feng, F. Z.; Si, A. W.

2012-11-01

175

Development of Intelligent Wind Turbine Generator with Tandem Wind Rotors and Double Rotational Armatures  

NASA Astrophysics Data System (ADS)

This paper proposes the superior wind turbine generator, which is composed of the tandem wind rotors and the double rotational armature type generator without the conventional stator. The large-sized front wind rotor and the small-sized rear wind rotor drive respectively the inner and the outer armatures of the generator, in keeping the rotational torque counter-balanced. Such operating conditions enable to make the output higher than the conventional wind turbine and to keep the output constant in the rated operating mode without using the brake and/or the pitch control mechanisms. Such wonderful advantages in the generating mode are discussed and verified experimentally with the model turbine generator.

Kanemoto, Toshiaki; Galal, Ahmed Mohamed

176

Candidate wind turbine generator site annual data summary for January 1979 through December 1979  

SciTech Connect

Summarized hourly meteorological data for fifteen candidate and wind turbine generator sites are presented in this report. These data are collected for the Department of Energy 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, data are given in eight tables and one figure. 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.; Renne, D.S.

1981-03-01

177

Candidate wind turbine generator site annual data summary for January 1980 through December 1980  

SciTech Connect

Summarized hourly meteorological data for fourteen candidate and wind turbine generator sites are presented in this report. These data are collected for the Department of Energy 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, data are given in eight tables and one figure. 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.; Renne, D.S.

1981-04-01

178

Advanced gas turbines: The choice for low-cost, environmentally superior electric power generation  

SciTech Connect

In July 1993, the US Department of Energy (DOE) initiated an ambitious 8-year program to advance state-of-the-art gas turbine technology for land-based electric power generation. The program, known as the Advanced Turbine System (ATS) Program, is a joint government/industry program with the objective to demonstrate advanced industrial and utility gas turbine systems by the year 2000. The goals of the ATS Program are to develop gas turbine systems capable of providing low-cost electric power, while maintaining environmental superiority over competing power generation options. A progress report on the ATS Program pertaining to program status at DOE will be presented and reviewed in this paper. The technical challenges, advanced critical technology requirements, and systems designs meeting the goals of the program will be described and discussed.

Zeh, C.M.

1996-08-01

179

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

180

Development of air-cooled ceramic nozzles for a power-generating gas turbine  

Microsoft Academic Search

The development of air-cooled ceramic nozzle vanes for a power-generating gas turbine has been reported. To make up the limited temperature resistance of present ceramic materials, the utilization of a small amount of cooling air has been studied for the first-stage nozzle vanes of a 1,500 C class gas turbine. A series of cascade tests were carried out for the

T. Tsuchiya; Y. Furuse; S. Yoshino; R. Chikami; Y. Tsukuda; M. Mori

1996-01-01

181

Modeling and simulation of a soft-starter for a 2 MW wind turbine generators  

Microsoft Academic Search

In this paper a soft-starter model and its control strategy for connecting solutions to the grid of different operation modes for a wind turbine generator of 2\\/0.5 MW are evaluated. The thyristors switching for different functions of the firing angle are discussed. A complete simulation model of a constant speed wind turbine with cage rotor and double stator windings induction

Lucian Mihet-Popa; Voicu Z. Groza

2010-01-01

182

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

183

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

184

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

185

Effects of turbulence on power generation for variable-speed wind turbines  

SciTech Connect

One of the primary advantages of variable-speed wind turbines over fixed-speed turbines should be improved aerodynamic efficiency. With variable-speed generation, in order to maintain a constant ratio of wind speed to tip speed, the wind turbine changes rotor speed as the wind speed changes. In this paper we compare a stall-controlled, variable-speed wind turbine to a fixed-speed turbine. The focus of this paper is to investigate the effects of variable speed on energy capture and its ability to control peak power. We also show the impact of turbulence on energy capture in moderate winds. In this report, we use a dynamic simulator to apply different winds to a wind turbine model. This model incorporates typical inertial and aerodynamic performance characteristics. From this study we found a control strategy that makes it possible to operate a stall-controlled turbine using variable speed to optimize energy capture and to control peak power. We also found that turbulence does not have a significant impact on energy capture.

Muljadi, E.; Butterfield, C.P.; Buhl, M.L. Jr.

1996-11-01

186

Early detection and diagnosis of overheating problems in turbine generators by instrumental chemical analysis  

Microsoft Academic Search

Overheating problems within turbine generators if undetected can lead to catastrophic failures associated with long and costly outages. Instrumental chemical analysis methods used to detect and diagnose these hot spots are described. The Core Monitor, gas chromatograph and mass spectrometer have been applied to the analysis of the generator hydrogen coolant. By determining the concentration and type of organic thermal

J. K. Kelley; J. W. Auld; V. J. Herter; K. A. Hutchinson; W. A. Rugenstein

1976-01-01

187

Power-Train Analysis for the DOE/NASA 100-KW Wind Turbine Generator.  

National Technical Information Service (NTIS)

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 characteristics of a wind-driven synchronous generator be...

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

1978-01-01

188

Reduced models of doubly fed induction generator system for wind turbine simulations  

NASA Astrophysics Data System (ADS)

This article compares three reduced models with a detailed model of a doubly fed induction generator system for wind turbine applications. The comparisons are based on simulations only. The main idea is to provide reduced generator models which are appropriate to simulate normal wind turbine operation in aeroelastic wind turbine models, e.g. for control system design or structural design of the wind turbine. The electrical behaviour such as grid influence will therefore not be considered. The work presented in this article shows that with an ideal, undisturbed grid the dynamics of the doubly fed induction generator system is very well represented by the dynamics due to the generator inertia and the generator control system, whereas the electromagnetic characteristics of the generator can be represented by the steady state relations. The parameters for the proposed models are derived from parameters typically available from the generator data sheet and from the controller settings. Thus the models are simple to apply in any case where the generator data sheet is available. Copyright

Sørensen, P.; Hansen, A. D.; Lund, T.; Bindner, H.

2006-07-01

189

Output power leveling of wind turbine Generator for all operating regions by pitch angle control  

Microsoft Academic Search

Wind energy is not constant and windmill output is proportional to the cube of wind speed, which causes the generated power of wind turbine generators (WTGs) to fluctuate. In order to reduce fluctuation, different methods are available to control the pitch angle of blades of windmill. In a previous work, we proposed the pitch angle control using minimum variance control,

Tomonobu Senjyu; Ryosei Sakamoto; Naomitsu Urasaki; Toshihisa Funabashi; Hideki Fujita; Hideomi Sekine

2006-01-01

190

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

191

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

192

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

193

3D computations of flow field in a guide vane blading designed by means of 2D model for a low head hydraulic turbine  

NASA Astrophysics Data System (ADS)

The paper presents the main parameters of the flow field behind the guide vane cascade designed by means of 2D inverse problem and following check by means of 3D commercial program ANSYS/Fluent applied for a direct problem. This approach of using different models reflects the contemporary design procedure for non-standardized turbomachinery stage. Depending on the model, the set of conservation equation to be solved differs, although the physical background remains the same. The example of computations for guide vane cascade for a low head hydraulic turbine is presented.

Krzemianowski, Z.; Puzyrewski, R.

2014-08-01

194

Methods of improving the output and cavitation properties of hydraulic turbine equipment of low-head hydroelectric stations  

Microsoft Academic Search

Conclusions  \\u000a1. \\u000aThe data obtained should be used when modernizing turbines at existing low-head stations; analogous investigations of other types of turbines with higher heads should be carried out.\\u000a2. \\u000aTo create improved and more economical large high-speed turbines and to determine the conditions of applicability of vertical and horizontal bulb units, it is required to conduct comprehensive investigations for

I. S. Samorukov

1978-01-01

195

Experimental investigation of dynamic characteristics of turbine generators and low-tuned foundations  

NASA Technical Reports Server (NTRS)

Turbine generator (T-G) units with low tuned concrete foundations were investigated experimentally during both startup and normal operating conditions. The dynamic response of the turbine generators and their foundation systems were characterized by resonance curves obtained during the startup transient and by vibration mode shapes at the normal operating condition. No severe resonance at the fundamental frequencies of the system was observed. The deflection or displacement of the foundation pedestal does not lead to unacceptable T-G vibration. The experimental results are compared and discussed with some previous theoretical studies.

Ying, S. P.; Forman, M. E.; Drumm, R. R.

1979-01-01

196

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

197

Turbine-generator transient monitoring; Torsional stress analysis and stability model identification  

SciTech Connect

A hardware and software system has been developed under EPRI sponsorship to monitor turbine-generator transient events, perform shaft torsional stress analysis for each event, and derive the best fit stability model parameters for each event. As the acquisition hardware is built around commercial digital transient recorder equipment, standard fault recorder type analysis of event data is also possible. The off-line analysis workstation is an 80386 personal computer running 32 bit FORTRAN under the XENIX operating system. The EPRI project is currently underway with two turbine-generators being monitored and events analyzed. Typical analysis results are presented in this paper along with implementation details.

Wegner, C.A.; Bowler, C.E.J.; Rubino, J.C.P. (Laboratoires d'Electronique et de Physique Appliquee (LEP), 75 - Paris (France)); Edmonds, J.S. (Electric Power Research Inst., Palo Alto, CA (United States))

1991-01-01

198

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

199

Direct grid connection of a slip-permanent magnet wind turbine generator  

Microsoft Academic Search

The slip-permanent magnet generator offers po- tential for direct-driven, direct-to-grid sub-100 kW wind tur- bine generators. This reduces complexity and cost, as well as maintenance requirements. A major challenge, however, is to synchronise the generator to the grid without the benefit of turbine torque control. This paper presents the simulation and testing of a synchronisation controller designed to achieve this

U. Hoffmann; P. Bouwer; M. J. Kamper

2011-01-01

200

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

201

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

202

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

203

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

204

Reduced order dynamic model for variable-speed wind turbine with synchronous generator and full power conversion topology  

Microsoft Academic Search

Wind turbine manufacturers are adapting their equipment to comply with increasingly strict transmission integration requirements. One class of the new turbines being developed is the synchronous machine (either wound field or permanent magnet excited) with full AC\\/DC\\/AC power electronic conversion. The topology of the new machines differs considerably from that of more conventional forms of power generation with synchronous generator

M. R. Behnke; E. Muljadi

2005-01-01

205

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

206

Reactive power optimization control of wind farms with fixed-speed wind turbine generators  

Microsoft Academic Search

As the level of wind power penetration into the grid increases, reactive power control will become more critical for wind farms with fixed-speed wind turbine generators. Capacitor banks are used for reactive power compensation in wind power plant (WPP). This paper focuses on our effort to develop a method to determine the number, sizes and control strategy of capacitor banks.

Xunwen Su; Zengqiang Mi; Xingjie Liu; Tao Wu

2008-01-01

207

Cycle Analysis on Ocean Geothermal Power Generation using Multi-staged Turbine  

E-print Network

Condenser 4 1 2 3 Geothermal water Deep seawater 2 34 1 S T Qe Qc WT WP Cycle simulation Basic thermodynamicCycle Analysis on Ocean Geothermal Power Generation using Multi-staged Turbine 2013. 09. 11 Korea Renewable energy.. Geothermal heat, Ocean energy, etc.. Geothermal heat.. one of the humankind's oldest

208

A sensorless control method for maximum power point tracking of wind turbine generators  

Microsoft Academic Search

Wind energy has been regarded as an environmentally friendly, logistically feasible and economically responsible alternative energy resource. In order to produce as much power as possible in variable speed wind turbine generators, the maximum power point tracking (MPPT) becomes a hotspot of research in this field. In this paper, a simple control method for maximum power point tracking (MPPT) in

Zhenyu Ma

2011-01-01

209

Waves Transmission and Generation in Turbine Stages in a Combustion-Noise Framework  

E-print Network

and jet noise are reduced with such technologies as chevrons, micro-jets or highly-swept and leanedWaves Transmission and Generation in Turbine Stages in a Combustion-Noise Framework M. Leyko SNECMA A non-negligible part of the noise emitted from aero-engines is due to combustion. The relative

Nicoud, Franck

210

The Effect of SFCL on Electric Power Grid With Wind-Turbine Generation System  

Microsoft Academic Search

This paper describes the study to analyse the effect of the superconducting fault current limiter (SFCL) on an electric power grid with the wind-turbine generation, which is a representative renewable energy source. Its connection to a power system might more easily increase the short-circuit current during a fault toward its maximum utilization level, which is closer to the rating of

Woo-Jae Park; Byung Chul Sung; Jung-Wook Park

2010-01-01

211

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.

212

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.

213

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

214

Control design for a wind turbine-generator using output feedback  

NASA Technical Reports Server (NTRS)

The modeling and approach to control design for a large horizontal axis wind turbine (WT) generator are presented. The control design is based on a suboptimal output regulator which allows coordinated control of WT blade pitch angle and field voltage for the purposes of regulating electrical power and terminal voltage. Results of detailed non-linear simulation tests of this controller are shown.

Javid, S. H.; Murdoch, A.; Winkelman, J. R.

1981-01-01

215

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

Microsoft Academic Search

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.

L. J. Gilbert

1977-01-01

216

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

217

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

Microsoft Academic Search

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

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

1989-01-01

218

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

219

Control Design and Performance Analysis of a 6 MW Wind Turbine-Generator  

Microsoft Academic Search

This paper discusses an approach to the modeling and performance for the preliminary design phase of a large (6.2 MW) horizontal axis wind turbine generator (WTG). Two control philosophies are presented, both of which are based on linearized models of the WT mechanical and electrical systems. The control designs are compared by showing the performance through detailed non-linear time simulation.

A. Murdoch; J. R. Winkelman; S. H. Javid; R. S. Barton

1983-01-01

220

A compact, high efficiency contra-rotating generator suitable for wind turbines in the urban environment  

Microsoft Academic Search

This paper is concerned with the design, development and performance testing of a permanent magnet (PM) generator for wind turbine applications in urban areas. The radially interacting armature windings and magnet array are carried on direct drive, contra-rotating rotors, resulting in a high torque density and efficiency. This topology also provides improved physical and mechanical characteristics such as compactness, low

J. D. Booker; P. H. Mellor; R. Wrobel; D. Drury

2010-01-01

221

Simulation of a doubly-fed induction machine for wind turbine generator fault analysis  

Microsoft Academic Search

For modern large wind farms, it is more and more interesting to design an efficient diagnostics system oriented to wind turbine generators based on doubly-fed induction machine (DFIM). In this paper, a complete system will be analyzed by suitable simulations to deeply study fault influence and to identify the best diagnostic procedure to perform predictive maintenance. All the research efforts

A. Yazidi; H. Henao; G. A. Capolino; D. Casadei; F. Filippetti; C. Rossi

2005-01-01

222

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

223

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

224

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

225

Modeling and Control of a Gas Micro Turbine Generator by Using a Causal Ordering Graph  

Microsoft Academic Search

A dynamic model of a micro gas turbine generator by using a causal ordering graph is proposed in this paper. This particular graphical representation is used to highlight the causal order of all mathematical equations. It is shown that the obtained model is interesting for developing a Matlab Simulink model and for designing the control strategy. In order to control

P. Li; P. Degobert; B. Francois; B. Robyns

2006-01-01

226

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

227

Synchronization of the ERDA-NASA 100 kW 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 for the first time. 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. Experiments have been recently performed on the ERDA-NASA 100 kW wind turbine. Experimental results matched computer study results very closely and confirmed that the synchronization can be accomplished by means of the existing speed control system and an automatic synchronizer.

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

1977-01-01

228

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

229

A Novel 500kW High-Speed Turbine PM Synchronous Generator Set for Distributed Power Generation  

NASA Astrophysics Data System (ADS)

The paper presents a power generation system based on the cogeneration of heat and electricity with a novel high speed turbogenerator. The machine consists of a single stage steam turbine and a directly coupled permanent magnet synchronous generator in one constructional unit. A PWM IGBT rectifier is the load to the generator and a PWM IGBT three-phase four-wire inverter feeds the power into the low voltage mains. In order to increase the turbine efficiency at light load, variable speed operation of the turbogenerator is realized. Different control schemes for mains parallel operation and stand alone operation are presented. The control schemes allow for the use of a lookup table based control with a speed-power-characteristic or for the use of a maximum power point tracker. Measurement results from the successfully tested turbogenerator set are presented.

Wendt, Sven; Benecke, Frank; Güldner, Henry

230

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

231

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

232

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

233

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

234

Steady-state analysis of an isolated self-excited induction generator driven by regulated and unregulated turbine  

Microsoft Academic Search

This paper examines the steady-state analysis and performance of an isolated three-phase self-excited induction generator (SEIG) driven by regulated and unregulated turbines. For the case of a regulated turbine, the equivalent circuit is solved with speed as a constant parameter, while for the unregulated turbine, the speed is considered as a variable which depends on the shaft torque according to

S. M. Alghuwainem

1999-01-01

235

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

236

Background and system description of the Mod 1 wind turbine generator  

NASA Technical Reports Server (NTRS)

The Mod-1 wind turbine considered is a large utility-class machine, operating in the high wind regime, which has the potential for generation of utility grade power at costs competitive with other alternative energy sources. A Mod-1 wind turbine generator (WTG) description is presented, taking into account the two variable-pitch steel blades of the rotor, the drive train, power generation/control, the Nacelle structure, and the yaw drive. The major surface elements of the WTG are the ground enclosure, the back-up battery system, the step-up transformer, elements of the data system, cabling, area lighting, and tower foundation. The final system weight (rotor, Nacelle, and tower) is expected to be about 650,000 pounds. The WTG will be capable of delivering 1800 kW to the utility grid in a wind-speed above 25 mph.

Ernst, E. H.

1978-01-01

237

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

238

A transient thermal hydraulic simulation of a steam generator feedwater header  

SciTech Connect

The transient thermal hydraulic behavior of a steam generator feedwater header is studied numerically using a commercial computational fluid dynamics package. The purpose of the simulation is to verify assumptions and methodologies used during the engineering design process. The domain is discretized using a structured, body-fitted computational mesh on which the time-accurate, fully three-dimensional Reynolds-averaged Navier-Stokes equations are solved. Calculations of the feedwater header flow for simulation times in excess of 200 seconds are performed. Results in the form of plots and graphs of flow field velocity and temperature distribution in space and time are presented. The effect of the feedwater header on upstream components, as well as, the effect of the initial temperature field on the transient solution are studied. The results from these simulations have proven the conservative assumptions used during the engineering design process to be acceptable.

Wyman, N.J. [Advanced Scientific Computing Ltd., Waterloo, Ontario (Canada); Klarner, R. [Babcock and Wilcox International, Cambridge, Ontario (Canada)

1996-09-01

239

Method for changing removable bearing for a wind turbine generator  

Microsoft Academic Search

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.

Bharat Sampathkumaran Bagepalli; Gadre Patrick Lee; Aniruddha Dattatraya

2008-01-01

240

A Stand-Alone Hybrid Generation System Combining Solar Photovoltaic and Wind Turbine with Simple Maximum Power Point Tracking Control  

Microsoft Academic Search

This paper proposes a hybrid energy system combing solar photovoltaic and wind turbine as a small-scale alternative source of electrical energy where conventional generation is not practical. A simple and cost effective control technique has been proposed for maximum power point tracking from the photovoltaic array and wind turbine under varying climatic conditions without measuring the irradiance of the photovoltaic

Nabil A. Ahmed; Masafumi Miyatake

2006-01-01

241

Hybrid Solar Photovoltaic\\/Wind Turbine Energy Generation System with Voltage-based Maximum Power Point Tracking  

Microsoft Academic Search

This article proposes a hybrid energy system combining solar photovoltaic and wind turbine as a small-scale alternative source of electrical energy where conventional generation is not practical. A simple and cost-effective control technique has been proposed for maximum power point tracking from the photovoltaic array and wind turbine under varying climatic conditions without measuring the irradiance of the photovoltaic or

Nabil A. Ahmed; Masafumi Miyatake; A. K. Al-Othman

2008-01-01

242

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.

243

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

244

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

245

Design of a 3 kW wind turbine generator with thin airfoil blades  

SciTech Connect

Three blades of a 3 kW prototype wind turbine generator were designed with thin airfoil and a tip speed ratio of 3. The wind turbine has been controlled via two control methods: the variable pitch angle and by regulation of the field current of the generator and examined under real wind conditions. The characteristics of the thin airfoil, called ''Seven arcs thin airfoil'' named so because the airfoil is composed of seven circular arcs, are analyzed with the airfoil design and analysis program XFOIL. The thin airfoil blade is designed and calculated by blade element and momentum theory. The performance characteristics of the machine such as rotational speed, generator output as well as stability for wind speed changes are described. In the case of average wind speeds of 10 m/s and a maximum of 19 m/s, the automatically controlled wind turbine ran safely through rough wind conditions and showed an average generator output of 1105 W and a power coefficient 0.14. (author)

Ameku, Kazumasa; Nagai, Baku M.; Roy, Jitendro Nath [Faculty of Mechanical Engineering, University of the Ryukyus, 1 Senbaru, Nishihara-cho, Okinawa 903-0213 (Japan)

2008-09-15

246

Analyzing the requirements for mass production of small wind turbine generators  

NASA Astrophysics Data System (ADS)

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 compiled for each component and subsystem. These data enabled analysts to develop cost breakdown profiles crucial in manufacturing decision-making. The appraisal also led to various design recommendations including replacement of aluminum towers with cost effective carbon steel towers. Extensive cost information is supplied in tables covering subassemblies, capital requirements, and levelized energy costs. The physical layout of the plant is depicted to guide manufacturers in taking advantage of the growing business opportunity now offered in conjunction with the national need for energy development.

Anuskiewicz, T.; Asmussen, J.; Frankenfield, O.

247

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

248

Next Generation Thermal Barrier Coatings for the Gas Turbine Industry  

NASA Astrophysics Data System (ADS)

The aim of this study is to develop the next generation of production ready air plasma sprayed thermal barrier coating with a low conductivity and long lifetime. A number of coating architectures were produced using commercially available plasma spray guns. Modifications were made to powder chemistry, including high purity powders, dysprosia stabilized zirconia powders, and powders containing porosity formers. Agglomerated & sintered and homogenized oven spheroidized powder morphologies were used to attain beneficial microstructures. Dual layer coatings were produced using the two powders. Laser flash technique was used to evaluate the thermal conductivity of the coating systems from room temperature to 1200 °C. Tests were performed on as-sprayed samples and samples were heat treated for 100 h at 1150 °C. Thermal conductivity results were correlated to the coating microstructure using image analysis of porosity and cracks. The results show the influence of beneficial porosity on reducing the thermal conductivity of the produced coatings.

Curry, Nicholas; Markocsan, Nicolaie; Li, Xin-Hai; Tricoire, Aurélien; Dorfman, Mitch

2011-01-01

249

Design and analysis of boiler-turbine-generator controls using optimal linear regulator theory  

Microsoft Academic Search

The demand for improved dynamic response of fossil-fired power plants has motivated a comprehensive program of control system design and analysis. Previous papers have reported the development of a nonlinear mathematical model of a drum-type, twin furnace, reheat boiler-turbine-generator (RBTG) system which is suitable for control system analysis and has been extensively verified by field test. On the basis of

J. McDonald; HARRY G. KWATNY

1973-01-01

250

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

251

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

252

Contributions to the Steady State Analysis of Wind-Turbine Driver Self-Excited Induction Generators  

Microsoft Academic Search

The paper makes the following three contributions: First, it presents a digital computer method of predicting the steady state performance of a self-excited induction generator for given spped, capacitance and load conditions along with results of validation studies on a laboratory machine. Secondly, a procedure is presented to check whether the operating point of a given uncontrolled wind-turbine driven self-excited

S. S. Yegna Narayanan; V. J. Johnny

1986-01-01

253

Dynamic response of a 330-kW horizontal axis wind turbine generator  

SciTech Connect

This report provides the results of a combined experimental and theoretical study of the dynamic response of a Howden 330/26 wind turbine generator. The work was undertaken to extend the current knowledge on the dynamic response of wind turbines, and to better understand 3-dimensional air-flow patterns. Tests involved performance and dynamic strain measurements on one of the three rotor blades and on the structural members of the wind turbine and its tower. Also, detailed measurements of the ambient wind inflow to the turbine were made using a vertical plane array of anemometers. The results of the tests were then compared with model predictions. In general, structural loads computed using the model were lower than their measured counterparts. Blade and mean flapwise loads, measured using time averaging, agreed reasonably with those derived from machine start/stop sequences. Tower steady bending loads, also measured from start/stop sequences, agreed fairly well with each other and with theoretical predictions using the dynamic response model. Power and wind speed are also much as predicted theoretically. Flow visualization was also conducted, where photographs were taken of the operating blade and correlated with real-time data records. Binned separation data produced convincing correlations. The measured separation point data were processed to yield lift coefficient values, which were compared with similarly processed separation data obtained from wind tunnel tufting studies. Stall appeared to be delayed on the blade, probably due to radial flow. 11 refs., 65 figs., 18 tabs.

Wehrey, M.; Redmond, I.; Anderson, C.; Jamieson, P.

1988-02-01

254

Dynamic response of a 330-kW horizontal axis wind turbine generator  

NASA Astrophysics Data System (ADS)

The results of a combined experimental and theoretical study of the dynamic response of a Howden 330/26 wind turbine generator are given. The work was undertaken to extend the current knowledge on the dynamic response of wind turbines, and to better understand 3-D air-flow patterns. Tests involved performance and dynamic strain measurements on one of the three rotor blades and on the structural members of the wind turbine and its tower. Also, detailed measurements of the ambient wind inflow to the turbine were made using a vertical plane array of anemometers. The results of the tests were then compared with model predictions. In general, structural loads computed using the model were lower than their measured counterparts. Blade and mean flapwise loads, measured using time averaging, agreed reasonably with those derived from machine start/stop sequences. Tower steady bending loads, also measured from start/stop sequences, agreed fairly well with each other and with theoretical predictions using the dynamic response model. Power and wind speed are also much as predicted. Flow visualization was also conducted, where photos were taken of the operating blade and correlated with real-time data records. Binned separation data produced convincing correlations. The measured separation point data were processed to yield lift coefficient values, which were compared with similarly processed separation data obtained from wind tunnel tufting studies. Stall appeared to be delayed on the blade, probably due to radial flow.

Wehrey, M.; Redmond, I.; Anderson, C.; Jamieson, P.

1988-02-01

255

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

256

THYC, a 3D thermal-hydraulic code for steam generators, heat-exchangers and condensers  

SciTech Connect

Electricite de France has developed, since 1986, a thermal hydraulic code, named THYC, designed to study three-dimensional single and two-phase flows in components involving rod or tube bundles: pressurized water reactor cores, steam generators, condensers, heat exchangers. The THYC model, based upon a porous media approach, is obtained by space-time averaging of the instantaneous equations (mass, momentum and energy) of each fluid phase over control volumes including fluid and solids. The THYC-EXCHANGERS release solves three to five conservation equations of the fluid outside the tubes, plus the energy equation of the fluid inside the tubes. That makes the code able to model all types of heat exchangers, from single phase heat exchangers, to components involving boiling or condensation. First of all, the paper will describe the physical model and the numerical method used in THYC-EXCHANGERS. Secondly, calculation results will be compared with measurements obtained on a single-phase heat exchanger mock-up, on the CLOTAIRE steam generator mock-up and on an industrial condenser.

David, F. [Electricite de France, Chatou (France). Research and Development Div.

1996-08-01

257

Modeling of the dynamic response of a Francis turbine  

NASA Astrophysics Data System (ADS)

The paper presents a detailed numerical model of the dynamic behaviour of a Francis turbine installed in a hydroelectric plant. The model considers in detail the Francis turbine with all the electromechanical subsystems, such as the main speed governor, the controller and the servo actuator of the turbine distributor, and the electrical generator. In particular, it reproduces the effects of pipeline elasticity in the penstock, the water inertia and the water compressibility on the turbine behaviour. The dynamics of the surge tank on low frequency pressure waves is also modelled together with the main governor speed loop and the position controllers of the distributor actuator and of the hydraulic electrovalve. Model validation has been made by means of experimental data of a 75 MW—470 m hydraulic head—Francis turbine acquired during some starting tests after a partial revamping, which also involved the control system of the distributor.

Pennacchi, Paolo; Chatterton, Steven; Vania, Andrea

2012-05-01

258

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

259

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

260

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

261

The calculation of fluid-structure interaction and fatigue analysis for Francis turbine runner  

NASA Astrophysics Data System (ADS)

Francis turbine, as a widely used hydro turbine, is especially suited for the hydropower station with high hydraulic head and higher hydraulic head. For such turbine generator units all around the world, the crack streaks usually come out after a long time use and the resulted accidents may cause huge losses. Hence, it is meaningful to refine the design assuring the stability and safety of the Francis turbine. In this paper, the stiffness and strength as well as the fatigue life of the Francis turbine are studied. Concerning on the turbine of one certain hydropower station, the flow field inside the turbine are first simulated and the pressure distribution around the blades are derived. Meanwhile, the stress distributions of the blades are also obtained. Based on these, the fatigue analyses are applied on the turbine. According to the results of fatigue analyses, some optimal designs on the turbine are verified. The results show that with the optimal designs, the hydraulic performances of the turbine do not change too much while the maximum stress on the turbine decrease and the fatigue life increase as well.

Wang, X. F.; Li, H. L.; Zhu, F. W.

2012-11-01

262

Design of a control scheme for a maximum power extraction in low power wind turbine-generator system  

Microsoft Academic Search

This document presents the modeling of a wind turbine-generator system and developing a control scheme for maximum power extraction. The system comprises a low-power variable speed wind rotor coupled to a squirrel cage induction generator through gearbox. The generator delivers electrical energy to a DC load through a PWM three phase rectifier which control variables are duty cycle and the

Elkin Edilberto Henao Bravo

2010-01-01

263

DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR  

SciTech Connect

The objective of this report period was to continue the development of the Gas Generator design, completion of the hardware and ancillary hardware fabrication and commence the Test Preparations for the testing of the non-polluting unique power turbine driven Gas Generator. Focus during this report period has been on completing the Gas Generator fabrication of hardware and ancillary hardware, and completion of unit closeout brazing and bonding. Because of unacceptable delays encountered in a previously competitively selected test site, CES initiated a re-competition of our testing program and selected an alternate test site. Following that selection, CES used all available resources to make preparations for testing the 10 Mw Gas Generator at the new testing site facilities of NTS at Saugus, CA.

E.W. (Gene) Baxter

2002-06-30

264

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

265

Investigation of self-excited induction generators for wind turbine applications  

SciTech Connect

The use of squirrel-cage induction machines in wind generation is widely accepted as a generator of choice. The squirrel-cage induction machine is simple, reliable, cheap, lightweight, and requires very little maintenance. Generally, the induction generator is connected to the utility at constant frequency. With a constant frequency operation, the induction generator operates at practically constant speed (small range of slip). The wind turbine operates in optimum efficiency only within a small range of wind speed variation. The variable-speed operation allows an increase in energy captured and reduces both the torque peaks in the drive train and the power fluctuations sent to the utility. In variable-speed operation, an induction generator needs an interface to convert the variable frequency output of the generator to the fixed frequency at the utility. This interface can be simplified by using a self-excited generator because a simple diode bridge is required to perform the ac/dc conversion. The subsequent dc/ac conversion can be performed using different techniques. The use of a thyristor bridge is readily available for large power conversion and has a lower cost and higher reliability. The firing angle of the inverter bridge can be controlled to track the optimum power curve of the wind turbine. With only diodes and thyristors used in power conversion, the system can be scaled up to a very high voltage and high power applications. This paper analyzes the operation of such a system applied to a 1/3-hp self-excited induction generator. It includes the simulations and tests performed for the different excitation configurations.

Muljadi, E.; Butterfield, C.P.; Sallan, J.; Sanz, M.

2000-02-28

266

Development of air-cooled ceramic nozzles for a power-generating gas turbine  

SciTech Connect

The development of air-cooled ceramic nozzle vanes for a power-generating gas turbine has been reported. To make up the limited temperature resistance of present ceramic materials, the utilization of a small amount of cooling air has been studied for the first-stage nozzle vanes of a 1,500 C class gas turbine. A series of cascade tests were carried out for the designed air-cooled Si{sub 3}N{sub 4} nozzle vanes under 6 atm and 1,500 C conditions. It was confirmed that the maximum ceramic temperature can be maintained below 1,300 C by a small amount of cooling air. In spite of the increased thermal stresses from local cooling, all Si{sub 3}N{sub 4} nozzle vanes survived the cascade tests, including both steady-state and transients of emergency shutdown. The potential for an air-cooled ceramic nozzle was demonstrated for a 1,500 C class gas turbine application.

Tsuchiya, T.; Furuse, Y.; Yoshino, S. [Tokyo Electric Power Co., Yokohama, Kanagawa (Japan). Engineering R and D Center; Chikami, R.; Tsukuda, Y.; Mori, M. [Mitsubishi Heavy Industries, Ltd., Takasago, Hyogo (Japan)

1996-10-01

267

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

268

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

269

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

270

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

271

Analytical investigation of thermal barrier coatings for advanced power generation combustion turbines  

NASA Technical Reports Server (NTRS)

An analytical evaluation was conducted to determine quantitatively the improvement potential in cycle efficiency and cost of electricity made possible by the introduction of thermal barrier coatings to power generation combustion turbine systems. The thermal barrier system, a metallic bond coat and yttria stabilized zirconia outer layer applied by plasma spray techniques, acts as a heat insulator to provide substantial metal temperature reductions below that of the exposed thermal barrier surface. The study results show the thermal barrier to be a potentially attractive means for improving performance and reducing cost of electricity for the simple, recuperated, and combined cycles evaluated.

Amos, D. J.

1977-01-01

272

Output Power Leveling of Wind Turbine Generator by Pitch Angle Control Using H? Control  

NASA Astrophysics Data System (ADS)

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 fluctuating power of wind turbine generator (WTG). In order to reduce the fluctuating power of WTG, this paper presents a output power leveling technique of WTG by pitch angle control using H? control. H? control is required to consider the measurement deviation and modeling error. The simulation results with using actual detailed model for WTG show the effectiveness of the proposed method.

Sakamoto, Ryosei; Senjyu, Tomonobu; Kaneko, Toshiaki; Urasaki, Naomitsu; Takagi, Teruo; Sugimoto, Shigeyuki

273

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

274

Candidate wind turbine generator site, Culebra, Puerto Rico. Annual data summary, October 1978-September 1979  

SciTech Connect

This report summarizes wind speed and direction data collected on meteorological towers at 14 candidate and wind turbine generator installation sites from October 1978 through September 1979. The basic method of data collection is by digital data cassette recording systems. For the digital data reported, an instantaneous sample is recorded every 2 minutes. An explanation is provided for each data summary table as well as information on how specific values were computed. The rest of the report presents the annual summarized data for each site.

Not Available

1980-07-01

275

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

276

Computer-assisted planning and technical direction of turbine generator outages  

SciTech Connect

The changing management and personnel environments in power utility companies, as well as the need for greater cost savings and ways to shorten maintenance outage time, have created a need for computer-assisted planning and documentation programs. To meet this need, a software tool is under development--Total Outage Planning Software (TOPS)--that will assist the planning and technical direction of turbine generator outages. This powerful, yet user-friendly software runs in Windows on a desktop or laptop personal computer. TOPS takes advantage of the mass data storage available with compact disc (CD) technology by archiving the complete outage documentation on CD. Previous outage records can then be indexed, searched, and viewed on a computer with the click of a mouse. Critical-path schedules, parts lists, parts order tracking, work instructions and procedures, custom data sheets, and progress reports can be generated by computer on site during an outage. After the initial documented outage, customized data sheet templates, drawing indexes, work scopes, contractor and vendor listings, schedules, man-hour cost estimations, previous repair documentation, and previous inspection documentation will be available for use during future outages. TOPS will increase future turbine generator outage quality and efficiency for the same unit or sister units of the same make and similar size. TOPS will also provide utilities with more independent control over outages. Furthermore, reliance on sometimes biased and often high-priced OEM maintenance services will be dramatically reduced.

Dove, B.W.; Reinhart, E.R. [Reinhart and Associates, Inc., Austin, TX (United States)

1996-12-31

277

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

278

Investigation of Control Strategies for Variable-Speed Pump-Turbine Units by Using a Simplified Model of the Converters  

Microsoft Academic Search

This paper presents the modeling, simulation, and analysis of the dynamic behavior of a fictitious 2 × 320 MW variable-speed pump-turbine power plant, including a hydraulic system, electrical equipment, rotating inertias, and control systems. The modeling of the hydraulic and electrical components of the power plant is presented. The dynamic performances of a control strategy in generating mode and one

Yves Pannatier; Basile Kawkabani; Christophe Nicolet; Jean-Jacques Simond; Alexander Schwery; Philippe Allenbach

2010-01-01

279

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

280

Output Power Leveling of Wind Turbine Generator by EDLC Energy Storage System  

NASA Astrophysics Data System (ADS)

The increased renewable energy utilization, especially photovoltaic panels using solar energy or wind turbine generators (WTGs) using wind energy, has been expected in recent years from view point of CO2 gas emission reduction and environmental conservation. However, the generated power is always fluctuating because the WTGs are driven by fluctuating wind. Therefore, an energy storage system should be installed to compensate these fluctuating elements. The energy capacitor system (ECS) which combined the electric double-layer capacitor (EDLC) and the electronic circuits are now under development. In this paper, control system configuration for active and reactive output power simultaneous control and the bi-directional inverter using current source EDLC are proposed. Moreover, we discusse control methods required in generating-power leveling for WTGs, and show the effectiveness of the proposed system through simulations.

Kinjyo, Tatsuto; Senjyu, Tomonobu; Uezato, Katsumi; Fujita, Hideki

281

Turbine design  

NASA Astrophysics Data System (ADS)

Turbines for most space propulsion applications, such as the hydrogen and oxygen pump turbines for the Vulcain engine, are characterized by a high pressure ratio, a highly energetic working fluid, and a small size. Data on Vulcain turbines are given. The following topics are reviewed: turbine concept design and design tools; blade design; losses occurring in a blade which are due to friction, secondary flow, tip clearance and shock formation; and turbine testing. The purpose of any turbine is to provide power for other parts of an engineering system (compressors, electrical generators, pumps) or to drive mechanical components such as wheels or propellers to give propulsion to a vehicle. It should therefore always be the performance and cost effectiveness of this larger system and not of the isolated turbine that are the main objectives for the turbine design engineer.

Andersson, Per

282

Self-excited induction generator for variable-speed wind turbine generation  

Microsoft Academic Search

When an induction generator is connected to a utility bus, the voltage and frequency at the terminal of the generator are the same as the voltage and frequency of the utility. The reactive power needed by the induction generator is supplied by the utility and the real power is returned to the utility. The rotor speed varies within a very

E. Muljadi; B. Gregory; D. Broad

1996-01-01

283

Tree shoot bending generates hydraulic pressure pulses: a new long-distance signal?  

PubMed

When tree stems are mechanically stimulated, a rapid long-distance signal is induced that slows down primary growth. An investigation was carried out to determine whether the signal might be borne by a mechanically induced pressure pulse in the xylem. Coupling xylem flow meters and pressure sensors with a mechanical testing device, the hydraulic effects of mechanical deformation of tree stem and branches were measured. Organs of several tree species were studied, including gymnosperms and angiosperms with different wood densities and anatomies. Bending had a negligible effect on xylem conductivity, even when deformations were sustained or were larger than would be encountered in nature. It was found that bending caused transient variation in the hydraulic pressure within the xylem of branch segments. This local transient increase in pressure in the xylem was rapidly propagated along the vascular system in planta to the upper and lower regions of the stem. It was shown that this hydraulic pulse originates from the apoplast. Water that was mobilized in the hydraulic pulses came from the saturated porous material of the conduits and their walls, suggesting that the poroelastic behaviour of xylem might be a key factor. Although likely to be a generic mechanical response, quantitative differences in the hydraulic pulse were found in different species, possibly related to differences in xylem anatomy. Importantly the hydraulic pulse was proportional to the strained volume, similar to known thigmomorphogenetic responses. It is hypothesized that the hydraulic pulse may be the signal that rapidly transmits mechanobiological information to leaves, roots, and apices. PMID:24558073

Lopez, Rosana; Badel, Eric; Peraudeau, Sebastien; Leblanc-Fournier, Nathalie; Beaujard, François; Julien, Jean-Louis; Cochard, Hervé; Moulia, Bruno

2014-05-01

284

Dynamic analysis of a grid-connected induction generator driven by a wave-energy turbine through hunting networks  

SciTech Connect

The presence of forced oscillations occurring in a Wells Turbine driven grid-connected induction generator enables one to seek a solution by considering the analogy between the dynamics of the Wells turbine driven systems with those associated with diesel-engine driven generators or electric motors driving reciprocating compressors, where also such forced oscillations occur, although there they occur in synchronism with shaft-position or speed. This difference is taken into account and the hunting network theory, which has hitherto been applied to the dynamic analysis of motors driving reciprocating compressors, is here applied to analyze the dynamics of a Wells Turbine driven grid-connected induction generator. The method enables the generator current, power and slip to be predicted from a knowledge of the shaft-torque harmonics. The result is compared with that obtained through d-q analysis.

Narayanan, S.S.Y.; Murthy, B.K.; Rao, G.S. [Indian Inst. of Tech., Madras (India). Dept. of Electrical Engineering

1995-12-31

285

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

286

A new control strategy of variable speed wind turbine generator for three-phase grid-connected applications  

Microsoft Academic Search

This paper discusses a new control scheme of a three-phase grid-connected wind energy conversion system (WECS). The control incorporates a maximum power point tracker (MPPT) for optimal use of the wind resource. In addition, reactive power compensation of the electric grid is included, operating simultaneously and independently of the active power generation. The wind turbine generator (WTG) consists of a

M. G. Molina; P. E. Mercado

2008-01-01

287

Comparison of the response of doubly fed and fixed-speed induction generator wind turbines to changes in network frequency  

Microsoft Academic Search

Synchronous and fixed-speed induction generators release the kinetic energy of their rotating mass when the power system frequency is reduced. In the case of doubly fed induction generator (DFIG)-based wind turbines, their control system operates to apply a restraining torque to the rotor according to a predetermined curve with respect to the rotor speed. This control system is not based

J. Ekanayake; N. Jenkins

2004-01-01

288

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

289

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

290

202 IEEE TRANS.4CTIONS Oh'AUTOMATIC CONTROL, VOL. AC-18,NO. 3, J U K E 1973 Design and Analysis of Boiler-Turbine-Generator  

E-print Network

of Boiler-Turbine-Generator Controls Using Optimal Linear Regulator Theory JOHN P. McDOKALD AND HARRY G of a nonlinear mathematical model of a drum-type, twin furnace, reheat boiler-turbine-generator (RBTG) system- tiveoperatingandcontrolstrategies for boiler-t.urbine- generator systems to meet different, system operating ob- jectives. Among

Kwatny, Harry G.

291

An Approach to Generating Summaries of Time Series Data in the Gas Turbine Domain Jin Yu and Jim Hunter and Ehud Reiter and Somayajulu Sripada  

E-print Network

An Approach to Generating Summaries of Time Series Data in the Gas Turbine Domain Jin Yu and Jim an approach to generating summaries of time series data in the gas turbine domain using AI techniques. Through. The approach to generating summaries of temporal data in the domain exploits archived temporal data in the gas

Sripada, Yaji

292

Integrally geared and integrated turbine generator energy recovery for high pressure natural gas  

SciTech Connect

Recovery of pressure let-down energy dates back to the early 1980`s. Several installations have proven the feasibility and attractive pay back of using turbine generator system in lieu of throttling valves. These installations, on average, are saving up to 200,000 barrels of fuel oil per year. Since the first installation, many improvements have been implemented in turboexpander packages and the associated control systems. Based on site requirements, two alternate designs may be introduced. One is a totally encapsulated integral turboexpander generator unit. The other is an integrally geared turboexpander. Both alternatives have the flexibility necessary to cope with a wide range of inlet gas conditions while maintaining required outlet gas conditions. These installations are environmentally friendly (no hazardous gas leakage) and operate within an acceptable noise level.

Agahi, R.R.; Ershaghi, B.; Moser, H.

1995-12-31

293

The Effect of Mounting Vortex Generators on the DTU 10MW Reference Wind Turbine Blade  

NASA Astrophysics Data System (ADS)

The aim of the current work is to analyze possible advantages of mounting Vortex Generators (VG's) on a wind turbine blade. Specifically, the project aims at investigating at which radial sections of the DTU 10 MW Reference Wind Turbine blade it is most beneficial to mount the VG's in order to increase the Annual Energy Production (AEP) under realistic conditions. The present analysis was carried out in several steps: (1) The clean two dimensional airfoil characteristics were first modified to emulate the effect of all possible combinations of VG's (1% high at suction side x/c=0.2-0.25) and two Leading Edge Roughness (LER) values along the whole blade span. (2) The combinations from Step 1, including the clean case were subsequently modified to take into account three dimensional effects. (3) BEM computations were carried out to determine the aerodynamic rotor performance using each of the datasets from Step 2 along the whole blade span for all wind speeds in the turbine control scheme. (4) Employing the assumption of radial independence between sections of the blades, and using the results of the BEM computations described in Step 3, it is possible to determine for each radial position independently whether it is beneficial to install VG's in the smooth and LER cases, respectively. The results indicated that surface roughness that corresponds to degradation of the power curve may to some extent be mitigated by installation of VG's. The present results also indicated that the optimal VG configuration in terms of maximizing AEP depends on the degree of severity of the LER. This is because, depending on the condition of blade surface, installation of VG's on an incorrect blade span or installation of VG's too far out on the blade may cause loss in AEP. The results also indicated that the worse condition of the blade surface, the more gain may be obtained from the installation of VG's.

Skrzypi?ski, Witold; Gaunaa, Mac; Bak, Christian

2014-06-01

294

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

295

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

296

Generation of a composite grid for turbine flows and consideration of a numerical scheme  

NASA Technical Reports Server (NTRS)

A composite grid was generated for flows in turbines. It consisted of the C-grid (or O-grid) in the immediate vicinity of the blade and the H-grid in the middle of the blade passage between the C-grids and in the upstream region. This new composite grid provides better smoothness, resolution, and orthogonality than any single grid for a typical turbine blade with a large camber and rounded leading and trailing edges. The C-H (or O-H) composite grid has an unusual grid point that is connected to more than four neighboring nodes in two dimensions (more than six neighboring nodes in three dimensions). A finite-volume lower-upper (LU) implicit scheme to be used on this grid poses no problem and requires no special treatment because each interior cell of this composite grid has only four neighboring cells in two dimensions (six cells in three dimensions). The LU implicit scheme was demonstrated to be efficient and robust for external flows in a broad flow regime and can be easily applied to internal flows and extended from two to three dimensions.

Choo, Y.; Yoon, S.; Reno, C.

1986-01-01

297

Three-dimensional unsteady flow calculations in an advanced gas generator turbine  

NASA Technical Reports Server (NTRS)

This paper deals with the application of a three-dimensional, unsteady Navier-Stokes code for predicting the unsteady flow in a single stage of an advanced gas generator turbine. The numerical method solves the three-dimensional thin-layer Navier-Stokes equations, using a system of overlaid grids, which allow for relative motion between the rotor and stator airfoils. Results in the form of time averaged pressures and pressure amplitudes on the airfoil surfaces will be shown. In addition, instantaneous contours of pressure, Mach number, etc. will be presented in order to provide a greater understanding of the inviscid as well as the viscous aspects of the flowfield. Also, relevant secondary flow features such as cross-plane velocity vectors and total pressure contours will be presented. Prior work in two-dimensions has indicated that for the advanced designs, the unsteady interactions can play a significant role in turbine performance. These interactions affect not only the stage efficiency but can substantially alter the time-averaged features of the flow. This work is a natural extension of the work done in two-dimensions and hopes to address some of the issues raised by the two-dimensional calculations. These calculations are being performed as an integral part of an actual design process and demonstrate the value of unsteady rotor-stator interaction calculations in the design of turbomachines.

Rangwalla, Akil A.

1993-01-01

298

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

299

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

300

Novel sensorless generator control and grid fault ride-through strategies for variable-speed wind turbines and implementation on a new real-time simulation platform  

Microsoft Academic Search

The usage of MW-size variable-speed wind turbines as sources of energy has increased significantly during the last decade. Advantages over fixed-speed wind turbines include more efficient wind power extraction, reduced grid power fluctuation, and improved grid reactive power support. Two types of typical generation systems for large-size variable-speed wind turbines exist. One is the doubly-fed induction generator (DFIG) with a

Sheng Yang

2010-01-01

301

Z-source converter based grid-interface for variable-speed permanent magnet wind turbine generators  

Microsoft Academic Search

A Z-source inverter based grid-interface for a variable-speed wind turbine connected to a permanent magnet synchronous generator is proposed. A control system is designed to harvest maximum wind energy under varied wind conditions with the use of the permanent magnet synchronous generator, diode-rectifier and Z-source inverter. Control systems for speed regulation of the generator and for DC- and AC- sides

D. Mahinda Vilathgamuwa; Wang Xiaoyu; C. J. Gajanayake

2008-01-01

302

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

E-print Network

turbines (MCTs). Due to the submarine environment, maintenance operations are very hard, very costly. These difficulties mainly concern installations high-cost and maintenance [3]. Marine current turbines are similar in many aspects to wind turbine technologies. However, because of tide low speeds and to avoid blade

Brest, Université de

303

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

304

Relax and refill: xylem rehydration prior to hydraulic measurements favours embolism repair in stems and generates artificially low PLC values.  

PubMed

Diurnal changes in percentage loss of hydraulic conductivity (PLC), with recorded values being higher at midday than on the following morning, have been interpreted as evidence for the occurrence of cycles of xylem conduits' embolism and repair. Recent reports have suggested that diurnal PLC changes might arise as a consequence of an experimental artefact, that is, air entry into xylem conduits upon cutting stems, even if under water, while under substantial tension generated by transpiration. Rehydration procedures prior to hydraulic measurements have been recommended to avoid this artefact. In the present study, we show that xylem rehydration prior to hydraulic measurements might favour xylem refilling and embolism repair, thus leading to PLC values erroneously lower than those actually experienced by transpiring plants. When xylem tension relaxation procedures were performed on stems where refilling mechanisms had been previously inhibited by mechanical (girdling) or chemical (orthovanadate) treatment, PLC values measured in stems cut under native tension were the same as those measured after sample rehydration/relaxation. Our data call for renewed attention to the procedures of sample collection in the field and transport to the laboratory, and suggest that girdling might be a recommendable treatment prior to sample collection for PLC measurements. PMID:24588546

Trifilò, Patrizia; Raimondo, Fabio; Lo Gullo, Maria A; Barbera, Piera M; Salleo, Sebastiano; Nardini, Andrea

2014-11-01

305

Characterization of seven power-generating turbine rotors using microscopy-based techniques  

NASA Astrophysics Data System (ADS)

Seven turbine generating rotors, either currently in service or recently retired, have been metallurgically examined using nondestructive techniques, including hardness testing and replication for optical and transmission electron microscopy. The aim has been to understand the microstructural changes occurring in a range of rotors due to service exposure. A decrease in hardness of up to 7% was noted, possibly arising from carbide-induced loss of molybdenum from solid solution. Optical microscopy was unable to detect service-induced microstructural changes. However, fine scale secondary precipitation of MC and M 2 C were observed using transmission electron microscopy. A range of carbide compositional parameters associated with M 3 C were found to vary with service exposure time.

Mitchell, D. R. G.; Moss, C. J.

1998-10-01

306

Macroscopic cross section generation and application for coupled spatial kinetics and thermal hydraulics analysis with SAS-DIF3DK  

SciTech Connect

This paper discusses the importance of modeling the transient behavior of multigroup cross sections in the context of coupled reactor physics and thermal-hydraulic computations with the SAS-DIF3DK computer code. The MACOEF macroscopic cross section methodology is presented. Results from benchmark verification calculations with a continuous-energy Monte Carlo are reported. Analysis of the Chernobyl accident is made using correlated WIMS-D4M generated group constants with special emphasis placed on the impact of modeling assumptions on the progression of the accident simulation.

Turski, R.B.; Morris, E.E.; Taiwo, T.A.; Cahalan, J.E.

1997-08-01

307

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

308

Steam Turbines  

NASA Astrophysics Data System (ADS)

Turbonetics Energy, Inc.'s steam turbines are used as power generating systems in the oil and gas, chemical, pharmaceuticals, metals and mining, and pulp and paper industries. The Turbonetics line benefited from use of NASA research data on radial inflow steam turbines and from company contact with personnel of Lewis Research Center, also use of Lewis-developed computer programs to determine performance characteristics of turbines.

1981-01-01

309

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

310

On-line partial discharge measurement of turbine generators with new noise rejection techniques on pulse-by-pulse basis  

Microsoft Academic Search

Online partial discharge tests for turbine generators are useful for recognizing abnormal or deteriorated stator winding insulation without a machine outage. One problem related to such a test is additional installation of sensors and their reliability. The authors propose that wires of a resistance temperature detector (RTD) embedded in a stator slot be applied as a partial discharge sensor in

R. Itoh; Y. Kaneda; S. Kitamura; K. Kimura; K. Otoba; T. Tanaka; H. Tokura; I. Okada

1996-01-01

311

Control of a doubly fed induction generator in a wind turbine during grid fault ride-through  

Microsoft Academic Search

This paper analyzes the ability of a doubly fed induction generator (DFIG) in a wind turbine to ride through a grid fault and the limitations to its performance. The fundamental difficulty for the DFIG in ride-through is the electromotive force (EMF) induced in the machine rotor during the fault, which depends on the dc and negative sequence components in the

Dawei Xiang; Li Ran; P. J. Tavner; S. Yang

2006-01-01

312

Dynamic modeling of GE 1.5 and 3.6 MW wind turbine-generators for stability simulations  

Microsoft Academic Search

GE power systems has an ongoing effort dedicated to development of models of GE wind turbine generators (WTG) suitable for use in system impact studies. This paper documents the present recommendations for dynamic modeling of the GE 1.5 and 3.6 MW WTG for use in system impact studies. The paper includes recommended model structure and data, as well the assumptions,

N. W. Miller; J. J. Sanchez-Gasca; W. W. Price; R. W. Delmerico

2003-01-01

313

Active power maximizing for Wind Electrical Energy Generating Systems moved by a Modular Multiple Blade Fixed Pitch Wind Turbine  

Microsoft Academic Search

This paper proposes a new solution for wind electrical energy generating system (WEEGS). The system here taken into account is moved by a modular multiple blade fixed pitch wind turbine (MMBFPWT) and foresees a new MPPT algorithm whose main characteristics are low cost, low noise, buildings simplicity and modularity. The mathematical model of the entire WEEGS has been here developed

V. Cecconi; V. Di Dio; A. O. Di Tommaso; S. Di Tommaso; D. La Cascia; R. Miceli

2008-01-01

314

Determination of the Optimum Capacity and Type of Wind Turbine Generators in a Power System Considering Reliability and Cost  

Microsoft Academic Search

The economic and reliability benefits of adding a wind energy conversion system (WECS) to a power system are highly de- pendent on the wind turbine generator (WTG) installation design, i.e., the type and number of WTG. This paper presents an ap- proach to determine the optimum installation design at each wind site considering the WTG parameters, the total cost of

Kaigui Xie; Roy Billinton

2011-01-01

315

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

316

Steady state stability of a remote gas-turbine generating station: field tests and validation of computer simulation results  

Microsoft Academic Search

This paper examines the steady state stability aspects of a remote power station. Results of staged-tests, performed on two gas turbine units, are utilized to validate and improve on the generator and excitation system models used in simulation studies. The validated models allow stability limits for these units to be determined much more accurately. A new underexcitation limiter scheme is

S. H. Choi; R. Larkin

1993-01-01

317

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

318

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

319

Final report of the key technology development program for a next-generation high-temperature gas turbine  

Microsoft Academic Search

There is a strong demand for efficient and clean power-generating systems to meet recent energy-saving requirements and environmental regulations. A combined cycle power plant is one of the best solutions to the above. Tohoku Electric Power Co., Inc., and Mitsubishi Heavy Industries, ltd., have jointly developed three key technologies for a next-generation 1,500 C class gas turbine. The three key

M. Sato; Y. Kobayashi; H. Matsuzaki; S. Aoki; Y. Tsukuda; E. Akita

1997-01-01

320

Grid Connected Based Six-Pulse Converter Applied A Self-Excited Induction Generator for Wind Turbine Applications  

Microsoft Academic Search

This paper the electrical power conversion system presents developed for a self-excited induction generator for wind turbine applications. In the wind energy conversion system a self-excited induction generator converts the mechanical energy into electrical energy. A B6 rectifier and inductor are utilized to maintain constant dc link current. The average power is converted entirely by the six-pulse converter, it's consists

Satean Tunyasrirut; Boonruang Wangsilabatra; Chakrapong Charumit; Tianchai Suksri

2011-01-01

321

A Review of Current Issues in Lightning Protection of New-Generation Wind-Turbine Blades  

Microsoft Academic Search

The salient issues related to lightning protection of long wind-turbine blades are discussed in this paper. We show that the lightning protection of modern wind turbines presents a number of new challenges due to the geometrical, electrical, and mechanical particularities of the turbines. The risk assessment for the lightning-protection-system design is solely based today on downward flashes. We show in

Farhad Rachidi; Marcos Rubinstein; Joan Montanya; JosÉ-Luis Bermudez; RubÉn Rodriguez Sola; GlÒria Sola; Nikolay Korovkin

2008-01-01

322

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

323

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

324

Tungsten fiber reinforced FeCrAlY - A first generation composite turbine blade material  

NASA Technical Reports Server (NTRS)

General and composite turbine blade material requirements are examined to identify a specific tungsten fiber reinforced superalloy (TFRS) having, in addition to strength, the desired combination of other material properties needed in turbine blades. Experimental data indicated that a thoriated tungsten fiber reinforced FeCrAlY matrix composite should have the stress-rupture, creep, tensile, fatigue, and impact strengths required for turbine blades operating from 1250 to 1370 K. Fabrication and design concepts are developed to demonstrate the feasibility of fabricating a hollow TFRS turbine blade at reasonable cost.

Petrasek, D. W.; Winsa, E. A.; Westfall, L. J.; Signorelli, R. A.

1979-01-01

325

Effect of front guide nozzle shape on the flow characteristics in an augmentation channel of a direct drive turbine for wave power generation  

Microsoft Academic Search

There is an increasing interest in cross flow turbines (also known as Banki turbines) for small and low head applications\\u000a because of their simple structure as well as low capital and maintenance costs. The present work aims at implementing the\\u000a direct drive turbine (DDT) of cross flow type for wave power generation. A numerical wave tank was used to simulate

Deepak Prasad; Mohammed Asid Zullah; Mohammed Rafiuddin Ahmed; Young-Ho Lee

2010-01-01

326

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.

327

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

328

Control apparatus for matching the exhaust flow of a gas turbine employed in a combined cycle electric power generating plant to the requirements of a steam generator also employed therein  

Microsoft Academic Search

A combined cycle electric power plant is described that includes gas and steam turbines, steam generators, afterburners and a digital\\/analog control system that is provided with inlet guide vane control apparatus adapted to match gas turbine exhaust flow to the requirements of the steam generator with which it is associated. The guide vane control apparatus operates to limit the inlet

1976-01-01

329

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

330

Modeling and Control of a Marine Current Turbine Driven Doubly-Fed Induction Generator  

E-print Network

with the modeling and the control of a variable speed DFIG-based marine current turbine with and without tidal synchronous speed); r = Rotor current frequency (r = s ­ ); = DFIG speed ( = /p); f = Viscosity coefficient; J = Rotor Inertia; p = Pole pair number. GLOSSARY MCT = Marine Current Turbine; DFIG = Doubly

Boyer, Edmond

331

Capacitive sensor for active tip clearance control in a palm-sized gas turbine generator  

Microsoft Academic Search

The efficiency of a gas turbine has an inverse relationship to the clearance between the rotor blades and the casing. Recent efforts in miniaturization of micro gas turbine engines have created a new challenge in blade tip clearance measurement. This paper describes the development of a capacitive tip clearance measurement system, based on a synchronous detection of a phase-modulated signal,

Tibor Fabian; Friedrich B. Prinz; Georg Brasseur

2005-01-01

332

A micro Tesla turbine for power generation from low pressure heads and evaporation driven flows  

Microsoft Academic Search

We report on the design, fabrication and testing of a low pressure head Tesla microturbine. We began developing this technology as a means of scavenging energy from fluids flows induced in plant-like evaporative systems. Unlike traditional inertial turbines, Tesla turbines have high efficiency when driven with low pressure flows, are relatively simple to manufacture and scale down very favorably. The

Vedavalli G. Krishnan; Zohora Iqbal; Michel M. Maharbiz

2011-01-01

333

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

334

ARCADIA{sup R} - A New Generation of Coupled Neutronics / Core Thermal- Hydraulics Code System at AREVA NP  

SciTech Connect

Anticipating future needs of our customers and willing to concentrate synergies and competences existing in the company for the benefit of our customers, AREVA NP decided in 2002 to develop the next generation of coupled neutronics/ core thermal-hydraulic (TH) code systems for fuel assembly and core design calculations for both, PWR and BWR applications. The global CONVERGENCE project was born: after a feasibility study of one year (2002) and a conceptual phase of another year (2003), development was started at the beginning of 2004. The present paper introduces the CONVERGENCE project, presents the main feature of the new code system ARCADIA{sup R} and concludes on customer benefits. ARCADIA{sup R} is designed to meet AREVA NP market and customers' requirements worldwide. Besides state-of-the-art physical modeling, numerical performance and industrial functionality, the ARCADIA{sup R} system is featuring state-of-the-art software engineering. The new code system will bring a series of benefits for our customers: e.g. improved accuracy for heterogeneous cores (MOX/ UOX, Gd...), better description of nuclide chains, and access to local neutronics/ thermal-hydraulics and possibly thermal-mechanical information (3D pin by pin full core modeling). ARCADIA is a registered trademark of AREVA NP. (authors)

Curca-Tivig, Florin; Merk, Stephan; Pautz, Andreas; Thareau, Sebastien [AREVA NP, an AREVA and Siemens Company, Freyeslebenstrasse 1, 91058 Erlangen (Germany)

2007-07-01

335

Thermal-Hydraulic Analyses of Steam Generator Tube Rupture Accident for the Kori Nuclear Unit 1 Pressurized Thermal Shock Study  

SciTech Connect

This paper discusses a thermal-hydraulic analysis methodology using RETRAN-3D and assembles system analyses for pressurized thermal shock resulting from a steam generator tube rupture accident in Kori Nuclear Unit 1. Through a systematic definition of sequences and thermal-hydraulic analyses using RETRAN-3D, the most important parameters on downcomer overcooling were identified. The break location that leads to the most significant overcooling was found to be the hot leg side in the loop that does not contain the charging flow inlet. The initial power level had a large effect on the downcomer overcooling. The closure failure of the pressurizer power operated relief valves and the termination failure of the safety injection were found to be the most significant operator actions. In contrast, auxiliary feedwater control failure had little effect on overcooling, and the steam dump valve closure failure merely resulted in a temperature rise in the latter half of the transient. Through these analyses, recommendations for sequence grouping and against downcomer overcooling are provided.

Hong, Soon-Joon [FNC Technology Company (Korea, Republic of); Kim, Jae-Hak [FNC Technology Company (Korea, Republic of); Kim, Yong-Soo [Seoul National University (Korea, Republic of); Park, Goon-Cherl [Seoul National University (Korea, Republic of)

2002-06-15

336

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

higher-efficiency land-based turbines for natural gas-fired power generation systems. The high inlet, vanes, and rotors in these hot sections. Advanced physics-based models for prediction is significant for modeling cyclic deformation in directionally solidified and single crystal turbine blades

Li, Mo

337

Conceptual design of a fixed-pitch wind turbine generator system rated at 400 kilowatts  

NASA Astrophysics Data System (ADS)

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.

1984-06-01

338

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

339

Theory and economics of by-generation of electricity at city gate stations using a gas expander turbine  

SciTech Connect

The transmission pressure of pipeline gas entering a city-gate station offers an untapped energy source that gas-distribution companies can easily use to produce low-cost electricity. The high-pressure inlet gas can be heated, then isentropically expanded through a turbine that powers a generator and simultaneously reduces the gas pressure and temperature. The gas turboexpander behaves like a pinwheel in the line as the gas flow creates the rotary motion that drives the generator. The pressure and temperature differential that occurs across the inlet and outlet of the device can be held constant, functioning similarly to a standard regulator. The gas exiting the turbine is thus available at entry conditions for the gas-distribution system, while the electricity can be either used onsite or (in the case of a combination utility) fed into the network for electrical baseloading.

Bockert, B.J.

1980-01-01

340

Practical on-line partial discharge tests for turbine generators and motors  

SciTech Connect

Several utilities have found partial discharge testing to be very useful for identifying motors or generators with deteriorated stator winding insulation. Such partial discharge tests are sensitive to problems associated with overheated insulation, loose stator bars, and pollution, all of which can cause in-service failures with long associated outages and high repair/rewind costs. Unfortunately, the partial discharge test is not widely applied since present test methods require considerable skill to perform, and/or require machine outages. These problems are due to the stator winding partial discharges being masked by high levels of internal and external electrical noise. Partial discharge tests have now been developed which eliminate the effect of noise, thus allowing plant personnel to perform the test without any machine outage. Installations on several machines have shown that external noise can be eliminated by a pair of capacitive couplers (bus couplers) mounted on each phase of the output bus. Sensors which are mounted within the slots of the stator winding (SSCs) have been shown to eliminate both external and internal noise. An instrument called the TGA has been developed to measure the signals from either type of sensor, distinguish noise from stator winding partial discharge, and perform a pulse height, pulse phase analysis on the partial discharge signals. Using the TGA, deteriorated windings have been found to have as much as 20 times higher partial discharge activity than good windings. The SSC type of sensor is best for use on large turbine generators or other critical machines, due to its ability to effectively eliminate false indications of deteriorated windings.

Campbell, S.R.; Stone, G.C. (Iris Power Engineering Inc., Mississauga, Ontario (Canada)); Sedding, H.G.; Klempner, G.S. (Ontario Hydro, Toronto, Ontario (Canada)); McDermid, W. (Manitoba Hydro, Winnipeg (Canada)); Bussey, R.G. (TransAlta Utilities, Calgary, Alberta (Canada))

1994-06-01

341

PIV and Hotwire Measurement and Analysis of Tip Vortices and Turbulent Wake Generated by a Model Horizontal Axis Wind Turbine  

NASA Astrophysics Data System (ADS)

Understanding vortical flow structures and turbulence in the wake flow behind a Horizontal Axis Wind Turbine (HAWT) has widespread applications in efficient blade design. Moreover, the knowledge of wake-turbine interactions allows us to devise optimal operational parameters, such as the spatial allocation and control algorithms of wind turbines, for a densely populated wind farm. To understand the influence of tip vortices on energy containing mean flow and turbulence, characteristics of vortical structures and turbulence must be quantified thoroughly. In this study, we conduct phase-locked Particle Image Velocimetry (PIV) measurements of the flow before and after a model HAWT, which is located in a zero-pressure gradient wind tunnel with a cross section of 1.7 × 1.7 m and a test section of 16 m in length. A three-blade model HAWT with a diameter of 605 mm and tip-speed ratio of 5 is used. PIV images are recorded by a 2048 × 2048 CCD camera and streamed at 6 Hz continuously; and phased locked with the passage of the blade at its vertical position. Each PIV measurement covers a 0.13 × 0.13 m2 sample area with the spatial resolution of 63 ?m and a vector spacing of 0.5 mm. All experiments are conducted at the free-stream wind speed of 10 m/s. Flow fields at thirty consecutive downstream locations up to six rotor diameters and 144 mid chord lengths are measured. At each location, we obtain at least 10,000 instantaneous PIV realizations or 20,000 images. Three different configurations: single, dual, and trio turbines located at 5 rotor diameter upstream to each other, are examined experimentally. The flow statistics include mean wake velocity distributions, characteristics of tip vortices evolving downstream, fluctuation velocity, turbulent kinetic energy, stresses, and energy spectra. We find that tip vortices decay much faster in the wake of the upstream turbines (multiple-turbine configurations), whereas they maintain the coherence and strength behind a single turbine. The tip vortices entrain the high speed free-stream fluids and subsequently replenish the loss of momentum into the wake. Such a mechanism is greatly mitigated in the multiple-turbine scenarios. On-going analysis is to elucidate the generation, evolution and dissipation of the tip vortices in the various configurations.

Green, D.; Tan, Y. M.; Chamorro, L. P.; Arndt, R.; Sotiropoulos, F.; Sheng, J.

2011-12-01

342

Runoff hydraulic characteristics and sediment generation in sloped grassplots under simulated rainfall conditions  

NASA Astrophysics Data System (ADS)

SummaryEvaluation of grass influence on soil erosion process can provide important information in soil and water conservation. The laboratory experiment was conducted to study runoff and sediment producing processes and runoff hydraulics in the grassplots with different covers (35%, 45%, 65% and 90%) and bare soil plot (control) at a slope of 15°. The results showed that grass significantly reduced runoff and sediment. Compared with bare soil plot, the grassplots had a 14-25% less runoff and an 81-95% less sediment, and played a more important role in reducing sediment at the final stage of rainfall. There was a significantly negative logarithmic relationship between sediment yield rate (SDR) and cover ( C): SDR = 1.077-2.911 ln( C) ( R2 = 0.999 ??). Sediment yield rate of grassplots decreased with rainfall duration, and decreased linearly as runoff rate increased. Overland flow velocities deceased with increase in grass cover, and the cover had greater effect on lower slope velocity than upper one. Froude numbers decreased with increase in cover, and flow regimes of all treatments were laminar and tranquil. Darcy-Weisbach and Manning friction coefficients of grassplots increased as ground cover increased. Therefore, increase in grass coverage can efficiently reduce soil loss and improve ecological environments.

Pan, Chengzhong; Shangguan, Zhouping

2006-11-01

343

Estimating of a nonlinear power curve for a Wind Turbine Generator  

NASA Astrophysics Data System (ADS)

The output power from a Wind Turbine Generator (WTG) is an intermittent resource, due to the high variability of the atmospheric wind at all spatial or temporal scales ranging from large scale variations to very short variations. Generally, a function transfer or a power curve of WTG is estimated with the IEC standard 61400 - 12 giving a relation of coupling between the measured wind speed and the output power for the considered WTG. However, this relation is a statistical representation and not takes into account the dynamics of the power output, more precisely on small time scales. The goal is to provide a method to estimate and to model the function transfer of a WTG, in order to synthesize the output power mimicking the statistical and the dynamical properties of the real output power. For that, we study the statistics of power curve in the multifractal framework motivated by the presence of spectral scaling for the wind speed and the output power data from a WTG. The first step consists to quantify the power curve or the transfer function of two intermittent stochastic processes such as the wind speed u(t) and the output power p(t) at all temporal scales and at all intensities. In this study, firstly, we define the time increment of the wind speed measurement u'(t) = u(t + ?) - u(t) and the time increment of the output power measurement p'(t) = p(t + ?) - p(t) characterized by mth and nth order structure functions to estimate the exponent functions ?u'(m) and ?p'(n) that characterize respectively the multifractal properties of the wind speed fluctuations u'(t) and the output power fluctuations p'(t) from the WTG. The exponent function ? defines the types of scaling behavior of a process: if ? is linear the statistical behavior is monoscaling corresponding to a monofractal process. If ? is nonlinear and concave, the statistical behavior is multiscaling corresponding to a multifractal process. The concavity of this function is a characteristic of the intermittency, the more the curve is concave, the more the process is intermittent [1,2]. Secondly, we apply a technique given in Seuront & Schmitt 2005 [3], to estimate the power curve of joint fluctuations < u'(t)mp'(t)n > at all scales and at all intensities, by the function Su'p'(m,n): Su'p'(m,n ) = ?u'(m )+ ?p'(n)- r(m,n) (1) where r(n,m) is estimated as the slope of the power law of c(n,m) versus ? in a log-log plot, that is defined as [3]: -- -r(m,n) c(m, n) = < u'm >< p'n > ~ ? (2) the brackets < . > defines the statistical average. The analysis presented in this work, is performed with simultaneous time series of wind speed u(t) and output power p(t) for two types of WTGs, loaded from the Database of Wind Characteristics of the Technical University of Denmark [4]: i) a 300 kW Nordtank wind turbine located in the North Jutland, on the south bank of the Limfjord, about 36 km west of Alborg and 8 km north east of Loegstoer, Denmark. The wind speed and the output power are measured with a sampling rate at 20 Hz during 746 hours. The measurement are obtained at 31 m above the ground. ii) a 2 MW wind turbine at Tjaereborg, Esbjerg, Denmark. The wind speed and the output power are measured with a sampling rate at 25 Hz during 64 hours. The measurement are obtained at 90 m above the ground.

Calif, R.; Schmitt, F. G.

2012-04-01

344

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

345

Design and finite-element analysis of an outer-rotor permanent-magnet generator for directly coupled wind turbines  

Microsoft Academic Search

This paper presents the design and finite-element analysis of a permanent-magnet generator using neodymium-iron-boron magnets for directly coupled wind turbines. For the sake of small size and light weight with extra low speed for direct coupling, the outer rotor structure is used. The simple magnetic equivalent circuit approach is used for initial design iteration, and the finite-element method is applied

Jianyi Chen; Chemmangot V. Nayar; Longya Xu

2000-01-01

346

Theory and economics of by-generation of electricity at city gate stations using a gas expander turbine  

Microsoft Academic Search

The transmission pressure of pipeline gas entering a city-gate station offers an untapped energy source that gas-distribution companies can easily use to produce low-cost electricity. The high-pressure inlet gas can be heated, then isentropically expanded through a turbine that powers a generator and simultaneously reduces the gas pressure and temperature. The gas turboexpander behaves like a pinwheel in the line

Bockert

1980-01-01

347

Gas–liquid flow generated by a Rushton turbine in stirred vessel: CARPT\\/CT measurements and CFD simulations  

Microsoft Academic Search

In this work, computer-automated radioactive particle tracking (CARPT), computed tomography (CT) and computational fluid dynamic (CFD) based models were used to investigate gas–liquid flow generated by a Rushton turbine. CARPT and CT measurements were carried out in a gas–liquid stirred vessel operating in two different flow regimes and captured the quantitative Eulerian information of gas–liquid flow. The CARPT data was

A. R. Khopkar; A. R. Rammohan; V. V. Ranade; M. P. Dudukovic

2005-01-01

348

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

349

Improving the Capacity or Output of a Steam Turbine Generator at XYZ Power Plant in Illinois  

E-print Network

Competition has been a prime mover in the energy industry and there is the drive to increase performance of steam turbine-driven equipment. Availability of a unit is also critical to the operation of a plant and ...

Amoo-Otoo, John Kweku

2006-05-19

350

Turbine power plant with steam and exhaust turbine systems  

Microsoft Academic Search

This patent describes a turbine power plant having a closed loop steam turbine system and a closed loop exhaust turbine system; a closed loop steam turbine system which comprises the combination of: a steam turbine having a fluid inlet and fluid outlet mounted on a shaft; a generator means operatively connected to the shaft; a condenser having a fluid inlet

Papastavros

1988-01-01

351

Turbine-generator. [For American Electric Power's 1300MW coal-fired series  

Microsoft Academic Search

The cross-compound turbine for the AEP coal-fired units has a guaranteed output of 1300 MW at a steam flow of more than 9,000,000 lb\\/h. Both shafts run at 3600 r\\/min. The nominal condenser pressure is 2 in. Hg. The turbine powering the boiler feed pump is a double-flow, throttle-controlled condensing machine with an individual condenser, rated 50 MW. The throttle

Hossli

1975-01-01

352

Hydraulic fracturing  

E-print Network

Hydraulic fracturing (also hydrofracturing, hydrofracking, fracking, or fraccing) is a well-stimulation technique in which rock is fractured by a hydraulically pressurized liquid. Some hydraulic fractures form naturally—certain veins or dikes are examp...

353

Design of a control scheme for a maximum power extraction in low power wind turbine-generator system  

NASA Astrophysics Data System (ADS)

This document presents the modeling of a wind turbine-generator system and developing a control scheme for maximum power extraction. The system comprises a low-power variable speed wind rotor coupled to a squirrel cage induction generator through gearbox. The generator delivers electrical energy to a DC load through a PWM three phase rectifier which control variables are duty cycle and the fundamental frequency of the modulated signal. The control scheme maintains constant relationship voltage/frequency in the stator of the generator to operate the machine with constant air gap flow at its nominal value, thereby decreasing electrical losses in the circuit of the stator and rotor. The controller is based on MPPT algorithms for determining the operating point the system and achieve the proper mechanical speed shaft. The performance is evaluated through simulations in MatlabRTM/simulink. and presents this type of control as a good alternative for handling low-power wind turbine-generator systems effectively and efficiently

Henao Bravo, Elkin Edilberto

354

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.

355

Impact study on the use of biomass-derived fuels in gas turbines for power generation  

SciTech Connect

This report evaluates the properties of fuels derived from biomass, both gaseous and liquid, against the fuel requirements of gas turbine systems for gernating electrical power. The report attempts to be quantitative rather than merely qualitative to establish the significant variations in the properties of biomass fuels from those of conventional fuels. Three general categories are covered: performance, durability, and storage and handling.

Moses, C.A.; Bernstein, H. [Southwest Research Inst., San Antonio, TX (United States)] [Southwest Research Inst., San Antonio, TX (United States)

1994-01-01

356

MOD-OA 200 kW wind turbine generator engineeringing  

NASA Technical Reports Server (NTRS)

Engineering drawings and the detailed mechanical and electrical design of a horizontal-axis wind turbine designed for DOE at the NASA Lewis Research Center and installed in Clayton, New Mexico are discussed. The drawings show the hub, pitch change mechanism, drive train, nacelle equipment, yaw drive system, tower, foundation, electrical power systems, and the control and safety systems.

Andersen, T. S.; Bodenschatz, C. A.; Eggers, A. G.; Hughes, P. S.; Lampe, R. F.

1980-01-01

357

Automatic generation control of a wind farm with variable speed wind turbines  

Microsoft Academic Search

Wind farms are considered to be negative loads from the point of view of a utility manager. Modern variable-speed wind turbines offer the possibility for controlling active and reactive power separately. This paper presents a new integrated control system of a wind farm according to the utility manager's requirements. This control system is based on two control levels: a supervisory

José Luis Rodríguez-Amenedo; Santiago Arnalte; Juan Carlos Burgos

2002-01-01

358

Output Power Smoothing for Wind Turbine Permanent Magnet Synchronous Generators Using Rotor Inertia  

Microsoft Academic Search

Due to wind speed variations, the output power of wind turbines fluctuates. This power fluctuation can cause frequency deviations and power outage, particularly when wind power penetration is significant. Energy storage devices, such as batteries, ultracapacitors, super inductors, and flywheels can be utilized in a hybrid system to solve this problem. These methods are effective, but they impose a significant

A. Abedini; A. Nasiri

2008-01-01

359

Development of vertical axial wind turbine driven by three hastate windmill and permanent magnet generator  

Microsoft Academic Search

Wind energy is a clear, safe and renewable green energy resource. Because it can be supplied inexhaustibly and always be used availably, it is exploited by countries all over the world and has gradually become a new energy type. According to the wind energy characteristics and the hydrodynamics theory, the vertical axial wind turbine of three hastate windmill, which can

Lei Song; ZongXiao Yang; ShuQi Hou; RuiTao Deng; ShuLing Ji

2010-01-01

360

Reliability survey of 600 to 1800 kW diesel and gas-turbine generating units  

Microsoft Academic Search

A study of the reliability, availability, and maintainability (RAM) characteristics of diesel and gas-turbine power systems producing less than 2 MW is discussed. The study included collection and examination of source data for power systems at commercial and military facilities operating in continuous or standby service. A database of system, subsystem, and component RAM data was established. These data will

C. A. Smith; M. D. Donovan; M. J. Bartos

1990-01-01

361

Interaction of turbine-generated turbulence with agricultural crops: Conceptual framework and preliminary results  

NASA Astrophysics Data System (ADS)

The US Midwest is a unique location for wind power production because wind farms in this region, unlike any other, are co-located within major agricultural production systems that are among the most highly productive in the world. Iowa has over 3,000 MW of installed power in wind farms typically consisting of 75-120 turbines positioned within agricultural fields with irregular spacing but inter-turbine distances in some cases less than 300 m. Wind turbines extract energy from the ambient flow and change mean and turbulent characteristics of wind flow over and within the crop canopy. Turbulent exchange of air from within the crop canopy regulates vertical fluxes of heat, moisture, momentum, and CO2. Changes in wind speed and turbulence structure by wind farms and isolated wind turbines will influence crop growth, productivity, and seed quality in unknown ways. For instance, enhanced vertical fluxes of heat and moisture may help cool the crop on hot summer days (beneficial) but may enhance loss of soil moisture (detrimental). Faster drying of dew from the crop in the morning reduces leaf wetness, which is a condition favoring growth of fungus, mold and toxins. Corn and soybeans typically draw down ambient CO2 levels by 15-20% during the day in the peak growing season, providing an opportunity to enhance downward fluxes of CO2 into the crop canopy by turbine-induced turbulence. Reduction of high winds and resulting leaf shredding and stalk lodging are documented positive effects of agricultural shelterbelts and may be benefits of turbines as well. Enhanced surface evaporation during fall dry-down would improve seed readiness for storage and reduce artificial drying costs. Modification of surface wind convergence/divergence patterns may enhance convection and change rainfall patterns and modify snow deposition, melting, and soil-moisture-recharge in winter. Wind machines are widely used in orchards and vineyards for avoiding killing freezes, but turbine benefits for such purposes for growing commodity agricultural crops are unknown. Suppressing effects of a premature freeze could extend the growing season by two or more weeks. Aerodynamic surface roughness influences the mean wind at hub height of wind turbines. Type of crop (e.g., corn vs. soybeans) and stage of growth will influence roughness, as will management practices (smooth surface vs. crop residue and tillage-induced roughness). Management of crop residue and snow cover influences surface albedo and hence diabatic influences on turbulent loss of momentum at the surface. We have launched a pilot project to assess the interaction of turbines with crops in Iowa by use of models and measurements. Preliminary studies show that turbulence kinetic energy in the lee of turbines may be enhanced by as much as 300% near hub height and 40% at 10 m above the ground under neutral flow conditions. Field observations of fluxes of CO2, heat, and water vapor have been made outside of wind farms, and plans call for simultaneous measurements to be made within and outside of wind farms.

Takle, E. S.; Rajewski, D. A.; Segal, M.; Elmore, R.; Hatfield, J.; Prueger, J. H.; Taylor, S. E.

2009-12-01

362

Preliminary analysis of the audible noise of constant-speed, horizontal-axis wind-turbine generators  

SciTech Connect

An analytical procedure has been developed for calculating certain aerodynamic sound levels produced by large, horizontal-axis wind-turbine generators (WTG's) such as the DOE/NASA Mods-0, -0A, -1, and -2. This preliminary procedure is based upon very limited field data from the Mod-0. 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. Mechanical sound from machinery, and low-frequency impulsive sounds produced by blade interaction with the wake of the support tower are not considered.

Keast, D. N.; Potter, R. C.

1980-07-01

363

Surface pressure measurements on the blade of an operating Mod-2 wind turbine with and without vortex generators  

NASA Technical Reports Server (NTRS)

Pressure measurements covering a range of wind velocities were made at one span location on the surface of an operating Mod-2, 2500 kW, wind turbine blade. The data, which were taken with and without vortex generators installed on the leading edge, show the existence of higher pressure coefficients than would be expected from two-dimensional wind tunnel data. These high pressure ratios may be the result of three-dimensional flow over the blade, which delays flow separation. Data are presented showing the repetitiveness of abrupt changes in the pressure distribution that occur as the blade rotates. Calculated values of suction and flap coefficients are also presented.

Nyland, Ted W.

1987-01-01

364

Wind turbines using self-excited three-phase induction generators: an innovative solution for voltage-frequency control  

NASA Astrophysics Data System (ADS)

A considerable number of communities throughout the world, most of them isolated, need hybrid energy solutions either for rural electrification or for the reduction of diesel use. Despite several research projects and demonstrations which have been conducted in recent years, wind-diesel technology remains complex and much too costly. Induction generators are the most robust and common for wind energy systems but this option is a serious challenge for electrical regulation. When a wind turbine is used in an off-grid configuration, either continuously or intermittently, precise and robust regulation is difficult to attain. The voltage parameter regulation option, as was experienced at several remote sites (on islands and in the arctic for example), is a safe, reliable and relatively simple technology, but does not optimize the wave quality and creates instabilities. These difficulties are due to the fact that no theory is available to describe the system, due to the inverse nature of the problem. In order to address and solve the problem of the unstable operation of this wind turbine generator, an innovative approach is described, based on a different induction generator single phase equivalent circuit.

Brudny, J. F.; Pusca, R.; Roisse, H.

2008-08-01

365

Evaluation of human exposure to the noise from large wind turbine generators  

NASA Technical Reports Server (NTRS)

The human perception of a nuisance level of noise was quantified in tests and attempts were made to define criteria for acceptable sound levels from wind turbines. Comparisons were made between the sound necessary to cause building vibration, which occurred near the Mod-1 wind turbine, and human perception thresholds for building noise and building vibration. Thresholds were measured for both broadband and impulsive noise, with the finding that noise in the 500-2000 Hz region, and impulses with a 1 Hz fundamental, were most noticeable. Curves were developed for matching a receiver location with expected acoustic output from a machine to determine if the sound levels were offensive. In any case, further data from operating machines are required before definitive criteria can be established.

Shepherd, K. P.; Grosveld, F. W.; Stephens, D. G.

1983-01-01

366

FLOW GENERATED BY PITCHED BLADE TURBINES I: MEASUREMENTS USING LASER DOPPLER ANEMOMETER  

Microsoft Academic Search

Mean flow and turbulence intensities have been measured using laser Doppler anemometer for pitched blade downflow turbines (PTD). Fully baffled, flat bottomed cylindrical vessels of 300 and 500 mm internal diameter were employed. The effect of impeller clearance on flow characteristics have been investigated. The influence of geometry of PTD, that is blade angle (30-60°), blade width (0.2D-0.4D) and impeller diameter

V. V. RANADE; J. B. JOSHI

1989-01-01

367

Simulation Analysis of Dynamic Performance for Hydro-Generator Under Loss of Excitation Condition  

Microsoft Academic Search

In order to analyze the dynamic performance for hydro-generator under loss of excitation (LOE) condition more effectively, based on MATALB, a mathematical model of hydro-generator under LOE condition is constructed in this paper. The model includes synchronous generator model, speed governor model, hydraulic turbine model, excitation regulation model and transmission line model. Several types of LOE faults are simulated by

Kanjun Zhang; Xianggen Yin; Deshu Chen; Zhe Zhang; Wei Chen

2006-01-01

368

Steam Turbine Cogeneration  

E-print Network

turbine classified by their conditions of exhaust and review quickly the fundamentals related to steam and steam turbine. Then the authors will analyze a typical steam turbine co-generation system and give examples to illustrate the benefits of the System....

Quach, K.; Robb, A. G.

2008-01-01

369

On-line partial discharge measurement of turbine generators with new noise rejection techniques on pulse-by-pulse basis  

SciTech Connect

On-line partial discharge tests for turbine generators are useful for recognizing abnormal or deteriorated stator winding insulation without a machine outage. One problem related to such a test is additional installation of sensors and their reliability. The authors proposed that wires of a resistance temperature detector (RTD) embedded in a stator slot are applied as a partial discharge sensor in the form of an RF coupler. The other problem is electrical noise that is a pulse similar to partial discharge in frequency characteristic and has higher amplitude than partial discharge. The authors developed on-line partial discharge monitor for turbine generator with three noise rejection techniques on pulse-by-pulse basis. The first one is founded on the correlation between pulse height in two frequency bands. The second one is based on the correlation between pulse height from the two partial discharge sensors. The last one is noise gating. It was found that most pulses of noise were successfully rejected with the monitor in a trial.

Itoh, K.; Kaneda, Y.; Kitamura, S.; Kimura, K. [Mitsubishi Electric Corp., Amagasaki, Hyogo (Japan); Otoba, K.; Tanaka, T.; Tokura, H.; Okada, I. [Kansai Electric Power Co., Inc., Kita, Osaka (Japan)

1996-12-31

370

Hydro turbine rehab benefits from modeling  

Microsoft Academic Search

The turbine aging process, while seemingly imperceptible, inevitably results in reduced turbine efficiency and capacity. The primary causes of these reductions are runner hydraulic profile changes during weld repairs, surface finish deterioration from cavitation, and runner seal clearance increases due to wear. Many aging turbines require more frequent repairs due to runner cavitation, and wicket gate mechanism, shaft seal, and

D. R. Froehlich; J. A. Veatch

1991-01-01

371

LMH Laboratory for Hydraulic Machines Supervisor  

E-print Network

rotating (runner-impeller) and stationary (guide vane and stay vane) blades in pump-turbine hydraulic and subsequently controlling rotating stall, a known issue frequently observed in annular blade arrays during-turbine machines during reverse mode operation, as well as bring insight on how to design blade profiles used

Diggavi, Suhas

372

Heat transfer in a two-pass internally ribbed turbine blade coolant channel with cylindrical vortex generators  

SciTech Connect

The effect of vortex generators on the mass (heat) transfer from the ribbed passage of a two pass turbine blade coolant channel is investigated with the intent of optimizing the vortex generator geometry so that significant enhancements in mass/heat transfer can be achieved. In the experimental configuration considered, ribs are mounted on two opposite walls; all four walls along each pass are active and have mass transfer from their surfaces but the ribs are non-participating. Mass transfer measurements, in the form of Sherwood number ratios, are made along the centerline and in selected inter-rib modules. Results are presented for Reynolds number in the range of 5,000 to 40,000, pitch to rib height ratios of 10.5 and 21, and vortex generator-rib spacing to rib height ratios of 0.55, and 1.5. Centerline and spanwise averaged Sherwood number ratios are presented along with contours of the Sherwood number ratios. Results indicate that the vortex generators induce substantial increases in the local mass transfer rates, particularly along the side walls, and modest increases in the average mass transfer rates. The vortex generators have the effect of making the inter-rib profiles along the ribbed walls more uniform. Along the side walls, horse-shoe vortices that characterize the vortex generator wake are associated with significant mass transfer enhancements. The wake effects and the levels of enhancement decrease somewhat with increasing Reynolds number and decreasing pitch.

Hibbs, R.; Acharya, S.; Chen, Y. [Louisiana State Univ., Baton Rouge, LA (United States)] [and others

1995-12-31

373

Shaken, not stirred: The recipe for a fish-friendly turbine  

SciTech Connect

It is generally agreed that injuries and mortalities among turbine-passed fish can result from several mechanisms, including rapid and extreme water pressure changes, cavitation, shear, turbulence, and mechanical injuries (strike and grinding). Advances in the instrumentation available for monitoring hydraulic conditions and Computational Fluid Dynamics (CFD) techniques now make it possible both to estimate accurately the levels of these potential injury mechanisms in operating turbines and to predict the levels in new turbine designs. This knowledge can be used to {open_quotes}design-out{close_quotes} the most significant injury mechanisms in the next generation of turbines. However, further improvements in turbine design are limited by a poor understanding of the levels of mechanical and hydraulic stresses that can be tolerated by turbine-passed fish. The turbine designers need numbers (biological criteria) that define a safety zone for fish within which pressures, shear forces, cavitation, and chance of mechanical strike are all at acceptable levels for survival. This paper presents the results of a literature review of fish responses to the types of biological stresses associated with turbine passage, as studied separately under controlled conditions in the laboratory rather than in combination at field sites. Some of the controlled laboratory and field studies reviewed here were bioassays carried out for reasons unrelated to hydropower production. Analysis of this literature was used to develop provisional biological criteria for hydroelectric turbine designers. These biological criteria have been utilized in the U.S. Department of Energy`s Advanced Hydropower Turbine System (AHTS) Program to evaluate the results of conceptual engineering designs and the potential value of future turbine models and prototypes.

Cada, G.F.

1997-03-01

374

Investigation of self-excited induction generators for wind turbine applications  

Microsoft Academic Search

The use of squirrel-cage induction machines in wind generation is widely accepted as a generator of choice. The squirrel-cage induction machine is simple, reliable, cheap, lightweight, and requires very little maintenance. Generally, the induction generator is connected to the utility at constant frequency. With a constant frequency operation, the induction generator operates at practically constant speed (small range of slip).

E. Muljadi; C. P. Butterfield; J. Sallan; M. Sanz

2000-01-01

375

Hydraulics Lectures  

NSDL National Science Digital Library

This page from the WindTech TV project provides a link to lectures created by Jim Pytel for his hydraulics course at Columbia Gorge Community College. The lectures consist of live videos and screen capture style presentations and may be viewed free of charge. Clicking on the video link in the center of the page will lead users to a YouTube page with 31 lectures. Topics include hydraulics math, hydraulic safety, basic hydraulic schematics, viscosity, piston pumps, actuators, troubleshooting and more. These lectures would be extremely useful for technical and community college students taking a fundamental hydraulics course. Flash is required to view the videos.

Pytel, Jim

2013-07-18

376

Heat Transfer and Flow on the First Stage Blade Tip of a Power Generation Gas Turbine. Part 1; Experimental Results  

NASA Technical Reports Server (NTRS)

A combined computational and experimental study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first stage blade tip surface for a geometry typical of large power generation turbines(>100MW). This paper is concerned with the design and execution of the experimental portion of the study. A stationary blade cascade experiment has been run consisting of three airfoils, the center airfoil having a variable tip gap clearance. The airfoil models the aerodynamic tip section of a high pressure turbine blade with inlet Mach number of 0.30, exit Mach number of 0.75, pressure ratio of 1.45, exit Reynolds number based on axial chord of 2.57 x 10(exp 6), and total turning of about 110 degrees. A hue detection based liquid crystal method is used to obtain the detailed heat transfer coefficient distribution on the blade tip surface for flat, smooth tip surfaces with both sharp and rounded edges. The cascade inlet turbulence intensity level took on values of either 5% or 9%. The cascade also models the casing recess in the shroud surface ahead of the blade. Experimental results are shown for the pressure distribution measurements on the airfoil near the tip gap, on the blade tip surface, and on the opposite shroud surface. Tip surface heat transfer coefficient distributions are shown for sharp-edge and rounded-edge tip geometries at each of the inlet turbulence intensity levels.

Bunker, Ronald S.; Bailey, Jeremy C.; Ameri, Ali A.

1999-01-01

377

Mass Transfer And Hydraulic Testing Of The V-05 And V-10 Contactors With The Next Generation Solvent  

SciTech Connect

The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent. To support this integration of NGS into the MCU facilities, Savannah River Remediation (SRR) requested that Savannah River National Laboratory (SRNL) perform testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing differs from prior testing by utilizing a blend of BOBCalixC6 based solvent and the NGS with the full (0.05 M) concentration of the MaxCalix as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. Stage efficiency and mass distribution ratios were determined by measuring Cs concentration in the aqueous and organic phases during single contactor testing. The nominal cesium distribution ratio, D(Cs) measured for extraction ranged from 37-60. The data showed greater than 96% stage efficiency for extraction. No significant differences were noted for operations at 4, 8 or 12 gpm aqueous salt simulant feed flow rates. The first scrub test (contact with weak caustic solution) yielded average scrub D(Cs) values of 3.3 to 5.2 and the second scrub test produced an average value of 1.8 to 2.3. For stripping behavior, the “first stage” D Cs) values ranged from 0.04 to 0.08. The efficiency of the low flow (0.27 gpm aqueous) was calculated to be 82.7%. The Spreadsheet Algorithm for Stagewise Solvent Extraction (SASSE) predicted equivalent DF for MCU from this testing is greater than 3,500 assuming 95% efficiency during extraction and 80% efficiency during scrub and strip. Hydraulically, the system performed very well in all tests. Target flows were easily obtained and stable throughout testing. Though some issues were encountered with plugging in the coalescer, they were not related to the solvent. No hydraulic upsets due to the solvent were experienced during any of the tests conducted. The first extraction coalescer element used in testing developed high pressure drop that made it difficult to maintain the target flow rates. Analysis showed an accumulation of sodium aluminosilicate solids. The coalescer was replaced with one from the same manufacturer’s lot and pressure drop was no longer an issue. Concentrations of Isopar™ L and Modifier were measured using semi-volatile organic analysis (SVOA) and high performance liquid chromatography (HPLC) to determine the amount of solvent carryover. For low-flow (0.27 gpm aqueous) conditions in stripping, SVOA measured the Isopar™ L post-contactor concentration to be 25 mg/L, HPLC measured 39 mg/L of Modifier. For moderate-flow (0.54 gpm aqueous) conditions, SVOA measured the Isopar™ L postcontactor to be ~69 mg/L, while the HPLC measured 56 mg/L for Modifier. For high-flow (0.8 gpm aqueous) conditions, SVOA measured the Isopar™ L post-contactor to be 39 mg/L. The post-coalescer (pre-decanter) measurements by SVOA for Isopar™ L were all less than the analysis detection limit of 10 mg/L. The HPLC measured 18, 22 and 20 mg/L Modifier for the low, medium, and high-low rates respectively. In extraction, the quantity of pre-coalescer Isopar™ L carryover measured by SVOA was ~280-410 mg/L at low flow (4 gpm aqueous), ~400-450 mg/L at moderate flow (8 gpm aqueous), and ~480 mg/L at high flow (12 gpm aqueous). The amount of post coalescer (pre-decanter) Isopar™ L carryover measured by SVOA was less than 45 mg/L for all flow rates. HPLC results for Modifier were 182, 217 and 22

Herman, D. T.; Duignan, M. R.; Williams, M. R.; Peters, T. B.; Poirier, M. R.; Fondeur, F. F.

2013-07-31

378

Constructing a plastic bottle wind turbine as a practical aid for learning about using wind energy to generate electricity  

Microsoft Academic Search

A simple horizontal axis wind turbine can be easily constructed using a 1.5 l PET plastic bottle, a compact disc and a small dynamo. The turbine operates effectively at low wind speeds and has a rotational speed of 500 rpm at a wind speed of about 14 km h?1. The wind turbine can be used to demonstrate the relationship between

S J Appleyard

2009-01-01

379

Constructing a plastic bottle wind turbine as a practical aid for learning about using wind energy to generate electricity  

Microsoft Academic Search

A simple horizontal axis wind turbine can be easily constructed using a 1.5 l PET plastic bottle, a compact disc and a small dynamo. The turbine operates effectively at low wind speeds and has a rotational speed of 500 rpm at a wind speed of about 14 km h-1. The wind turbine can be used to demonstrate the relationship between

S. J. Appleyard

2009-01-01

380

The Use of a Code-generating System for the Derivation of the Equations for Wind Turbine Dynamics  

Microsoft Academic Search

For many reasons the size of wind turbines on the rapidly growing wind energy market is increasing. Relations between aeroelastic properties of these new large turbines change. Modifications of turbine designs and control concepts are also influenced by growing size. All these trends require development of computer codes for design and certification. Moreover, there is a strong desire for design

Hans Ganander

2003-01-01

381

Coal-gasification/MHD/steam-turbine combined-cycle (GMS) power generation  

SciTech Connect

The coal-gasification/MHD/steam-turbine combined cycle (GMS) refers to magnetohydrodynamic (MHD) systems in which coal gasification is used to supply a clean fuel (free of mineral matter and sulfur) for combustion in an MHD electrical power plant. Advantages of a clean-fuel system include the elimination of mineral matter or slag from all components other than the coal gasifier and gas cleanup system; reduced wear and corrosion on components; and increased seed recovery resulting from reduced exposure of seed to mineral matter or slag. Efficiencies in some specific GMS power plants are shown to be higher than for a comparably sized coal-burning MHD power plant. The use of energy from the MHD exhaust gas to gasify coal (rather than the typical approach of burning part of the coal) results in these higher efficiencies.

Lytle, J.M.; Marchant, D.D.

1980-11-01

382

Environmental noise characteristics of the MOD5-B (3.2 MW) wind turbine generator  

NASA Technical Reports Server (NTRS)

Both narrow band and broad band acoustic data were obtained for the MOD5-B wind turbine for a range of wind speeds from 5.8 to 14.3 m/s; for a range of power outputs from 300 to 3100 kW; and for various azimuth angles and distances. Comparisons are made with those of other large machines and with predictions by available methods. The highest levels occur at the lower frequencies and generally decrease as the frequency increases. Low frequency rotational noise components were more intense than expected for an upwind machine and are believed to result from localized wind gradients across the rotor disk due to upwind terrain features. Predicted broad band spectra follow the general trends of the data but tend to underestimate the levels in the frequency range where the turbulent boundary layer-trailing edge interaction noise is expected to be significant.

Shepherd, Kevin P.; Hubbard, Harvey H.

1989-01-01

383

The probability distribution of wind power from a dispersed array of wind turbine generators  

NASA Astrophysics Data System (ADS)

A method is presented for estimating the probability distribution of wind power from a dispersed array of wind turbine sites where the correlation between wind speeds at distinct sites is less than unity. The distribution is obtained from a model for the joint probability distribution of wind speeds. This is able to incorporate arbitrary inter-site correlations. It is shown that this joint distribution reduces in the single site case to a wind speed distribution closely approximating the widely used Weibull; the multiple site power distribution is also shown to fit adequately to data on wind speeds from four sites in Western Australia. Results presented in graphical and tabular form for a range of representative cases show that a significant reduction in the variability of total wind power output may result from dispersion of aerogenerator sites; a quantitative guide to the magnitude of these effects is also provided.

Carlin, J.; Haslett, J.

1982-03-01

384

A Frequency Control Method by Wind Turbine Generator/Battery using Load Estimation in Isolated Power System  

NASA Astrophysics Data System (ADS)

This paper presents a frequency control method by a coordinated control of a wind turbine generator (WTG) and a battery energy storage system (BESS) using load estimation in an isolated power system. The load variation is assumed as a disturbance to the power system and can be estimated by using a disturbance observer. For the load estimation, H? control theory and parameter identification are applied to achieve robust control performance. Each output power command of the WTG and the BESS is determined by using the estimated load. Low frequency component in the load variation is reduced by the WTG with pitch angle control, while high frequency component in the load variation is reduced by the BESS with charge/discharge operation, respectively. In addition to the frequency control, a capacity reduction technique for BESS is proposed. The effectiveness of the proposed method is verified by numerical simulations.

Uehara, Akie; Asato, Bungo; Yona, Atsushi; Urasaki, Naomitsu; Senjyu, Tomonobu; Funabashi, Toshihisa

385

The dynamic characteristics of an isolated self-excited induction generator driven by a wind turbine  

Microsoft Academic Search

This paper presents the effect of magnetizing inductance on self-excitation. It also describes the loading analysis of an isolated induction generator, and how the operating frequency and generated voltage are affected by the change in operating slip value for regulated and unregulated rotor speed. Wind powered self-excited induction generators (SEIG) have an input wind which is not controllable, but they

D. Seyoum; M. F. Rahman

2002-01-01

386

The dynamic characteristics of an isolated self-excited induction generator driven by a wind turbine  

Microsoft Academic Search

The analysis of self-excited induction generator (SEIG) starts from its magnetizing inductance. The value of magnetizing inductance at very low terminal voltage is one of the key factors for self excitation. This paper presents the effect of magnetizing inductance on self-excitation and describes the loading analysis of an isolated induction generator. It also describes how the operating frequency and generated

C. Grantham; D. Seyoum

2008-01-01

387

Design and Analysis of an Axial Bypass Compressor Blade in a Supercritical CO2 Gas Turbine  

Microsoft Academic Search

A supercritical carbon dioxide gas turbine can generate power at a high cycle thermal efficiency, even at modest temperatures of 500-550°C. Consequently, a more reliable and economically advantageous power generation system is achieved by coupling with a Na-cooled fast reactor. This paper mainly describes the bypass compressor (a key component) design and thermal hydraulic analysis using CFD (with FLUENT code).

Takao Ishizuka; Yasushi Muto; Masanori Aritomi; Nobuyoshi Tsuzuki; Hiroshige Kikura

2010-01-01

388

Heat transfer and flow on the first-stage blade tip of a power generation gas turbine: Part 1 -- Experimental results  

Microsoft Academic Search

A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (> 100 MW). This paper is concerned with the design and execution of the experimental portion of the study, which represents the first reported investigation to

Ronald S. Bunker; Jeremy C. Bailey; Ali A. Ameri

2000-01-01

389

Adjustable speed generators for wind turbines based on doubly-fed induction machines and 4-quadrant IGBT converters linked to the rotor  

Microsoft Academic Search

Wind turbines are being built at power levels above 1.5 MW. Higher power levels are being anticipated for offshore applications. To limit mechanical stresses and power surges in these high power systems, speed control is necessary. The doubly-fed induction generator (DFIG) system is investigated as a viable alternative to adjust speed over a wide range while keeping the cost of

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

2000-01-01

390

Development of an 8 kilowatt wind turbine generator for residential type applications. Phase 1: Design and analyses. Volume 1: Executive summary  

Microsoft Academic Search

The objectives for this program were threefold. The first was to develop a technology capable of designing, building, and selling (at a cost competitive with alternative energy) wind turbine generators (WTGs) in the 8 kW size range for use in a number of rural and residential applications The second was to provide fabrication cost data which may be used to

F. M. Adler; L. G. Angeloff; P. Henton; P. W. King

1980-01-01

391

Abstract--A bi-objective optimization model of power and power changes generated by a wind turbine is discussed in this  

E-print Network

production. Power ramp rate (PRR) expresses the change of power for a given time interval, e.g., a minute of a photovoltaic generator by using an electric double-layer capacitor. Zheng et al. [3] applied data results at 10-min to 60-min intervals was demonstrated in their research. The operation of wind turbines

Kusiak, Andrew

392

The dynamic characteristics of an isolated self-excited induction generator driven by a wind turbine  

Microsoft Academic Search

This paper presents the effect of magnetizing inductance on self-excitation. It also describes the loading analysis of an isolated induction generator, and how the operating frequency and generated voltage are affected by the change in operating slip value for regulated and unregulated rotor speed. Wind-powered self-excited induction generators have an input wind which is not controllable, but they can be

D. Seyoum; C. Grantham; M. F. Rahman

2003-01-01

393

Synthetic Vortex Generator Jets Used to Control Separation on Low-Pressure Turbine Airfoils  

NASA Technical Reports Server (NTRS)

Low-pressure turbine (LPT) airfoils are subject to increasingly stronger pressure gradients as designers impose higher loading in an effort to improve efficiency and lower cost by reducing the number of airfoils in an engine. When the adverse pressure gradient on the suction side of these airfoils becomes strong enough, the boundary layer will separate. Separation bubbles, particularly those that fail to reattach, can result in a significant loss of lift and a subsequent degradation of engine efficiency. The problem is particularly relevant in aircraft engines. Airfoils optimized to produce maximum power under takeoff conditions may still experience boundary layer separation at cruise conditions because of the thinner air and lower Reynolds numbers at altitude. Component efficiency can drop significantly between takeoff and cruise conditions. The decrease is about 2 percent in large commercial transport engines, and it could be as large as 7 percent in smaller engines operating at higher altitudes. Therefore, it is very beneficial to eliminate, or at least reduce, the separation bubble.

Ashpis, David E.; Volino, Ralph J.

2005-01-01

394

CHARACTERIZATION OF A FULLY-INTEGRATED PERMANENT-MAGNET TURBINE GENERATOR  

E-print Network

capabilities when operated at high speeds [1]. Miniaturization of generators is advantageous due to the cube krpm [3]. This rotor was supported by ball bearings. More recently, Herrault et al. fabricated of 203 krpm. The 2 mm diameter rotor for this generator was polymer-based and also supported by high-speed

395

Second-Generation Pressurized Fluidized Bed Combustion: Small gas turbine induustrial plant study  

SciTech Connect

Second-Generation Pressurized Fluidized Bed Combustion (PFBC) plants provide a coal-fired, high-efficiency, combined-cycle system for the generation of electricity and steam. The plants use lime-based sorbents in PFB combustors to meet environmental air standards without back-end gas desulfurization equipment. The second-generation system is an improvement over earlier PFBC concepts because it can achieve gas temperatures of 2100[degrees]F and higher for improved cycle efficiency while maintaining the fluidized beds at 1600[degrees]F for enhanced sulfur capture and minimum alkali release. Second-generation PFBC systems are capable of supplying the electric and steam process needs of industrial plants. The basic second-generation system can be applied in different ways to meet a variety of process steam and electrical requirements. To evaluate the potential of these systems in the industrial market, conceptual designs have been developed for six second-generation PFBC plants. These plants cover a range of electrical outputs from 6.3 to 41.5 MWe and steam flows from 46,067 to 442,337 lb/h. Capital and operating costs have been estimated for these six plants and for equivalent (in size) conventional, coal-fired atmospheric fluidized bed combustion cogeneration plants. Economic analyses were conducted to compare the cost of steam for both the second-generation plants and the conventional plants.

Shenker, J.; Garland, R.; Horazak, D.; Seifert, F.; Wenglarz, R.

1992-07-01

396

Second-Generation Pressurized Fluidized Bed Combustion: Small gas turbine industrial plant study  

SciTech Connect

Second-Generation Pressurized Fluidized Bed Combustion (PFBC) plants provide a coal-fired, high-efficiency, combined-cycle system for the generation of electricity and steam. The plants use lime-based sorbents in PFB combustors to meet environmental air standards without back-end gas desulfurization equipment. The second-generation system is an improvement over earlier PFBC concepts because it can achieve gas temperatures of 2100{degrees}F and higher for improved cycle efficiency while maintaining the fluidized beds at 1600{degrees}F for enhanced sulfur capture and minimum alkali release. Second-generation PFBC systems are capable of supplying the electric and steam process needs of industrial plants. The basic second-generation system can be applied in different ways to meet a variety of process steam and electrical requirements. To evaluate the potential of these systems in the industrial market, conceptual designs have been developed for six second-generation PFBC plants. These plants cover a range of electrical outputs from 6.3 to 41.5 MWe and steam flows from 46,067 to 442,337 lb/h. Capital and operating costs have been estimated for these six plants and for equivalent (in size) conventional, coal-fired atmospheric fluidized bed combustion cogeneration plants. Economic analyses were conducted to compare the cost of steam for both the second-generation plants and the conventional plants.

Shenker, J.; Garland, R.; Horazak, D.; Seifert, F.; Wenglarz, R.

1992-07-01

397

Constructing a Plastic Bottle Wind Turbine as a Practical Aid for Learning about Using Wind Energy to Generate Electricity  

ERIC Educational Resources Information Center

A simple horizontal axis wind turbine can be easily constructed using a 1.5 l PET plastic bottle, a compact disc and a small dynamo. The turbine operates effectively at low wind speeds and has a rotational speed of 500 rpm at a wind speed of about 14 km h[superscript -1]. The wind turbine can be used to demonstrate the relationship between open…

Appleyard, S. J.

2009-01-01

398

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

E-print Network

pollution and noise exposure for the population [3]. This work is funded by the French Navy and is supported) The gearbox: it can be used to increase the drive speed of the generator. Nonetheless, this element causes

Paris-Sud XI, Université de

399

Operating experience with four 200 kW Mod-0A wind turbine generators  

NASA Technical Reports Server (NTRS)

The windpowered generator, Mod-0A, and its advantages and disadvantages, particularly as it affects reliability, are discussed. The machine performance with regard to power availability and power output is discussed.

Birchenough, A. G.; Saunders, A. L.; Nyland, T. W.; Shaltens, R. K.

1982-01-01

400

The dynamics of an isolated self-excited induction generator driven by a wind turbine  

Microsoft Academic Search

This paper presents the effect of magnetizing inductance in self-excitation and also the minimum and maximum value of speeds necessary to initiate the self-excitation process in an isolated three-phase induction generator for a given capacitance value and load. Wind powered self-excited induction generators (SEIG) have an input which is not controllable, wind, but they can be set to operate within

D. Seyoum; C. Grantham; F. Rahman

2001-01-01

401

Hydraulic Car  

NSDL National Science Digital Library

In this activity, learners build cars using syringes and water-powered hydraulics. Learners construct the car frame out of cardboard and set up a hydraulic system to raise and lower the car. Use this project to introduce learners to incompressible fluids and Pascal's Principle.

Workshop, Watsonville E.

2011-01-01

402

Kaman 40 kW wind turbine generator - control system dynamics  

NASA Technical Reports Server (NTRS)

The generator design incorporates an induction generator for application where a utility line is present and a synchronous generator for standalone applications. A combination of feed forward and feedback control is used to achieve synchronous speed prior to connecting the generator to the load, and to control the power level once the generator is connected. The dynamics of the drive train affect several aspects of the system operation. These were analyzed to arrive at the required shaft stiffness. The rotor parameters that affect the stability of the feedback control loop vary considerably over the wind speed range encountered. Therefore, the controller gain was made a function of wind speed in order to maintain consistent operation over the whole wind speed range. The velocity requirement for the pitch control mechanism is related to the nature of the wind gusts to be encountered, the dynamics of the system, and the acceptable power fluctuations and generator dropout rate. A model was developed that allows the probable dropout rate to be determined from a statistical model of wind gusts and the various system parameters, including the acceptable power fluctuation.

Perley, R.

1981-01-01

403

Failure analysis of a Francis turbine runner  

NASA Astrophysics Data System (ADS)

The variable demand on the energy market requires great flexibility in operating hydraulic turbines. Therefore, turbines are frequently operated over an extended range of regimes. Francis turbines operating at partial load present pressure fluctuations due to the vortex rope in the draft tube cone. This phenomenon generates strong vibrations and noise that may produce failures on the mechanical elements of the machine. This paper presents the failure analysis of a broken Francis turbine runner blade. The failure appeared some months after the welding repair work realized in situ on fatigue cracks initiated near to the trailing edge at the junction with the crown, where stress concentration occurs. In order to determine the causes that led to the fracture of the runner blade, the metallographic investigations on a sample obtained from the blade is carried out. The metallographic investigations included macroscopic and microscopic examinations, both performed with light and scanning electron microscopy, as well as EDX - analyses. These investigations led to the conclusion, that the cracking of the blade was caused by fatigue, initiated by the surface unevenness of the welding seam. The failure was accelerated by the hydrogen embrittlement of the filling material, which appeared as a consequence of improper welding conditions. In addition to the metallographic investigations, numerical computations with finite element analysis are performed in order to evaluate the deformation and stress distribution on blade.

Frunz?verde, D.; Muntean, S.; M?rginean, G.; Câmpian, V.; Mar?avina, L.; Terzi, R.; ?erban, V.

2010-08-01

404

A Study on Wind-Turbine Generator System Sizing Considering Overcurrent Relay Coordination With SFCL  

Microsoft Academic Search

This paper analyses the effect of a superconducting fault current limiter (SFCL) on the optimal sizing of a wind-tur- bine generator system (WTGS), which is a representative renew- able energy source. When the WTGS is connected to a radial dis- tribution system, the level of fault current during a contingency is increased. This increased fault current can reduce the coordi-

Hee-Jin Lee; Gumtae Son; Jung-Wook Park

2011-01-01

405

Doubly fed induction generator (DFIG) in wind turbine modeling and power flow control  

Microsoft Academic Search

In this work, the doubly fed induction generator (DFIG) for wind energy conversion system is studied. First, the dq model of the wound rotor induction machine in rotor reference frame and then how it can be implemented in simulink for fast simulations. In order to control the power flowing between the stator of (DFIG) and the grid, a control law

M. B. Mohamed; M. Jemli; M. Gossa; K. Jemli

2004-01-01

406

Modeling of Wind Turbines Based on Doubly-Fed Induction Generators for Power System Stability Studies  

Microsoft Academic Search

This paper deals with modeling of the doubly-fed induction generator (DFIG) and the corresponding converter for stability studies. To enable efficient computation, a reduced-order DFIG model is developed that restricts the calculation to the fundamental frequency component. However, the model enhancement introduced in this paper allows the consideration of the alternating components of the rotor current as well, which is

Istvan Erlich; JÖrg Kretschmann; Jens Fortmann; Stephan Mueller-Engelhardt; Holger Wrede

2007-01-01

407

Velocity pump reaction turbine  

DOEpatents

An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

House, Palmer A. (Walnut Creek, CA)

1984-01-01

408

Operating experience with the 200 kW MOD-OA wind turbine generators  

NASA Technical Reports Server (NTRS)

The machine configuration and its advantages and disadvantages, particularly as it affects reliability are discussed. The machine performance, both availability and power output characteristics are described. The Mod-OA operational experience is documented. The characteristics of the wind energy generated, the machine performance, and the subsystem strengths and weaknesses are discussed. An assessment of the project success in fulfilling its goals and objectives is also presented.

Birchenough, A. G.; Saunders, A. L.; Nyland, T. W.; Shaltens, R. K.

1981-01-01

409

The single-phase brushless doubly-fed machine as a generator for wind turbines  

Microsoft Academic Search

This paper proposes a single-phase variant of the Brushless Doubly-Fed Machine, the Single-Phase BDFM, SPB. Like the BDFM it is a variable speed generator which requires a converter rated at only a fraction of the machine rating, using structure with no brushes. Unlike the BDFM, most of its power is delivered directly into a single-phase grid connection. As such it

Thomas Logan; Teng Long; Richard McMahon

2011-01-01

410

The use of propeller turbines in low head stand alone micro hydro electric power generation units  

Microsoft Academic Search

The mountainous regions of developing countries offer a great potential for small scale hydroelectric schemes, running as stand alone units. Such schemes with power output less than 100kW are usually referred to as micro-hydro power generation units. For low—head sites (available head less than 10 m), there is a vast number of suitable sites in countries with less mountainous areas

G. M. Demetriades; A. A. Williams; N. P. A. Smith

1995-01-01

411

Comparison of stator and rotor induced transients in solid rotor turbine generators  

Microsoft Academic Search

The eddy current distribution arising from stator and rotor decrement tests are calculated in the cross -section of a 333 MVA 4-pole generator. The stator winding is represented by an equivalent current sheet, voltages in it being calculated from a two-axis consideration of the air-gap field, Coupling equations for the field in the machine and the windings are formulated with

A. Hannalla; D. MacDonald

1979-01-01

412

Three-Dimensional Measurements of Fuel Distribution in High-Pressure, High- Temperature, Next-Generation Aviation Gas Turbine Combustors  

NASA Technical Reports Server (NTRS)

In our world-class, optically accessible combustion facility at the NASA Lewis Research Center, we have developed the unique capability of making three-dimensional fuel distribution measurements of aviation gas turbine fuel injectors at actual operating conditions. These measurements are made in situ at the actual operating temperatures and pressures using the JP-grade fuels of candidate next-generation advanced aircraft engines for the High Speed Research (HSR) and Advanced Subsonics Technology (AST) programs. The inlet temperature and pressure ranges used thus far are 300 to 1100 F and 80 to 250 psia. With these data, we can obtain the injector spray angles, the fuel mass distributions of liquid and vapor, the degree of fuel vaporization, and the degree to which fuel has been consumed. The data have been used to diagnose the performance of injectors designed both in-house and by major U.S. engine manufacturers and to design new fuel injectors with overall engine performance goals of increased efficiency and reduced environmental impact. Mie scattering is used to visualize the liquid fuel, and laser-induced fluorescence is used to visualize both liquid and fuel vapor.

Hicks, Yolanda R.; Locke, Randy J.; Anderson, Robert C.; Zaller, Michelle M.

1998-01-01

413

Hydraulic calipers  

NASA Technical Reports Server (NTRS)

Hydraulic calipers determine area of annular openings in irregular or concealed passages. With modifications the device could be adapted to investigations of cross-sectional changes in heat flow passages, ducts, conduits, and heat exchanger elements.

Benson, J. A.

1969-01-01

414

Control of a dynamic brake to reduce turbine-generator shaft transient torques  

SciTech Connect

A resistive, thyristor-controlled brake is used to damp transient torques in large thermo-electric generators supplying series-compensated transmission lines. Emphasis is placed on developing a suitable control algorithm and testing the algorithm through a wide variety of different operating configurations. Discrete-level Generalized Predictive Control is examined as one possible approach to optimal control of the brake. Some problems with implementation of GPC on the system are discussed. Prony analysis is used to identify system transfer functions which are then related to control design considerations and robustness properties.

Donnelly, M.K.; Smith, J.R.; Johnson, R.M. (Montana State Univ., Bozeman, MT (United States)); Hauer, J.F. (Bonneville Power Administration, Kalispell, MT (United States)); Brush, R.W. (Montana Power Co., Butte, MT (United States)); Adapa, R. (Electric Power Research Inst., Palo Alto, CA (United States))

1993-02-01

415

Replacing methyl chloroform for cleaning turbine generator components and NDE applications  

SciTech Connect

Industrial applications of methyl chloroform (1,1,1-trichloroethane) have proven to be a significant concern to the environment. As a chlorofluorocarbon (CFC), the chemical is classified by the Environmental Protection Agency as an ozone-layer-depleting substance (OLDS). CFCs are effective cleaners of organic-based materials (oils, greases, cutting fluids, etc.). The Westinghouse Power Generation Business Unit (PGBU) has taken a proactive approach to this problem and instituted two programs in 1991 and 1992 to eliminate their consumption of CFCs. The scope of the first program was to establish an alternate cleaner for the removal of oil on generator stator windings. The second program built on the work of the first program, extending the scope to include general purpose cleaning of various contaminants prior to and at the completion of nondestructive examinations (NDE). The article that follows details the methodology, results, discussions, and conclusions of the second program and the data extrapolated from the first program. The specific NDE qualification requirements are highlighted in the methodology section.

Bailey, K.P.; O'Shanka, J.J.; Corley, T.J. (Westinghouse Electric Corp., Orlando, FL (United States). Power Generation Business Unit); Sadhir, R.K. (Westinghouse Electric Corp. Science and Technology Center, Pittsburgh, PA (United States))

1993-08-01

416

Wind turbine acoustics  

Microsoft Academic Search

Available information on the physical characteristics of the noise generated by wind turbines is summarized, with example sound pressure time histories, narrow- and broadband frequency spectra, and noise radiation patterns. Reviewed are noise measurement standards, analysis technology, and a method of characterizing wind turbine noise. Prediction methods are given for both low-frequency rotational harmonics and broadband noise components. Also included

Harvey H. Hubbard; Kevin P. Shepherd

1990-01-01

417

Predicting Noise From Wind Turbines  

NASA Technical Reports Server (NTRS)

Computer program WINDY predicts broadband noise spectra of horizontal-axis wind-turbine generators. Enables adequate assessment of impact of broadband wind-turbine noise. Effects of turbulence, trailing-edge wakes, and bluntness taken into account. Program has practical application in design and siting of wind-turbine machines acceptable to community. Written in GW-Basic.

Grosveld, Ferdinand W.

1990-01-01

418

Turbopump Turbines developed by Volvo  

Microsoft Academic Search

This paper describes the design and development process for the Rocket Turbopump turbines, which has been developed by Volvo. Volvo has designed Vulcain, Vulcain 2 and Vinci turbines for hydrogen and oxygen turbopump, and is in the midst of testing the newly developed turbines for Vinci turbopumps. Conceptual work for the third generation of Vulcain turbopumps is under process. The

S. Trollheden; B. Bergenlid; S. Brodin; Volvo Aero

419

Effect of water injection and off scheduling of variable inlet guide vanes, gas generator speed and power turbine nozzle angle on the performance of an automotive gas turbine engine  

NASA Technical Reports Server (NTRS)

The Chrysler/ERDA baseline automotive gas turbine engine was used to experimentally determine the power augmentation and emissions reductions achieved by the effect of variable compressor and power engine geometry, water injection downstream of the compressor, and increases in gas generator speed. Results were dependent on the mode of variable geometry utilization. Over 20 percent increase in power was accompanied by over 5 percent reduction in SFC. A fuel economy improvement of at least 6 percent was estimated for a vehicle with a 75 kW (100 hp) engine which could be augmented to 89 kW (120 hp) relative to an 89 Kw (120 hp) unaugmented engine.

Warren, E. L.

1980-01-01

420

Gaseous fuels (derived from oil shale) for heavy-duty gas turbines and combined-cycle power generators  

Microsoft Academic Search

Using the TURBOMATCH and GATE\\/CYCLE computational thermal-models, detailed design-point performance predictions (relating to efficiency, net specific work and fuel flow), when a low-calorific-value fuel gas is employed (instead of natural gas) are presented. With slight modifications in the fuel supply, combustor and turbomachinery of the engine, in order to accommodate the increase in the mass flow rate across the turbine’s

J. O. Jaber; S. D. Probert; P. T. Williams

1998-01-01

421

Enhancing consumers' voluntary use of small-scale wind turbines to generate own electricity in South Africa  

Microsoft Academic Search

This paper investigates whether South African households and small businesses can take advantage of the country’s substantial wind resources to produce their own power from small-scale wind turbines in a viable way. The viability of small-scale wind turbines is assessed by means of a financial analysis based on the internal rate of return method. The recently announced wind feed-in tariff

Brendan Whelan; Edwin Muchapondway

2009-01-01

422

Development of a more fish-tolerant turbine runner, advanced hydropower turbine project  

SciTech Connect

Alden Research Laboratory, Inc. (ARL) and Northern Research and Engineering Corporation (NREC) conducted a research program to develop a turbine runner which will minimize fish injury and mortality at hydroelectric projects. ARL?NREC have developed a runner shape which minimizes the number of blade leading edges, reduces the pressure versus time and the velocity versus distance gradients within the runner, minimizes or eliminates the clearance between the runner and runner housing, and maximizes the size of the flow passages, all with minimal penalty on turbine efficiency. An existing pump impeller provided the starting point for developing the fish tolerant turbine runner. The Hidrostal pump is a single bladed combined screw/centrifugal pump which has been proven to transport fish with minimal injury. The focus of the ARL/NREC research project was to develop a new runner geometry which is effective in downstream fish passage and hydroelectric power generation. A flow of 1,000 cfs and a head in the range of 75 ft to 100 ft were selected for conceptual design of the new runner. Conceptual design of the new runner began with a re-evaluation of studies which have been previously conducted to identify probable sources of injury to fish passing through hydraulic turbines. Criteria relative to hydraulic characteristics which are favorable for fish passage were prepared based on a reassessment of the available information. Important criteria used to develop the new runner design included low pressure change rates, minimum absolute pressures, and minimum shear. Other criteria which are reflected in the runner design are a minimum number of blades (only two), minimum total length of leading edges, and large flow passages. 86 figs., 5 tabs.

Cook, T.C.; Hecker, G.E. [Worcester Polytechnic Inst., Holden, MA (United States). Alden Research Lab.; Faulkner, H.B.; Jansen, W. [Northern Research and Engineering Corp., Woburn, MA (United States)

1997-02-01

423

An integrated system combining chemical looping hydrogen generation process and solid oxide fuel cell/gas turbine cycle for power production with CO2 capture  

NASA Astrophysics Data System (ADS)

In this paper, the solid oxide fuel cell/gas turbine (SOFC/GT) cycle is integrated with coal gasification and chemical looping hydrogen generation (CLHG) for electric power production with CO2 capture. The CLHG-SOFC/GT plant is configurated and the schematic process is modeled using Aspen Plus® software. Syngas, produced by coal gasification, is converted to hydrogen with CO2 separation through a three-reactors CLHG process. Hydrogen is then fueled to SOFC for power generation. The unreacted hydrogen from SOFC burns in a combustor and drives gas turbine. The heat of the gas turbine exhaust stream is recovered in HRSG for steam bottoming cycle. At a system pressure of 20 bar and a cell temperature of 900 °C, the CLHG-SOFC/GT plant has a net power efficiency of 43.53% with no CO2 emissions. The hybrid power plant performance is attractive because of high energy conversion efficiency and zero-CO2-emission. Key parameters that influence the system performance are also discussed, including system operating pressure, cell temperature, fuel utilization factor, steam reactor temperature, CO2 expander exhaust pressure and inlet gas preheating.

Chen, Shiyi; Xue, Zhipeng; Wang, Dong; Xiang, Wenguo

2012-10-01

424

Evaluation test on a landfill gas-fired turbine at the Los Angeles County Sanitation District's Puente Hill Landfill Electric Generation Station. Air pollution test report  

SciTech Connect

A cooperative test program was conducted from February 25 through February 27, 1986 by Air Resources Board (ARB) and South Coast Air Quality Management District (SCAQMD) staff to evaluate the gaseous constituents from untreated landfill gas used to fuel a turbine and the emissions from that turbine located at the Los Angeles County Sanitation District's Puente Hills Electric Generating Station. The turbine was fueled with gases generated by the anaerobic decomposition of buried refuse at the Los Angeles County Sanitation District's Puente Hills Landfill. Emissions of criteria pollutant as determined from ARB test data are reported. Mass flow rates and destruction and removal efficiencies (DRE) of non-criteria pollutant compounds determined at the stack from SCQAMD bag-sample test data and mass-flow rates and DRE's for chlorinated and aromatic compounds determined from data from ARB resin samples are presented. Destruction and removal efficiencies based on mass-flow rates for chlorinated compounds ranged from 17 to 99+ percent and for aromatic compounds ranged from negative to 99+ percent. The possible formation of the compounds - chlorinated dioxins, furans, and polychlorinated biphenyls - was considered and samples were taken for analyses for these compounds. Dioxins, furans, and polychlorinated biphenyls were not detected in the inlet nor the outlet gas stream samples.

Not Available

1986-07-01

425

5th International Meeting Wind Turbine Noise  

E-print Network

1 5th International Meeting on Wind Turbine Noise Denver 28 ­ 30 August 2013 Wind Turbine Noise Broadband noise generated aerodynamically is the dominant noise source for a modern wind turbine(Brooks et, clean energy. While profiting from wind energy, the noise produced by a modern wind turbine becomes

Paris-Sud XI, Université de

426

Environmental Assessment for the Installation and Operation of Combustion Turbine Generators at Los Alamos National Laboratory, Los Alamos, New Mexico  

SciTech Connect

NEPA requires Federal agency officials to consider the environmental consequences of their proposed actions before decisions are made. In complying with NEPA, the U.S. DOE, NNSA, follows the Council on Environmental Quality regulations (40 Code of Federal Regulations [CFR] 1500-1508) and DOE's NEPA implementing procedures (10 CFR 1021). The purpose of an environmental assessment (EA) is to provide Federal decision makers with sufficient evidence and analysis to determine whether to prepare an environmental impact statement (EIS) or issue a Finding of No Significant Impact (FONSI). At this time, the NNSA must make a decision regarding installing, operating and maintaining two approximately 20 Megawatt (MW) combustion turbine generators (CTGs) within the Technical Area (TA)-3 Co-generation Complex (Building 3-22) at Los Alamos National Laboratory (LANL). LANL is a Federal facility located at Los Alamos, New Mexico, that comprises 43 square miles (111 square kilometers) of buildings, structures, and forested land (Figure 1). LANL is administered by NNSA for the Federal government and managed and operated under contract by the University of California (UC). This EA has been prepared to assess the potential environmental consequences of the Proposed Action--installing and operating two CTGs--and of the No Action Alternative. The objectives of this EA are to (1) describe the underlying purpose and need for DOE action; (2) describe the Proposed Action and identify and describe any reasonable alternatives that satisfy the purpose and need for Agency Action; (3) describe baseline environmental conditions at LANL; (4) analyze the potential indirect, direct, and cumulative effects to the existing environment from implementation of the Proposed Action; and (5) compare the effects of the Proposed Action with the effects of the No Action Alternative and other reasonable alternatives. For the purposes of compliance with NEPA, reasonable alternatives are identified as being those that meet NNSA's purpose and need for action by virtue of timeliness, appropriate technology, and applicability to LANL. The EA process provides NNSA with environmental information that can be used in developing mitigation, if necessary, to minimize or avoid adverse effects to the quality of the human environment and natural ecosystems should NNSA decide to proceed with implementing the Proposed Action at LANL.

N /A

2002-12-12

427

Fish-Friendly Hydropower Turbine Development & Deployment: Alden Turbine Preliminary Engineering and Model Testing  

SciTech Connect

The Alden turbine was developed through the U.S. Department of Energy's (DOE's) former Advanced Hydro Turbine Systems Program (1994-2006) and, more recently, through the Electric Power Research Institute (EPRI) and the DOE's Wind & Water Power Program. The primary goal of the engineering study described here was to provide a commercially competitive turbine design that would yield fish passage survival rates comparable to or better than the survival rates of bypassing or spilling flow. Although the turbine design was performed for site conditions corresponding to 92 ft (28 m) net head and a discharge of 1500 cfs (42.5 cms), the design can be modified for additional sites with differing operating conditions. During the turbine development, design modifications were identified for the spiral case, distributor (stay vanes and wicket gates), runner, and draft tube to improve turbine performance while maintaining features for high fish passage survival. Computational results for pressure change rates and shear within the runner passage were similar in the original and final turbine geometries, while predicted minimum pressures were higher for the final turbine. The final turbine geometry and resulting flow environments are expected to further enhance the fish passage characteristics of the turbine. Computational results for the final design were shown to improve turbine efficiencies by over 6% at the selected operating condition when compared to the original concept. Prior to the release of the hydraulic components for model fabrication, finite element analysis calculations were conducted for the stay vanes, wicket gates, and runner to verify that structural design criteria for stress and deflections were met. A physical model of the turbine was manufactured and tested with data collected for power and efficiency, cavitation limits, runaway speed, axial and radial thrust, pressure pulsations, and wicket gate torque. All parameters were observed to fall within ranges expected for conventional radial flow machines. Based on these measurements, the expected efficiency peak for prototype application is 93.64%. These data were used in the final sizing of the supporting mechanical and balance of plant equipment. The preliminary equipment cost for the design specification is $1450/kW with a total supply schedule of 28 months. This equipment supply includes turbine, generator, unit controls, limited balance of plant equipment, field installation, and commissioning. Based on the selected head and flow design conditions, fish passage survival through the final turbine is estimated to be approximately 98% for 7.9-inch (200-mm) fish, and the predicted survival reaches 100% for fish 3.9 inches (100 mm) and less in length. Note that fish up to 7.9- inches (200 mm) in length make up more than 90% of fish entrained at hydro projects in the United States. Completion of these efforts provides a mechanical and electrical design that can be readily adapted to site-specific conditions with additional engineering development comparable to costs associated with conventional turbine designs.

None

2011-10-01

428

Calculating the Energy Cost of CO2 Removal in a Coal Based Gas Turbine Fuel Cell Hybrid Power Generation System with an Isolated Anode Stream  

SciTech Connect

In recent years there has been significant interest in identifying carbon capturing technologies that can be applied to fossil fuel power generation plants.CO2 capture technologies seek to reduce the amount of CO2 that would normally be emitted into the atmosphere from the daily operation of these plants. In terms of system efficiency and operating costs, this carbon capture is expensive. Further, the additional equipment that would be used to capture CO2 emissions greatly adds to the complexity of the system. There has also been significant interest in coal based gas turbine fuel cell hybrid power plants. A hybrid power plant can have much greater system efficiency than a normal gas turbine power plant because the heat that is normally unused in a standalone solid oxide fuel cell (SOFC) is recovered and used to drive a power producing turbine. It is thought that the increased system efficiency of the hybrid system might compensate for the increased expense of performing carbon capture. In order to provide some analytical insight on this tradeoff we present a 100 MW class coal fired gas turbine SOFC hybrid power generation system. The hybrid system operates at a pressure ratio of 6, and uses heat recuperation and cathode air recirculation to control the SOFC inlet temperature and the temperature change across the SOFC. A carbon capture scheme is added to this system in order to calculate the relative energy cost in terms of system efficiency due to CO2 ompression. The carbon capture is performed by burning the unused fuel from the SOFC in an isolated anode stream using pure O2 injection. The resulting heat that is generated from this process is then used to drive a secondary turbine that is placed in the anode exhaust stream where more work is extracted. With an isolated anode stream, the products of combustion from this secondary combustion process are mostly water and carbon dioxide. The water by-product is then condensed out of the stream leaving a relatively high concentration of CO2. This is then compressed, and removed from the system. In this study we present power plant efficiency calculations for the performance of the hybrid system with the carbon capturing loop. Our results show the effects on system performance that result from a changing fuel utilization factor.

Vanosdol, J.G.; Gemmen, R.S.; Liese, E.A.

2007-10-01

429

MOD-2 wind turbine farm stability study  

NASA Technical Reports Server (NTRS)

The dynamics of single and multiple 2.5 ME, Boeing MOD-2 wind turbine generators (WTGs) connected to utility power systems were investigated. The analysis was based on digital simulation. Both time response and frequency response methods were used. The dynamics of this type of WTG are characterized by two torsional modes, a low frequency 'shaft' mode below 1 Hz and an 'electrical' mode at 3-5 Hz. High turbine inertia and low torsional stiffness between turbine and generator are inherent features. Turbine control is based on electrical power, not turbine speed as in conventional utility turbine generators. Multi-machine dynamics differ very little from single machine dynamics.

Hinrichsen, E. N.

1980-01-01

430

Design of a hybrid battery charger system fed by a wind-turbine and photovoltaic power generators.  

PubMed

This paper is aimed to develop a digital signal processor (DSP) for controlling a solar cell and wind-turbine hybrid charging system. The DSP consists of solar cells, a wind turbine, a lead acid battery, and a buck-boost converter. The solar cells and wind turbine serve as the system's main power sources and the battery as an energy storage element. The output powers of solar cells and wind turbine have large fluctuations with the weather and climate conditions. These unstable powers can be adjusted by a buck-boost converter and thus the most suitable output powers can be obtained. This study designs a booster by using a dsPIC30F4011 digital signal controller as a core processor. The DSP is controlled by the perturbation and observation methods to obtain an effective energy circuit with a full 100 W charging system. Also, this DSP can, day and night, be easily controlled and charged by a simple program, which can change the state of the system to reach a flexible application based on the reading weather conditions. PMID:21456789

Chang Chien, Jia-Ren; Tseng, Kuo-Ching; Yan, Bo-Yi

2011-03-01

431

Design of a hybrid battery charger system fed by a wind-turbine and photovoltaic power generators  

NASA Astrophysics Data System (ADS)

This paper is aimed to develop a digital signal processor (DSP) for controlling a solar cell and wind-turbine hybrid charging system. The DSP consists of solar cells, a wind turbine, a lead acid battery, and a buck-boost converter. The solar cells and wind turbine serve as the system's main power sources and the battery as an energy storage element. The output powers of solar cells and wind turbine have large fluctuations with the weather and climate conditions. These unstable powers can be adjusted by a buck-boost converter and thus the most suitable output powers can be obtained. This study designs a booster by using a dsPIC30F4011 digital signal controller as a core processor. The DSP is controlled by the perturbation and observation methods to obtain an effective energy circuit with a full 100 W charging system. Also, this DSP can, day and night, be easily controlled and charged by a simple program, which can change the state of the system to reach a flexible application based on the reading weather conditions.

Chang Chien, Jia-Ren; Tseng, Kuo-Ching; Yan, Bo-Yi

2011-03-01

432

Steam turbine control  

SciTech Connect

In a power plant which includes a steam turbine with main control valves for admitting steam into the steam turbine and a steam bypass with bypass control valves for diverting steam around the steam turbine directly into a condenser, it is necessary to coordinate the operation of the respective valves so that the steam turbine can be started, brought up to speed, synchronized with a generator and then loaded as smoothly and efficiently as possible. The present invention provides for such operation and, in addition, allows for the transfer of power plant operation from the so-called turbine following mode to the boiler following mode through the use of the sliding pressure concept. The invention described is particularly applicable to combined cycle power plants.

Priluck, D.M.; Wagner, J.B.

1982-05-11

433

Optimizing small wind turbine performance in battery charging applications  

Microsoft Academic Search

Many small wind turbine generators (10 kW or less) consist of a variable speed rotor driving a permanent magnet synchronous generator (alternator). One application of such wind turbines is battery charging, in which the generator is connected through a rectifier to a battery bank. The wind turbine electrical interface is essentially the same whether the turbine is part of a

Stephen Drouilhet; Eduard Muljadi; Richard Holz; Vahan Gevorgian

1995-01-01

434

7 CFR 3201.107 - Water turbine bearing oils.  

Lubricants that are specifically formulated for use in the bearings found in water turbines for electric power generation. Previously designated turbine drip oils are used to lubricate bearings of shaft driven water well turbine pumps. (b) Minimum biobased...

2014-01-01

435

Topping Turbines: Adding New Life to Older Plants  

E-print Network

pressure, non-condensing turbine (topping turbine) . The high pressure steam generated in the new boilers is supplied to the throttle of the high pressure turbine and exhausted at the pressure required by the existing, old, low pressure, condensing...

Cadrecha, M.

1984-01-01

436

77 FR 32497 - Grant of Authority for Subzone Status; Mitsubishi Power Systems Americas, Inc. (Wind Turbine...  

Federal Register 2010, 2011, 2012, 2013

...Power Systems Americas, Inc. (Wind Turbine Nacelles and Generating Sets) Fort Smith...special-purpose subzone at the wind turbine nacelle and generating set manufacturing...activity related to the manufacturing of wind turbine nacelles and generating sets at the...

2012-06-01

437

Electrokinetic high pressure hydraulic system  

DOEpatents

A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force. The electrokinetic pump, which can generate hydraulic pressures greater than 2500 psi, can be employed to compress a fluid, either liquid or gas, and manipulate fluid flow. The pump is particularly useful for capillary-base systems. By combining the electrokinetic pump with a housing having chambers separated by a flexible member, fluid flow, including high pressure fluids, is controlled by the application of an electric potential, that can vary with time.

Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA)

2000-01-01

438

The concept of new-generation steam turbines for coal power engineering of Russia. Part 1. Economic and technical substantiation of the concept  

Microsoft Academic Search

Development of the concept of designing modern steam turbines and its application to turbines for ultrasupercritical steam conditions are considered. The results from predraft designing of a turbine for ultrasupercritical steam conditions with a capacity of around 700 MW in a two-cylinder version that corresponds to this concept are presented. Main problems relating to construction of such turbines under the

A. G. Kostyuk; V. G. Gribin; A. D. Trukhnii

2010-01-01

439

Wind turbine acoustics  

NASA Astrophysics Data System (ADS)

Available information on the physical characteristics of the noise generated by wind turbines is summarized, with example sound pressure time histories, narrow- and broadband frequency spectra, and noise radiation patterns. Reviewed are noise measurement standards, analysis technology, and a method of characterizing wind turbine noise. Prediction methods are given for both low-frequency rotational harmonics and broadband noise components. Also included are atmospheric propagation data showing the effects of distance and refraction by wind shear. Human perception thresholds, based on laboratory and field tests, are given. Building vibration analysis methods are summarized. The bibliography of this report lists technical publications on all aspects of wind turbine acoustics.

Hubbard, Harvey H.; Shepherd, Kevin P.

1990-12-01

440

Wind turbine acoustics  

NASA Technical Reports Server (NTRS)

Available information on the physical characteristics of the noise generated by wind turbines is summarized, with example sound pressure time histories, narrow- and broadband frequency spectra, and noise radiation patterns. Reviewed are noise measurement standards, analysis technology, and a method of characterizing wind turbine noise. Prediction methods are given for both low-frequency rotational harmonics and broadband noise components. Also included are atmospheric propagation data showing the effects of distance and refraction by wind shear. Human perception thresholds, based on laboratory and field tests, are given. Building vibration analysis methods are summarized. The bibliography of this report lists technical publications on all aspects of wind turbine acoustics.

Hubbard, Harvey H.; Shepherd, Kevin P.

1990-01-01

441

Effects Of Single And Three-Pole Switching And High-Speed Reclosing On Turbine-Generator Shafts And Blades  

Microsoft Academic Search

A cause of high cycle fatigue in turbine blades is the resonance of blade vibratory modes with steam excitation. Single-pole switching (SPS) and high-speed reclosing (HSR) can excite 120 Hz torque oscillations that may resonate with the coupled blade-rotor torsional natural frequency and inflict damage on the blades. Using a new advanced continuum model, this paper analyzes the effect of

Avelino Gonzalez; G. C. Kung; C. Raczkowski; C. W. Taylor; D. Thonn

1984-01-01

442

Regenerative superheated steam turbine cycles  

NASA Technical Reports Server (NTRS)

PRESTO computer program was developed to analyze performance of wide range of steam turbine cycles with special attention given to regenerative superheated steam turbine cycles. It can be used to model standard turbine cycles, including such features as process steam extraction, induction and feedwater heating by external sources, peaking, and high back pressure. Expansion line efficiencies, exhaust loss, leakages, mechanical losses, and generator losses are used to calculate cycle heat rate and generator output. Program provides power engineer with flexible aid for design and analysis of steam turbine systems.

Fuller, L. C.; Stovall, T. K.

1980-01-01

443

3rd Int'l Workshop on Micro & Nano Tech. for Power Generation & Energy Conv. (PowerMEMS'03), Makuhari, Japan, 4-5 Dec. 2003. PRELIMINARY DESIGN OF A MEMS STEAM TURBINE POWER PLANT-ON-A-CHIP  

E-print Network

. These micro heat engines could also be useful to generate power from solar radiation or scavenge energy from) Aircraft in-flight power generation, device cooled with ambient air (Tamb= - 50°C) and forced cooling is available from motion of the aircraft. Figure 1 - Cross-section schematic of micro steam-turbine power plant

Frechette, Luc G.

444

General overview of the AxialT project: A partnership for low head turbine developments  

Microsoft Academic Search

An overview of the AxialT project is presented. Initiated in 2007 by the Consortium on Hydraulic Machines, the aim of this four years project is to contribute to the study of time-dependent hydraulic phenomena in a propeller turbine. The geometry of the entire turbine is generously shared by all partners. Numerical simulations carried out by all partners are confronted with

C. Deschênes; G. D. Ciocan; V. De Henau; F. Flemming; J. Huang; M. Koller; F. A. Naime; M. Page; R. Qian; T. Vu

2010-01-01

445

Gas turbine control system having optimized ignition air flow control  

Microsoft Academic Search

This patent describes apparatus for generating an ignition enabling signal for use with a given combustion turbine, wherein a turbine speed signal is given and wherein the combustion turbine includes ignition means for igniting the turbine in response to an ignition enabling signal. It comprises: sensor means for sensing the temperature of ambient air and for generating an ambient air

S. E. Mumford; W. L. McCarty

1992-01-01

446

Study on safety operation for large hydroelectric generator unit  

NASA Astrophysics Data System (ADS)

Hydroelectric generator unit is a complex mechanical system which is composed of hydraulic turbine and electric generator. Rotary system is supported by the bearing bracket and the reinforced concrete structures, and vibration problem can't be avoided in the process of operating. Many large-scale hydroelectric units have been damaged because of the vibration problem in recent years. As the increase of the hydraulic turbine unit capacity and water head, the safe operation of hydraulic turbine has become a focus research in many countries. The operating characteristics of the hydraulic turbine have obvious differences at different working conditions. Based on the combination of field measurement and theoretical calculation, this paper shows a deep research on the safe operation of a large-scale Francis turbine unit. Firstly, the measurements of vibration, swing, pressure fluctuation and noise were carried out at 4 different heads. And also the relationships between vibrations and pressure fluctuations at different heads and working conditions were analysed deeply. Then the scientific prediction of safe operation for the unit at high head were done based on the CFD numerical calculation. Finally, this paper shows the division of the operating zone for the hydroelectric unit. According to the experimental results (vibrations, swings, pressure fluctuations and noise) as well as the theoretical results, the operating zone of the unit has been divided into three sections: prohibited operating zone, transition operating zone and safe operating zone. After this research was applied in the hydropower station, the security and economic efficiency of unit increased greatly, and enormous economic benefits and social benefits have been obtained.

Yan, Z. G.; Cui, T.; Zhou, L. J.; Zhi, F. L.; Wang, Z. W.

2012-11-01

447

In-line hydraulic dashpot  

NASA Astrophysics Data System (ADS)

An in-line hydraulic dashpot is disclosed that effectively decelerates the piston of a power cylinder by controllably choking off the oil which is providing pressure to the piston. The in-line hydraulic dashpot of the invention includes a valve spool member movable between an open and closed position along a fluid flow path that supplies oil to the power cylinder. An actuator rod is cooperative with the valve spool member and the piston shaft of the power cylinder to move tile valve spool member between its open and closed positions. The in-line hydraulic dashpot eliminates the clashing of mechanical parts and therewith eliminates the noise that would otherwise be generated thereby. The in-line hydraulic dashpot of the present invention makes possible the adaptation of a fixed stroke power cylinder to applications that call for a variable stroke length.

Moody, Paul E.

1992-10-01

448

Hydraulic fracturing-1  

SciTech Connect

This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

Not Available

1990-01-01

449

Fireproof Brake Hydraulic System.  

National Technical Information Service (NTIS)

The feasibility of a fireproof two-fluid brake hydraulic system which utilizes nonflammable chlorotrifluoroethylene (CTFE) fluid in a dead ended brake hydraulic system mechanically isolated from the primary MIL-H-5606 hydraulic system was studied. Experim...

S. M. Warren, J. R. Kilner

1981-01-01

450

Fireproof Hydraulic Brake System.  

National Technical Information Service (NTIS)

The Fireproof Hydraulic Brake System (FHBS) flight test program verified that the FHBS is a feasible method of eliminating aircraft hydraulic fluid fires ignited by hot brakes. The FHBS uses a new nonflammable hydraulic fluid, chlorotrifluoroethylene (CTF...

M. W. Dillard

1986-01-01

451

Hydraulic servo system increases accuracy in fatigue testing  

NASA Technical Reports Server (NTRS)

Hydraulic servo system increases accuracy in applying fatigue loading to a specimen under test. An error sensing electronic control loop, coupled to the hydraulic proportional closed loop cyclic force generator, provides an accurately controlled peak force to the specimen.

Dixon, G. V.; Kibler, K. S.

1967-01-01

452

Radial turbine cooling  

NASA Technical Reports Server (NTRS)

Radial turbines have been used extensively in many applications including small ground based electrical power generators, automotive engine turbochargers and aircraft auxiliary power units. In all of these applications the turbine inlet temperature is limited to a value commensurate with the material strength limitations and life requirements of uncooled metal rotors. To take advantage of all the benefits that higher temperatures offer, such as increased turbine specific power output or higher cycle thermal efficiency, requires improved high temperature materials and/or blade cooling. Extensive research is on-going to advance the material properties of high temperature superalloys as well as composite materials including ceramics. The use of ceramics with their high temperature potential and low cost is particularly appealing for radial turbines. However until these programs reach fruition the only way to make significant step increases beyond the present material temperature barriers is to cool the radial blading.

Roelke, Richard J.

1992-01-01

453

The concept of new-generation steam turbines for coal power engineering of Russia. Part 1. Economic and technical substantiation of the concept  

Microsoft Academic Search

Development of the concept of designing modern steam turbines and its application to turbines for ultrasupercritical steam\\u000a conditions are considered. The results from predraft designing of a turbine for ultrasupercritical steam conditions with a\\u000a capacity of around 700 MW in a two-cylinder version that corresponds to this concept are presented. Main problems relating\\u000a to construction of such turbines under the

A. G. Kostyuk; V. G. Gribin; A. D. Trukhnii

2010-01-01

454

Turbine with heating and cooling  

Microsoft Academic Search

An improvement in a turbine for generating power is described. The turbine contains: (1) a casing for supporting rotor shafts; (2) shafts journalled in bearings in the casing for rotation; (3) a rotating first rotor mounted on a shaft so as to rotate therewith; the first rotor is of circular configuration, and has an entry port for a fluid near

Eskeli

1974-01-01

455

Development of a more fish tolerant turbine runner advanced hydropower turbine project. Final report  

SciTech Connect

The Hidrostal pump is a single bladed combined screw/centrifugal pump which has been proven to transport fish with minimal injury. The focus of the ARL/NREC research project was to develop a new runner geometry which is effective in downstream fish passage and hydroelectric power generation. A flow of 1,000 cfs and a head in the range of 75 ft to 100 ft were selected for conceptual design of the new runner. Criteria relative to hydraulic characteristics which are favorable for fish passage were prepared based on a reassessment of the available information. Important criteria used to develop the new runner design included low pressure change rates, minimum absolute pressures, and minimum shear. Other criteria which are reflected in the runner design are a minimum number of blades (only two), minimum total length of leading edges, and large flow passages. Flow characteristics of the new runner were analyzed using two- dimensional and three-dimensional Computational Fluid Dynamic (CFD) models. The basic runner geometry was initially selected using the two-dimensional model. The three-dimensional model was used to investigate the flow characteristics in detail through the entire runner and to refine the design by eliminating potential problem areas at the leading and trailing edges. Results of the analyses indicated that the runner has characteristics which should provide safe fish passage with an overall power efficiency of approximately 90%. The size of the new runner, which is larger than conventional turbine runners with the same design flow and head, will provide engineering, fabrication, and installation.challenges related to the turbine components and the civil works. A small reduction in the overall efficiency would reduce the size of the runner considerably, would simplify the turbine manufacturing operations, and would allow installation of the new turbine at more hydroelectric sites.

Cook, T.C.; Hecker, G.E. [Worcester Polytechnic Inst., Holden, MA (United States). Alden Research Lab.; Faulkner, H.B.; Jansen, W. [Northern Research and Engineering Corp., Cambridge, MA (United States)

1997-01-01

456

Comparison of 5th order and 3rd order machine models for doubly fed induction generator (DFIG) wind turbines  

Microsoft Academic Search

With increasing concern over climate change, a number of countries have implemented new renewable energy targets, which require significant amounts of wind generation. It is now recognized that much of this new wind generation plant will be variable speed type using doubly fed induction generators (DFIG). In order to investigate the impacts of these DFIG installations on the operation and

J. B. Ekanayake; L. Holdsworth; N. Jenkins

2003-01-01

457

Gas turbine engine fuel control  

NASA Technical Reports Server (NTRS)

A variable orifice system is described that is responsive to compressor inlet pressure and temperature, compressor discharge pressure and rotational speed of a gas-turbine engine. It is incorporated into a hydraulic circuit that includes a zero gradient pump driven at a speed proportional to the speed of the engine. The resulting system provides control of fuel rate for starting, steady running, acceleration and deceleration under varying altitudes and flight speeds.

Gold, H. S. (inventor)

1973-01-01

458

Pressure variable orifice for hydraulic control valve  

NASA Technical Reports Server (NTRS)

Hydraulic valve absorbs impact energy generated in docking or joining of two large bodies by controlling energy release to avoid jarring shock. The area of exit porting presented to the hydraulic control fluid is directly proportional to the pressure acting on the fluid.

Ammerman, R. L.

1968-01-01

459

ORCENT2. Nuclear Steam Turbine Cycle Analysis  

Microsoft Academic Search

ORCENT2 performs heat and mass balance calculations at valves-wide-open design conditions, maximum guaranteed rating conditions, and an approximation of part-load conditions for steam turbine cycles supplied with throttle steam, characteristic of contemporary light-water reactors. The program handles both condensing and back-pressure turbine exhaust arrangements. Turbine performance calculations are based on the General Electric Company method for 1800-rpm large steam turbine-generators

Fuller

1979-01-01

460

Comparative performance tests on the Mod-2, 2.5-mW wind turbine with and without vortex generators  

NASA Technical Reports Server (NTRS)

A test program was conducted on the third Mod-2 unit at Goldendale, Washington, to systematically study the effect of vortex generators (VG's) on power performance. The subject unit was first tested without VG's to obtain baseline data. Vortex generators were then installed on the mid-blade assemblies, and the resulting 70% VG configuration was tested. Finally, vortex generators were mounted on the tip assemblies, and data was recorded for the 100% VG configuration. This test program and its results are discussed in this paper. The development of vortex generators is also presented.

Miller, G. E.

1995-01-01

461

Tree Hydraulics: How Sap Rises  

ERIC Educational Resources Information Center

Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

Denny, Mark

2012-01-01

462

Duct Water Current Turbine and Extremely Low Head Helical Turbine  

NASA Astrophysics Data System (ADS)

This research introduces the Duct Water Current Turbine Triple Helix with very low head less than 2m and water current at river or in the ocean, economical ecological use for small hydro power rating between 100 to 1000 kW still represents an unsolved problem. Unlike conventional hydro installation, water current turbine in open flow and generate power from flowing water with almost zero in environmental impact. Developments in water current turbine design are reviewed and some potential advantages of duct or "diffuser augmented" current turbine and extremely low head turbine will be explored. For the output expected from the project is helical turbine with control flow on duct. The research aims to apply the helical turbine inside the duct to find the parameter of the power coefficient against tip speed ratio ?, pitch angle and twist angle y which is also the optimum parameter to design a helical cross flow turbine with duct. Parameters are obtained from numerical simulation and through the experimental result. For ducted turbines the theoretical limit depends on (i) the pressure difference that can be created between duct inlet and outlet, and (ii) the volumetric flow through the duct.

Phommachanh, Sounthisack; Sutikno, Priyono; Shinnosuke, Obi

2010-06-01

463

Single condenser arrangement for side exhaust turbine  

Microsoft Academic Search

This patent describes a large-scale power generating apparatus for converting steam energy into electrical energy. It comprises: a large turbine capable of converting steam energy into mechanical energy; a large generator for converting mechanical energy into electrical energy; a shaft disposed in and axially connecting the turbine and the generator, the shaft capable of being turned by steam energy in

Stock

1989-01-01

464

Frequency control and wind turbine technologies  

Microsoft Academic Search

Increasing levels of wind generation has resulted in an urgent need for the assessment of their impact on frequency control of power systems. Whereas increased system inertia is intrinsically linked to the addition of synchronous generation to power systems, due to differing electromechanical characteristics, this inherent link is not present in wind turbine generators. Regardless of wind turbine technology, the

Gillian Lalor; Alan Mullane; Mark O'Malley

2005-01-01

465

Advanced wind turbine design studies: Advanced conceptual study  

Microsoft Academic Search

In conjunction with the US Department of Energy and the National Renewable Energy Laboratory's Advanced Wind Turbine Program, the Atlantic Orient Corporation developed preliminary designs for the next generation of wind turbines. These 50 kW and 350 kW turbines are based upon the concept of simplicity. By adhering to a design philosophy that emphasizes simplicity, we project that these turbines

P. Hughes; R. Sherwin

1994-01-01

466

Economic Analysis of the Stability in the Wind Turbine Selection  

Microsoft Academic Search

Selection of wind turbine is one of the main factors which affect the economics of wind power projects. The current domestic economic analysis of wind turbine selection are relatively backward and the evaluation indexes are imperfect- -major concerned indicators are theoretic indicators such as characteristics of wind turbine and rated generating capacity, lacking of the assessment of actual wind turbine

Zeng Ming; A. Sikaer; Geng Weiting; Li Chen

2010-01-01

467

Heat transfer and flow on the first-stage blade tip of a power generation gas turbine: Part 1 -- Experimental results  

SciTech Connect

A combined experimental and computational study has been performed to investigate the detailed distribution of convective heat transfer coefficients on the first-stage blade tip surface for a geometry typical of large power generation turbines (> 100 MW). This paper is concerned with the design and execution of the experimental portion of the study, which represents the first reported investigation to obtain nearly full surface information on heat transfer coefficients within an environment that develops an appropriate pressure distribution about an airfoil blade tip and shroud model. A stationary blade cascade experiment has been run consisting of three airfoils, the center airfoil having a variable tip gap clearance. The airfoil models the aerodynamic tip section of a high-pressure turbine blade with inlet Mach number of 0.30, exit Mach number of 0.75, pressure ratio of 1.45, exit Reynolds number based on axial chord of 2.57 x 10{sup 6}, and total turning of about 110 degrees. A hue detection based liquid crystal method is used to obtain the detailed heat transfer coefficient distribution on the blade tip surface for flat, smooth tip surfaces with both sharp and rounded edges. The cascade inlet turbulence intensity level took on values of either 5 or 9%. The cascade also models the casing recess in the shroud surface ahead of the blade. Experimental results are shown for the pressure distribution measurements on the airfoil near the tip gap, on the blade tip surface, and on the opposite shroud surface. Tip surface heat transfer coefficient distributions are shown for sharp edge and rounded edge tip geometries at each of the inlet turbulence intensity levels.

Bunker, R.S.; Bailey, J.C.; Ameri, A.A.

2000-04-01

468

Numerical Simulation of the Francis Turbine and CAD used to Optimized the Runner Design (2nd).  

NASA Astrophysics Data System (ADS)

Hydro Power is the most important renewable energy source on earth. The water is free of charge and with the generation of electric energy in a Hydroelectric Power station the production of green house gases (mainly CO2) is negligible. Hydro Power Generation Stations are long term installations and can be used for 50 years and more, care must be taken to guarantee a smooth and safe operation over the years. Maintenance is necessary and critical parts of the machines have to be replaced if necessary. Within modern engineering the numerical flow simulation plays an important role in order to optimize the hydraulic turbine in conjunction with connected components of the plant. Especially for rehabilitation and upgrading existing Power Plants important point of concern are to predict the power output of turbine, to achieve maximum hydraulic efficiency, to avoid or to minimize cavitations, to avoid or to minimized vibrations in whole range operation. Flow simulation can help to solve operational problems and to optimize the turbo machinery for hydro electric generating stations or their component through, intuitive optimization, mathematical optimization, parametric design, the reduction of cavitations through design, prediction of draft tube vortex, trouble shooting by using the simulation. The classic design through graphic-analytical method is cumbersome and can't give in evidence the positive or negative aspects of the designing options. So it was obvious to have imposed as necessity the classical design methods to an adequate design method using the CAD software. There are many option chose during design calculus in a specific step of designing may be verified in ensemble and detail form a point of view. The final graphic post processing would be realized only for the optimal solution, through a 3 D representation of the runner as a whole for the final approval geometric shape. In this article it was investigated the redesign of the hydraulic turbine's runner, medium head Francis type, with following value for the most important parameter, the rated specific speed ns.

Sutikno, Priyono

2010-06-01

469

Electokinetic high pressure hydraulic system  

DOEpatents

A compact high pressure hydraulic system having no moving parts for converting electric potential to hydraulic force and for manipulating fluids. Electro-osmotic flow is used to provide a valve and means to compress a fluid or gas in a capillary-based system. By electro-osmotically moving an electrolyte between a first position opening communication between a fluid inlet and outlet and a second position closing communication between the fluid inlet and outlet the system can be configured as a valve. The system can also be used to generate forces as large as 2500 psi that can be used to compress a fluid, either a liquid or a gas.

Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA)

2000-01-01

470

Design study of an advanced gas generator. [which can be ignited during start-up period of turbine engines  

NASA Technical Reports Server (NTRS)

A gas generator which can be ignited reliably during the initial start-up period and offers fairly uniform gas temperature at the exit was studied numerically. Various sizes and shapes of the mixing enhancement devices and their positions were examined to evaluate the uniformity of the exit gas temperature and the change of internal pressure drop incurred by introducing the mixing enhancement devices. By introducing a turbulence ring and a splash plate with an appropriate size and position, it was possible to obtain fairly uniform gas temperature distributions and a maximum gas temperature that is within the design limit temperature of 1600 R at the generator exit. However, with the geometry studied, the pressure drop across the generator was great, approximately 1150 psi, to satisfy the assigned design limit temperature. If the design limit temperature is increased to 1650 R, the pressure drop across the generator could be lowered by as much as 350 psi.

Kim, S.; Trinh, H. P.

1993-01-01

471

Electronic module for the hydraulic system of mobile equipment used in road maintenance  

Microsoft Academic Search

Modern electro-mechanic-hydraulic systems are well suited to mobile equipment used in agriculture and road maintenance fields. This paper presents a system realized in the Hydraulic and Pneumatic Research Institute that contains a hydraulic energy generator group actuated by a thermal motor, and two rotary hydraulic motors. In order to control the hydraulic parameters, a system consisting of two proportional electro-