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1

A high power factor flyback-half-bridge converter for fluorescent lighting  

Microsoft Academic Search

This paper presents the analysis, design and practical considerations of a high power factor electronic ballast for fluorescent lamps. The proposed topology is the combination of a flyback converter and a half-bridge series-resonant parallel-loaded inverter. The high power factor is guaranteed by the use of a flyback converter operating in discontinuous-conduction mode. The high-frequency supply of the lamp is given

Ricardo N. do Prado; S. A. Bonalso; Diego S. Greff

1998-01-01

2

A high efficiency photovoltaic module integrated converter with the asymmetrical half-bridge flyback converter  

SciTech Connect

A module integrated converter (MIC) for a photovoltaic (PV) cell is important part of power conditioning system (PCS). It performs maximum power point tracking of a PV cell to generate the power as much as possible from solar energy. There are several methods for connection between the PV modules and the MICs. In order to avoid partial shading effects, converter-per-module approach was proposed. The MIC that performs maximum power point tracking (MPPT), if it is low efficiency, is no use. The MIC whose output is connected to the output of PV module was proposed for high efficiency. However, there are some problems. In this study, an asymmetrical half-bridge flyback converter is proposed instead of the original flyback converter with same method to solve the problems. The proposed MIC was built to verify the performance. The new topology using soft switching technique showed good performance for the efficiency. At the higher power, the efficiency of the proposed converter is higher than existing converter. (author)

Kim, Heeje; Kim, Jongrak; Shin, Dongsul [Department of Electrical Engineering, Pusan National University, Jangjeon, Geumjeong, Busan 609-735 (Korea); Kim, Hosung; Lee, Kyungjun [Department of Electrical Engineering, Pusan National University, Jangjeon, Geumjeong, Busan 609-735 (Korea); New and Renewable Energy System Research Center, Korea Electro-technology Research Institute, 28-1, Sungju-dong Changwon-si, Kyungsannam-do, 641-120 (Korea); Kim, Jonghyun; Yoo, Dongwook [New and Renewable Energy System Research Center, Korea Electro-technology Research Institute, 28-1, Sungju-dong Changwon-si, Kyungsannam-do, 641-120 (Korea)

2010-08-15

3

Isolated Bidirectional Full-Bridge DC–DC Converter With a Flyback Snubber  

Microsoft Academic Search

An isolated bidirectional full-bridge dc-dc converter with high conversion ratio, high output power, and soft start-up capability is proposed in this paper. The use of a capacitor, a diode, and a flyback converter can clamp the voltage spike caused by the current difference between the current-fed inductor and leakage inductance of the isolation transformer, and can reduce the current flowing

Tsai-Fu Wu; Yung-Chu Chen; Jeng-Gung Yang; Chia-Ling Kuo

2010-01-01

4

High Efficiency Flyback Converter Technology  

Microsoft Academic Search

Technologies are discussed to realize a DC\\/DC Flyback converter with high power conversion efficiency. The focus is on efficiency because of its high value in the application to process electricity generated by photovoltaic modules. Experiments with a 200 W active-clamped bidirectional Flyback converter prototype demonstrate power train efficiencies above 90% between 10% and 100% of the rated power and peak

U. Boeke

2007-01-01

5

A ZCS bidirectional flyback converter  

Microsoft Academic Search

This paper addresses the design and analysis of a zero-current-switched (ZCS) bi-directional flyback dc\\/dc converter. The converter is based on extending a previously developed unidirectional ZCS flyback converter and replacing the output diode with a controlled switch, which acts as either a rectifier or a power control switch in the corresponding power flow direction. By adding an auxiliary winding in

H. S. H. Chung; Wai-leung Cheung; Kam-shing Tang

2004-01-01

6

Research on a Novel Interleaved Flyback DC\\/DC Converter  

Microsoft Academic Search

Flyback converter has been widely used in low-power applications because of its relative simplicity when compared with other topologies. This paper proposes a novel interleaved flyback DC\\/DC converter, which provides the additional benefit of recycling transformer leakage inductance energy and reducing voltage stress of the power switches. Its input and output current ripple is much smaller than basic flyback converter.

Hongmei Wang; Chunying Gong; Haixiao Ma; Yangguang Yan

2006-01-01

7

Novel Forward–Flyback Hybrid Bidirectional DC–DC Converter  

Microsoft Academic Search

This paper presents a novel topology named forward-flyback bidirectional DC-DC converter (BDC), which is a hybrid of forward and flyback converters. The windings of forward and flyback transformers are connected in series on the primary side and in parallel on the secondary side. The proposed converter has no startup problem and no high voltage spikes on the switches, which otherwise

Fanghua Zhang; Yangguang Yan

2009-01-01

8

A dual mode forward/flyback converter  

NASA Astrophysics Data System (ADS)

This paper presents a single transistor dc-dc converter that combines both forward and flyback action. The resulting circuit is ohmically isolated and can operate over a wide range of input-to-output voltage ratios. An analysis of the circuit indicates that the forward and flyback portions of the circuit interact to produce three distinct regions of operation. With the design information presented, the circuit can be tailored to utilize the desirable characteristics of either converter action for a specific application. The dynamics of the dual mode circuit are modeled by means of the state-space averaging technique. An ac-dc regulator that takes advantage of the wide operating range of the dual mode circuit operating off the ac line, with only a small input filter, is described.

Park, J. N.; Zaloum, T. R.

9

A ZCS bidirectional flyback DC\\/DC converter  

Microsoft Academic Search

This paper addresses the design and analysis of a zero-current-switched (ZCS) bidirectional flyback dc\\/dc converter. The converter is based on extending a previously developed unidirectional ZCS flyback converter and replacing the output diode with a controlled switch, which acts as either a rectifier or a power control switch in the corresponding power flow direction. By adding an auxiliary winding in

H. S.-H. Chung; Wai-Leung Cheung; K. S. Tang

2004-01-01

10

Average modeling of Single Stage Flyback PFC+Flyback DC\\/DC converter  

Microsoft Academic Search

With the use of this novel everage model for Single Stage Flyback PFC+Flyback DC\\/DC converter, voltage control mode, peak\\u000a current control mode and average current control mode can be simulated easily by changing the model's parameters. It can be\\u000a used to do various analysis not only for small signal and static behavior but also for large signal and dynamic behavior

Shen Miao-sen; Kang Wan-ying; Qian Zhao-ming

2002-01-01

11

Four-quadrant flyback converter for direct audio power amplification  

Microsoft Academic Search

This paper presents a bidirectional, four-quadrant flyback converter for use in direct audio power amplification. When compared to the standard class-D switching-mode audio power amplifier with separate power supply, the proposed four-quadrant flyback converter provides simple and compact solution with high efficiency, higher level of integration, lower component count, less board space and eventually lower cost. Both peak and average

Petar Ljusev; M. A. E. Andersen

2005-01-01

12

Buck converter associated with active clamp flyback converter for PV power system  

Microsoft Academic Search

This paper presents an LED lighting system with a PV source. The circuit structure of the proposed system separately adopts buck converter and flyback converter as the charger and discharger. With this circuit structure, buck converter can vary its duty ratio to regulate charging current of battery, while flyback converter with active clamp circuit can recover energy stored in leakage

S.-Y. Tseng; Y.-J. Li; Y.-J. Wu

2008-01-01

13

Buck-flyback dc-dc converter  

NASA Astrophysics Data System (ADS)

It is difficult to obtain a large input/output voltage ratio with a dc-dc converter, because the duty factor d may not reach very small values. For the same reason, it is difficult to obtain an output voltage that is adjustable in a large range. A dc-dc converter circuit is proposed that overcomes this limitation by performing a voltage ratio d2/(1 - d) in the best operating mode. Circuit operation is analyzed, operating modes are evidenced, and the voltage ratio is deduced in each operating mode as a function of output current, duty factor, and circuit component values. Boundary conditions between different operating modes are obtained; consequently, it is concluded that these conditions do not occur for some operating modes. Finally, component ratings are summarized, to facilitate circuit design. The buck-flyback dc-dc converter is very suitable for low-voltage (e.g., computer) power supplies and for power supplies with the output voltage (adjustable in a large range) supplied from the mains without a mains voltage transformer.

Birca-Galateanu, Serban

1988-11-01

14

An integrated flyback converter for DC uninterruptible power supply  

SciTech Connect

An integrated flyback converter performing the combined functions of uninterruptible power supply (UPS) and switch-mode power supply (SMPS) is presented. This converter has a high voltage main power input and a low voltage backup battery input. DC output is obtained form the main input via a flyback converter during normal operation and from the backup battery via another flyback converter when input power fails. High conversion efficiency is achieved in normal, backup, and charging modes as there is only a single dc-dc conversion in each mode. The converter circuit is very simple, with two switching transistors, a relay for mode switching, and a single magnetic structure only. This new design offers substantial improvement in efficiency, size, and cost over the conventional cascade of UPS and SMPS due to single voltage conversion, high frequency switching, and removal of design redundancy. The operation, design, analysis, and experimental results of the converter are presented.

Ma, K.W. [Ericsson Ltd., Quarry Bay (Hong Kong). Energy System Div.; Lee, Y.S. [Hong Kong Polytechnic Univ., Kowloon (Hong Kong). Dept. of Electronic Engineering

1996-03-01

15

A modified flyback DC-DC converter topology  

Microsoft Academic Search

This paper proposes a modified flyback converter topology, its steady state analysis at constant frequency and a control strategy in variable frequency constant ripple mode of operation. The transient characteristics of the converter with proposed variable frequency control law has fast dynamics. That is, the output voltage remains almost constant for any change in load and supply voltage. The converter

R. K. Singh; A. Joshi; Arindam Ghosh

1998-01-01

16

Bidirectional forward-flyback DC-DC converter  

Microsoft Academic Search

Bi-directional DC-DC converter is widely used in more and more areas. The paper proposed a novel type of bi-directional DC-DC converter topologies-forward-flyback bi-directional DC-DC converters. The converter has the following merits: 1) The spike on the switches is much smaller than the current-fed type converter, the energy that cause the spike is much smaller than that in the current-fed converter;

Fanghua Zhang; Lan Xiao; Yangguang Yan

2004-01-01

17

Experimental analysis of a flyback converter with excellent efficiency  

Microsoft Academic Search

Power conversion modules in consumer products are optimised for cost and not for efficiency. On the other side, efficiency has a value when using renewable energies such as photovoltaic. A bidirectional active-clamped flyback converter has been investigated to identify its maximum possible conversion efficiency for the principal use as maximum power point converter. A power train efficiency has been measured

U. Boeke; D. Itzenga; K. Rigbers; R. W. De Doncker

2006-01-01

18

Quasiresonant flyback converter for transdermal drug delivery applications  

Microsoft Academic Search

This paper explores a new application field of power electronics. A soft-switching quasiresonant flyback converter is designed for transdermal drug delivery (TDD) applications with the processes of electroporation and phonophoresis. The converter can generate a constant DC voltage output for a pulsed generator in electroporation processing and can generate a variable DC voltage to drive a radial type of piezoelectric

S.-Y. Tseng; Y.-M. Chen; Y.-K. Huang; H.-T. Hsieh; T.-F. Wu

2004-01-01

19

Flyback DC-DC converters stabilized by using ripple  

Microsoft Academic Search

An instructive block diagram for development of the flyback DC-DC converters is given. Two derived examples, one from 5 V to 2000 V and another from 3 V to 7.5 V are presented. The converters use output ripple for direct determination of operating frequency which compensates all instabilities in the circuit except a change of a reference voltage. This approach

DRAGOLJUB DAMLJANOVI?

1988-01-01

20

Simulating the EMI characteristics of flyback DC\\/DC converters  

Microsoft Academic Search

In this article, the influence of diode reverse recovery on EMI performance of a low power flyback converter is investigated. Two different diode models (SPICE and SABER®) are analyzed and the conducted emissions from a simulated converter with a thorough characterization of the parasitic elements are compared to measurements. It is concluded that the emission levels to a large extent

Andreas Karvonen; Torbjorn Thiringer

2011-01-01

21

Planar LTCC Transformers for High Voltage Flyback Converters Part II.  

National Technical Information Service (NTIS)

This paper is a continuation of the work presented in SAND2007-2591 Planar LTCC Transformers for High Voltage Flyback Converters. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechno...

D. Abel D. Schofield G. Slama J. M. Schare

2009-01-01

22

Small-signal analysis of open-loop PWM flyback dc-dc converter for CCM  

Microsoft Academic Search

A flyback dc-dc converter is obtained from the conventional buck-boost converter by replacing the inductor with an isolation transformer. A transformer in the flyback converter is used to achieve a dc isolation between the input and the output of the converter. This paper presents dc and small-signal circuit models for the flyback converter for continuous conduction mode (CCM). The parasitic

Marian K. Kazimierczuk; Sonny T. Nguyen

1995-01-01

23

A transformer assisted ZVS scheme for flyback converter  

Microsoft Academic Search

This paper presents a novel zero-voltage-switching (ZVS) scheme for flyback converter. The principle of operation of the converter is analyzed in detail. A comparatively small assisted transformer is in series with the main transformer. The ZVS conditions are achieved when the current across the magnetizing inductance of assisted transformer is bi-directional. By using hysteresis current control, ZVS conditions are ensured

Shijie Chen; Yilei Gu; Zhengyu Lu; Zhaoming Qian; Wenxi Yao

2005-01-01

24

Design and implementation of interleaved quasi-resonant DC-DC flyback converter  

Microsoft Academic Search

This paper presents the interleaved quasi-resonant (QR) DC-DC flyback converter, which uses two parallel-connection DC-DC flyback converters. The interleaved technique is used to control the active switches of the two flyback converters. Also, the active switches are turned on at voltage-valley condition to reduce switching losses. Thus, this converter can achieve large output power, low output-current ripple, and high efficiency.

Zi-Shiuan Ling; Tsorng-Juu Liang; Lung-Sheng Yang; Tzuu-Hseng Li

2009-01-01

25

Buck-Boost Combined with Active Clamp Flyback Converter for PV Power System  

Microsoft Academic Search

This paper presents an LED lighting system with PV sources. The circuit of the proposed system adopts buck-boost converter associated with flyback converter to charge battery and to drive an LED lighting system. In this research, buck-boost converter is used as a charger for charging battery, and flyback converter with active clamp circuit is adopted to drive the LED lighting.

S.-Y. Tseng; J.-S. Kuo; S.-W. Wang; C.-T. Hsieh

2007-01-01

26

Planar LTCC transformers for high voltage flyback converters: Part II.  

SciTech Connect

This paper is a continuation of the work presented in SAND2007-2591 'Planar LTCC Transformers for High Voltage Flyback Converters'. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechnoloy, Inc, who collaborated in the design and manufacturing of the planar LTCC flyback converters. The output/volume requirements were targeted to DoD application for hard target/mini fuzing at around 1500 V for reasonable primary peak currents. High voltages could be obtained but with considerable higher current. Work had begun on higher voltage systems and is where this report begins. Limits in material properties and processing capabilities show that the state-of-the-art has limited our practical output voltage from such a small part volume. In other words, the technology is currently limited within the allowable funding and interest.

Schofield, Daryl (NASCENTechnology, Inc., Watertown, SD); Schare, Joshua M., Ph.D.; Slama, George (NASCENTechnology, Inc., Watertown, SD); Abel, David (NASCENTechnology, Inc., Watertown, SD)

2009-02-01

27

Study of a DC Glow Discharge Supplied by a Flyback Converter  

SciTech Connect

An experimental method aimed to study the characteristics of the equivalent electrical circuit for the dc glow discharges is described. The high voltage necessary to initiate and sustain the discharge is provided by a self-oscillating flyback converter. The flyback converter is also used to detect the discharge changes. The detection principle is based on the variation of the flyback converter electrical parameters (supply current, duty cycle and operating frequency) as a function of the load characteristics.

Stoican, O. S. [INFLPR, Bucharest-Magurele, 077125 (Romania)

2007-04-23

28

A self-controlled flyback DC\\/DC converter  

Microsoft Academic Search

In the present paper a self-controlled switch-mode DC\\/DC converter circuit is proposed for power supplies in low power applications where light weight, low cost and good efficiency are required. The use of a simple feed-forward flyback topology makes the circuit spontaneously switch at high operating frequency, so that it can transfer power to the loads via a DC\\/DC transformer. The

M. Tosi

1994-01-01

29

Efficiency characterization and optimization in flyback DC-DC converters  

Microsoft Academic Search

This paper presents efficiency characterization and optimization in conventional flyback DC-DC converters over wide ranges of operating conditions based on power loss modeling and multi-variable non-linear constrained optimization over design parameters and controller parameters. A valley switching technique is applied to reduce MOSFET turn-on switching loss in discontinuous conduction mode (DCM). An optimization procedure is formulated to minimize power loss

Sang Hee Kang; Hien Nguyen; D. Maksimovic?; I. Cohen

2010-01-01

30

The high efficiency charge equalized system for serially connected VRLA battery string using synchronous flyback converter  

Microsoft Academic Search

This article presents a high efficiency charge equalized system for balancing energy in serially connected battery strings using synchronous flyback converter. The efficiency of this synchronous flyback converter is 80.1 percent. By applying this proposed converter along with DC Link Bus technique in charge equalized system, the unbalance charging problem can be eliminated. The validity of this approach can be

Charnyut Karnjanapiboon; Kamon Jirasereeamornkul; Veerapol Monyakul

2010-01-01

31

Active Clamp Interleaved Flyback Converter with Single-Capacitor Turn-off Snubber for Stunning Poultry Applications  

Microsoft Academic Search

The paper proposes an active clamp interleaved flyback converter with a single-capacitor turn-off snubber associated with a full-bridge inverter for stunning poultry applications. The proposed converter can use active clamp circuit to recover the energy of transformer and to achieve zero-voltage switching at turn-on transition. In addition, the proposed one adopts a single-capacitor snubber not only to smooth out switch

S.-Y. Tseng; C.-T. Hsieh; H.-C. Lin

2007-01-01

32

1.5 kW isolated bi-directional DC-DC converter with a flyback snubber  

Microsoft Academic Search

An isolated bi-directional full-bridge DC-DC converter with high conversion ratio, high output power and soft start-up capability for battery charging\\/discharging is proposed in this paper. The use of a capacitor and a flyback converter can clamp the voltage spike caused by the current difference between the current-fed inductor and leakage inductance of the isolation transformer, and can reduce the current

T.-F. Wu; Y.-C. Chen; J.-G. Yang; Y.-C. Huang; S.-S. Shyu; C.-L. Lee

2009-01-01

33

Series resonant converter using flyback control  

Microsoft Academic Search

Series resonant converters are widely used in applications requiring high power density. They offer several advantages over other topologies such as simplicity of design, switching at zero current levels, and high efficiency due to low switching losses. A new converter will be proposed that delivers pulses of equal energy to the load with comparatively small pulse-to-pulse delay and draws sinusoidal

H. T. Lee; L. C. Josephs

1985-01-01

34

Analysis of conducted and radiated noise of soft-switched flyback DC-DC converter  

Microsoft Academic Search

This paper is aimed at the design of soft-switched flyback DC-DC converters taking into account conducted and radiated emission noise aspects. In fact, by a proper system design, the use of an active voltage clamp in flyback converters may result in reduced voltage stresses, soft switching of the main devices, and improved EMI. The paper discusses different design aspects and

G. Spiazzi; A. Zuccato; P. Tenti

1996-01-01

35

The application of flyback DC\\/DC converter in Li-ion batteries active balancing  

Microsoft Academic Search

The two major classifications of active cell balancing methods are charge shuttling and energy converting. In this paper, flyback transformer is used as storage element to move energy from one cell to another. A multi-output flyback transformer DC\\/DC converter prototype is built and tested. The test batteries used in this study were 8 Ah manganese lithium battery pack. Through experiment,

XueZhe Wei; Xiaopeng Zhao; Dai Haifeng

2009-01-01

36

Buck-flyback dc-dc converter  

Microsoft Academic Search

It is difficult to obtain a large input\\/output voltage ratio with a dc-dc converter, because the duty factor d may not reach very small values. For the same reason, it is difficult to obtain an output voltage that is adjustable in a large range. A dc-dc converter circuit is proposed that overcomes this limitation by performing a voltage ratio d2\\/(1

Serban Birca-Galateanu

1988-01-01

37

Low voltage flyback DC-DC converter for power supply applications  

Microsoft Academic Search

In this paper, we design a low voltage DC-DC converter with a flyback transformer. The converter will be used as a biased power supply to drive IGBTs. The flyback transformer using planar EI-core is designed and simulated using ANSYS PExprt software. Besides, anLT3574 IC chip from Linear Technology has been chosen for converter control. Finally, the converter modeling and simulation

Hanzhou Liu; John Elmes; Kejiu Zhang; Thomas X. Wu; Issa Batarseh

2011-01-01

38

Modeling analysis and simulation of high-voltage flyback DC-DC converter  

Microsoft Academic Search

Based on the mechanism that the primary and secondary currents of flyback converter do not appear at the same time, two different equivalent models of flyback transformer are brought forward correspondingly. Stage by stage analysis of the working process of both continuous conduction mode(CCM) and discontinuous conduction mode(DCM) is presented by using appropriate transformer equivalent model in different stages. The

Huang Kewei; Li Jie; Fan Ningjun; Li Yuebin; Hu Xiaolin; Wu Luo

2009-01-01

39

Two-switch flyback-forward PWM DC-DC converter with reduced switch voltage stress  

Microsoft Academic Search

This paper introduces a two-switch flyback-forward pulse-width modulated (PWM) DC-DC converter along with the steady-state analysis, simplified design procedure, and experimental verification. The proposed converter topology is the result of integrating the secondary sides of the two-switch flyback and the two-switch forward converters in an anti-parallel connection, while retaining the two-main switches and the clamping diodes on a single winding

Dakshina Murthy-Bellur; Marian K. Kazimierczuk

2010-01-01

40

Analysis of leakage-inductance effect in a flyback DC-DC converter using time keeping control  

Microsoft Academic Search

Flyback DC-DC converter is often used as power supply for many electronic systems because of circuit simplicity. We have already presented novel flyback DC-DC converter with improved stability (time keeping controlled flyback converter) by using the technique of keeping inductor current constant (H.Terashi, et al.). This converter behaves as like forward converter without RHPZ (Right Half Plane Zero), therefore the

Hiroto Terashi; Tarnotsu Ninomiya

2004-01-01

41

Zero-voltage-switching buck-flyback isolated DC-DC converter with synchronous rectification  

Microsoft Academic Search

This paper presents a zero-voltage-switching (ZVS) buck-flyback isolated DC-DC converter with two isolated outputs on the primary side and secondary side respectively, wherein primary-side feedback control is used. The primary output is tightly regulated while achieving rough regulation for the secondary output. Since no control isolation is needed, the cost and complexity are reduced as compared with conventional flyback converters

Liangbin Yao; Hong Mao; Jun Liu; Issa Batarseh

2006-01-01

42

A novel ZVS-ZCS Bidirectional flyback DC-DC converter for low power application  

Microsoft Academic Search

A new ZVS-ZCS bidirectional flyback DC-DC converter is proposed, which provides low output voltages 24V–60V. With proposed ZVS-ZCS concept, the MATLAB simulation results of the applications to a battery application have been obtained and compared with those of ZCS flyback bidirectional converter. In addition to this an experimental setup has been developed. Experimental results are compared with simulation results.

V. V. Subrahmanya Kumar Bhajana; S. Rama Reddy; P. Chandra Sekhar

2011-01-01

43

Comparison of bi-directional isolated full-bridge converters with combinations of active and passive snubbers  

Microsoft Academic Search

A bi-directional isolated full-bridge dc-dc converter with high conversion ratio is widely used for battery charg- ing\\/discharging. Active or passive snubbers are usually adopted to supplement the operation of a dual full-bridge configuration. In the paper, a bi-directional isolated full-bridge converter with an active flyback snubber, and the one with an active flyback snubber and two passive capacitor-diode snubbers are

Tsai-Fu Wu; Jeng-Gung Yang; Chia-Ling Kuo; Kun-Han Sun; Yu-Kai Chen

2011-01-01

44

Pulse Current Regenerative Resonant Snubber-Assisted Two-Switch Flyback Type ZVS PWM DC-DC Converter  

Microsoft Academic Search

In this paper, a two-switch high frequency flyback transformer type zero voltage soft switching PWM DC-DC converter using IGBTs is proposed. Effective applications for this power converter can be found in auxiliary power supplies of rolling stock transportation and electric vehicles. This power converter is basically composed of two active power switches and a flyback high frequency transformer. In addition

Claudio Y. Inaba; Yoshihiro Konishi; Mutsuo Nakaoka

2004-01-01

45

Lagrangian modeling of DC-DC buck-boost and flyback converters  

Microsoft Academic Search

In this paper, mathematical modeling of the DC-DC converters which are regarded as switched systems are examined. The Lagrangian formalism is used to derive the mathematical models of the DC-DC converters and the Euler Lagrange models of DC-DC Buck-Boost and Flyback converters are obtained using this Lagrangian formalism.

H. A. Yildiz; Leyla Gören-Sümer

2009-01-01

46

Demonstration of MHz-frequency operation of a monolithic self-synchronized rectifier IC in flyback DC\\/DC converter  

Microsoft Academic Search

Synchronous rectification offers an effective solution to improve efficiency of low-output-voltage flyback converters. Conventional synchronous flyback topologies using the discrete synchronous rectifier face challenges in precise timing control on the secondary side at high switching frequency. In this paper, we demonstrate the MHz-frequency operation of a flyback DC-DC converter using a new monolithic self-synchronized rectifier (SSR). The SSR IC, acting

Hongwei Jia; Osama Abdel-Rahman; Karthik Padmanabhan; Patrick Shea; Issa Batarseh; Z. John Shen

2010-01-01

47

Two-switch flyback transformer soft switching PWM DC-DC converter with passively energy regeneration lossless snubbers  

Microsoft Academic Search

In this paper, a two-switch high frequency flyback type zero voltage soft switching PWM DC-DC converter using IGBTs is proposed. This power converter is basically composed of two active power switches and a flyback high frequency transformer. In addition to these, two passive lossless snubbers with power regeneration loops for energy recovery, consisting of a three winding auxiliary high frequency

Yoshihiro Konishi; Claudio Y. Inaba; Mutsuo Nakaoka

2003-01-01

48

Analysis of the Output Capacitor and Lamp voltage Inversion for the Bidirectional Flyback Converter  

Microsoft Academic Search

This paper presents a lamp voltage inversion methodology and output capacitor analysis applied to a bidirectional flyback converter. The converter integrates the power control and the inversion stage, feeding a HPS lamp with a low frequency symmetrical square waveform, avoiding the acoustic resonance phenomenon occurrence. A detailed design of the lamp parallel capacitor is developed with parameters of stability, lamp

Tiago B. Marchesan; A. L. Kirsten; M. Cervi; Alexandre Campos; Ricardo N. do Prado

2008-01-01

49

The topology design of the multiple flyback DC-DC converter  

Microsoft Academic Search

A topology of a multiple flyback DC-DC power converter is proposed in this paper. Because of the use of this topology, the problem of designing a switched mode power converter for a high input-bus voltage has been solved successfully. The advantages of this topology are discussed and some useful circuits are also given

Zheng Lijun; Ren Tianliang

1999-01-01

50

Stability and dynamic response improvement of flyback DC-DC converter by a novel control scheme  

Microsoft Academic Search

In the conventional flyback DC-DC converter, the frequency bandwidth of the open-loop transfer function is less than the forward converter because this transfer function has a right-half-plane zero (RHPZ). In addition, a sudden decrease of output voltage called \\

H. Terashi; I. Cohen; T. Ninomiya

2002-01-01

51

A wide-band modeling of DC-DC two-transistor flyback converter  

Microsoft Academic Search

This paper presents results on wide-band modeling of DC-DC flyback converter. The model of converter is composed of detailed models of transformer, transistors, diodes and tracks. Parameter identification methods are based on manufacturer data sheet and externally measurable characteristics and parameters. The templates of models are written in the MAST and implemented for simulation in the SABER simulator. Validation of

Marek Turzynski; Maciej Haras; Grzegorz Kostro; Piotr Musznicki

2011-01-01

52

Modeling and Simulation of Flyback DC-DC Converter under Heavy Load  

Microsoft Academic Search

Appropriate simulation models of converters under heavy loads are crucial for designing a high reliability converter system. This paper presents the modeling and simulation of flyback DC-DC converters operating in heavy loads such as over-current and under-voltage modes, based on the concept of energy self-holding. An existing converter, which was once damaged in the experiment due to a short-circuited output,

Jiaxin Chen; Jianguo Zhu; Youguang Guo; Jianxun Jin

2006-01-01

53

Novel regulation method for low-current, high-voltage-output flyback DC-DC converter with isolation  

Microsoft Academic Search

A method is described for regulating a low-output-current, high-voltage (16 kV) flyback DC-DC converter without access to the high-voltage side. The voltage error, sensed at the collector of the output transistor where the flyback voltage is directly proportional to the voltage across the output capacitor, controls the duty cycle.

A. G. Deshpande

1978-01-01

54

Narrow pulsed electric field generator using forward \\/ flyback hybrid converters for liquid food processing  

Microsoft Academic Search

This paper presents a high pulsed electric field generator for microbial inhibition of liquid food in continuous treatment applications. The proposed pulsed electric field generator adopts forward\\/flyback hybrid converters to achieve a bidirectional narrow pulse voltage output. With this circuit structure, the proposed one can reduce voltage stresses of output diodes and switches in secondary winding of transformer, resulting in

Y.-D. Chang; S.-Y. Tseng; T.-F. Wu; H.-R. Yang

2008-01-01

55

DC-DC flyback converters in the critical conduction mode: a re-examination  

Microsoft Academic Search

The critical conduction mode for DC-DC flyback SMPS, in which the converter is forced to operate at the boundary between continuous and discontinuous conduction modes, represents an interesting alternative to the classical constant-frequency PWM technique. In fact, such an operating mode allows for a soft turn off of the freewheeling diode, zero voltage commutations of the switch and a reduction

G. Spiazzi; D. Tagliavia; S. Spampinato

2000-01-01

56

Planar LTCC transformers for high voltage flyback converters.  

SciTech Connect

This paper discusses the design and use of low-temperature (850 C to 950 C) co-fired ceramic (LTCC) planar magnetic flyback transformers for applications that require conversion of a low voltage to high voltage (> 100V) with significant volumetric constraints. Measured performance and modeling results for multiple designs showed that the LTCC flyback transformer design and construction imposes serious limitations on the achievable coupling and significantly impacts the transformer performance and output voltage. This paper discusses the impact of various design factors that can provide improved performance by increasing transformer coupling and output voltage. The experiments performed on prototype units demonstrated LTCC transformer designs capable of greater than 2 kV output. Finally, the work investigated the effect of the LTCC microstructure on transformer insulation. Although this paper focuses on generating voltages in the kV range, the experimental characterization and discussion presented in this work applies to designs requiring lower voltage.

Schofield, Daryl (NASCENT Technology Inc. , Watertown, SD); Schare, Joshua M.; Glass, Sarah Jill; Roesler, Alexander William; Ewsuk, Kevin Gregory; Slama, George (NASCENT Technology Inc. , Watertown, SD); Abel, Dave (NASCENT Technology Inc. , Watertown, SD)

2007-06-01

57

Series connected forward-flyback converter for high step-up power conversion  

Microsoft Academic Search

This paper presents a newly-suggested high step-up topology employing a Series-connected Forward-FlyBack converter (SFFB), which has a series-connected output for high boosting voltage-transfer gain. SFFB is a hybrid type of forward and flyback converter, sharing the transformer for increasing the utilization factor. By stacking the outputs of them, extremely high voltage gain can be obtained with small volume and high

Jong-Hyun Lee; Do-Hyun Kim; Sol Mun; Minh Thao Nguyen; Viet Thang Tran; Joung-Hu Park

2011-01-01

58

An approach to achieve ride-through of an adjustable speed drive with flyback converter modules powered by super capacitors  

Microsoft Academic Search

Adjustable speed drives (ASDs) under short-term power interruptions (STPIs) can interrupt a critical process. In this paper an approach to provide ride-through with flyback converter modules (FBCMs) powered by super capacitors is explored. The proposed approach is modular and facilitates additional modules to be added to suit higher voltage\\/power ratings. Both unidirectional and bidirectional flyback DC\\/DC converter topologies are examined.

J. L. Duran-Gomez; Prasad N. Enjeti; Annette von Jouanne

1999-01-01

59

A ZCS bi-directional flyback DC\\/DC converter using the leakage inductance of the coupled inductor  

Microsoft Academic Search

This paper describes a zero-current-switched (ZCS) bi-directional flyback DC\\/DC converter. The methodology is based on replacing the output diode in the existing flyback converter with a controlled switch, acting as either a synchronous rectifier or a main power control switch in the corresponding power flow operation. By adding an auxiliary winding in the coupled inductor, a bi-directional switch, and a

Henry S. H. Chung; S. Y. R. Hui; K. M. Chan; C. T. Chung

2000-01-01

60

A General Method for Deciding the Input Filter Capacitance of Flyback Switching AC-DC Converter with Peak Current-Controlled Mode  

Microsoft Academic Search

This paper presents a general method for deciding the input filter capacitance of flyback switching ac- dc converters with peak current-controlled mode. Firstly, a simulation model for flyback ac-dc converter is obtained by adding the rectifier and filter circuit to a flyback dc-dc converter model developed by the authors. The simulation results show that the processes of capacitor charging and

Jiaxin Chen; Jianguo Zhu; Youguang Guo

2007-01-01

61

Calculation of Power Loss in Output Diode of a Flyback Switching DC-DC Converter  

Microsoft Academic Search

Based on the mathematical model of flyback switching DC-DC converter in the continuous current mode and the simulation model under heavy loads, this paper presents a study of the steady-state power loss in the output diode, including the loss calculation models under three operational modes (voltage control, under-voltage, and over-current modes), the relations of the diode loss versus the input

Jiaxin Chen; Jianguo Zhu; Youguang Guo

2006-01-01

62

Efficiency Optimization in Digitally Controlled Flyback DC–DC Converters Over Wide Ranges of Operating Conditions  

Microsoft Academic Search

This paper presents an approach to efficiency optimization in digitally controlled flyback dc–dc converters over wide ranges of operating conditions. Efficiency is characterized and optimized based on power loss modeling and multivariable nonlinear constrained optimization over power-stage and controller parameters. A valley switching technique is adopted to reduce MOSFET turn-on switching loss in discontinuous conduction mode. An optimization procedure is

Sang Hee Kang; Dragan Maksimovi?; Isaac Cohen

2012-01-01

63

A new flyback-current-fed push-pull DC-DC converter  

Microsoft Academic Search

This paper introduces a new flyback-current-fed push-pull DC-DC power converter whose significant advantages in comparison with conventional designs are: reduction in the number of output diodes; and unified output characteristics to represent both the buck and the boost operation modes in the continuous conduction mode. Theoretical analysis, design methodology and experimental results taken from a 600 W, 25 kHz laboratory

D. A. Ruiz-Caballero; I. Barbi

1998-01-01

64

A new flyback-current-fed push-pull DC-DC converter  

Microsoft Academic Search

This paper introduces a new flyback-current-fed push-pull DC-DC converter whose significant advantages in comparison with the conventional one are a reduction in the number of output diodes and unified output characteristics to represent both the buck and the boost operation modes in the continuous conduction mode. Theoretical analysis, design methodology and experimental results taken from a 600 W 25 kHz

Domingo A. Ruiz-Caballero; Ivo Barbi

1999-01-01

65

A three-port half-bridge converter with synchronous rectification for renewable energy application  

Microsoft Academic Search

A three-port half-bridge converter for stand-alone renewable power system is proposed. The converter, featuring one input port, one bidirectional port and one isolated output port, is derived by integrating half-bridge, forward-flyback and Buck topologies. The magnetizing inductor of the transformer functions as an inductor, by which a power flow path can be configured between the renewable source and the battery,

Hongfei Wu; Yan Xing; Runruo Chen; Junjun Zhang; Kai Sun; Hongjuan Ge

2011-01-01

66

A soft switching flyback current-fed push pull Dc-Dc Converter with active clamp circuit  

Microsoft Academic Search

In this paper, an active clamp circuit is applied to a flyback current-fed push pull converter to limit the voltage stress across the switch due to transformer leakage inductance. In addition, this clamp circuit provides soft switching condition for all switches. This allows the designer to increase the switching frequency in order to reduce the converter size. The proposed converter

M. Delshad; H. Farzanehfard

2008-01-01

67

Heavy Load Simulation Model of Flyback Switching DC-DC Converters and its Application for Reliability Improvement  

Microsoft Academic Search

This paper presents the simulation model of flyback switching DC-DC converters operating in heavy load modes, and the application of the model in the converter design for improving the system reliability. To derive the simulation model, different operational modes and atomic circuit blocks (ACB) are established first. Then, the state-machine of the system is studied. Finally, the transfer function of

Jiaxin Chen; Youguang Guo; Jianguo Zhu; Jianxun Jin

2007-01-01

68

The design and development of a novel flyback planar transformer for high frequency switch mode DC–DC converter applications  

Microsoft Academic Search

In this work a 2cm×2cm novel thick film planar transformer is designed and developed. The planar transformer height effect on the power density was studied. This planar transformer was used in a Flyback switch-mode DC–DC converter with a pulse width modulator feedback control circuit. The switch mode converter and the planar transformer showed a high efficiency of 90 and 99%

K. I. Arshak; B. Almukhtar

2000-01-01

69

Single-switch flyback power-factor-corrected AC\\/DC converter with loosely regulated intermediate storage capacitor voltage  

Microsoft Academic Search

Single-stage power-factor-corrected AC\\/DC converters (SSPFC) usually bear high voltage stress on the intermediate storage capacitor due to the lack of control of this voltage. The storage capacitor voltage varies largely with line voltage and load current and is usually higher than the peak line voltage. This paper presents a new single-switch SSPFC based on flyback topology for which the storage

Dylan Dah-chuan Lu; David Ki-wai Cheng; Yim-shu Lee

2003-01-01

70

On-line efficiency optimization in flyback dc-dc converters over wide ranges of operating conditions  

Microsoft Academic Search

This paper presents a look-up table based digital control approach to on-line efficiency optimization over wide ranges of operating conditions. The proposed digital controller allows programmable modes of operation based on off-line efficiency characterization and optimization. Applied to a flyback dc-dc converter, the controller adopts valley switching in discontinuous conduction mode (DCM), which significantly reduces the MOSFET turn-on switching loss.

Sang Hee Kang; Dragan Maksimovic; Isaac Cohen

2011-01-01

71

A novel series resonant ZCS-PFM DC-DC power converter with loosely-coupled flyback inductors  

Microsoft Academic Search

This paper presents a novel topological prototype of voltage source series quasi-resonant zero current soft-switching pulse frequency modulated DC-DC power converter circuit using IGBTs which incorporates a high-frequency flyback transformer link. Its steady-state operating principle is described on the basis of simulation analysis, along with the open loop controlled power regulation characteristics of the multi-functional coupled inductors linked DC-DC power

Enhui Chu; S. Chandhaket; S. Moisseev; H. Kifune; E. Hiraki; M. Nakaoka

2001-01-01

72

Pulse Current Regenerative Resonant Snubber-Assisted Two-Switch Flyback Type ZVS PWM DC-DC Converter  

NASA Astrophysics Data System (ADS)

In this paper, a two-switch high frequency flyback transformer type zero voltage soft switching PWM DC-DC converter using IGBTs is proposed. Effective applications for this power converter can be found in auxiliary power supplies of rolling stock transportation and electric vehicles. This power converter is basically composed of two active power switches and a flyback high frequency transformer. In addition to these, two passive lossless snubbers with power regeneration loops for energy recovery, consisting of a three winding auxiliary high frequency transformer, auxiliary capacitors and diodes are introduced to achieve zero voltage soft switching from light to full load conditions. Furthermore, this power converter has some advantages such as low cost circuit configuration, simple control scheme and high efficiency. Its operating principle is described and to determine circuit parameters, some practical design considerations are discussed. The effectiveness of the proposed power converter is evaluated and compared with the hard switching PWM DC-DC converter from an experimental point of view and the comparative electromagnetic conduction and radiation noise characteristics of both DC-DC power converter circuits are also depicted.

Inaba, Claudio Y.; Konishi, Yoshihiro; Nakaoka, Mutsuo

73

DC bias analysis and small-signal characteristic of active-clamp forward-flyback DC-DC converter with a current doubler rectifier  

Microsoft Academic Search

The paper presents the steady-state and dynamic small-signal models for the active-clamp forward-flyback DC-DC converter with a current doubler rectifier. Based on the established models, several issues, such as inductor current sharing, transformer DC bias of magnetizing current and converter design, are discussed

Yangyang Wen; Hong Mao; Issa Batarseh

2005-01-01

74

Analysis and experimental results of a single-stage high-power-factor electronic ballast based on flyback converter  

SciTech Connect

A new single-stage high-power-factor electronic ballast based on a flyback converter is presented in this paper. The ballast is able to supply a fluorescent lamp assuring a high-input power factor for the utility line. Other features are lamp power regulation against line voltage variations and low lamp current crest factor, both assuring long lamp life. The ballast is analyzed at steady-state operation, and design equations and characteristics are obtained. Also, a procedure for the ballast design is presented. Finally, simulation and experimental results from a laboratory prototype are shown.

Calleja, A.J.; Alonso, J.M.; Lopez, E.; Ribas, J.; Martinez, J.A.; Rico-Secades, M.

1999-11-01

75

Closed-loop voltage-mode-controlled PWM flyback dc-dc converter for CCM with integral-lead controller  

Microsoft Academic Search

This paper presents an analysis of a closed-loop voltage-mode-controlled pulse-width-modulated (PWM) flyback dc-dc converter for continuous conduction mode with an integral-lead controller. An integral-lead controller is designed so that it completely meets the system specifications. The closed-loop dynamic performance of the system is analyzed. The Bode plots are illustrated for closed-loop control-to-output transfer function, input-to-output transfer function, input impedance, and

M. K. Kazimierczuk; S. T. Nguyen

1995-01-01

76

Isolated bi-directional full-bridge soft-switching dc-dc converter with active and passive snubbers  

Microsoft Academic Search

An isolated bi-directional full-bridge soft-switching dc-dc converter with high conversion ratio, high output power, soft start-up and soft-switching capability for battery charging\\/discharging is proposed in this paper. The use of an active flyback and two passive capacitor-diode snubbers can alleviate the voltage spike caused by the current difference between the leakage inductance of the transformer and the current-fed inductor, can

T.-F. Wu; J.-G. Yang; C.-L. Kuo; S.-Z. Lan

2011-01-01

77

A Universal-Input Single-Stage High-Power-Factor Power Supply for HB-LEDs Based on Integrated Buck-Flyback Converter  

Microsoft Academic Search

Due to the high rise in luminous efficiency that HB-LEDs have experienced in the last recent years, many new applications have been researched. In this paper, a streetlight LED application will be covered, using the integrated buck-flyback converter developed in previous works, which performs power factor correction (PFC) from a universal AC source, as well as a control loop using

D. Gacio; J. M. Alonso; A. J. Calleja; J. Garcia; M. Rico-Secades

2009-01-01

78

A Universal-Input Single-Stag2e High-Power-Factor Power Supply for HB-LEDs Based on Integrated Buck–Flyback Converter  

Microsoft Academic Search

Due to the high rise in luminous efficiency that high- brightness light-emitting diodes (HB-LEDs) have experienced in recent years, many new applications have been researched. This paper covers a streetlight LED application using the offline in- tegrated buck-flyback converter (IBFC) developed in previous works. In this application, the converter is used to provide power- factor correction from a universal ac

David Gacio; J. Marcos Alonso; Antonio J. Calleja; Jorge Garcia; Manuel Rico-Secades

2011-01-01

79

The design and development of a novel flyback planar transformer for high frequency switch mode DC-DC converter applications-Part 2  

Microsoft Academic Search

For pt.I see ibid., vol.2, pp.505-8 (2000). In this work a 2 cm×2 cm×0.4 cm novel thick film planar transformer is developed. This planar transformer was used in a flyback switch mode DC-DC converter with a pulse width modulator (PWM) feedback control circuit. The switch mode converter and the planar transformer showed a high efficiency of 90% and 99% at

K. I. Arshak; B. Almukhtar

2000-01-01

80

Half-Bridge Type Immittance Converter  

NASA Astrophysics Data System (ADS)

The immittance converter has the input impedance that is proportional to the admittance of the load connected across output terminals. Therefore, in this converter, the output current is proportional to the input voltage and the input current is proportional to the output voltage. Consequently, it converts a constant voltage source into a constant current source and a constant current source into a constant voltage source. In this paper, we propose a new type immittance converter, named half-bridge type immittance converter, consists of a tapped transformer and a pair of L, C. The new immittance converter is developed from the hybrid type immittance converter, and has almost same characteristics of that.

Irie, Hisaichi; Takayama, Nobuyuki

81

The design and development of a novel flyback planar transformer for high frequency switch mode DC-DC converter applications-Part 1  

Microsoft Academic Search

In this work a step by step planar transformer design procedure for Flyback switch-mode DC-DC converter application is presented. This transformer has a maximum dimension of 2 cm×2 cm×0.4 cm aiming to achieve an efficiency of 99% at an operating frequency of 500 kHz. This planar transformer is designed specially for thick film technology development

K. I. Arshak; B. Almukhtar

2000-01-01

82

Simplified sensing and A\\/D conversion for digitally controlled flyback DC-DC converters with on-line efficiency optimization  

Microsoft Academic Search

This paper presents simplified sensing and analog-to-digital (A\\/D) conversion techniques, targeting low-cost, low-pin-count controller implementation for digitally controlled flyback DC-DC converters with on-line efficiency optimization. Precise output voltage regulation is accomplished by sensing an auxiliary winding voltage on the primary side at the end of the diode conduction interval, thus eliminating the need for secondary-side circuitry and isolation in the

Sang Hee Kang; Dragan Maksimovic

2012-01-01

83

Single-switch dual output flyback DC\\/DC converter with time multiplexing control  

Microsoft Academic Search

Controlling two outputs with a single controlling switch in the power converter presents difficulties when two contrasting actions are required to raise one output and decrease the other. This paper studies the application of time multiplexing control (TMC) technique on power converters, with particular interest on single-switch multiple-output converters. Each output has its own feedback control circuit but these discrete

D. D. C. Lu; J. W. Hill; R. Y. W. Chan

2008-01-01

84

A single-switch flyback-current-fed DC-DC converter  

Microsoft Academic Search

This work presents a novel DC-DC converter, whose significant advantages are the single power switch, single-input inductor, purely capacitive output filter, isolation, low current ripple through the output capacitor, and operation at constant frequency in a conventional pulse-width-modulation scheme. The new converter operates over a wide input-voltage range and can be employed in power factor correction and multiple-output power supplies.

Peter Mantovanelli Barbosa; Ivo Barbi

1998-01-01

85

Research on Single-Stage Flyback Inverter  

Microsoft Academic Search

In this paper, a novel flyback inverter is proposed. It is composed of two basic bi-directional flyback converters, which can operate independently. This circuit can fulfil the isolation, transformation and the control of output performance simultaneously. It only includes four power switches, and the inductor of output filter is eliminated. The circuit is very simple and in the same period

Lin Sun; Yongchun Liang; Chunying Gong; Yangguang Yan

2005-01-01

86

Flyback-based PFC converter with sinusoidal output for use in AC UPS  

Microsoft Academic Search

Nowadays, the number of sensitive loads connected to the utility line increases fast. These loads need a highly reliable power supply. One way to provide this kind of energy is using an uninterruptible power supply (UPS). Basically, a UPS providing input power factor correction (PFC) is a three stage system: PFC stage, DC-DC converter stage and inverter stage. The approach

J. Hoyo; J. Araul; C. Aguilar; E. Martinez

2002-01-01

87

A double-input flyback DC\\/DC converter with single primary winding  

Microsoft Academic Search

The traditional isolated multiple-input converter (MIC) has a simple configuration and can be used in the system with two or more sources. However, it has some disadvantages such as complex transformer structure due to multiple primary windings, higher voltage stresses on the power switches, and only one source transferring energy to the load at any time. This paper proposes a

Qin Wang; Jie Zhang; Xinbo Ruan; Ke Jin

2010-01-01

88

Energy self-holding in flyback switching DC-DC converters  

Microsoft Academic Search

Based on putting the conception of energy self-holding (ESH) forward, two kinds of energy self-holding model in fly back switching converters: alpha-model and beta-model are pointed out here. Then, the mechanism and mathematics model for each kind of energy self-holding are researched. During this process, two new conceptions of depth of energy self-holding and rating of energy-transfer are put forward.

Chen Jia-Xin

2005-01-01

89

Use of leading-edge modulation to transform boost and flyback converters into minimum-phase-zero systems  

Microsoft Academic Search

In leading-edge modulation, the pulsewidth-modulated (PWM) signal is turned off at the clock signal and turned on when the error signal crosses the ramp waveform. It is shown that the positive zero in the power stage transfer function of boost and flyback regulators can be shifted into the left-half-plane under suitable conditions. These conditions are as follows: (1) leading-edge modulation

Dan M. Sable; Bo H. Cho; Ray B. Ridley

1991-01-01

90

Comparative analysis of full bridge and half bridge current resonant DC-DC converter  

Microsoft Academic Search

This paper deals with a comparative analysis of full bridge and half bridge current resonant DC-DC converter. The novel current resonant DC-DC converter has been proposed to improve the power efficiency. The full bridge DC-DC converter is suitable for the low input voltage and large input current as in the fuel cell power supply system, and the half bridge one

Hisatsugu Kato; Hirofumi Matsuo; Tsubasa Ito; Shuhei Kawazu; Daiki Kawahara; Satoshi Motomura; Ryota Hamaguchie

2011-01-01

91

Multiple-input full bridge dc\\/dc converter  

Microsoft Academic Search

In the renewable power system with two or more sources, the application of multiple-input converter (MIC) instead of several single-input converters can simplify the circuit and reduce the cost. A novel multiple-input full bridge dc\\/dc converter is proposed in this paper. Taking the two inputs as the example, the operation principles and characteristics of the double-input full bridge dc\\/dc converter

Dongsheng Yang; Xinbo Ruan; Yan Li; Fuxin Liu

2009-01-01

92

A New Control Strategy of Single-Stage Flyback Inverter  

Microsoft Academic Search

This paper presents a new control strategy for a single-stage flyback inverter, which consists of two flyback converters. The two converters alternately work in the proposed control scheme, which eliminate about 30% additional freewheeling power compared with a conventional differential control scheme. The control scheme is analyzed in detail. The 100-VA prototype with improved efficiency verifies the analysis.

Fanghua Zhang; Chunying Gong

2009-01-01

93

A comparison of half-bridge resonant converter topologies  

Microsoft Academic Search

The half-bridge series-resonant, parallel-resonant, and combination series-parallel resonant converters are compared for use in low-output-voltage power supply applications. It is shown that the combination series-parallel converter, which takes on the desirable characteristics of the pure series and the pure parallel converter, avoids the main disadvantages of each of them. Analyses and breadboard results show that the combination converter can run

R. L. Steigerwald

1988-01-01

94

Switching Control Strategy to Minimize Dual Active Bridge Converter Losses  

Microsoft Academic Search

A switching control strategy to control the power flow and minimize the total power losses of the dual active bridge converter topology is proposed in this paper. The control strategy consists of driving the bridge with the largest DC voltage to generate a three-level pulsewidth-modulated (PWM) voltage waveform. This PWM is ruled by two manipulated variables: the phase shift between

GermÁn G. Oggier; Guillermo O. GarcÍa; Alejandro R. Oliva

2009-01-01

95

Simulation of Cascaded H-Bridge Converter based DSTATCOM  

Microsoft Academic Search

Voltage source converter based DSTATCOM has been established as the most preferred solution for management of reactive power in distribution utilities and for improving voltage regulation, power factor and power quality in industries. For high power applications, cascaded H-bridge converter is the most ideal choice compared to neutral point clamped inverter and two-level inverter with series connected power devices. This

K. Anuradha; B. P. Muni; A. D. Raj Kumar

2006-01-01

96

Soft switching PWM DC-DC flyback converter with transformer - assisted pulse current regenerative passive resonant snubbers  

Microsoft Academic Search

In this paper, a two-switch high frequency fly back transformer linked zero voltage soft switching PWM DC-DC power converter implemented in distributed power conditioning supplies is proposed. This DC-DC power converter circuit is mainly composed of two active power switches and a fly back high-frequency transformer. In addition to this, two passive loss less resonant snubbers with pulse current regeneration

Claudio Y. Inaba; Yoshihiro Konishi; H. Tanimatsu; K. Hirachi; M. Nakaoka

2003-01-01

97

A Three-in-One Converter for Regular and Emergency Lighting Applications  

Microsoft Academic Search

This paper presents a three-in-one converter for regular and emergency lighting applications. The converter can function as regular ballast, emergency ballast, and battery charger\\/discharger, achieving regular and emergency lighting features. The three-in-one converter used in the ballast is an integration of a bidirectional flyback converter and two half-bridge series-resonant parallel-loaded inverters. The derivation and operating principle of the proposed converter

Yung-Chun Wu; Yu-Kai Chen

2009-01-01

98

A compact single-stage converter for emergency lighting applications  

Microsoft Academic Search

This paper presents a compact single-stage converter for emergency lighting applications. The converter is derived by integrating a bi-directional flyback converter and a half-bridge series-resonant parallel-loaded inverter, which can fulfill the functions of battery charging, discharging and lamp ballasting. Unlike conventional approaches, the rectified and filtered input voltage is directly added on the battery voltage in the proposed system, which

Y.-C. Wu; T.-F. Wu; Y.-K. Chen

2002-01-01

99

Reliability consideration for a high power zero-voltage-switching flyback power supply  

Microsoft Academic Search

In this study, a high power zero-voltages-witching flyback power supply is presented. An appropriate efficiency is achieved by designing an auxiliary circuit for reduction of dynamic losses in the power switch. Due to the importance of reliability in the switch mode power supplies, reliability assessment is discussed for this zero-voltage-switching flyback converter in details. This paper illustrates that flyback topology

Arash Rahnamaee; Jafar Milimonfared; Kaveh Malekian; Mohammad Abroushan

2008-01-01

100

ZVS Bridge Leg and ZCS Bridge Leg DC-DC Converter with Tapped Inductor Filter  

NASA Astrophysics Data System (ADS)

In this paper, a novel full-bridge soft-switching phase-shifted PWM DC-DC power converter circuit is presented. A tapped inductor filter is implemented in the proposed converter topology to achieve soft switching commutation for the active power switches under wide load variation range, to minimize circulating current without using additional resonant circuit and/or auxiliary switching devices. The effectiveness of the proposed soft-switching DC-DC power converter is verified in experiment with 2kW-100kHz breadboard circuit using IGBTs.

Moisseev, Serguei; Hamada, Satoshi; Nakaoka, Mutsuo

101

Low Cost Embedded Controlled Full Bridge LC Parallel Resonant Converter  

NASA Astrophysics Data System (ADS)

In this paper the converter requirements for an optimum control of an electrolyser linked with a DC bus are analyzed and discussed. An electrolyser is a part of renewable energy system which generates hydrogen from water electrolysis. The hydrogen generating device is part of a complex system constituted by a supplying photovoltaic plant, the grid and a fuel cell battery. The characterization in several operative conditions of an actual industrial electrolyser is carried out in order to design and optimize the DC/DC converter. A dedicated zero voltage switching DC/DC converter is presented and simulated inside the context of the distributed energy production and storage system. The proposed supplying converter gives a stable output voltage and high circuit efficiency in all the proposed simulated scenarios. The adopted DC/DC converter is realized in a full-bridge topology technique in order to achieve zero voltage switching for the power switches and to regulate the output voltage. This converter has advantages like high power density, low EMI and reduced switching stresses. The simulation results are verified with the experimental results.

Chandrasekhar, P.; Reddy, S.

2009-01-01

102

Non-isolated flyback switching capacitor voltage regulator  

Microsoft Academic Search

This paper proposes a novel non-isolated flyback switching capacitor voltage regulator. The converter is a combination of a switching capacitor converter and a PWM voltage regulator, and it has the following advantages: 1) The switches achieve zero voltage switching (ZVS). 2) Applying the additional transformer winding self-driven method to reduce the driver loss and the synchronous rectifier body diode conduction

Wenjing Cao; Ke Jin; Xinbo Ruan

2011-01-01

103

Three-Port Triple-Half-Bridge Bidirectional Converter With Zero-Voltage Switching  

Microsoft Academic Search

A three-port triple-half-bridge bidirectional dc-dc converter topology is proposed in this paper. The topology comprises a high-frequency three-winding transformer and three half-bridges, one of which is a boost half-bridge interfacing a power port with a wide operating voltage. The three half-bridges are coupled by the transformer, thereby providing galvanic isolation for all the power ports. The converter is controlled by

Haimin Tao; Jorge L. Duarte; Marcel A. M. Hendrix

2008-01-01

104

Bridge-output-to-frequency converter for smart thermal air-flow sensors  

Microsoft Academic Search

A fully integrated bridge-output-to-frequency converter has been realized as signal-conditioning circuitry for a one-chip smart thermal mass-flow sensor. The frequency converter reads out four separate resistor bridges of the air-flow sensor in order to realize high sensitivity and directional flow measurement over the full angle range of 360°. The converter selects the sensor bridges individually by means of a microprocessor-controlled

Gert J. A. van Dijk; Johan H. Huijsing

1995-01-01

105

A current-sourced DC-DC converter derived via the duality principle from the half-bridge converter  

Microsoft Academic Search

A current-sourced switch-mode power supply topology is developed by applying a duality principle to a voltage-sourced half-bridge converter. The converter has boost converter characteristics and is suited to low-voltage high-current input applications. It is shown to compare favorably with the center-tapped transformer converter. Two optional enhancements-nondissipative snubber networks and inductor clamping windings-are also examined. Some results obtained with a low-power

Peter J. Wolfs

1993-01-01

106

A Novel ZVZCS Full-Bridge DC\\/DC Converter Used for Electric Vehicles  

Microsoft Academic Search

This paper presents a novel ZVZCS full-bridge DC\\/DC converter, which is able to process and deliver power efficiently over very wide load variations. The proposed DC\\/DC converter is part of a plug-in AC\\/DC converter used to charge the traction battery (high voltage battery) in an electric vehicle. The key challenge in this application is operation of the full-bridge converter from

Majid Pahlevaninezhad; Pritam Das; Josef Drobnik; Praveen K. Jain; Alireza Bakhshai

2012-01-01

107

ZVS-ZCS bidirectional full-bridge DC-DC converter  

Microsoft Academic Search

A bidirectional zero-voltage-switching (ZVS) and zero-current-switching (ZCS) full-bridge dc-dc converter is proposed in this paper. The proposed full-bridge converter topology with low ripple input current, which converts the energy from battery to DC bus (or load) and vice versa. In order to improve the overall efficiency, the proposed bidirectional converter uses the leakage inductance of the transformer and a capacitor

Ching-Lung Chu; Yi Chen

2009-01-01

108

Analysis and design considerations of an improved ZVS full-bridge DC-DC converter  

Microsoft Academic Search

An improved full-bridge (FB) pulse-width-modulated (PWM) converter is proposed featuring zero-voltage-switching (ZVS) of all primary switches in the entire line and load range. Compared to the conventional full bridge dc\\/dc converter, the proposed converter achieves ZVS with substantially reduced duty-cycle loss and circulating current. The operation principle of the circuit is described and design considerations of the converter are discussed.

Zhong Chen; Biao Ji; Feng Ji; Lei Shi

2010-01-01

109

Family of Half-Bridge PWN Zero-Voltage Switching Converters, Employing Switched Capacitor Snubber.  

National Technical Information Service (NTIS)

A class of soft switching half bridge DC-DC Converters regulated by Pulse Width Modulation (PWM), where the transistors commutate at zero voltage are introduced. The full bridge DC-DC Converter, because of three level modulation, can be regulated by PWM w...

I. Barbi H. L. Hey

1991-01-01

110

Bidirectional isolated dual full-bridge dc-dc converter with active clamp for EDLC  

Microsoft Academic Search

A high-power bidirectional isolated dual full-bridge dc-dc converter with an active clamp for a electric double layer capacitor (EDLC), which is installed into a dc distribution system, is investigated. This dc-dc converter consists of two full-bridge converters on both low and high voltage sides, a high-frequency transformer, an active clamp switch and a capacitor. Phase-shift control is employed to regulate

Yushi Miura; Masato Kaga; Yasuhisa Horita; Toshifumi Ise

2010-01-01

111

A Zero-Voltage Switching Three-Port Isolated Full-Bridge Converter  

Microsoft Academic Search

This paper proposes an integrated single-stage three-port DC-DC converter. The proposed converter interfaces two bidirectional source\\/storage ports, and a galvanically isolated loading port. The power topology is based on the integration of a bi-phase boost pre-regulator stage into a phase-shift controlled full-bridge converter. The four bridge switches play the combined role of realizing synchronous boost conversion, and driving the transformer.

Hussam Al-Atrash; Michael Pepper; Issa Batarseh

2006-01-01

112

Investigation on Capacitor Voltage Regulation in Cascaded H-Bridge Multilevel Converters With Fundamental Frequency Switching  

Microsoft Academic Search

Multilevel power electronic converters have gained popularity in high-power applications due to their lower switch voltage stress and modularity. Cascaded H-bridge converters are a promising breed of multilevel converters which generally require several separate dc voltage sources. By utilizing the redundant switching states, it is possible to replace the separate dc voltage sources with capacitors and keep only the one

Hossein Sepahvand; Jingsheng Liao; Mehdi Ferdowsi

2011-01-01

113

Tri-Modal Half-Bridge Converter for Three-Port Interface  

Microsoft Academic Search

This paper proposes a novel converter topology that interfaces three power ports: a source, a bidirectional storage port, and an isolated load port. The proposed converter is based on a modified version of the isolated half-bridge converter topology that utilizes three basic modes of operation within a constant-frequency switching cycle to provide two independent control variables. This allows tight control

Hussam Al-Atrash; Justin Reese; Issa Batarseh

2007-01-01

114

Tri-Modal Half-Bridge Converter Topology for Three-Port Interface  

Microsoft Academic Search

This letter proposes a novel converter topology that interfaces three power ports: a source, a bidirectional storage port, and an isolated load port. The proposed converter is based on a modified version of the isolated half-bridge converter topology that utilizes three basic modes of operation within a constant-frequency switching cycle to provide two independent control variables. This allows tight control

Hussam Al-Atrash; Feng Tian; Issa Batarseh

2007-01-01

115

Zero voltage soft-commutation PWM DC-DC converter with saturable reactor switch-cascaded diode rectifier  

Microsoft Academic Search

An improved single-ended push-pull (SEPP) half-bridge type zero-voltage soft-switching pulse width modulation (ZVS-PWM) DC-DC power converter is presented in this paper, which makes use of a saturable reactor-assisted lossless capacitor type zero voltage soft-switching method. The SEPP power converter with a high-frequency forward and flyback hybrid transformer link has some advantages such as lowered switching and conduction losses, soft-switching transition

Junming Sun; Satoshi Hamada; Junji Yoshitsugu; Bin Guo; Mutsuo Nakaoka

1998-01-01

116

Digital control of a ZVS full-bridge DC-DC converter  

Microsoft Academic Search

The paper describes the design and realization of a digital controller for a DC-DC power converter with zero-voltage switching (ZVS). The chosen power converter, usually called the phase-shifted bridge, is valuable because it combines advantages from both conventional PWM and resonant-mode power converters. It is therefore an important topology for investigating the advantages of digital control for DC-DC power converters.

P. F. Kocybik; K. N. Bateson

1995-01-01

117

Boost-Integrated Phase-Shift Full-Bridge Converter for Three-Port Interface  

Microsoft Academic Search

Numerous modern systems require energy harvesting from multiple sources and the management of energy storage. The adoption of converter topologies specifically tailored for such applications offers great improvement potential over conventional systems. In this paper, two three-port converter topologies are proposed based on the integration of a boost stage into the popular phase-shift full-bridge converter. Each of the proposed converters

Hussam Al-Atrash; Issa Batarseh

2007-01-01

118

Performance characterization of a high-power dual active bridge DC-to-DC converter  

Microsoft Academic Search

The performance of a high-power, high-power-density DC-to-DC converter based on the single-phase dual active bridge (DAB) topology is described. The dual active bridge converter has been shown to have very attractive features in terms of low device and component stresses, small filter components, low switching losses, high power density and high efficiency, bidirectional power flow, buck-boost operation, and low sensitivity

Mustansir H. Kheraluwala; Randal W. Gascoigne; Deepakraj M. Divan; Eric D. Baumann

1992-01-01

119

A hybrid driving scheme for full-bridge synchronous rectified LLC resonant DC\\/DC converter  

Microsoft Academic Search

A novel hybrid driving scheme for full-bridge synchronous rectified LLC resonant DC\\/DC converter is proposed in this paper. With the full-bridge type rectifier, the voltage stress of the synchronous rectifiers (SRs) is well clamped to the output voltage. Also the transformer structure is very simple due to only one secondary winding is needed. Therefore, the converter can utilize SRs with

Xiucheng Huang; Jianfeng Wang; Junming Zhang; Zhaoming Qian

2011-01-01

120

A Pulse-Frequency-Modulated Full-Bridge DC\\/DC Converter With Series Boost Capacitor  

Microsoft Academic Search

The conventional zero-voltage switching phase-shift full-bridge (ZVS PSFB) converter has a large circulating energy during the freewheeling interval caused by the small duty cycle, which could increase the primary-side conduction losses, the turn-off switching losses of lagging-leg switches, and the current ripple through the output inductor. To overcome these problems, this paper proposes a new pulse-frequency-modulated full-bridge direct-current (dc)\\/dc converter

Yong-Saeng Shin; Chang-Seop Kim; Sang-Kyoo Han

2011-01-01

121

An Isolated Full-Bridge DC–DC Converter With 1MHz Bidirectional Communication Channel  

Microsoft Academic Search

This paper presents a novel isolated full-bridge dc\\/dc converter with bidirectional communication capability. The trans- former in the proposed converter is utilized as an isolation inter- face for transferring both energy and data. Power delivery and forward data transfer are conducted simultaneously by modifying the full-bridge switching phase. Backward data transfer is realized by manipulating the amplitude of the resonant

Ru-Shiuan Yang; Lon-Kou Chang; Hung-Chi Chen

2011-01-01

122

An isolated full-bridge DC\\/DC converter with bidirectional communication capability  

Microsoft Academic Search

This work presents a novel isolated full-bridge DC\\/DC converter with bidirectional communication capability. The transformer in the proposed converter is utilized as an isolation interface for transferring energy and data. Power delivery and forward data transfer are conducted simultaneously by modifying the full-bridge switching phase. Backward data transfer is realized by manipulating the amplitude of the resonant signal through modulating

Lon-Kou Chang; Ru-Shiuan Yang

2008-01-01

123

A novel zero-current technique for high power full bridge DC-DC converter  

Microsoft Academic Search

A novel zero-current switching control technique for IGBT full-bridge (FB) PWM power converters has been proposed. The key idea of the technique is to delay the turn-off time of one switch in each diagonal pair of IGBT switches in conventional PWM full-bridge power converters in order to achieve zero current turn-off of this IGBT switch. This new control technique is

Chuangshe Wang; Yushan Tan; Jianping Xu; Qun Zhang

1998-01-01

124

Feasibility of capacitor voltage regulation and output voltage harmonic minimization in cascaded H-bridge converters  

Microsoft Academic Search

Multilevel converters have found popularity in electric-drive vehicles. In cascaded H-bridge multilevel converters, it is advantageous to use only one DC voltage source for the main H-bridge cell and supply the rest of the cells with capacitors. However, regulating the capacitors' voltage level becomes a challenging issue. This paper studies the existing constraints on regulating the capacitor voltage levels especially

Hossein Sepahvand; Mostafa Khazarei; Mehdi Ferdowsi; Keith Corzine

2010-01-01

125

Reliability considerations for full-bridge DC-DC converter in fuel-cell applications  

Microsoft Academic Search

In this paper, the reliability of a full bridge DC-DC converter of fuel cell application has been determined. In the full bridge topology, MOSFETs should be paralleled in order to increase current rating. In this paper it is shown that this paralleling extremely decreases the reliability. But IPM switch application significantly increases the reliability in high power applications.

A. H. Ranjbar; B. Abdi; G. B. Gharehpetian; J. Milimonfared

2008-01-01

126

Unified analog and digital models for half bridge DC-DC converter with current doubler rectifier  

Microsoft Academic Search

The half bridge DC-DC topology with current doubler rectification is suitable for high current low voltage applications. In this paper, both analog and digital unified state space models and small signal models valid for symmetric, asymmetric and duty cycle shifted controlled half bridge DC-DC converter are derived. The discretized analog model and derived digital model are compared based on the

Liangbin Yao; Jaber A. Abu-Qahouq; Issa Batarseh

2005-01-01

127

A high performance dual output dc-dc converter combined the phase shift full bridge and LLC resonant half bridge with the shared lagging leg  

Microsoft Academic Search

A new dual output dc-dc converter is proposed in this paper. The first output works as a conventional full bridge converter; by connecting a LLC resonant tank to the lagging leg, a half bridge resonant converter is structured, and the second output is obtained. The first output is regulated by the phase shift and the second output by the switching

Yu Chen; Xuejun Pei; Li Peng; Yong Kang

2010-01-01

128

Pseudo-resonant full bridge DC\\/DC converter  

Microsoft Academic Search

A DC-DC power converter topology that combines the ease of control and wide range of conventional DC-DC converters, with low switching losses, low dv\\/dt and low electromagnetic interference that is typical of zero voltage switched resonant converters is proposed. Consequently, the ratings of these components are substantially lower than for similarly rated resonant topologies. While resonant elements are used to

O. D. Patterson; D. M. Divan

1991-01-01

129

Pseudo-resonant full bridge dc/dc converter  

SciTech Connect

In this paper a new dc/dc converter topology is proposed which combines the ease of control and wide range of conventional dc/dc converters, with low switching losses, low dv/dt and low EMI that is typical of zero voltage switched resonant converters. Consequently, the ratings of these components are substantially lower than for similarly rated resonant topologies. Operation at very high frequencies is possible and is shown with the fabrication of a 200 W 1 MHz d/dc converter.

Patterson, O.D.; Divan, D.M. (Wisconsin Univ., Madison, WI (United States). Dept. of Electrical and Computer Engineering)

1991-10-01

130

Analysis of a Voltage-fed Full Bridge DC-DC Converter in Fuel Cell Systems  

Microsoft Academic Search

Fuel cells at moderate power levels have a high output current and low output voltage. In order to make them usable for applications with a higher voltage demand, a DC-DC converter with large voltage gain is needed. This paper deals with a voltage-fed full bridge converter that is designed to reach a high voltage gain. Analytical calculations are given, completely

A. Averberg; A. Mertens

2007-01-01

131

Fully equipped half bridge building block for fast prototyping of switching power converters  

Microsoft Academic Search

With the advent of high performance digital controllers, the time and effort to implement new control algorithms for the control of power electronic converters have decreased drastically. Nevertheless, the design and the practical implementation of power electronic converters, intended for testing new control algorithms, are still complicated and time consuming activities. Therefore, a fully equipped half bridge test platform was

Koen De Gusseme; David M. Van de Sype; Jeroen Van den Keybus; Alex P. Van den Bossche; Jan A. Melkebeek

2004-01-01

132

Quick identification technique of fault conditions in cascaded H-Bridge multilevel converters  

Microsoft Academic Search

With reference to multilevel converters in cascaded H-bridge configuration, the paper presents a technique suitable to quickly identify fault conditions during normal operations. First a modulation technique generalized to m-level converters is synthetically illustrated in order to evidence the presence of different modulation patterns and the corresponding criteria of selection in normal operating conditions. Then, all the \\

G. Brando; A. Dannier; A. Del Pizzo; R. Rizzo

2007-01-01

133

Control of Cascaded H-Bridge Converter based DSTATCOM for High Power Applications  

Microsoft Academic Search

This paper presents the simulation studies on a cascaded H-bridge converter based distribution static synchronous compensator (DSTATCOM) for improving the power quality of a distribution system. Voltage source converter based DSTATCOM has been established as the most preferred solution for management of reactive power in distribution utilities and for improving voltage regulation, power factor and power quality in industries. For

K. Anuradha; B. P. Muni; A. D. R. Kumar

2006-01-01

134

Cascaded H-bridge with bidirectional boost converters for energy storage  

Microsoft Academic Search

This paper presents the design and control of a cascaded H-bridge converter for energy storage with bidirectional boost converter as charge\\/discharge unit. The disadvantage of the second harmonic on the main energy storage unit as well as its voltage variation with the state of charge is solved by this structure. The independent phase grid control is proposed for this topology.

Ionut Trintis; Stig Munk-Nielsen; Remus Teodorescu

2011-01-01

135

Prototype development of a full-bridge isolated boost converter for solar photovoltaic systems integration  

Microsoft Academic Search

A critical aspect of solar photovoltaic (PV) systems integration is the power electronics interface technologies for DC power conversion. Successful integration of PV systems at all levels requires reliable, low-cost, and efficient interface capabilities. The research work for this paper presents a novel PV architecture and the development of a low voltage full bridge isolated boost converter prototype DC converter

Gregory F. Reed; Luke A. Solomon; Brandon M. Grainger

2010-01-01

136

High-Efficiency Boost Half-Bridge Converter With Fast Boost Current Transferring ZVS Operation  

Microsoft Academic Search

A new boost half bridge (BHB) converter is presented. It is composed of additional switch, diode and coupled winding to boost inductor of BHB converter. Using the transferring of boost inductor current to coupled winding in a short period, the cancellation of zero voltage switching (ZVS) current, which always occurs in convention one, is prevented. Therefore, the ZVS operation is

Sung Sae Lee; Gun Woo Moon

2008-01-01

137

DC Voltage Balancing for PWM Cascaded H-Bridge Converter Based STATCOM  

Microsoft Academic Search

This paper presents a new control method for cascaded connected H-bridge converter based STATCOMs. These converters have been classically commutated at fundamental line-frequencies, but the evolution of power semiconductors has allowed to increase switching frequencies and the power ratings of these devices, permitting the use of PWM modulation techniques. This paper mainly focuses the DC bus voltage balancing problems, and

Jon Andoni Barrena; Luis Marroyo; Miguel Ángel Rodríguez; Óscar Alonso; José Ramón Torrealday

2006-01-01

138

Evaluation and design of megahertz-frequency off-line zero-current-switched quasi-resonant converters  

NASA Astrophysics Data System (ADS)

A performance comparison of flyback, forward, and half-bridge zero-current-switched quasi-resonant converter topologies for high-frequency offline applications is presented. It is shown that the half-bridge topology with secondary side resonance operating in half-wave mode is most suitable. A complete design procedure for the half-bridge power stage and the voltage-feedback control is presented together with experimental results for a 300-V DC hybridized converter which operates with conversion frequencies from 400 kHz to 2 MHz and delivers 1.5-16 A at 5 V DC.

Jovanovic, Milan M.; Lee, Fred C. Y.; Hopkins, Douglas C.

1989-01-01

139

Small-signal modeling of soft-switched asymmetrical half-bridge DC\\/DC converter  

Microsoft Academic Search

A small-signal model of soft-switched asymmetrical half-bridge DC\\/DC converter operating in a continuous inductor conduction mode is proposed. The analysis of this model is applicable to converters with any type of output rectifier (full-wave or half-wave). Based on the proposed model, the feedback compensation network for a prototype converter was designed. An open loop frequency response and voltage ripple attenuation

Sergey Korotkov; Valery Meleshin; Alexey Nemchinov; Simon Fraidlin

1995-01-01

140

Optimizing design of soft-switching dual-input full-bridge DC\\/DC converter  

Microsoft Academic Search

single-input DC\\/DC converter, especially for the soft-switching converter. That is because soft-switching conditions need to be considered in the procedure of the design of the parameters. This paper will focus on this issue and give some corresponding conclusions. In this paper, a dual-input full-bridge DC\\/DC converter will be taken as an example to show an optimizing design method of dual-input

Yan Li; Chuang Zhao; Jia Yao Chen; Rui Du; Yujin Zhang

2011-01-01

141

Cascaded H-bridge multilevel converter multistring topology for large scale photovoltaic systems  

Microsoft Academic Search

Large scale grid connected photovoltaic (PV) energy conversion systems have reached the megawatt level. This imposes new challenges on existing grid interface converter topologies and opens new opportunities to be explored. In this paper a new medium voltage multilevel-multistring configuration is introduced based on a three-phase cascaded H-bridge (CHB) converter and multiple string dc-dc converters. The proposed configuration enables a

S. Rivera; S. Kouro; B. Wu; J. I. Leon; J. Rodriguez; L. G. Franquelo

2011-01-01

142

Controller design for a single-phase two-cell multilevel cascade H-bridge converter  

Microsoft Academic Search

In this paper is studied the single-phase two-cell multilevel cascade H-bridge power converter connected to the grid, acting as a synchronous rectifier. The power exchange process between the cells of the converter and the grid is analyzed. Based on this analysis and on the power converter model the stages of the controller design process are shown. A new controller for

S. Vazquez; J. I. Leon; J. M. Carrasco; L. G. Franquelo; E. Galvan; J. A. Sanchez; E. Dominguez

2008-01-01

143

Analysis and design considerations of a load and line independent zero voltage switching full bridge DC\\/DC converter topology  

Microsoft Academic Search

The analysis and design of a zero voltage switching (ZVS) full bridge DC\\/DC power converter topology is presented in this paper. The converter topology presented here employs an asymmetrical auxiliary circuit consisting of a few passive components. With this auxiliary circuit, the full bridge converter can achieve ZVS independent of line and load conditions. The operating principle of the circuit

Praveen K. Jain; Wen Kang; Harry Soin; Youhao Xi

2002-01-01

144

A Method for Balancing Capacitor Voltages in Single-Phase Half-Bridge PFC Converter  

NASA Astrophysics Data System (ADS)

A single-phase half-bridge Power Factor Correction converter has no common-mode noise theoretically. The output dc capacitor voltages, however, happen to be unbalanced sometimes. In this paper, it is made clear that the unbalanced voltages are principally caused by the asymmetry on the reference signal or the detected current wave. We investigate an improved converter, which has double half-bridge PFC converters in common with two output dc capacitors and should be connected to the single-phase three-wired distribution system. It can output their balanced capacitor voltages even if the reference signal wave has the asymmetry due to the offset in the control circuit. As a result, it can be operated with the lower distortion in source currents, the higher power factor, and the lower ripple in output dc voltage as compared with the conventional converter. Moreover, their output capacitors can be downsized for saving the costs and the maintenances.

Fujita, Takayuki; Iida, Shoji

145

High-efficiency standby forward converter integrated with DC\\/DC Phase-Shift Full Bridge converter for server power supply system  

Microsoft Academic Search

This paper presents high-efficiency standby forward converter integrated with the DC\\/DC Phase-Shift Full Bridge (PSFB) converter. By sharing one leg of DC\\/DC PSFB converter, the proposed converter features low- voltage stress, no snubber and zero-voltage switching (ZVS) over the entire load range. Thus, the proposed converter has high-efficiency, especially under half load condition. Furthermore, by using forward-type transformer instead of

Shin-Young Cho; Jae-Kook Kim; Il-Woon Lee; Moon-Young Kim; Gun-Woo Moon

2011-01-01

146

Stress analysis of a full bridge ZVS DC-DC converter  

Microsoft Academic Search

This paper presents the MOSFET electrical stresses in a full bridge (FB) ZVS DC-DC converter with a detailed study of the MOSFET body diode reverse recovery stress under normal and low load operating conditions. Experimental results are presented under normal and low load operation for a 350 V-3.5 V, 225 A FB ZVS DC-DC converter. Two-dimensional (2-D) numerical simulation results

S. Abedinpour; R. Burra; K. Shenai

2001-01-01

147

A novel zero-current-transition full bridge DC\\/DC converter  

Microsoft Academic Search

This paper proposes a novel zero-current-transition pulse-width modulation full-bridge dc\\/dc converter. The proposed converter not only achieves zero current switching for the main switches and auxiliary switch in the entire load ranges, but it also realizes soft commutation for the output rectifier diodes. Furthermore, the auxiliary circuit also helps to turn on the main switches softly. Simulation results and experimental

Junming Zhang; Xiaogao Xie; Xinke Wu; Guoliang Wu; Zhaoming Qian

2006-01-01

148

A novel zero-current-transition full bridge DC-DC converter  

Microsoft Academic Search

This paper proposes a novel zero-current-transition (ZCT) PWM full bridge DC\\/DC converter. The proposed converter not only achieves ZCS for the main switches and auxiliary switch in the entire load ranges but also realizes soft commutation for the output rectifier diodes. Furthermore, the auxiliary circuit also helps softly turn on the main switches. Simulation results and experimental results verify the

J. M. Zhang; X. G. Xie; X. K. Wu; Zhaoming Qian

2005-01-01

149

A novel zero-current-transition full-bridge DC-DC converter  

Microsoft Academic Search

A new soft-switching full-bridge converter with IGBTs as the main switch is presented. On one hand soft-switching is used to achieve higher possible switching frequencies, and on the other hand to reduce the effect of current derating of the IGBT, i.e. the overrating of the switches is reduced. The presented DC-DC converter uses two auxiliary resonant circuits based on the

M. Marx; D. Schroder

1996-01-01

150

A Novel PWM Modulation Strategy for DC Voltage Balancing in Cascaded H-Bridge Multilevel Converters  

Microsoft Academic Search

This paper presents a novel Voltage Balancing PWM modulation strategy for Cascaded H-Bridge multilevel converters. These converters have been classically commu-tated at fundamental line-frequencies, but the evolution of Power Semiconductors has allowed to increase switching frequencies and the power ratings of these devices, permitting the use of PWM modulation techniques. This paper presents a new PWM modulation strategy that solves

Jon Andoni Barrena; Luis Marroyo; M. A. Rodriguez; J. R. Torrealday

2007-01-01

151

Individual Voltage Balancing Strategy for PWM Cascaded H-Bridge Converter-Based STATCOM  

Microsoft Academic Search

This paper presents a new control method for cascaded connected H-bridge converter-based static compensators. These converters have classically been commutated at fundamental line frequencies, but the evolution of power semiconductors has allowed the increase of switching frequencies and power ratings of these devices, permitting the use of pulsewidth modulation techniques. This paper mainly focuses on dc-bus voltage balancing problems and

Jon Andoni Barrena; Luis Marroyo; Miguel Ángel Rodriguez Vidal; JosÉ RamÓn Torrealday Apraiz

2008-01-01

152

A new half bridge converter for the personal computer power supply  

Microsoft Academic Search

A new half bridge converter for the personal computer (PC) power supply is proposed in this paper. Generally, PC power supply has two unique input\\/output specifications which are wide input voltage range and long hold up time. Therefore, it has to be operated with a small duty ratio. That makes it difficult to apply ZVS PWM topology to the PC

Kyu-Min Cho; Won-Sik Oh; Keun-Wook Lee; Gun-Woo Moon

2008-01-01

153

Power efficiency improvement of the full bridge current resonant DC-DC converter  

Microsoft Academic Search

This paper deals with a power efficiency improvement of the full bridge current resonant DC-DC converter, which is developed to be applied to the power conditioner of the fuel cell generation system. The loss by the backward current of the side rectification diode can be decreased with a voltage doubler rectifier. The center tap rectifier is used for the conventional

Hisatsugu Kato; Hirofumi Matsuo; Tsubasa Ito; Shuhei Kawazu; Daiki Kawahara; Satoshi Motomura; Ryota Hamaguchie

2011-01-01

154

High power high frequency zero current transition full bridge DC\\/DC converter  

Microsoft Academic Search

A novel zero current transition (ZCT) full bridge PWM DC\\/DC power converter is proposed. Based on the ZCT technique, this circuit realizes the ZCS of the active switches and the auxiliary switches. In the full range of loads, it can be operated in the constant frequency soft-switching mode. On the basis of the illustration of its operation principle, a detailed

X. H. Wu; D. M. Xu; J. H. Kong; C. Yang; Z. Qian

1998-01-01

155

Load and line independent zero voltage switching full bridge DC\\/DC converter topology  

Microsoft Academic Search

A full bridge DC\\/DC converter topology is proposed in this paper that can achieve zero voltage switching (ZVS) independent of line and load conditions. It employs a simple auxiliary circuit that consists of a few passive components. The analysis of the operation of the circuit and the simulation are presented. Experiments on a 400 V to 55 V, 500 W

Praveen Jain; Wen Kang; Harry Soin; Youhao Xi

1998-01-01

156

A pulse frequency modulated full bridge DC\\/DC converter with series boost capacitor  

Microsoft Academic Search

The conventional Zero Voltage Switching (ZVS) Phase Shift Full Bridge converter(PSFB) has large circulating energy during freewheeling interval caused by the small duty cycle, which could increase the primary side conduction losses, turn off switching losses of lagging leg switches and current ripple through the output inductor. To overcome these problems, this paper proposes a new pulse frequency modulated full

Yong-Saeng Shin; Chung-Wook Roh; Sung-Soo Hong; Sang-Kyoo Han

2010-01-01

157

A new mode changeable full bridge dc\\/dc converter for wide input voltage range  

Microsoft Academic Search

Generally, a zero voltage switching (ZVS) phase shift full bridge (PSFB) converter is suitable for high power density\\/high efficiency application and its efficiency is maximized at 50% duty cycle. However, the steady state duty cycle is as small as approximately 30% at full load and nominal input voltage conditions which is because the PSFB must be designed to be ensure

Yong-Saeng Shin; Sung-Soo Hong; Dong-Joong Kim; Dong-Sung Oh; Sang-Kyoo Han

2011-01-01

158

Novel control strategy for cascaded H-bridge converter based DSTATCOM  

Microsoft Academic Search

Reactive power management in a power distribution network of a power utility and industry plays a major role in reducing distribution loss, in maintaining constant distribution voltage and in improving power factor. The paper presents the simulation studies on a cascaded H-bridge converter based DSTATCOM for power factor improvement in power distribution set-up using load side compensation. In this novel

K. Anuradha; B. P. Muni; A. D. RajKumar

2006-01-01

159

Novel Control Strategy for Cascaded H-Bridge Converter based DSTATCOM  

Microsoft Academic Search

Reactive power management in a power distribution network of a power utility and industry plays a major role in reducing distribution loss, in maintaining constant distribution voltage and in improving power factor. The paper presents the simulation studies on a cascaded H-Bridge converter based DSTATCOM for power factor improvement in power distribution set-up using load side compensation. In this novel

K. Anuradha; B. P. Muni; A. D. RajKumar; K. Balaji

2006-01-01

160

Cascaded bidirectional flyback converter driving DEAP transducers  

Microsoft Academic Search

For the control of Dielectric Elastomer Generators (DEGs) a special high voltage power-electronic (HVPE) is necessary, driving this kind of novel generators at high voltages and typically low currents. In order to supply the generator with initial charges and to harvest the generated energy, the HVPE must also enable a bidirectional energy transfer. After introducing the functional principle of DEGs

Lars Eitzen; Christian Graf; Jurgen Maas

2011-01-01

161

Double-flyback DC-DC converter  

Microsoft Academic Search

Circuit operation is analyzed for the ideal and real circuit of a DC-DC power convertor. The voltage ratio is deduced for each operating mode as a function of load current, duty factor and component values. Boundary conditions between different operating modes are obtained. Component ratings are summarized, to facilitate circuit design

S. Birca-Galateanu; Philippe Clavier

1995-01-01

162

Comparison of zero-voltage-switching current-fed full-bridge and half-bridge isolated Dc\\/Dc converters with active-clamp  

Microsoft Academic Search

This short paper presents a comparison between high-frequency current-fed full-bridge and half-bridge isolated dc\\/dc converters with active-clamp snubber. Active-clamp snubber, in addition to absorbing the turn-off voltage spike across the switch, acts as a zero-voltage transition auxiliary circuit resulting in zero-voltage switching (ZVS) of the semiconductor devices of converters. ZVS range depends upon the design, in particular, ratio of leakage

Akshay K Rathore; Xiaodong Li

2011-01-01

163

Handheld Flyback driven coaxial dielectric barrier discharge: Development and characterization  

SciTech Connect

The development of a handheld single and triple chamber atmospheric pressure coaxial dielectric barrier discharge driven by Flyback circuitry for helium and argon discharges is described. The Flyback uses external metal-oxide-semiconductor field-effect transistor power switching technology and the transformer operates in the continuous current mode to convert a continuous dc power of 10-33 W to generate a 1.2-1.6 kV 3.5 {mu}s pulse. An argon discharge breakdown voltage of {approx}768 V is measured. With a 50 kHz, pulse repetition rate and an argon flow rate of 0.5-10 argon slm (slm denotes standard liters per minute), the electrical power density deposited in the volume discharge increases linearly at a rate of 75{+-}20% mW/cm{sup 3} per 1 slm of gas. Electrical power transfer efficiency between the secondary Flyback coil and the discharge volume increases from 0.1% to 0.65%. Neutral argon gas forced convection analysis yields a similar energy loss rate to the electrical discharge process. Optical emission spectroscopy studies of the expanding discharge plume into ambient air reveal that the air climatically controls the plume chemistry to produce an abundance of neutral argon atoms and molecular nitrogen.

Law, V. J. [National Center of Plasma Science and Technology (NCPST), Dublin City University, Dublin 9 (Ireland); Milosavljevic, V. [School of Physics and NCPST, Dublin City University, Dublin 9, Ireland and Faculty of Physics, University of Belgrade, P.O. Box 368, Belgrade (Serbia); O'Connor, N.; Daniels, S. [School of Electronic Engineering and NCPST, Dublin City University, Dublin 9 (Ireland); Lalor, J. F. [NCPST, Dublin City University, Dublin 9 (Ireland)

2008-09-15

164

Feasibility study of 200 kW half-bridge and full-bridge DC\\/DC converters with 6.5 kV IGBTs  

Microsoft Academic Search

This paper discusses the half- and full-bridge DC\\/DC converter topologies for high-power (200 kW) high-voltage (3.6 kV) applications. Focus is on the primary part of these topologies, i.e. the feasibility of two high-voltage IGBTs replacement in the full-bridge by two high-voltage film capacitors in the half-bridge.

D. Vinnikov; M. Lehtla

2008-01-01

165

High-voltage, high-power, ZVS, full-bridge PWM converter employing an active snubber  

Microsoft Academic Search

The authors present the analysis, design, and applications of a high-voltage, high-power, zero-voltage switched (ZVS), full-bridge (FB) pulse-width-modulated (PWM) converter with an active snubber in the secondary circuit. The nondissipative snubber completely eliminates the voltage overshoot and ringing across the rectifiers. The ringing of the parasitic capacitance of the rectifiers and the leakage inductance of the transformer are eliminated in

J. A. Sabate; V. Vlatkovic; R. B. Ridley; F. C. Lee

1991-01-01

166

A Zero-Voltage transition full bridge DC-DC converter for photovoltaic applications  

Microsoft Academic Search

The paper focuses on a high efficiency Zero Voltage Transition (ZVT) DC-DC full-bridge converter using a high-frequency transformer. A novel structure with recovery of energy on load side is proposed. Such solution is particularly suitable for photovoltaic applications which require low losses and cannot recovery energy on source side. Moreover, a suitable architecture of snubber circuit that permits to improve

Armando Bellini; Stefano Bifaretti; Vincenzo Iacovone

2010-01-01

167

High power full bridge DC\\/DC converter using digital-to-phase-shift PWM circuit  

Microsoft Academic Search

With the advent of the high-speed microprocessor and DSP, the possibility of executing a control strategy in the digital domain has become a reality. Therefore, by the use of a DSP controller instead of using the analog controller UC3879, a phase-shifted zero-voltage-switching (ZVS) full-bridge (FB) DC\\/DC power converter can be controlled easily. In this paper, a digital-to-phase shift PWM circuit

Eun-Soo Kim; Tae-Jin Kim; Young-Bok Byun; Tae-Geun Koo; Yoon-Ho Kim

2001-01-01

168

A modular power electronic transformer based on a cascaded H-bridge multilevel converter  

Microsoft Academic Search

In this paper a modular power electronic transformer (PET) for feeding critical loads is presented. The PE-based transformer is a multi-cellular step-down converter that can directly connect to medium voltage levels on the primary side and provide a low voltage, highly stable interface for consumer applications. The presented structure consists of three stages: a cascaded H-bridge (CHB) rectifier, an isolation

H. Iman-Eini; Sh. Farhangi; J.-L. Schanen; M. Khakbazan-Fard

2009-01-01

169

Analysis and design of a saturable reactor assisted soft-switching full-bridge dc-dc converter  

SciTech Connect

Analysis and design considerations for a saturable reactor assisted soft-switching full-bridge dc-dc converter are presented. The converter has advantages such as low switching losses with no substantial increase in conduction losses, wide load range, and constant frequency operation. To show how to utilize the analysis results, a 350-W, 500-kHz converter is chosen as a design example. The results are verified experimentally on a prototype converter.

Hamada, Satoshi (Sansha Electric Manufacturing Co., Ltd., Osaka (Japan)); Nakaoka, Mutsuo (Kobe Univ. (Japan). Dept. of Electrical and Electronics Engineering)

1994-05-01

170

Full bridge soft-switching phase-shifted PWM DC-DC converter using tapped inductor filter  

Microsoft Academic Search

In this paper, a novel high frequency transformer linked full-bridge type soft-switching phase-shift PWM control scheme DC-DC power converter is presented. A tapped inductor filter is implemented in the proposed soft-switching converter topology to achieve wide load variation range soft-switching PWM constant frequency operation of the DC-DC converter, to minimize circulating current. The presented converter operates with ZVS for leading

Serguei Moisseev; Shinji Sato; Satoshi Hamada; Mutsuo Nakaoka

2003-01-01

171

Soft-switching PWM full-bridge DC-DC converter with energy recovery transformer and auxiliary passive lossless snubbers  

Microsoft Academic Search

This paper proposes a novel soft-switching full-bridge PWM DC-DC converter using passive regenerative snubber. The newly proposed circuit topology is composed of a full-bridge converter with a high frequency linked transformer and passive snubbers configured with energy regenerative circuit and controlled under the conventional PWM actions to prevent freewheeling current. The leakage inductance of main transformer (Tm) helps to achieve

Yung-Fu Huang; Chih-Wen Liu; Yoshihiro Konishi

2007-01-01

172

Fault-Tolerant Design and Control Strategy for Cascaded H-Bridge Multilevel Converter-Based STATCOM  

Microsoft Academic Search

Cascaded H-bridge multilevel converter (CHMC) is a promising topology for flexible ac transmission systems such as static synchronous compensator (STATCOM) applications. Attention was drawn to the issue of converter reliability due to the large number of power devices used in CHMC applications. This paper proposed an effective fault-tolerant strategy by using H-bridge building block (HBBB) redundancy in CHMC-based STATCOM. The

Wenchao Song; Alex Q. Huang

2010-01-01

173

Novel dual mode operation of phase-shifted full bridge converter to improve efficiency under light load condition  

Microsoft Academic Search

The main theme of this paper is to propose switching method to reduce the loss of phase-shift controlled full-bridge converter under light load and standby conditions. It will be shown that the efficiency can be improved using the proposed switching control technique. The presented switching control technique controls the full-bridge converter by PWM switching mode under light load condition and

Bo-Yuan Chen; Yen-Shin Lai

2009-01-01

174

Modulation Extension Control of Hybrid Cascaded H-bridge Multilevel Converters with 7-level Fundamental Frequency Switching Scheme  

Microsoft Academic Search

This paper presents a modulation extension control algorithm for hybrid cascaded H-bridge multilevel converters. The hybrid cascaded H-bridge multilevel motor drive using only a single DC source for each phase is promising for high power motor drive applications since it can greatly decrease the number of required DC power supplies, has high quality output power due to its high number

Zhong Du; Burak Ozpineci; Leon M. Tolbert

2007-01-01

175

Analysis of DC-DC converter based on single phase full bridge inverter operating in zero voltage switching  

Microsoft Academic Search

Soft switching techniques have been applied in the design of DC-DC converters, in order to achieve better performance. Soft switching techniques imply higher efficiency, lower EMI radiation and smaller heat sink required. This paper presents an analysis of a DC-DC converter based on single phase full bridge inverter zero voltage switching (ZVS)

J. Sutanto; Syafrudin

2001-01-01

176

Zero-voltage and zero-current-switching full bridge PWM converter for high-power applications  

Microsoft Academic Search

A novel zero-voltage and zero-current-switching (ZVZCS) full-bridge (FB) pulse-width modulated (PWM) converter is proposed. The new converter overcomes the limitations of the zero-voltage-switching (ZVS)-FB-PWM converter, such as high circulating energy, loss of duty cycle, and limited ZVS load range for the lagging-leg switches. By using the DC blocking capacitor and adding a saturable inductor, the primary current during the freewheeling

Jung-Goo Cho; J. A. Sabate; Guichao Hua; Fred C. Lee

1996-01-01

177

A Novel Three Level Full Bridge Resonant Dc-Dc Converter Suitable for High Power Wide Range Input Applications  

Microsoft Academic Search

To make downstream dc-dc converters compatible with both single and three phases PFC stages for system integration, a novel three-level full bridge resonant dc-dc converter was proposed. This converter combines the LLC topology, which maintains merits as ZVS for all primary side main switches and ZCS for secondary side diodes under wide range inputs, and the three-level technique, which is

Wei Chen; Yilei Gu; Zhengyu Lu

2007-01-01

178

Analysis and design of a saturable reactor assisted soft-switching full-bridge DC-DC converter  

Microsoft Academic Search

The analysis and design of a saturable reactor-assisted soft-switching full-bridge DC-DC converter are presented. The converter has advantages such as low switching losses (with no substantial increase in conduction losses), wide load range, and constant switching frequency. In order to show how to utilize the analysis results in designing, a 350 W 500 kHz converter is chosen as an example.

S. Hamada; M. Nakaoka

1991-01-01

179

Analysis and design of a saturable reactor assisted soft-switching full-bridge DC-DC converter  

Microsoft Academic Search

Analysis and design considerations for a saturable reactor assisted soft-switching full-bridge DC-DC converter are presented. The converter has advantages such as low switching losses with no substantial increase in conduction losses, wide load range, and constant frequency operation. To show how to utilize the analysis results, a 350 W, 500 kHz converter is chosen as a design example. The results

Satoshi Hamada; Mutsuo Nakaoka

1994-01-01

180

A new soft switching technique for bi-directional power flow, full-bridge DC-DC converter  

Microsoft Academic Search

This paper proposes a new soft switching technique for the phase-shift controlled bi-directional DC-DC converter. The described converter employs a low profile high frequency transformer and two active full-bridge converters for bidirectional power flow capability. A new soft switching technique is proposed, which guarantees soft switching over wide range (no load to full load) without any additional circuit components. In

Yujin Song; Prasad N. Enjeti

2002-01-01

181

A Novel Half-Bridge Asymmetrical ZCS-PWM DC-DC Converter with High Frequency-Link  

NASA Astrophysics Data System (ADS)

A novel zero current soft-switching (ZCS)-PWM cell-assisted half-bridge DC-DC converter topology with a high frequency link is proposed in this paper. The newly-proposed DC-DC converter consists of a PWM-controlled single-ended half-bridge high frequency (HF) inverter and a current doubler rectifier linked with a HF transformer. In order to attain the wide range of ZCS-PWM operation in the primary-side HF inverter, an active edge resonant snubber cell composed by a switched capacitor and a lossless inductor is adopted in the half-bridge leg, providing ZCS commutation for a wide range of output power. The operation characteristics of the DC-DC converter proposed here are described, and its feasibility data is demonstrated and evaluated with simulation and experimental results.

Mishima, Tomokazu; Hiraki, Eiji; Tanaka, Toshihiko; Nakaoka, Mutsuo

182

Optimized active-clamp circuit design for an isolated full-bridge current-fed DC-DC converter  

Microsoft Academic Search

This paper presents a new method for the capacitance selection of an active-clamp circuit to enhance the performance of an isolated current-fed full-bridge DC- DC converter. The developed approach can reduce the circulating energy through the bridge switches using an appropriate choice of the resonant frequency between the transformer leakage inductance and the clamp capacitance in relation to the switching

O. A. Ahmed; Jam Bleijs

2011-01-01

183

Modulation Extension Control of Hybrid Cascaded H-bridge Multilevel Converters with 7-level Fund mental Frequency Switching Scheme  

Microsoft Academic Search

This paper presents a modulation extension control al- gorithm for hybrid cascaded H-bridge multilevel converters. The hybrid cascaded H-bridge multilevel motor drive using only a single dc source for each phase is promising for high-power mo- tor drive applications since it can greatly decrease the number of required dc power supplies, has high-quality output power be- cause of its high

Zhong Du; Burak Ozpineci; Leon M. Tolbert

2009-01-01

184

Three-Level Half-Bridge DC\\/DC Converter based on Two-Level Full bridge DC\\/DC Converter  

Microsoft Academic Search

This paper studies the approach of derivation of three-level (TL) half-bridge (HB) topology from conventional full bridge DC\\/DC topology. The derived TL HB topology has same device count and performance as the corresponding full bridge topology, and it is more suitable for high voltage applications. The derivation approach for different control method, i.e. PWM control, frequency control and phase shift

J. M. Zhang; X. K. Wu; Chen Zhao; Yu Ma; Zhaoming Qian

2006-01-01

185

A New Full Bridge Zero Voltage Switched Phase Shifted DC-DC Converter with Enlarged Duty Cycle and ZVS Range  

Microsoft Academic Search

This paper presents the complete theoretical analysis, simulation and design optimisation of a Full-Bridge Zero- Voltage-Switched Phase-Shift (FB-ZVS-PS) DC-DC converter with an LCC auxiliary circuit, working with a frequency of 250kHz and with an output power of 1kW. The converter uses a voltage capacitor divider to create half of the input voltage in one terminal of the auxiliary inductor. The

João Pedro Beirante; Beatriz Vieira Borges

2001-01-01

186

Transformer Core Unbalancing Issue in a Full-Bridge DC-DC Converter with Current Doubler Rectifier  

Microsoft Academic Search

Transformer core saturation in a full-bridge, phase-shift DC-DC converter with current doubler rectifier has been considered. Equations allowing to calculate maximum value of the flux density in the core have been obtained. The theoretical analysis and calculations were verified by simulation and experiments of DC-DC converter with 2500 W output power. Main causes of asymmetrical regimes have been revealed and

B. A. Gusev; V. I. Meleshin; D. A. Ovchinnikov

2006-01-01

187

Analysis and Optimal Design Considerations for an Improved Full Bridge ZVS DC–DC Converter With High Efficiency  

Microsoft Academic Search

This paper proposes an improved full bridge dc-dc converter, which can achieve zero-voltage-switching (ZVS) with wide input voltage range and load range. The operation principle of the converter and the optimal design considerations for high efficiency and ZVS range are analyzed. By adding two clamp diodes and two small coupled inductors at the primary side of the transformer, the voltage

Xinke Wu; Junming Zhang; Xiaogao Xie; Zhaoming Qian

2006-01-01

188

A zero-voltage and zero-current switching full bridge DC-DC converter with transformer isolation  

Microsoft Academic Search

A new primary-side-assisted zero-voltage and zero-current switching full bridge DC-DC converter with transformer isolation is proposed. The proposed DC-DC converter uses only one auxiliary transformer and two diodes to obtain ZCS for the leading leg. It has a simple and robust structure, and load current control capability even in short circuit conditions, The possibility of magnetic saturation due to asymmetricity

Seong-Jeub Jeon; Gyu-Hyeong Cho

2001-01-01

189

An improved soft-switching PWM full-bridge DC-DC converter modification operating at reduced conduction loss  

Microsoft Academic Search

An improved soft-switching PWM full-bridge DC-DC converter is presented. This employs a tapped inductor for low-pass filter to minimize a circulating current flowing through the transformer and switching devices. By using the tapped inductor and a saturable reactor(s), the converter achieves soft-switching with both low commutating and low circulating currents, resulting in low switching and conduction losses. Principle of operation

S. Hamada; Y. Maruyama; M. Nakaoka; Y. Murakami

1993-01-01

190

High frequency transformer-assisted passive soft switching PWM DC-DC converter with energy recovery for compact auxiliary power supply in rolling stock transportation  

Microsoft Academic Search

In this paper, a two-switch high frequency flyback type zero voltage soft switching PWM DC-DC converter using IGBTs is proposed. Effective applications for this power converter can be found in auxiliary power supplies of rolling stock transportation and electric vehicles. This power converter is basically composed of two active power switches and a flyback high frequency transformer. In addition to

Claudio Y. Inaba; Yoshihiro Konishi; Mutsuo Nakaoka

2003-01-01

191

A High-Efficiency Single-Phase AC\\/DC Converter With Enabling Window Control and Active Input Bridge  

Microsoft Academic Search

The conventional continuous conduction mode boost converter has been widely used for power factor correction (PFC) applications because of its high input power factor and simplicity, but it suffers from conduction loss in the input rectifier bridge and switching loss due to the high switching frequency. The efficiency decreases significantly under the low input voltage or the light-load work condition.

Xudan Liu; Dehong Xu; Changsheng Hu; Heng Yue; Yashun Li; Ping Lin; Hangwen Pan

2012-01-01

192

Cardiomyopathy mutations reveal variable region of myosin converter as major element of cross-bridge compliance.  

PubMed

The ability of myosin to generate motile forces is based on elastic distortion of a structural element of the actomyosin complex (cross-bridge) that allows strain to develop before filament sliding. Addressing the question, which part of the actomyosin complex experiences main elastic distortion, we suggested previously that the converter domain might be the most compliant region of the myosin head domain. Here we test this proposal by studying functional effects of naturally occurring missense mutations in the beta-myosin heavy chain, 723Arg --> Gly (R723G) and 736Ile --> Thr (I736T), in comparison to 719Arg --> Trp (R719W). All three mutations are associated with hypertrophic cardiomyopathy and are located in the converter region of the myosin head domain. We determined several mechanical parameters of single skinned slow fibers isolated from Musculus soleus biopsies of hypertrophic cardiomyopathy patients and healthy controls. Major findings of this study for mutation R723G were i), a >40% increase in fiber stiffness in rigor with a 2.9-fold increase in stiffness per myosin head (S( *)(rigor R723G) = 0.84 pN/nm S( *)(rigor WT) = 0.29 pN/nm); and ii), a significant increase in force per head (F( *)(10 degrees C), 1.99 pN vs. 1.49 pN = 1.3-fold increase; F( *)(20 degrees C), 2.56 pN vs. 1.92 pN = 1.3-fold increase) as well as stiffness per head during isometric steady-state contraction (S( *)(active10 degrees C), 0.52 pN/nm vs. 0.28 pN/nm = 1.9-fold increase). Similar changes were found for mutation R719W (2.6-fold increase in S( *)(rigor); 1.8-fold increase in F( *)(10 degrees C), 1.6-fold in F( *)(20 degrees C); twofold increase in S( *)(active10 degrees C)). Changes in active cross-bridge cycling kinetics could not account for the increase in force and active stiffness. For the above estimates the previously determined fraction of mutated myosin in the biopsies was taken into account. Data for wild-type myosin of slow soleus muscle fibers support previous findings that for the slow myosin isoform S( *) and F( *) are significantly lower than for fast myosin e.g., of rabbit psoas muscle. The data indicate that two mutations, R723G and R719W, are associated with an increase in resistance to elastic distortion of the individual mutated myosin heads whereas mutation I736T has essentially no effect. The data strongly support the notion that major elastic distortion occurs within the converter itself. Apparently, the compliance depends on specific residues, e.g., R719 and R723, presumably located at strategic positions near the long alpha-helix of the light chain binding domain. Because amino acids 719 and 723 are nonconserved residues, cross-bridge stiffness may well be specifically tuned for different myosins. PMID:19651039

Seebohm, B; Matinmehr, F; Köhler, J; Francino, A; Navarro-Lopéz, F; Perrot, A; Ozcelik, C; McKenna, W J; Brenner, B; Kraft, T

2009-08-01

193

Flyback battery equalizer with voltage doubler rectifier  

Microsoft Academic Search

In this paper, a new flyback battery equalizer employing a voltage doubler rectifier is proposed. The proposed circuit transfers electric charges by utilizing the resonance between the transformer leakage inductor and secondary capacitor. Therefore, the proposed battery equalizer can reduce the switch turn off loss and snubber loss by a sinusoidal shaped current. Furthermore, the voltage stress on the rectifier

Hyoung-Suk Kim; Ki-Bum Park; Hyun-Wook Seong; Gun-Woo Moon; Myung-Joong Youn

2011-01-01

194

Method of controlling switching of a multiphase inductor-converter bridge  

DOEpatents

In an inductor-convertor circuit for transferring electrical energy between a storage coil and a load coil using a storage thyristor bridge, a load thyristor bridge, and a set of commutating capacitors, operation is improved by a method of changing the rate of delivery of energy in a given direction. The change in rate corresponds to a predetermined change in phase angle between the load bridge and the storage bridge and comprises changing the phase of the bridge by two steps, each equal to half the predetermined change and occurring 180.degree. apart. The method assures commutation and minimizes imbalances that lead otherwise to overvoltages.

Kustom, Robert L. (Palos Heights, IL); Fuja, Raymond E. (Justice, IL)

1981-01-01

195

A digital pulse-width modulator for phase-shift operation of full-bridge isolated DC-DC converters  

Microsoft Academic Search

This paper presents the concept, implementation and testing of a digital pulse-width modulator for phase-shift driving of full-bridge isolated DC-DC converters. The proposed phase-shift digital modulator employs a hybrid counter\\/delay line structure in order to achieve a 1.25 ns phase-shift resolution with a switching frequency of about 400 kHz on the secondary side, using a clock frequency of 25 MHz.

L. Corradini; D. Maksimovic

2010-01-01

196

Performance of single-phase DC drive system controlled by uniform PWM full-bridge DC-DC converter  

Microsoft Academic Search

DC drive systems controlled by pulse-width modulation (PWM) techniques are expected to replace the conventional phase-controlled systems. This is due to their simple control, high reliability, low cost and fast response. This paper presents the performance of a single-phase DC drive system controlled by uniform PWM full-bridge DC-DC converter. Two different uniform PWM control techniques are considered; PWM with bipolar

T. H. Abdelhamid

2000-01-01

197

Low Voltage and Current Stress ZVZCS Full Bridge DC–DC Converter Using Center Tapped Rectifier Reset  

Microsoft Academic Search

An improved zero-voltage and zero-current-switching (ZVZCS) full bridge dc-dc converter is proposed based on phase shift control. With an auxiliary center tapped rectifier at the secondary side, an auxiliary voltage source is applied to reset the primary current of the transformer winding. Therefore, zero-voltage switching for the leading leg switches and zero-current switching for the lagging leg switches can be

Xinke Wu; Xiaogao Xie; Chen Zhao; Zhaoming Qian; Rongxiang Zhao

2008-01-01

198

High power high frequency half-wave-mode ZCT-PWM full bridge DC\\/DC converter  

Microsoft Academic Search

A novel ZCT-PWM type full bridge DC\\/DC converter is proposed. This circuit realizes the ZCS of the main switches and the auxiliary switch, while achieving the soft recovery of the secondary side diodes. In the full range of loads, if can be operated in the constant frequency soft-switching mode. A 5 kW 100 kHz IGBT type SMPS module has achieved

David M. Xu; X. H. Wu; J. M. Zhang; Z. Qian

2000-01-01

199

A nonlinear optimization tool for the full-bridge zero-voltage-switched DC-DC converter  

Microsoft Academic Search

The fundamental equations characterizing the full-bridge zero-voltage-switched (ZVS) DC-DC power converter are utilized in a nonlinear design optimization routine. The design is subject to realistic constraints along with an objective function of minimal total volume and\\/or maximum efficiency. The routine is used to study the effects of switching frequency, leakage inductance and load range for ZVS on the efficiency and

Ashraf W. Lotfi; Q. Chen; Fred C. Lee

1992-01-01

200

A model-based controller for the cascade h-bridge multilevel converter used as a shunt active filter  

Microsoft Academic Search

This paper presents the modeling and control processes of the cascade h-bridge multilevel converter used as a shunt active filter. The single-phase five-level topology is studied, however, it can be easily scaled to more levels. Based on the model, a controller is proposed to compensate harmonic distortion and reactive power due to a nonlinear load which is equivalent to guarantee

G. Escobar; M. F. Martinez-Montejano; P. R. Martinez-Rodriguez; M. Hernandez-Gomez

2006-01-01

201

Applications of soft-switching full-bridge converter and rotational electric field to transdermal drug delivery  

Microsoft Academic Search

This paper presents applications of a soft-switching full-bridge converter to generate pulsed voltage (PV) for exciting tissue, which includes transdermal drug delivery (TDD), transcutaneous electrical nerve stimulation, functional electrical stimulation, etc. Particularly, in TDD it offers many potential advantages over conventional methods, such as oral and injection, and it avoids drug degradation through gastro-intestinal and liver. To design a portable

T.-F. Wu; S.-Y. Tseng; D.-S. Su; Y.-M. Chen; Y.-K. Chen

2004-01-01

202

1MHz self-driven ZVS full-bridge converter for 48-V power pod and DC\\/DC brick  

Microsoft Academic Search

In this paper, a self-driven zero-voltage-switching (ZVS) full-bridge converter is proposed. With the proposed self-driven scheme, the combination of the ZVS technique and Self-driven technique recycles the gate driving energy by making use of the input capacitor of the secondary side synchronous rectifier (SR) as the snubber capacitor of the primary side switches. Compared with the external driver, the proposed

Ming Xu; Yuancheng Ren; Jinghai Zhou; Fred C. Lee

2005-01-01

203

Three-level half-bridge ZVS DC\\/DC converter for electrolyzer integration with renewable energy systems  

Microsoft Academic Search

This paper presents findings of a R&D project tar geted to the development of a galvanically isolated step-down DC\\/DC converter for electrolyzer integration with renewable energy systems. The topology proposed is a three-level neutral point clamped half-bridge with a high-frequency isolation transformer and a current doubler rectifier that fulfils all the targets set by the designers. Despite an increased component

Anna Andrijanovits; Dmitri Vinnikov; Indrek Roasto; Andrei Blinov

2011-01-01

204

New one-phase dual converter for superconducting inductive energy storage and transfer applications: the one-phase inductor-converter bridge  

SciTech Connect

This report presents the results of theoretical and experimental development of the one-phase Inductor-Converter Bridge (ICB). The basic operating principles of the circuit are described followed by a theoretical treatment of the dynamics and control of the system. The successful results of the first experimental operation and control of the one-phase ICB are presented and explained. Finally, a discussion of some of the interesting transient and steady state behavior of the circuit, along with some of its unique features, is given.

Ehsani, M.; Kustom, R.L.

1984-03-01

205

The research on the active power filter based on the cascaded H-bridge converter  

Microsoft Academic Search

The model and the normal control method of the cascaded H-bridge active power filter is described firstly in this paper. However, problems exist in the normal control. One of the main problems is the unbalance of DC capacitor voltages of the H-bridge units. In this paper, an improved method for DC capacitor voltages control of the cascaded H-bridge active power

Yonggang Chen; Junling Chen; Ping Wang; Yaohua Li; Longcheng Tan; Zixin Li; Wei Xu

2008-01-01

206

A novel PWM control for a bi-directional full-bridge DC–DC converter with smooth conversion mode transitions  

Microsoft Academic Search

A novel CMOS integrated pulse-width modulation (PWM) control circuit allowing smooth transitions between conversion modes in full-bridge based bi-directional DC–DC converters operating at high switching frequencies is presented. The novel PWM control circuit is able to drive full-bridge based DC–DC converters performing step-down (i.e. buck) and step-up (i.e. boost) voltage conversion in both directions, thus allowing charging and discharging of

V. R. H. Lorentz; H. Schwarzmann; M. März; A. J. Bauer; H. Ryssel; L. Frey; P. Poure; F. Braun

2011-01-01

207

A Novel Soft-Commutating Isolated Boost Full-Bridge ZVS-PWM DC–DC Converter for Bidirectional High Power Applications  

Microsoft Academic Search

A soft-commutating method and control scheme for an isolated boost full bridge converter is proposed in this paper to implement dual operation of the well-known soft-switching full bridge dc\\/dc buck converter for bidirectional high power applications. It provides a unique commutation logic to minimize a mismatch between current in the current-fed inductor and current in the leakage inductance of the

Lizhi Zhu

2006-01-01

208

Study and Implementation of a Current-Fed Full-Bridge Boost DC–DC Converter With Zero-Current Switching for High-Voltage Applications  

Microsoft Academic Search

This paper presents a comprehensive study of a current-fed full-bridge boost dc-dc converter with zero-current switching (ZCS), based on the constant on-time control for high-voltage applications. The current-fed full-bridge boost converter can achieve ZCS by utilizing the leakage inductance and parasitic capacitance as the resonant tank. In order to achieve ZCS under a wide load range and with various input

Ren-Yi Chen; Tsorng-Juu Liang; Jiann-Fuh Chen; Ray-Lee Lin; Kuo-Ching Tseng

2008-01-01

209

A novel soft-commutating isolated boost full-bridge ZVS-PWM DC-DC converter for bidirectional high power applications  

Microsoft Academic Search

A soft-commutating method and control scheme for an isolated boost full bridge converter is proposed in this paper to implement dual operation of the well-known soft switching full bridge DC\\/DC (buck) converter for bi-directional high power applications. It provides a unique commutation logic to minimize a mismatch between current in the current-fed inductor and current in the leakage inductance of

Lizhi Zhu

2004-01-01

210

Switching Control Technique of Phase-Shift-Controlled Full-Bridge Converter to Improve Efficiency Under Light-Load and Standby Conditions Without Additional Auxiliary Components  

Microsoft Academic Search

The main theme of this paper is to propose a switching method to reduce the loss of phase-shift-controlled full-bridge converter under light-load and standby conditions. It will be shown that the efficiency can be improved using the proposed switching control technique. The presented switching control technique controls the full-bridge converter by pulsewidth-modulated (PWM) switching mode under light-load condition and PWM

Bo-Yuan Chen; Yen-Shin Lai

2010-01-01

211

Operation principles of bi-directional full-bridge DC\\/DC converter with unified soft-switching scheme and soft-starting capability  

Microsoft Academic Search

A new bi-directional dual full-bridge DC\\/DC converter with a unified soft-switching scheme and soft-start capability is proposed in this paper. A simple voltage clamp branch is used to limit transient voltage across the current-fed bridge and realize zero-voltage-switching (ZVS) in boost mode operation, while achieving hybrid zero-voltage\\/zero-current switching (ZVZCS) for the voltage-fed bridge in buck mode operation. The theory of

Kunrong Wang; Fred C. Lee; Jason Lai

2000-01-01

212

Bridges  

NSDL National Science Digital Library

Through a five-lesson series that includes numerous hands-on activities, students are introduced to the importance and pervasiveness of bridges for connecting people to resources, places and other people, with references to many historical and current-day examples. In learning about bridge types â arch, beam, truss and suspension â students explore the affect of tensile and compressive forces. Students investigate the calculations that go into designing bridges; they learn about loads and cross-sectional areas by designing and testing the strength of model piers. Geology and soils are explored as they discover the importance of foundations, bearing pressure and settlement considerations in the creation of dependable bridges and structures. Students learn about brittle and ductile material properties. Students also learn about the many cost factors that comprise the economic considerations of bridge building. Bridges are unique challenges that take advantage of the creative nature of engineering.

Integrated Teaching And Learning Program

213

High frequency full bridge converter using multilayer coreless printed circuit board step up power transformer  

Microsoft Academic Search

In designing switch mode power supply (SMPS), the desirable feature is to have an efficient and compact design. The main idea is to increase the switching frequency and reduce the bulky magnetic parts of the converter. This leads to a compact size, less weight, reduced cost and increased power density of the converter. This paper presents a high frequency full

Jawad Saleem; Abdul Majid; Radhika Ambatipudi; Hari Babu Kotte; Kent Bertilsson

2011-01-01

214

Feasibility study of half- and full-bridge isolated DC\\/DC converters in high-voltage high-power applications  

Microsoft Academic Search

This paper discusses the half- and full-bridge DC\\/DC converter topologies for high-power (200 kW) high-voltage (3.6 kV) applications. Focus is on the primary part of these topologies, i.e. the feasibility of replacement of two high-voltage IGBTs in the full-bridge by two high-voltage film capacitors in the half-bridge. The implementation of a half-bridge topology will lead to a sufficient simplification of

Dmitri Vinnikov; Tanel Jalakas; Mikhail Egorov

2008-01-01

215

Narrow Pulse Elimination PWM for Multilevel Digital Audio Power Amplifiers Using Two Cascaded H-Bridges as a Nine-Level Converter  

Microsoft Academic Search

This paper presents a methodology to reduce total harmonic distortion (THD) in digital audio power amplifiers, using two new approaches: 1) a multilevel converter made of two cascaded full-bridges, with suitable power supplies to operate as a nine-level hybrid type converter and 2) a new pulsewidth modulation (PWM) technique called narrow pulse elimination (NPE) PWM. The proposed nine-level converter uses

Victor M. E. Antunes; V. Fernão Pires; J. Fernando A. Silva

2007-01-01

216

Study and implementation of a novel bidirectional DC-DC converter with high conversion ratio  

Microsoft Academic Search

A novel bidirectional DC-DC converter with high conversion ratio is proposed in this paper. The proposed converter uses the coupled-inductor to achieve high voltage conversion ratio. In the boost mode, the proposed converter is cascaded by boost converter and flyback converter with voltage double to increase the voltage gain. The switch voltage stress is reduced by a voltage clamping circuit,

W. C. Liao; T. J. Liang; H. H. Liang; H. K. Liao; L. S. Yang; K. C. Juang; J. F. Chen

2011-01-01

217

Converter  

NSDL National Science Digital Library

In this activity, students enter in a fraction and the applet calculates the decimal representation of the fraction and vice versa. This activity allows students to explore converting fractions from decimals and from decimals to fractions. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

218

A new isolated bidirectional buck-boost PWM converter  

Microsoft Academic Search

In this paper, a new isolated dc-dc bidirectional converter is introduced. This converter consists of flyback and forward transformers and only one switch in primary side and one switch in secondary side of transformers. In this converter energy transfers to the output in both on and off switch states and controlled by PWM signal. Therefore implementation of control circuits is

M. Delshad; H. Farzanehfard

2010-01-01

219

An improved full-bridge zero-voltage-transition PWM DC\\/DC converter with zero-voltage\\/zero-current switching of the auxiliary switches  

Microsoft Academic Search

In this paper, an improved full-bridge (FB) zero-voltage-transition (ZVT) PWM DC\\/DC power converter topology is proposed. The proposed FB-ZVT PWM DC\\/DC power converter has the advantage of achieving zero voltage and zero current switching of the auxiliary switches using an auxiliary network. The auxiliary network is simply composed of a saturable inductor, auxiliary capacitors and auxiliary diodes. With the help

Dong-Yun Lee; Byoung-Kuk Lee; Dong-Seok Hyun

1998-01-01

220

Design, implementation, and experimental results of bi-directional full-bridge DC\\/DC converter with unified soft-switching scheme and soft-starting capability  

Microsoft Academic Search

The PWM control, design and implementation issues of the bi-directional dual full-bridge DC\\/DC converter with a unified soft-switching scheme and soft-start capability, which was proposed in a companion paper, are presented in this part of the two-paper sequel. Test results on a 5 kW prototype converter, which is connected between a 12 V battery and a high voltage bus, and

Kunrong Wang; Lizhi Zhu; Dayu Qu; Hardus Odendaal; Jason Lai; Fred C. Lee

2000-01-01

221

Design considerations of a voltage-fed full bridge DC-DC converter with high voltage gain for fuel cell applications  

Microsoft Academic Search

Fuel cells in the kW range have a high output current and low output voltage. To connect them to the mains, a DC-DC converter with a high voltage gain and an inverter are needed. In this paper an investigation of the voltage-fed full bridge dc-dc converter with high voltage gain is presented. A detailed analysis of the different operating modes,

Andreas AVERBERG; Axel MERTENS

2007-01-01

222

An improved full-bridge zero-voltage-transition PWM DC\\/DC converter with zero-voltage\\/zero-current switching of the auxiliary switches  

Microsoft Academic Search

In this paper, a novel full-bridge (FB) zero-voltage-transition (ZVT) pulsewidth modulation (PWM) DC\\/DC converter topology is proposed. The proposed FB-ZVT PWM DC\\/DC converter has zero-voltage switching (ZVS) of main switches for the entire line and load range and an advantage of achieving ZVS and zero-current switching of the auxiliary switches using the auxiliary network. The auxiliary network is simply composed

Dong-Yun Lee; Byoung-Kuk Lee; Sang-Bong Yoo; Dong-Seok Hyun

2000-01-01

223

Analysis and design of a simple digital control algorithm for a phase-shift full-bridge DC-DC power converter  

Microsoft Academic Search

In this paper it is presented an analysis and design of a digital control algorithm implemented on a digital signal processor, a dsPIC30F2020. A dc-dc converter prototype is built based on a full-bridge (FB) dc-dc converter topology. Extensive simulations in time domain and digital domain are explored and experimental results are also shown to validate the performance of this particular

David R. López-Flores; José L. Durán-Gómez; Roberto Herrera-Salcedo; J. A. Pineda-Go?mez

2010-01-01

224

Maximum power point tracking by incremental conductance method for photovoltaic systems with phase shifted full-bridge dc-dc converter  

Microsoft Academic Search

th 3 Abstract- Because of sunshine variation, output power of photo­ voltaic (PV) array can be fluctuated. In order to obtain fully uti­ lization from the PV array, an algorithm of maximum power point tracking (MPPT) functions with a high efficiency of dc-dc converter is necessary. This paper presents a phase-shifted full­ bridge dc-to-dc converter which is appropriate for PV

Phattara Suwannatrai; Pisit Liutanakul; Pongpit Wipasuramonton

2011-01-01

225

A novel full-bridge zero-voltage-transition PWM DC\\/DC converter with zero-voltage\\/zero-current switching of the auxiliary switches  

Microsoft Academic Search

In this paper, a novel full-bridge (FB) zero-voltage-transition (ZVT) PWM DC\\/DC converter topology is proposed. The proposed FB-ZVT PWM DC\\/DC converter has ZVS of main switches for wide load and line ranges and an advantage of achieving zero voltage and zero current switching of the auxiliary switches using the auxiliary network. The auxiliary network is simply composed of saturable inductor,

Dong-Yun Lee; Byoung-Kuk Lee; Dong-Seok Hyun

1998-01-01

226

Comparison of DC-bus voltage balancing strategies for three-phase DSTATCOM based on cascaded H-bridge multilevel converter  

Microsoft Academic Search

This paper presents a comparison of two DC-bus voltage balancing strategies for cascaded connected H-bridge converter-based STATCOMs. These converters have classically been commutated at fundamental line-frequencies, but the evolution of power semiconductors has allowed the increase switching frequencies and the power ratings of these devices, permitting the use of PWM modulation techniques. This paper mainly focuses the DC bus voltage

Jon Andoni Barrena; Luis Marroyo; Miguel Ángel Rodríguez; José Ramón Torrealday

2008-01-01

227

A zero voltage switching full-bridge DC-DC converter with capacitive output filter for a plug-in-hybrid electric vehicle battery charger  

Microsoft Academic Search

In this paper, a novel zero voltage switching full-bridge converter with trailing edge pulse width modulation and capacitive output filter is presented. The target application for this work is the second stage dc-dc converter in a two stage 1.65 kW on-board charger for a plug-in hybrid electric vehicle (PHEV). For this application the design objective is to achieve high efficiency

Deepak Gautam; Fariborz Musavi; Murray Edington; Wilson Eberle; William G. Dunford

2012-01-01

228

Single phase grid-connected PV system with time-sharing modulation and Pi-type regulators for DC-DC boost converter and full-bridge inverter  

Microsoft Academic Search

The paper presents investigation, digital control realization and efficiency evaluations of a single-phase grid connected photovoltaic system, composed of DC-DC boost converter and full-bridge inverter with timesharing modulation. The system is analyzed with the use of Matlab-Simulink and FPGA-based real-time models.

Robert Stala; L. Stawiarski; M. Szarek

2010-01-01

229

A General Method for Two-Level Bridge Type DC\\/DC Converter to Three-Level DC\\/DC Converter  

Microsoft Academic Search

This paper studies the approach of derivation of three-level (TL) half-bridge (HB) topology from conventional full bridge DC\\/DC topology. The derived TL HB topology has same device count and performance as the corresponding full bridge topology, and it is more suitable for high voltage applications. The derivation approach for different control method, i.e. PWM control, frequency control and phase shift

Junming Zhang; Zhaoming Qian; Lei Miao; Xinke Wu; Chen Zhao

2006-01-01

230

Free-running flyback dc power supply  

SciTech Connect

A free-running flyback dc power supply includes a transformer having at least one primary and one secondary winding, a transistor switch in series with the primary winding for controlling when current from a source of dc power is coupled through said winding, and a rectifier circuit attached to the secondary winding for generating a dc output voltage. A conventional regulator circuit causes the transistor switch to turn off primary winding current as a function of the present value of dc output voltage. A second circuit senses excessive current in the primary winding and causes the transistor switch to turn off independently of said regulator circuit, to protect against damage to the transistor switch or transformer. A third circuit detects when the dc source voltage is below a predetermined minimum and causes the transistor switch to turn off independently of said regulator circuit. Regulation of the output dc voltage is also maintained as a function of the present value of dc source voltage. An additional circuit causes the regulator circuit to turn off the transistor switch early if the dc output voltage drops below a predetermined minimum.

Josephson, E.

1982-04-06

231

A new zero voltage switching buck-boost bidirectional DC_DC converter  

Microsoft Academic Search

In this paper a new zero voltage switching bidirectional dc-dc converter is introduced. This converter consists of flyback and forward transformers and only one main switch in primary side and one main switch in secondary side of transformers. Auxiliary circuits in this converter consist of a switch and one clamp capacitor. These circuits not only absorb spikes across the switches

Majid Delshad; M. Mahdavi

2010-01-01

232

Optimum ZVS full-bridge DC\\/DC converter with PWM phase-shift control: analysis, design considerations, and experimental results  

Microsoft Academic Search

By adding a simple external commutating aid circuit to the full-bridge DC\\/DC converter with phase-shift control and by reducing the magnetizing inductance, optimum performance (i.e. ZVS operation and high conversion efficiency) can be achieved from full load down to almost zero load. An analysis is presented to determine the required and available commutation energies. The analysis is complemented with design

R. Redl; Laszlo Balogh; David W. Edwards

1994-01-01

233

Dynamic Modeling of a PWM plus Phase-Shift (PPS) Controlled Active Clamping Boost to Full Bridge Bidirectional DC\\/DC Converter  

Microsoft Academic Search

PWM plus phase-shift (PPS) control technique is a technique combining PWM control technique and phase-shift control technique. PPS control bidirectional DC-DC converters have two regulating parameters, that is duty cycle D and phase-shift angles Phi. The paper proposed a new technique based on state-space averaging technique for modeling PWM plus phase-shift (PPS) controlled active clamping boost to full bridge bi-directional

Liping Sun; Dehong Xu; Min Chen

2006-01-01

234

A high-frequency 1.5 MVA H-bridge building block for cascaded multilevel converters using emitter turn-off thyrister  

Microsoft Academic Search

This paper proposes a 1.5 MVA H-bridge building block (HBBB) using the newly developed emitter turn-off (ETO) thyristor to demonstrate the superior performance of the ETO. The modular HBBB is intended to be used in high-power cascaded multilevel voltage source converters for reactive power compensation applications. Because of theirs identical layouts, the HBBB are easily manufactured for both the building

Siriroj Sirisukprasert; Zhenxue Xu; Bin Zhang; Jason Lai; Alex Q. Huang

2002-01-01

235

A novel soft-switching full-bridge converter for ZVS in light and full load conditions with current-doubler rectifier  

Microsoft Academic Search

A novel full-bridge converter suitable for low-voltage high-current output applications is proposed. It realizes ZVS for all switches over the entire load range with the use of voltage complementary auxiliary network on the primary side. A current-doubler rectifier is adopted on the secondary side which has no duty cycle loss and no secondary voltage spike. The operation principle and characteristic

Zhong Chen; Feng Ji; Biao Ji; Xin Zhang

2010-01-01

236

A novel soft-switching full-bridge DC\\/DC converter: Analysis, design considerations, and experimental results at 1.5 kW, 100 kHz  

Microsoft Academic Search

The authors present an improved soft-switching full-bridge converter which is especially suitable for high-power application (e.g. more than 1 kW output) because of its inherently high efficiency. The addition of an external commutating inductor and two clamp diodes to the phase-shifted PWM (pulse width modulation) full-bridge DC-DC converter substantially reduced the switching losses of the transistors and the rectifier diodes,

Richard Redl; N. O. Sokal; L. Balogh

1990-01-01

237

Analysis of DC\\/DC converters with resonant filters  

Microsoft Academic Search

Conventional DC\\/DC power converter topologies contain a single semiconductor switch, a diode and various arrangements of inductors and capacitors to filter the resulting waveforms into low ripple DC. The output or input voltage is limited to the rating of the semiconductor switch and diode. For high voltage performance, transformers are added to form forward, flyback or push-pull topologies. For high

Rene J Thibodeaux

1997-01-01

238

Conceptual study on vertically launched fly-back boosters  

NASA Astrophysics Data System (ADS)

A conceptual study is conducted of fly-back boosters as the proposed candidates for future transportation systems which can be realized in the near future. System design requirements such as policy and scope of design study are reviewed. Conceptual design of the body such as the design flow and design conditions, optimization of performance sharing between fly-back boosters and upper-stage rockets, body configurations, weight estimates and weight balance of the body, trade-off of candidate optimized configurations, and flight profiles is conducted. Baselines and candidates of configuration, required performance, weights of engines for cruising, and dimensions of the body are presented. Results of body weight analyses, and flight profiles are also presented.

Yonemoto, Kouichi; Mugitani, Takashi

1991-07-01

239

Novel Current Mode AC\\/AC Converters with High Frequency AC Link  

Microsoft Academic Search

A novel circuit topologies family of the current mode AC\\/AC converter with high frequency ac link, based on flyback converter, are proposed. These circuit topologies which can transfer one unregulated sinusoidal voltage with high THD into another regulated constant frequency sinusoidal voltage with low THD, are constituted of input cycloconverter, high frequency storage transformer and output cycloconverter. The circuit topologies

Daolian Chen; Lei Li; Jian Liu; Shengyang Lin; Chen Song

2005-01-01

240

An adaptive reconfigurable dc-dc converter for renewable energy applications  

Microsoft Academic Search

A new adaptive reconfigurable flyback dc-dc converter topology is provided that can be used in a wide range of applications including PV energy systems. It provides the ability for plug and play use, as the output power can be adjusted by varying the energy passing through the reconfigurable secondary winding. A variable turn's ratio configuration adopted in the proposed converter

Muhammad F. Zulfiqar; Mahmoud Alahmad

2009-01-01

241

Liquid flyback booster pre-phase: A study assessment  

NASA Astrophysics Data System (ADS)

The concept of a flyback booster has been around since early in the shuttle program. The original two-stage shuttle concepts used a manned flyback booster. These boosters were eliminated from the program for funding and size reasons. The current shuttle uses two Redesigned Solid Rocket Motors (RSRM's), which are recovered and refurbished after each flight; this is one of the major cost factors of the program. Replacement options have been studied over the past ten years. The conclusion reached by the most recent study is that the liquid flyback booster (LFBB) is the only competitive option from a life-cycle cost perspective. The purpose of this study was to assess the feasibility and practicality of LFBB's. The study provides an expansion of the recommendations made during the aforementioned study. The primary benefits are the potential for enhanced reusability and a reduction of recurring costs. The potential savings in vehicle turnaround could offset the up-front costs. Development of LFBB's requires a commitment to the shuttle program for 20 to 30 years. LFBB's also offer enhanced safety and abort capabilities. Currently, any failure of an RSRM can be considered catastrophic, since there are no intact abort capabilities during the burn of the RSRM's. The performance goal of the LFBB's was to lift a fully loaded orbiter under optimal conditions, so as not to be the limiting factor of the performance capability of the shuttle. In addition, a final benefit is the availability of growth paths for applications other than shuttle.

Peterson, W.; Ankney, W.; Bell, J.; Berning, M.; Bryant, L.; Bufkin, A.; Cain, L.; Caram, J.; Cockrell, B.; Curry, D.

1994-09-01

242

A new two-switch flyback battery equalizer with low voltage stress on the switches  

Microsoft Academic Search

In this paper, a new battery equalizer applying two-switch flyback topologies is proposed. Since the proposed circuit is based on two-switch flyback structure, voltage stress on the switches can be clamped at the battery stack voltage level. Furthermore, the number of active devices is minimized by using a common switch and a common clamping diode. The operational principle, theoretical analysis,

Hyoung-Suk Kim; Ki-Bum Park; Sang-Hyun Park; Gun-Woo Moon; Myung-Joong Youn

2009-01-01

243

Design considerations for high-voltage high-power full-bridge zero-voltage-switched PWM converter  

Microsoft Academic Search

A steady-state analysis is presented with complete characterization of the converter operation. A small-signal model of the converter is established. The design procedures based on the analysis are presented and the various losses in the circuit assessed. Critical design considerations for a high-power, high-voltage application are analyzed. The results of the analysis are verified using a high-voltage. 2 kW prototype

J. A. Sabate; V. Vlatkovic; R. B. Ridley; F. C. Lee; B. H. Cho

1990-01-01

244

A Hamiltonian viewpoint in the modeling of switching power converters  

Microsoft Academic Search

In this paper we show how, using the Hamiltonian formalism, we can systematically derive mathematical models that describe the behaviour of a large class of switching power converters, including the “Boost”, “Buck”, “Buck-Boost”, “?uk” and “Flybackconverters. We follow the approach proposed by van der Schaft and Maschke and extract from the basic (energy-conserving) LC–circuit the remaining elements, i.e., resistors,

Gerardo Escobar; Arjan J. van der Schaft; Romeo Ortega

1999-01-01

245

Current ripple bounds in interleaved DC-DC power converters  

Microsoft Academic Search

In distributed power supply systems, the parallelism of DC-DC power converters is a basic architecture. In this paper, the authors use the time domain method to show that the amplitude of the input\\/output current ripple of N(⩾1) parallelly interleaved modules is always upper bounded by that of the individual modules for buck, boost, flyback, Cuk, and SEPIC power converters if

Chin Chang

1995-01-01

246

Efficient modulation technique and NL control of H-bridge boost converters for battery-supplied AC motor drives  

Microsoft Academic Search

Previous works have shown the design effectiveness of novel two-phase H-bridge DC-DC boost conversion in battery-supplied AC motor drives, increasing the exploitation of power components through DC-link voltage adaptation to AC load. In this work the highest performances of real-time voltage control are investigated, as needed to minimize the DC-link capacitor size and to allow for efficient DC voltage tracking

A. Fratta; P. Guglielmi; G. M. Pellegrino; P. Scapino; F. Viliata

1999-01-01

247

A study of two control methods for full bridge converters: Soft switch bypass and current mode control  

NASA Astrophysics Data System (ADS)

In a broad sense, there are now 3 basic categories for high power (above several KW) DC/DC converters: (1) Forced commutation (FC); (2) Resonant (R); and (3) Soft switch (SS). Some topologies that are combinations of the above also have been proposed, such as certain pulse width modulation (PWM)-resonant arrangements. The first part of this project was a proposed improvement of the third category, the soft switch. The basic idea of this new converter was to use two additional switches that would bypass the loading during part of the operating cycle if the current decreased below a certain level. The motivation for this was to retain the soft switching characteristic at light loads (a common problem with soft switch converters). Although the bypass circuit proved functional, certain problems were uncovered which raise doubts about its ultimate feasibility. Because of these problems, the research emphasis was shifted from the bypass to an improve current mode control (CMC) converter that promised better results.

Stuart, Thomas A.

1990-06-01

248

Advanced High Power DC-DC Converter using A Novel Type Voltage Source Full-Bridge Soft-Switching PWM Inverter with High Frequency Transformer Link for Arc Welding Applications  

Microsoft Academic Search

This paper presents a new circuit topology of full-bridge soft-switching PWM inverter linked DC-DC power converter composed of conventional full-bridge high frequency PWM inverter with high frequency transformer and an active quasi-resonant snubber consisting of an additional power switching device in series with DC busline and a lossless capacitor in parallel with DC busline. Under this proposed high frequency soft-switching

Keiki Morimoto; Toshimitsu Doi; Haruhiko Manabe; Tarek Ahmed; Eiji Hiraki; Hyun-Woo Lee; Mutsuo Nakaoka

2006-01-01

249

Next generation high efficiency high power dc-dc converter incorporating active switch and snubbing capacitor assisted full-bridge soft-switching PWM inverter with high frequency transformer for large current output  

Microsoft Academic Search

This paper presents a new circuit topology of dc busline switch-assisted full-bridge soft-switching PWM inverter type dc-dc power converter which is composed of typical voltage source H full-bridge type high frequency PWM inverter in addition to a single dc busline side power semiconductor switching device for PWM scheme and a capacitive lossless snubber. Under the newly-proposed high frequency inverter link

Keiki Morimoto; T. Doi; H. Manabe; M. Nakaoka; Hyun-Woo Lee; Nabil A. Ahmed; E. Hiraki; T. Ahmed

2005-01-01

250

Design and Comparison of Two Front-end Dc\\/Dc Converters: LLC Resonant Converter and Soft-switched Phase-shifted Full-bridge Converter with Primary-side Energy Storage Inductor  

Microsoft Academic Search

This paper presents detailed design and comparison of two front-end Dc\\/Dc converters which are suitable especially for the medium-power level applications with low output voltage and high output current both. Where, the LLC resonant converter drawn more and more attention recently shows its essential advantages in high conversion efficiency and high power density. However, due to the variable-frequency control strategy,

Chen Zhao; Xinke Wu; Zhaoming Qian

2009-01-01

251

Analysis of the switching process in the Asymmetrical Half-Bridge converter for street led-lighting applications  

Microsoft Academic Search

High-Brightness Light Emitting Diodes (HB-LEDs) are considered as a remarkable lighting device due to their high reliability, chromatic variety and increasing efficiency. As a consequence, a high number of solutions for supplying LED strings are coming out. One-stage solutions are cost-effective, but their efficiency is low as they have to fulfill several purposes with only one converter: Power Factor Correction

Manuel Arias; Diego G. Lamar; Aitor Vazquez; Javier Sebastian; Didier Balocco; Almadidi Diallo

2012-01-01

252

A novel soft-switching full-bridge DC\\/DC converter: analysis, design considerations, and experimental results at 1.5 kW, 100 kHz  

Microsoft Academic Search

The addition of an external commutating inductor and two clamp diodes to the phase-shifted PWM (pulsewidth modulated) full-bridge DC\\/DC converter substantially reduces the switching losses of the transistors and the rectifier diodes, under all loading conditions. The authors give analyses, practical design considerations, and experimental results for a 1.5 kW converter with 60 V, 25 A output, operating at 100

R. Redl; N. O. Sokal; L. Balogh

1991-01-01

253

Novel current mode bi-directional high-frequency link DC\\/AC converter for UPS  

Microsoft Academic Search

The novel current mode bidirectional high-frequency link DC\\/AC power converter proposed in the paper is based on the flyback power converter. Its operation modes, basic operational principle, instantaneous voltage control method and brief design are explained. The experimental result of 250 W\\/50 Hz output power with 50 kHz switching frequency shows that the proposed HFL converter has the following advantages:

Minchao Huang; Weixun Lin; Jianpin Ying

1998-01-01

254

An On-Line UPS System With Power Factor Correction and Electric Isolation Using BIFRED Converter  

Microsoft Academic Search

This paper presents the design consideration and performance analysis of an on-line, low-cost, high performance, and single-phase uninterruptible power supply (UPS) system based on a boost integrated flyback rectifier\\/energy storage dc\\/dc (BIFRED) converter. The system consists of an isolated ac\\/dc BIFRED converter, a bidirectional dc\\/dc converter, and a dc\\/ac inverter. It provides input power factor correction, electric isolation of the

Adel Nasiri; Zhong Nie; Stoyan B. Bekiarov; Ali Emadi

2008-01-01

255

Generalized small-signal dynamical modeling of multi-port DC-DC converters  

Microsoft Academic Search

A general method is presented for modeling multiport DC-DC converters. It copes with multiple inputs, multiple outputs and bidirectional ports, and is based on an averaging formulation. A matrix description is adopted, so the technique can be extended to converters with any number of ports. As an example, a three-port forward-flyback converter is analyzed using symbolic computation software (Maple V)

David C. Hamill

1997-01-01

256

An on-line UPS system with power factor correction and electric isolation using BIFRED converter  

Microsoft Academic Search

This paper presents design consideration and performance analysis of an on-line, low-cost, high performance single-phase Uninterruptible Power Supply (UPS) system based on Boost Integrated Flyback Rectifier\\/Energy storage DC\\/DC (BIFRED) converter. The system consists of an isolated AC\\/DC BIFRED converter, a bi-directional DC\\/DC converter, and a DC\\/AC inverter. It has input power factor correction, electric isolation of the input from the

Z. Nie; S. B. Bekiarov; A. Emadi

2003-01-01

257

Reference to output frequency compensation of bidirectional DC-DC converter  

Microsoft Academic Search

A bidirectional flyback converter with output voltage tracking capabilities was designed and tested. For the first time an H? approach was used for a controller design. A better performance of the H? controller over a traditional reference-to-output frequency-compensated one was shown. Theoretical results were validated by simulations and experiments

Wieslaw E. Bury; Dariwz Czarkowski; Jerzy Dzieza

2001-01-01

258

Design and implementation of an H? controller for a bi-directional DC-DC converter  

Microsoft Academic Search

An H? controller for use in a bi-directional flyback converter was designed and tested. Earlier work has shown that the H? controller is superior to that of a traditional reference-to-output frequency-compensated controller. The design of the H? controller was verified in open and closed loop simulations and on-going experimentation.

Wieslaw E. Bury; J. Dzieza; D. Czarkowski; Stanley Lewis

2002-01-01

259

DSP H? controller for a variable output DC-DC converter: design and implementation  

Microsoft Academic Search

An H? controller for power conversion was designed and tested employing a DSP (digital signal processor) to implement the 2nd order transfer function. The DSP was programmed for and tested with a bi-directional flyback converter. The results of the DSP control conform to that of theory and analog control results.

Wieslaw E. Bury; Dariusz Czarkowski; J. Dzieza; Stanley Lewis; Shashi Ramamurthy

2002-01-01

260

Applying time-multiplexing control to single-stage forward-based power-factor-corrected converter  

Microsoft Academic Search

A new forward-based single-stage power-factor-corrected converter is proposed. A portion of input power is directly transferred to the output through the forward converter to improve the efficiency of power conversion. The flyback auxiliary circuit is added to the forward converter to reduce low line-frequency output voltage ripple. In an effort to lower the size and cost of the converter, a

Ting Sun; Dylan Dah-Chuan Lu

2009-01-01

261

Design of a cost-effective DC-DC converter with high power density for magnetron power supplies  

Microsoft Academic Search

This paper presents a new cost-effective, high power density dc-dc converter for magnetron power supply applications. The proposed dc-dc converter consists of three main circuitry; front-end quasi-resonant flyback converter, high-frequency transformer, and diode rectifier circuit. Experimental results are provided to verify the superiority of the proposed converter under 200 W\\/4 kV magnetron operations. The magnetron power supply, based on the

Byeong-Mun Song; Moon-Ho Kye; Rae-Young Kim

2010-01-01

262

Advanced High Power DC-DC Converter using A Novel Type Voltage Source Full-Bridge Soft-Switching PWM Inverter with High Frequency Transformer Link for Arc Welding Applications  

NASA Astrophysics Data System (ADS)

This paper presents a new circuit topology of full-bridge soft-switching PWM inverter linked DC-DC power converter composed of conventional full-bridge high frequency PWM inverter with high frequency transformer and an active quasi-resonant snubber consisting of an additional power switching device in series with DC busline and a lossless capacitor in parallel with DC busline. Under this proposed high frequency soft-switching PWM inverter linked DC-DC converter, four power switches in the full-bridge arms and DC busline series switch can achieve ZVS at turn-off commutation. By developing the advanced soft-switching PWM high frequency inverter type DC-DC converter, although the conduction power loss of DC busline series power switch increases a little, the total turn-off switching loss of full-bridge high frequency inverter power modules can be sufficiently lowered more and more in the higher frequency range of 60kHz. As a result, when the switching frequency of high frequency inverter power stage using IGBT power modules is designed so as to be more than about 10kHz, the more the switching frequency of inverter increases, the more this high frequency soft-switching DC-DC converter has remarkable advantage as for the power conversion efficiency as compared with the conventional hard-switching PWM inverter DC-DC converter. Its practical effectiveness of high power density and high performance is actually proved for TIG arc welding equipment in industry.

Morimoto, Keiki; Doi, Toshimitsu; Manabe, Haruhiko; Ahmed, Tarek; Hiraki, Eiji; Lee, Hyun-Woo; Nakaoka, Mutsuo

263

Recognition of dynamic patterns in dc-dc switching converters  

NASA Astrophysics Data System (ADS)

Techniques are presented for analyzing the dynamic patterns of power flow in high-frequency dc-dc switching converters. Emphasis is placed on exploring methods for developing reduced-order models of power electronic circuits for simulation and state-space averaging. Tools from selective modal analysis are used to develop the dynamic pattern recognition algorithm that facilitates the classification of circuit modules. The algorithm is intended for the analysis of converters derived from the canonical switching call, i.e., the buck, boost, and flyback converters.

Leeb, Steven B.; Kirtley, James L.; Verghese, George C.

264

Novel Current-Mode AC\\/AC Converters With High-Frequency AC Link  

Microsoft Academic Search

A novel circuit-topology family of the current-mode AC\\/AC converter with high-frequency AC link, based on a Flyback converter, is proposed. These circuit topologies, which can transfer one unregulated sinusoidal voltage with high total harmonic distortion (THD) into another regulated constant-frequency sinusoidal voltage with low THD, are composed of input cycloconverter, high-frequency storage transformer, and output cycloconverter. The circuit-topology family includes

Daolian Chen

2008-01-01

265

A new low-stress buck-boost converter for universal-input PPC applications  

Microsoft Academic Search

In converters for power-factor-correction (PFC), universal-input capability (ability to operate from any AC line voltage, world-wide) comes with a heavy price in terms of component stresses and losses, size of components, and restrictions on the output DC voltage. A new two-switch topology is proposed to offer very significant performance improvements over the single-switch buck-boost converters (including flyback, SEPIC, and Cuk

Jingquan Chen; Dragan MaksimoviC; Robert Erickson

2001-01-01

266

A novel full-bridge DC-DC converter for battery charging using secondary-side control combines soft switching over the full load range and low magnetics requirement  

Microsoft Academic Search

A novel full-bridge DC-DC configuration with a tapped transformer and secondary side control is proposed. It achieves zero-voltage switching for the primary side switches and zero-current switching for the secondary side switches, under all operating conditions. The conduction losses are significantly lower than those in the conventional soft-switching DC-DC converters. Due to superior filter waveforms, the filter requirements, both at

Rajapandian Ayyanar; Ned Mohan

2001-01-01

267

High-efficiency grid-connected photovoltaic module integrated converter system with high-speed communication interfaces for small-scale distribution power generation  

SciTech Connect

This paper presents a high-efficiency grid-connected photovoltaic (PV) module integrated converter (MIC) system with reduced PV current variation. The proposed PV MIC system consists of a high-efficiency step-up DC-DC converter and a single-phase full-bridge DC-AC inverter. An active-clamping flyback converter with a voltage-doubler rectifier is proposed for the step-up DC-DC converter. The proposed step-up DC-DC converter reduces the switching losses by eliminating the reverse-recovery current of the output rectifying diodes. To reduce the PV current variation introduced by the grid-connected inverter, a PV current variation reduction method is also suggested. The suggested PV current variation reduction method reduces the PV current variation without any additional components. Moreover, for centralized power control of distributed PV MIC systems, a PV power control scheme with both a central control level and a local control level is presented. The central PV power control level controls the whole power production by sending out reference power signals to each individual PV MIC system. The proposed step-up DC-DC converter achieves a high-efficiency of 97.5% at 260 W output power to generate the DC-link voltage of 350 V from the PV voltage of 36.1 V. The PV MIC system including the DC-DC converter and the DC-AC inverter achieves a high-efficiency of 95% with the PV current ripple less than 3% variation of the rated PV current. (author)

Choi, Woo-Young; Lai, Jih-Sheng (Jason) [Future Energy Electronics Center, Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA (United States)

2010-04-15

268

Power converters and amplifiers (review of \\  

Microsoft Academic Search

This book is a comprehensive textbook in the areas of electrical, electronics, and telecommunications engineering. It consists of 17 chapters and two appendices. Some of the topics covered include: buck PWM DC-DC converters; boost PWM DC-DC converters; buck-boost-PWM DC-DC converters; half-bridge and full-bridge converters; push-pull PWM DC-DC converters; open-loop small-signal characteristics of boost converters for CCM; current-mode control of boost

Marian Kazmierkowski

2009-01-01

269

Flyback Inverter Controlled by Sensorless Current MPPT for Photovoltaic Power System  

Microsoft Academic Search

This paper presents a flyback inverter controlled by sensorless current maximum power point tracking (MPPT) for a small photovoltaic (PV) power system. Although the proposed system has small output power such as 300 W, a few sets of small PV power systems can be easily connected in parallel to yield higher output power. When a PV power system is constructed

N. Kasa; T. Iida; L. Chen

2005-01-01

270

Comparison of Two Liquid FlyBack Booster Configurations Based on Wind Tunnel Measurements  

Microsoft Academic Search

\\/RESUME In the frame of German future space transportation technology and research program ASTRA a concept of a reusable winged liquid fly-back booster (LFBB) is under investigation. It has two booster stages attached to the expendable Ariane 5 core stage. During the first phase of the study several empirical and numerical analysis methods were used with respect to the configuration

F. Tarfeld

2005-01-01

271

Zero-current transition flyback inverter for small scale wind power generation systems  

Microsoft Academic Search

This paper presents a zero-current transition (ZCT) flyback inverter for small scale wind power generation systems. Although the proposed system has such small output power as 500 W, a few sets of wind power generation systems can be easily connected in parallel for the higher output power requirements. When the wind power generation system is constructed by a lot of

Nobuyuki Kasa; Takahiko Iida

2006-01-01

272

[Design of a flyback switch mode power supply for multichannel electrophysiological stimulators].  

PubMed

In order to supply the multichannel electrical stimulator, a DC-DC flyback switch mode power supply based on a high-performance current mode controller UC3845 has been designed. The experimental results indicate that the power supply has satisfied the demands and can supply the multichannel electrical stimulator and similar apparatuses. PMID:18754421

Zhou, Yu; Fang, Zu-Xiang; Li, Wei-Jiao; Liu, Zu-Wang

2008-05-01

273

Parallel Power Flow AC\\/DC Converter with High Input Power Factor and Tight Output Voltage Regulation for Universal Voltage Application  

Microsoft Academic Search

In this paper, a new parallel-connected single phase power factor correction (PFC) topology using flyback converter in parallel with forward converter is proposed to improve the input power factor with simultaneously output voltage regulation taking consideration of current harmonic norms. Paralleling of converter modules is a well-known technique that is often used in medium-power applications to achieve the desired output

A. K. Jha; K. H. Babu; B. M. Karan

2006-01-01

274

High Power Density DC/DC Converter: Selection of Converter Topology.  

National Technical Information Service (NTIS)

The work involved in the identification and selection of a suitable converter topology is described. Three new dc/dc converter topologies are proposed: Phase-Shifted Single Active Bridge DC/DC Converter; Single Phase Dual Active Bridges DC/DC Converter; a...

D. M. Divan

1990-01-01

275

Full-load-range-ZVS hybrid DC-DC converter with two full-bridges for high-power battery charging  

Microsoft Academic Search

A novel soft switching DC-DC power converter is proposed that is ideal for high-power battery charging applications. Its main advantages are zero-switching under all operating conditions without significant conduction loss penalty, and significantly lower filter requirement compared to conventional power converters. The application of the proposed converter for high-power battery charging is discussed along with simulation and experimental results

Rajapandian Ayyanar; Ned Mohan

1999-01-01

276

Multi Power Port Converter for Hybrid Electric Vehicles Using Multi Phase Bidirectional FlyBack Topology  

Microsoft Academic Search

For hybrid electric vehicles the batteries and the drive DC-link may be at different voltages. The batteries are at low voltage to obtain higher volumetric efficiencies and the DC-link is at higher voltage to have higher efficiency on the motor side. Therefore a power interface between the batteries and the drive's DC-link is essential. This power interface should handle power

T. Bhattacharya; S. Giri V; K. Mathew; L. Umanand

2006-01-01

277

A single switch boost-flyback DC-DC converter integrated with switched-capacitor cell  

Microsoft Academic Search

Without extreme duty ratio or complexity of circuits, by employing coupled-inductor and switched-capacitor cell achieved high voltage conversion ratio with a single switch is proposed in this paper. Coupled-inductor transfer source energy to secondary side through entire switching period, the leakage energy of coupled inductor is efficiently recycled; the inrush current problem on switched capacitors was restrained by leakage inductor

Tsorng-Juu Liang; Shih-Ming Chen; Lung-Sheng Yang; Jiann-Fuh Chen; Adrian Ioinovici

2011-01-01

278

Tam Köprü PSPWM DC-DC Dönü?türücülerin Kar?ila?tirilmasi Comparison of the Full Bridge PSPWM DC-DC Converters  

Microsoft Academic Search

In this paper, Phase Shift Pulse Width Modulated (PSPWM) DC-DC converters existing in the literature have been analyzed under the same operation conditions and compared in terms of losses and efficiency. Basic PSPWM DC-DC converter circuit and some other circuits developed in order to solve the problems of this basic circuit have been analyzed with PROTEUS program. In the simulations,

A. Faruk BAKAN; Haci BODUR; Elektrik Mühendisli?i

279

A single-switch AC\\/DC converter with voltage regulated storage capacitor  

Microsoft Academic Search

A single-stage power-factor-corrected AC\\/DC converter (SSPFC) usually causes high voltage stress on the intermediate storage capacitor, due to the lack of control of this voltage. The storage capacitor voltage varies largely with line voltage, and load current and is usually higher than the peak line voltage. This paper presents a new single-switch SSPFC based on a flyback topology for which

Dylan Dah-Chuan Lu; David Ki-Wai Cheng; Yim-Shu Lee

2003-01-01

280

High-speed 3T MR spectroscopic imaging of prostate with flyback echo-planar encoding  

Microsoft Academic Search

Prostate MR spectroscopic imaging (MRSI) at 3T may provide two-fold higher spatial resolution over 1.5T, but this can result in longer acquisition times to cover the entire gland using conventional phase-encoding. In this study, flyback echo-planar readout trajectories were incorporated into a Malcolm Levitt's composite-pulse decoupling sequence (MLEV)-point-resolved spectroscopy sequence (PRESS) to accelerate the acquisition of large array (16 x

Albert P. Chen; Charles H. Cunningham; Esin Ozturk-Isik; Duan Xu; Ralph E. Hurd; Douglas A. C. Kelley; John M. Pauly; John Kurhanewicz; Sarah J. Nelson; Daniel B. Vigneron

2007-01-01

281

Comparison of converter topologies for charging capacitors used in pulsed load applications  

NASA Astrophysics Data System (ADS)

The authors present a qualitative comparison of different power converter topologies which may be utilized for charging capacitors in pulsed power applications requiring voltages greater than 1 kV. The operation of the converters in capacitor charging applications is described, and relevant advantages are presented. All of the converters except one may be classified in the high-frequency switching category. One of the benefits from high-frequency operation is a reduction in size and weight. The other converter discussed is a member of the command resonant changing category. The authors first describe a boost circuit which functions as a command resonant charging circuit and utilizes a single pulse of current to charge the capacitor. The discussion of high-frequency converters begins with the flyback and Ward converters. Then, the series, parallel, and series/parallel resonant converters are examined.

Nelms, R. M.; Schatz, J. E.; Pollard, Barry

282

A Family of Electronic Ballasts Integrating Power Factor Correction and Power Control Stages to Supply HPS Lamps  

Microsoft Academic Search

This paper presents a family of high power factor electronic ballasts applied to the public lighting system. Flyback, buck-boost, boost or SEPIC converter is employed in the power factor correction stage, integrated to the power control stage through a single active switch. The use of a half-bridge inverter, to supply the lamp, becomes possible through the employment of a flyback

Tiago Bandeira Marchesan; Murilo Cervi; Alexandre Campos; R. N. do Prado

2006-01-01

283

Bridge Replacement: Alternate Design.  

National Technical Information Service (NTIS)

A money and time saving innovative design was used to convert two old slab bridges into multipipe culverts on an FM 18 widening project in District 8 (Abilene). Hydraulic analysis indicated that the existing structures had been overdesigned and that conve...

B. R. Lindley

1992-01-01

284

Comparison of Two Liquid Fly-Back Booster Configurations Based on Wind Tunnel Measurements  

NASA Astrophysics Data System (ADS)

/RESUME In the frame of German future space transportation technology and research program ASTRA a concept of a reusable winged liquid fly-back booster (LFBB) is under investigation. It has two booster stages attached to the expendable Ariane 5 core stage. During the first phase of the study several empirical and numerical analysis methods were used with respect to the configuration definition, which lead to the booster configuration LFBB Y7. The subsequent design loop required a more detailed investigation including wind tunnel measurements along the complete trajectory from separation at hypersonic speeds down to the subsonic fly-back cruise regime. Tests were performed not only creating a complete aerodynamic data set for trim and balance in longitudinal motion but also achieving a deeper understanding of the characteristics of the flow field of this vehicle including the influence between the canards and the wing. With the results of this test campaign and further calculations an improved aerodynamic design could be realised. The resulting configuration LFBB Y8 was tested again and compared to it's predecessor. Measurements were carried out in the DLR trisonic wind tunnel TMK (0.5 < Ma < 4) and the hypersonic wind tunnel H2K (Ma = 6.0 and Ma = 7.0). The angle of attack was varied from 2° to +8° and from 2° to +38° in TMK and H2K respectively. The angle of side slip was varied between -5° and 5°.

Tarfeld, F.

2005-02-01

285

Three Bridge Fryer's Ford Bridge, Nimrod Bridge, and Ward's ...  

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

Three Bridge - Fryer's Ford Bridge, Nimrod Bridge, and Ward's Crossing Bridge - Fryer's Ford Bridge, Spanning East Fork of Point Remove Creek at Fryer Bridge Road (CR 67), Solgohachia, Conway County, AR

286

Grid-connected boost-half-bridge photovoltaic micro inverter system using repetitive current control and maximum power point tracking  

Microsoft Academic Search

This paper presents a novel boost-half-bridge micro inverter and its control implementations for single-phase grid-connected photovoltaic systems. The proposed topology consists of a transformer isolated boost-half-bridge DC-DC converter and a full-bridge pulse-width-modulated inverter. The boost-half-bridge converter integrates the conventional boost converter and the half-bridge converter by using only two active devices. The promising features such as circuit simplicity, low cost,

Shuai Jiang; Dong Cao; Fang Z. Peng; Yuan Li

2012-01-01

287

Spaghetti Bridge  

NSDL National Science Digital Library

Civil engineers design structures such as buildings, dams, highways and bridges. Students explore the field of engineering by making a bridge using spaghetti as their primary building material. Then they test their bridges to see how much weight they can carry before breaking.

K-12 Outreach Office,

288

Bridge Cutout.  

National Technical Information Service (NTIS)

The subject of Main Patent No. 180,993 is a bridge cutout for automatic short-circuiting of series-connected incandescent lamps that have become defective. In this bridge cutout, the two electrodes are bridged by a thermite mixture, possibly with the addi...

O. Maresch F. Viehboeck

1980-01-01

289

Digital Bridges  

NSDL National Science Digital Library

"The Digital Bridges Web site consists of a collection of thirty representative 19th century American bridge engineering monographs, manuals, and documents from the Lehigh University Libraries' Special Collections." The archive provides an interesting retrospective into the beginnings of major bridge projects; the material is complete with high-resolution photographs and text scanned from original books. In addition to historical literature, Digital Bridges also features brief accounts of notable people and companies that influenced bridge construction across the country. A glossary of terms commonly used in the documents is also provided.

2002-01-01

290

Cellular bridges  

PubMed Central

Cell-to-cell communication is the basis of all biology in multicellular organisms, allowing evolution of complex forms and viability in dynamic environments. Though biochemical interactions occur over distances, physical continuity remains the most direct means of cellular interactions. Cellular bridging through thin cytoplasmic channels—plasmodesmata in plants and tunneling nanotubes in animals—creates direct routes for transfer of signals and components, even pathogens, between cells. Recently, two new cellular connections, designated epithelial (EP) bridges, were discovered and found to be structurally distinct from other cellular channels. The first EP bridge type facilitates material transport between cells similar to plasmodesmata and tunneling nanotubes, the second EP bridge type mediates migration of cells between EP cell masses representing a novel form of cell migration. Here, we compare the structures and functions of EP bridges with other cellular channels and discuss biochemical and cellular interactions involved in EP bridge formation. Potential roles for EP bridges in health and disease are also presented.

Edelman, Elazer R

2010-01-01

291

Bidirectional converter interface for a battery energy storage test bench  

Microsoft Academic Search

This paper presents the bidirectional converter interface for a 6 kV battery energy storage test bench. The power electronic interface consists a two stage converter topology having a low voltage dc-ac grid connected converter and a new dual active bridge dc-dc converter with high transformation ratio. The dc-dc converter controls the battery charge\\/discharge current while the grid converter controls the

Ionut Trintis; Stephan Thomas; Tobias Blank; Christoph Roggendorf; Stig Munk-Nielsen; Remus Teodorescu

2011-01-01

292

Single-Stage Power-Factor-Correction Circuit with Flyback Converter to Drive LEDs for Lighting Applications  

Microsoft Academic Search

White light emitting diode (LED) with high brightness has attracted a lot of attention from both industry and academia for its high efficiency, ease to drive, environmental friendliness, and long lifespan. They become possible applications to replace the incandescent bulbs and fluorescent lamps in residential, industrial and commercial lighting. The realization of this new lighting source requires both tight LED

Ying-Chun Chuang; Yu-Lung Ke; Hung-Shiang Chuang; Chia-Chieh Hu

2010-01-01

293

Operation-mode control of active-clamped bi-directional flyback converter as EDLC charger and discharger  

Microsoft Academic Search

An EDLC (electric double layer capacitor) is attractive as a new energy-storage element, and its application as a substitute of the battery has been proposed. However, as the characteristics of EDLC are different from the battery, it is necessary to control charging and discharging procedures under some conditions matched to the demand and the system scale. This paper proposes to

Teruhiko KOHAMA; Masayuki YAMASHIMA; Tamotsu NINOMIYA

2002-01-01

294

Design considerations of a self-biased current driven SR in DCM flyback DC\\/DC converter  

Microsoft Academic Search

In this paper, different kinds of driving methods for synchronous rectifier (SR) are compared, and a self-biased current driven circuit for SR is proposed. The circuit uses a current transformer (CT) to generate driving signal, as well as provide the driving power. With a capacitor to produce bias voltage, this circuit can be used without considering the location of SR

Shuai Shao; Xinke Wu; Min Chen; F. Z. Peng

2010-01-01

295

Spaghetti Bridge  

NSDL National Science Digital Library

Learners explore the field of civil engineering by making a bridge using spaghetti as their primary building material. Then they test their bridges to see how much weight they can carry before breaking. This activity allows learners to engage in the entire engineering process as they design, build, test, then discuss their bridges. Resource includes investigating questions to extend learning. Time estimated for activity can be split across multiple meetings.

Institute, Worcester P.

2005-01-01

296

Continuous power source with bi-directional converter  

SciTech Connect

A power source provides continuous ac power by employing a bidirectional converter which interfaces a rechargable dc power storage device with ac mains power and ac loads. The bidirectional converter includes a transformer having first and second windings coupled in reverse polarity through dual switching means in parallel with one another. The switching means are coupled to a state controller responsive to conditions at the ac mains terminal, the ac load terminal and the dc power terminal. There are two general operating conditions, an active condition wherein dc power is provided to the ac load, and a standby condition wherein power is recovered by the dc storage device. In the standby condition, the converter operates in a socalled ''flyback'' mode to recover power and to direct it to the dc storage device. In the active condition, the converter is pulse-width modulated according to a predetermined duty cycle to produce an ac sine wave output at the ac load terminals. Where the ac load includes reactive components, the converter operates to recover unused power from the load and to transfer power back to the dc power source whenever the polarity of the output voltage differs from the polarity of the output current.

Small, K.T.

1981-07-07

297

Bookmark Converter  

NSDL National Science Digital Library

This windows utility enables user to convert their bookmarks from Netscape Navigator to Internet explorer and vice versa. It is small, fast, and simple to use. The latest version has been tested up to Netscape 4.6 and IE 5.0. Bookmark Converter is shareware and can be registered for $8.

Broding, Magnus.

298

Catalytic converter  

Microsoft Academic Search

A catalytic converter for oxidation of internal combustion engine exhausts is described which overcomes problems resulting from thermal expansion of core members and casings at a relatively low cost as compared to prior art solutions. The converter consists of pairs of circular and generally frusto-conical or funnel-shaped and concentric metal housings or casings forming a container surrounding a circularly cylindrical

1974-01-01

299

Active Bridging  

Microsoft Academic Search

Active networks accelerate network evolution by permitting the network infrastructure to be programmable, on a per-user, per-packet, or other basis. This programmability must be balanced against the safety and security needs inherent in shared resources.This paper describes the design, implementation, and performance of a new type of network element, an Active Bridge. The active bridge can be reprogrammed \\

D. Scott Alexander; Marianne Shaw; Scott M. Nettles; Jonathan M. Smith

1997-01-01

300

Compressed sensing for resolution enhancement of hyperpolarized 13C flyback 3D-MRSI  

NASA Astrophysics Data System (ADS)

High polarization of nuclear spins in liquid state through dynamic nuclear polarization has enabled the direct monitoring of 13C metabolites in vivo at very high signal-to-noise, allowing for rapid assessment of tissue metabolism. The abundant SNR afforded by this hyperpolarization technique makes high-resolution 13C 3D-MRSI feasible. However, the number of phase encodes that can be fit into the short acquisition time for hyperpolarized imaging limits spatial coverage and resolution. To take advantage of the high SNR available from hyperpolarization, we have applied compressed sensing to achieve a factor of 2 enhancement in spatial resolution without increasing acquisition time or decreasing coverage. In this paper, the design and testing of compressed sensing suited for a flyback 13C 3D-MRSI sequence are presented. The key to this design was the undersampling of spectral k-space using a novel blipped scheme, thus taking advantage of the considerable sparsity in typical hyperpolarized 13C spectra. Phantom tests validated the accuracy of the compressed sensing approach and initial mouse experiments demonstrated in vivo feasibility.

Hu, Simon; Lustig, Michael; Chen, Albert P.; Crane, Jason; Kerr, Adam; Kelley, Douglas A. C.; Hurd, Ralph; Kurhanewicz, John; Nelson, Sarah J.; Pauly, John M.; Vigneron, Daniel B.

2008-06-01

301

Fast Referenceless PRF Thermometry Using Spatially Saturated, Spatial-spectrally Excited Flyback EPI  

NASA Astrophysics Data System (ADS)

High intensity focused ultrasound (HIFU) is a promising technique for noninvasive treatment of liver tumors. To safely monitor HIFU, accurate temperature measurements must be acquired. However, respiratory motion impairs the performance of conventional MR-guided PRF-thermometry sequences, leading to inaccurate temperature measurements and locations. We developed an MR imaging system to minimize these with the following key elements: imaging at 3.62 frames/sec and utilizing real-time referenceless thermometry processing. A spatially saturated, spectral-spatially excited flyback echo planar readout pulse sequence that allows rapid temperature acquisition was developed. The spatial-spectral pulse ignores lipids, and other off-resonance effects are mitigated with linear delays of the EPI readout. The saturation pulse restricts the field of view in the phase encode direction, allowing for increased resolution without aliasing. The pulse sequence was constructed in RTHawk, a real time MR environment, and tested by creating lesions in a phantom using the ExAblate 2000 (Insightec, Haifa, Israel). The experiment was performed when the transducer and phantom were stationary and when both were manually moved back and forth to simulate respiratory motion. Both lesions mainly followed the same shape, and the lesion appeared as a round growing spot during motion. The real-time sequence in conjunction with referenceless thermometry is promising for HIFU in the presence of motion.

Holbrook, Andrew B.; Kaye, Elena; Santos, Juan M.; Rieke, Viola; Pauly, Kim Butts

2009-04-01

302

TRIAC dimmable electronic ballast with lamp power equalization  

Microsoft Academic Search

A two-stage, two-wire TRIAC dimmable electronic ballast for fluorescent lamps is presented in this paper. It is constructed by using a flyback converter as the input power factor corrector to supply a half-bridge series-resonant parallel-loaded inverter to ballast the lamp. The flyback converter is operated in discontinuous conduction mode so that the filtered input current profile is same as the

Stephen T. S. Lee; Henry S. H. Chung; S. Y. R. Hui

2004-01-01

303

TRIAC dimmable ballast with power equalization  

Microsoft Academic Search

A two-stage, two-wire TRIAC dimmable electronic ballast for fluorescent lamps is presented in this paper. It is constructed by using a flyback converter as the input power factor corrector to supply a half-bridge series-resonant parallel-loaded inverter to ballast the lamp. The flyback converter is operated in discontinuous conduction mode so that the filtered input current profile is the same as

Stephen T. S. Lee; Henry Shu-Hung Chung; S. Y. R. Hui

2005-01-01

304

Soft switching active snubbers for DC/DC converters  

SciTech Connect

A soft-switching active snubber is proposed to reduce the turn-off losses of the insulated gate bipolar transistor (IGBT) in a buck converter. The soft-switching snubber provides zero-voltage switching for the IGBT, thereby reducing its high turn-off losses due to the current tailing. The proposed snubber uses an auxiliary switch to discharge the snubber capacitor. This auxiliary switch also operates at zero-voltage and zero-current switching. The size of the auxiliary switch compared to the main switch makes this snubber a good alternative to the conventional snubber or even to passive low-loss snubbers. The use of the soft-switching active snubber permits the IGBT to operate at high frequencies with an improved RBSOA. In the experimental results reported for a 1 kW, 40 kHz prototype, combined switching/snubbing losses are reduced by 36% through the use of the active snubber compared to a conventional RCD snubber. The use of an active snubber capacitor during turn-off. The generic snubber cell for the buck converter is generalized to support the common nonisolated dc/dc converters (buck, boost, buck-boost, Cuk, sepic, zeta) as well as isolated dc/dc converters (forward, flyback, Cuk, and sepic).

Elasser, A.; Torrey, D.A. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Electric Power Engineering

1996-09-01

305

Myocardial Bridge  

MedlinePLUS

... Cardiovascular Disease Diagnostic Tests and Procedures Ask a Texas Heart Institute Doctor: Search "myocardial bridge" Updated October ... Outside the U.S., call 1-832-355-6536.) Texas Heart Institute Heart Information Center Through this community ...

306

A Zero-Voltage-Switching DC–DC Converter With High Voltage Gain  

Microsoft Academic Search

A zero-voltage-switching (ZVS) dc-dc converter with high voltage gain is proposed. It consists of a ZVS boost converter stage and a ZVS half-bridge converter stage and two stages are merged into a single stage. The ZVS boost converter stage pro- vides a continuous input current and ZVS operation of the power switches. The ZVS half-bridge converter stage provides a high

Hyun-Lark Do

2011-01-01

307

Spaghetti Bridge  

NSDL National Science Digital Library

Play with your food while learning about engineering! Build a spaghetti bridge, then test its strength by piling on the marshmallows, raw spaghetti, raw linguine and coins. Investigate the difference between the strength of bridges made from flat and round building materials (spaghetti is round, while linguine is flat). Learn by doing that circles are among the strongest shapes in nature, and that external and internal stress distributes itself evenly throughout a round structure.

Sciencenter

1999-01-01

308

Photothermophotovoltaic converter  

SciTech Connect

A photothermophotovoltaic energy conversion system for converting solar energy to electrical energy is described comprising: a radiator; and photovoltaic cell means for receiving incoming electromagnetic radiant energy including the solar energy and converting a first portion of the incoming energy to electrical energy and having reflecting means for reflecting a second portion of the incoming energy to the radiation. The radiator is disposed to receive the second portion of the energy from at least one photovoltaic cell and be heated thereby for radiating energy back to the photovoltaic cell means for subsequent energy conversion therein.

Woolf, L.D.

1988-05-24

309

Measurement Converter  

NSDL National Science Digital Library

Many online calculators require a Java-capable browser. Here's one that doesn't, and will perform over 500 different unit conversions for distance, area, volume, mass, speed, temperature, pressure, energy, power, force, etc. And when you convert, say, 5 kilometers to miles, you not only get the conversion result, but a wealth of related measurements and sample conversions.

2007-12-13

310

Advanced bridge management systems  

Microsoft Academic Search

In this paper, development of advanced bridge management systems is discussed, with special emphasis on reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way. The proposed procedures are illustrated by the EU-supported management systems BRIDGE1 and BRIDGE2. The paper is strongly based on reports produced within the EU

P. Thoft-Christensen

1995-01-01

311

Basswood Bridges  

NSDL National Science Digital Library

The Elementary Engineering Design course for freshmen students at Purdue University Calumet consists of two components: one ME and one EE. Due to the two part structure and in order to expose the students to the faculty, it is also team taught. The course counts as two credits, with the format one hour lecture and three hours lab. The basswood bridge is the major project of the ME half and counts for one quarter of the total course grade. The object, as is usual with bridge projects, is to design, build and test a truss bridge having a high strength to weight ratio. The design process includes statics analysis in combination with the tensile and compressive properties of the basswood. The details of the project from initial design to final testing are provided.

Abramowitz, Harvey

2009-09-16

312

Cascaded H-bridge Multilevel Inverters -A Reexamination  

Microsoft Academic Search

Multilevel converters have gained popularity in high-power applications due to their low switch voltage stress and modularity. Cascaded H-bridge converters are a promising breed of multilevel converters which generally require several independent dc sources. Recently, existence of a redundant switching state has been utilized to replace the independent voltage sources with capacitors except for the one with the highest voltage

Jingsheng Liao; Kai Wan; M. Ferdowsi

2007-01-01

313

DECONSTRUCTING BRIDGES  

Microsoft Academic Search

ON THE BRINK … We found ourselves getting close to The Gap. The other side was covered in mist and I suddenly realised that, although heavily armed with the shiny weaponry and strongest determination, we would not be able to bridge The Gap. Stuck, desperate, we were waiting for someone to show us the way. Why don't we just shout

Janko Calic; Ebroul Izquierdo

314

Design of low cost power Converter system for fuel cell  

Microsoft Academic Search

This paper studies the design of DC-DC Converter to convert low-voltage energy sources generated from renewable power like battery power, photovoltaic power, or fuel cells into high-voltage ones. The circuit topology of H-bridge converter to convert input voltage, 24 V, into out voltage, 270 V, was realized through applying phase shift angle control so as to manage electric power and

Taeuk Jung; Juyong Kim; Cheol Choi

2009-01-01

315

High power density dc/dc converter: Selection of converter topology  

NASA Astrophysics Data System (ADS)

The work involved in the identification and selection of a suitable converter topology is described. Three new dc/dc converter topologies are proposed: Phase-Shifted Single Active Bridge DC/DC Converter; Single Phase Dual Active Bridges DC/DC Converter; and Three Phase Dual Active Bridges DC/DC Converter (Topology C). The salient features of these topologies are: (1) All are minimal in structure, i.e., each consists of an input and output bridge, input and output filter and a transformer, all components essential for a high power dc/dc conversion process; (2) All devices of both the bridges can operate under near zero-voltage conditions, making possible a reduction of device switching losses and hence, an increase in switching frequency; (3) All circuits operate at a constant frequency, thus simplifying the task of the magnetic and filter elements; (4) Since, the leakage inductance of the transformer is used as the main current transfer element, problems associated with the diode reverse recovery are eliminated. Also, this mode of operation allows easy paralleling of multiple modules for extending the power capacity of the system; (5) All circuits are least sensitive to parasitic impedances, infact the parasitics are efficently utilized; and (6) The soft switching transitions, result in low electromagnetic interference. A detailed analysis of each topology was carried out. Based on the analysis, the various device and component ratings for each topology operating at an optimum point, and under the given specifications, are tabulated and discussed.

Divan, Deepakraj M.

1990-01-01

316

The Belizean Bridge Activity.  

ERIC Educational Resources Information Center

|Describes the famous swing bridge in Belize. Students build bridges from a variety of materials and answer the questions, What are different types of bridges?, How do bridges work?, How can you tell if a bridge design will be safe?, and What is the best way to build a bridge over a river while still allowing boat traffic? (SAH)|

Murfin, Brian

2000-01-01

317

Bridge Inspector's Training Manual.  

ERIC Educational Resources Information Center

|A guide for the instruction of bridge inspectors is provided in this manual as well as instructions for conducting and reporting on a bridge inspection. The chapters outline the qualifications necessary to become a bridge inspector. The subject areas covered are: The Bridge Inspector, Bridge Structures, Bridge Inspection Reporting System,…

Federal Highway Administration (DOT), Washington, DC. Bureau of Public Roads.

318

Bridge Inspector's Training Manual.  

ERIC Educational Resources Information Center

A guide for the instruction of bridge inspectors is provided in this manual as well as instructions for conducting and reporting on a bridge inspection. The chapters outline the qualifications necessary to become a bridge inspector. The subject areas covered are: The Bridge Inspector, Bridge Structures, Bridge Inspection Reporting System,…

Federal Highway Administration (DOT), Washington, DC. Bureau of Public Roads.

319

General analysis of harmonic transfer through converters  

Microsoft Academic Search

Harmonic transfer from DC-side to AC-side and vice-versa through a three-phase bridge power converter is treated by using space vectors. The dependency of the relative frequency of a harmonic and its sequence (positive\\/negative) is illustrated. It is shown that the derived relationships are valid for both voltage-source and current-source power converters. Thereby, the relationships for the frequency transformation through power

Ying Jiang; A. Ekstrom

1997-01-01

320

Bridge Building  

NSDL National Science Digital Library

This is a quick activity (on page 2 of the PDF) about how the arrangement of carbon atoms determines carbon's different properties. Learners will build bridges with Post-It notes that model two types of carbon molecules, graphite and carbon nanotubes, and test which structure of the same material can bear the weight of the most pennies. Also relates to linked video, DragonflyTV Nano: Hockey Sticks.

Twin Cities Public Television, Inc.

2008-01-01

321

Resonant converter topologies with three and four energy storage elements  

Microsoft Academic Search

Generalized half-bridge and full-bridge resonant converter topologies with two, three and four energy storage elements are presented. All possible circuit topologies for such converters under voltage\\/current driven and voltage\\/current sinks are discussed. Many of these topologies have not been investigated in open literature. Based on their circuit element connections and source and load excitation types, these topologies are classified into

I. Batarseh

1994-01-01

322

Novel Converter Concept for Bearingless Slice Motor Systems  

Microsoft Academic Search

The general trend towards smaller and more economical designs has also reached bearingless slice motor (BSM) systems. Up to now, full-bridge converters have been used in order to independently control the phases of the active magnetic bearing and the drive system. In this paper, a simplified topology based on three half-bridges is proposed to replace two conventional full-bridges. With this,

Martin T. Bartholet; Thomas Nussbaumer; Peter Dirnberger; Johann. W. Kolar

2006-01-01

323

Effect of leakage inductance in bidirectional DC to DC converter  

Microsoft Academic Search

This work presents an isolated full-bridge bidirectional DC\\/DC converter for battery charging\\/discharging operation. In the proposed scheme, the full-bridge isolated topology is used for the DC-DC conversion. The full bridge scheme is widely used for the high power application. High frequency transformer is used for isolation purpose. This paper deals with the effect of leakage inductance of high frequency transformer

Kunalkumar P. Bhatt; M. T. Shah; Vinod Patel; Vijendra Kharbikar

2011-01-01

324

The effect of bandgap engineering on IC-VBE fly-back characteristic of power SiGe heterojunction bipolar transistor  

Microsoft Academic Search

The effect of bandgap engineering on IC-VBE flyback characteristic of power SiGe heterojunction bipolar transistor is studied through theoretical analysis, computer simulations, and experimental measurements. It is found that because of the existence of Ge composition, SiGe Heterojunction Bipolar Transistors have better thermal stability compared with homojunction bipolar transistors under the same operating condition which will be beneficial to decrease

Chen Liang; Zhang Wan-rong; Jin Dong-yue; Ding Chun-bao; Zhang Yu-jie; Lu Zhi-yi

2011-01-01

325

A novel soft-switching double modulation converter (DMC)  

Microsoft Academic Search

This paper introduces a new and simple power converter topology by which both the amplitude and the duty cycle are modulated to achieve soft switching characteristic in a standard half bridge configuration. This novel double modulation power converter (DMC) is able to provide zero voltage switching and nonpulsating input ripple current. Constant switching frequency, simple control and gate drive circuit

N. K. Poon; W. C. Ho; M. H. Pong

1995-01-01

326

Building Big: Bridges  

NSDL National Science Digital Library

This web page describes different aspects of designing bridges. It relates the concept of bridge designing with the real life scenarios. It also includes some bridges around the world and gives some specifications of them.

Foundation, Wgbh E.

2006-07-11

327

Building Big--Bridges  

NSDL National Science Digital Library

This web page describes different aspects of designing bridges. It relates the concept of bridge designing with the real life scenarios. It also includes some bridges around the world and gives some specifications of them.

2008-05-22

328

Bridge Management System Update.  

National Technical Information Service (NTIS)

The objective of this project was to assist the NCDOT in updating parameters used in analysis of bridge inspection data for purposes of bridge management. Various parameters are used in OPBRIDGE, a bridge manage system decision support program for predict...

D. W. Johnston S. A. Duncan

2002-01-01

329

Build A Bridge  

NSDL National Science Digital Library

This wonderful site, provided by NOVA Online, brings to life the engineering challenges inherent to bridge-building. Designed for those who want the challenge, the site offers four bridging scenarios (with photos): "a 5,000-foot span across an ocean bay where huge ships come and go, ... a 700-foot span across a deep canyon gorge," and two others. A step-by-step tutorial teaches about four different bridge types (arch, beam, suspension, and cable-stayed), after which the user may select a bridge type for each scenario. The site is enhanced by links to other bridge resources, such as the famous bridge-building disaster of the century (Tacoma Narrows Bridge) and the Golden Gate Bridge site, which in turn, links users to other famous bridges including Japan's brand new Akashi Kaikyo Bridge, the longest bridge in the world.

1997-01-01

330

Soft-Switching Converter With HF Transformer for Grid-Connected Photovoltaic Systems  

Microsoft Academic Search

In this paper, the design, realization, and performance evaluation of a single-phase 3-kW dc\\/ac power converter, using an active-bridge dc\\/dc converter and a full-bridge dc\\/ac, are introduced, presenting a novel solution on the industrial scenario for the considered application. Control algorithms, including the maximum power point tracking, paralleling to the grid, and converter switching signals, are digitally implemented on a

Mario Cacciato; Alfio Consoli; Rosario Attanasio; Francesco Gennaro

2010-01-01

331

A ZVS bi-directional DC-DC converter for vehicular electronics  

Microsoft Academic Search

A ZVS bi-directional DC-DC converter for vehicular electronics is analyzed in this paper. As a kind of current-voltage hybrid converter, the converter is composed of an isolated boost converter and a bridge converter. The principle of soft switching is presented in detail. The boost inductor is designed appropriately to satisfy the ZVS for all power devices. A control scheme adopting

Huafeng Xiao; Donghua Chen; Shaojun Xie

2005-01-01

332

Second Bosporus Bridge.  

National Technical Information Service (NTIS)

The Second Bosporus Bridge spans Bosporus Strait some 5 km north of the First Bosporus Bridge in Istanbul, the Republic of Turkey. It is a suspension bridge with a 1,090 m center span and will be the 6th longest in the world after completion. The bridge h...

W. C. Brown E. Hemmi H. Yamauchi T. Tanabe S. Uehira

1987-01-01

333

Generalized Gaussian Bridges  

Microsoft Academic Search

A generalized bridge is the law of a stochastic process that is conditioned on linear functionals of its path. We consider two types of representations of such bridges: orthogonal and canonical. In the canonical representation the filtrations and the linear spaces generated by the bridge process and the original process coincide. In the orthogonal representation the bridge is constructed from

Tommi Sottinen; Adil Yazigi

2012-01-01

334

Investigation of candidate topologies for brick DC-DC  

Microsoft Academic Search

Characteristics of electrical specifications, which is peculiar for brick DC\\/DC power product, is analyzed in detail in this paper, selective requirement of topologies for this type product is presented as well. The topologies listed as follows are the presented appropriate candidate ones for brick DC\\/DC: active-clamped forward converter, resonant reset forward converter, symmetrical half-bridge converter, forward-flyback converter, isolated boost-buck converter,

Yilei Gu; Huiming Chen; Zhengyu Lu; Zhaoming Qian; Kun Wei

2005-01-01

335

Bidirectional power electronics for driving dielectric elastomer transducers  

NASA Astrophysics Data System (ADS)

The operation of Dielectric Elastomer Transducers typically requires high voltages in the kilovolt range and relatively low currents. Therefore, for driving Dielectric Elastomer Transducers a high voltage power electronics is necessary. For realization of energy efficient actuator and generator applications bidirectional switched-mode converter topologies should be used enabling a bidirectional energy transfer as well as a high efficiency. In this contribution a modular converter system consisting of several switched-mode converter modules featuring galvanic isolation is presented as a basic concept for realization of a high voltage power supply. Three converter topologies - bidirectional flyback, Dual Active Bridge and Isolated Bidirectional Full-Bridge converter - are investigated and suitable modulation schemes are presented, which are based on hysteretic current-mode control, enabling a high converter dynamic and limitation of the converter output current in order to prevent electrode damage. Simulation results for the proposed converter topologies are presented and experimental results for a single bidirectional flyback converter module are shown.

Eitzen, L.; Graf, C.; Maas, J.

2012-03-01

336

Bridge Deck Program Development.  

National Technical Information Service (NTIS)

The report identified, classifies and addresses WSDOT's needs and questions regarding concrete bridge deck deterioration. Included is a state-of-the-art assessment regarding any major areas of concern to the statewide bridge deck program. Recommendations ...

K. Babaei

1985-01-01

337

Bridge Management Systems.  

National Technical Information Service (NTIS)

The bridge management system (BMS) is a rational and systematic approach to organizing and carrying out the activities related to planning, designing, constructing, maintaining, rehabilitating, and replacing bridges vital to the transportation infrastruct...

S. W. Hudson R. F. Carmichael L. O. Moser W. R. Hudson W. J. Wilkes

1987-01-01

338

Development of a bridge management system for existing bridges  

Microsoft Academic Search

Recently, the rehabilitation of bridges has become a major social concern because the number of damaged bridges has increased in Japan. Thus, there is a need to develop a practical bridge management system. The present study is an attempt to develop a new bridge management system (J-BMS) for damaged concrete bridges. The J-BMS not only evaluates the performance of bridges,

Ayaho Miyamoto; Kei Kawamura; Hideaki Nakamura

2001-01-01

339

Low nasal bridge  

MedlinePLUS

A low nasal bridge is a flattening of the top part of the nose. ... Decreased growth (hypoplasia) of the nasal bridge can occur with infections or genetic diseases. A decrease in the height of the nasal bridge is best seen from a side ...

340

Science Shorts: Building Bridges  

NSDL National Science Digital Library

London Bridge is falling down, falling down...Can you finish the song? Although there are various stories that suggest the meaning of this famous nursery rhyme, the London Bridge, which spans the River Thames, did indeed "fall down" several times throughout history. This month's Science Shorts explores what makes bridges stay up. A corresponding activity is included.

Adams, Barbara

2006-07-01

341

A 40Pulse AC--DC Converter Fed Vector-Controlled Induction Motor Drive  

Microsoft Academic Search

In this paper, a novel autotransformer for a 40-pulse ac-dc converter configuration is designed, modeled, simulated, and implemented to feed vector-controlled induction motor drive (VCIMD). The proposed converter consists of two paralleled ten-pulse ac-dc converters along with pulse doubling circuit at dc bus. Each ten-pulse ac-dc converter involves five-phase diode bridge rectifiers. It improves power quality at ac mains, and

Bhim Singh; Sanjay Gairola

2008-01-01

342

Design of photovoltaic high frequency link inverter based on push-pull forward converter  

Microsoft Academic Search

In this paper, a photovoltaic high frequency link inverter is proposed. The inverter is constituted of push-pull forward DC-DC converter and DC-AC inverter full bridge. The push-pull forward converter has some superiority in low voltage high current situation and achieves electrical isolation between the photovoltaic battery and the AC output. The push-pull forward converter is used to convert the photovoltaic

Shungang Xu

2010-01-01

343

Realization of digital audio amplifier using zero-voltage-switched PWM power converter  

Microsoft Academic Search

This paper presents a simple methodology to convert a hard-switched pulse-width-modulated (PWM) H-bridge converter used in a classical digital audio amplifier into a zero-voltage-switching (ZVS) converter. The ZVS is simply achieved by connecting an L-C series branch across the converter output. ZVS occurs during the dead time interval of the PWM signals, giving an effective improvement in the conversion efficiency,

Wing-Hong Lau; Henry Shu-Hung Chung; C. M. Wu; Franki N. K. Poon

2000-01-01

344

PWM Converter Topologies.  

National Technical Information Service (NTIS)

Dc to dc converters using an electrical switch to control power flow between a dc source and a dc load are discussed. Only Pulse Width Modulation (PWM) type converter topologies are considered. A basic three element, three terminal converter topology is d...

E. R. W. Meerman H. J. N. Spruyt

1989-01-01

345

Bridging the Gap: Linking Simulation and Testing  

SciTech Connect

The Materials Genome Initiative (MGI) which is a key enabler for the Advanced Manufacturing Partnership, announced in 2011 by U.S. President Barack Obama, was established to accelerate the development and deployment of advanced materials. The MGI is driven by the need to "bridge the gap" between (I) experimental results and computational analysis to enable the rapid development and validation of new mateirals, and (II) the processes required to convert these materials into useable goods.

Krajewski, Paul E.; Carsley, John; Stoudt, Mark R.; Hovanski, Yuri

2012-09-01

346

Superconductive energy storage inductor-converter units for power systems  

Microsoft Academic Search

Large magnets with superconductive windings could serve to perform a power system function analogous to pumped storage hydro. A conventional Graetz bridge converter as used in dc transmission provides an ideal interface between the three-phase power system and the superconductive magnet or inductor. Such Inductor-Converter or I-C units, when properly controlled, provide significant power system benefits. Power reversibility is achievable

H. A. Peterson; N. Mohan; R. W. Boom

1975-01-01

347

Nanoparticle bridge DNA biosensor  

NASA Astrophysics Data System (ADS)

A new DNA sensing method is demonstrated in which DNA hybridization events lead to the formation of nanoparticle satellites that bridge two electrodes and are detected electrically. The hybridization events are exclusively carried out only on specific locations, the surfaces of C-ssDNA modified 50 nm GNPs. The uniqueness of this work is that only a small number of T-ccDNA molecules (<10) is required to form the nanoparticle satellites, allowing ultra-sensitive DNA sensing. The principle of this new DNA sensing technique has been demonstrated using target DNA and three-base-pair-mismatched DNA in 20nM concentrations. Three single-stranded DNA (ssDNA) system is used in our experiment which includes Capture-ssDNA (C-ssDNA), Target-ssDNA (T-ssDNA) and Probe-ssDNA (P-ssDNA). Both C-ssDNA and P-ssDNA are modified by a thiol group and can hybridize with different portions of T-ssDNA. T-ssDNA requires no modification in three ssDNA system, which is beneficial in many applications. C-ssDNA modified 50nm gold nanoparticle (C-50au) and P-ssDNA modified 30nm gold nanoparticle (P-30au) are prepared through the reaction of thiol-gold chemical bonding between thiolated ssDNA and gold nanoparticle (GNP) (C-ssDNA with 50nm GNP, P-ssDNA with 30nm GNP). We controllably place the C-50au only on the SiO2 band surface (˜ 90nm width) between two gold electrodes (source and drain electrodes) by forming positively- and negatively-charged self-assembled monolayers (SAMs) on SiO2 and gold surface, respectively. DNA modified GNP is negatively charged due to ionization of phosphate group on DNA back bone. C-50au therefore is negatively charged and can only be attracted toward SiO2 area (repelled by negatively charged gold electrode surface). The amine group of positively-charged SAMs on SiO2 surface is then passivated by converting to non-polar methyl functional group after C-50au placement. P-30au is first hybridized with T-ssDNA in the solution phase (T-P- 30au formed) and is introduced into DNA detection device in which C-50au are immobilized on ˜90nm width SiO2 band (between two gold electrodes). The passivation step ensures every TP-30au are attached only to C-50au through hybridization (T-P-30au will not be attracted toward SiO2 surface or gold electrodes). GNP bridges are formed across the electrodes and provide an electrical path between two gold electrodes. We ensure that every T-P-30au only hybridizes on the surface of C-50au by (1) accurately controlling C-50au placement between two gold electrodes, (2) passivating positively-charged SAMs on SiO2 surface after C-50au immobilization. When T-P-30au hybridize with C-50au on ˜90nm wide SiO 2 surface, GNP bridges form and provide an electrical path between two gold electrodes even with only a few hybridization events. Experimental results show that even a few GNP bridges formed on SiO2 band can provide a significant conductance change from an open circuit to a conductive circuit (current = 0.5 uA at voltage = 0.1 V with four GNP bridge). We also used 3-base-pair-mismatched ssDNA (3mm-ssDNA) as a control experiment, which always resulted in an open circuit (no GNP bridge formed). Our detection device is compatible with current CMOS fabrication technology and can be manufactured on a wafer scale. The direct electrical output of this DNA detection technique provides a promising basis for high-throughput screening (can be fabricated on a wafer scale) with no expensive equipment required.

Huang, Hong-Wen

348

Leakage Energy Recovered Narrow Pulsed Voltage Generator Associated with Ultrasound Generator for Liquid Food Sterilization  

Microsoft Academic Search

This paper presents a narrow pulsed voltage generator along with an ultrasound generator for liquid food sterilization. The generator is derived from a bidirectional flyback converter with leakage energy recovery circuits, which can improve efficiency about 12%. In addition, the proposed generator is associated with a half-bridge inverter for generating ultrasound to clean sterilizer electrodes. In this combined generator, the

S.-Y. Tseng; Y.-D. Chang; P.-L. Huang; T.-F. Wu; Y.-M. Chen

2007-01-01

349

Tapped-inductor filter assisted soft-switching PWM DC-DC power converter  

Microsoft Academic Search

A novel high-frequency transformer linked full-bridge type soft-switching phase-shift pulsewidth modulated (PWM) controlled dc-dc power converter is presented, which can be used as a power conditioner for small-scale photovoltaic and fuel cell power generation systems as well as isolated boost dc-dc power converter for automotive ac power supply. In these applications with low-voltage large-current sources, the full-bridge circuit is the

SERGUEI MOISSEEV; KOJI SOSHIN; MUTSUO NAKAOKA

2005-01-01

350

A Current Mode Analysis on Ground Leakage Current Noise Generation in Unbalanced and Balanced Switching Converters  

NASA Astrophysics Data System (ADS)

This paper presents the new switching converter model used for analyzing the generation mechanism of ringing ground leakage (GL) current, generated during the transient, at switch on/off of any switching converter. By applying the Norton model, the proposed new model of switching converter can be formulated. The ringing GL current is evaluated at the switching on/off of the unbalanced (half-bridge converter) and the balanced converter (full-bridge converter) for bidirectional D.C. motor drive used as an example. It is concluded that the measured and simulated results of the generated GL current agree well with the numerical analysis results, analyzed by the proposed new model of switching converter, in terms of the minimum or maximum peak currents and the ringing frequency.

Intachot, Terdsak; Chuladaycha, Nontawat; Prempraneerach, Yothin; Nitta, Shuichi

351

Overcurrent Protection Criteria in Large AC to DC Thyristor Converters  

Microsoft Academic Search

The paper refers to thyristor ac to dc converters for industrial applications, nonreversing and reversing, in full-controlled three-phase bridge connection, as used for armature supply of dc motors and excitation of large ac generators. The possible causes of incorrect operation as well as the types of fault currents produced are investigated; the means available to interrupt or limit the value

Vito Vaccaro

1974-01-01

352

Floating capacitor voltage regulation in diode clamped hybrid multilevel converters  

Microsoft Academic Search

The family of hybrid topologies consisting primarily of a main neutral point clamped (NPC) 3-phase inverter followed by one or more series connected H-bridges in each output phase show promise in medium voltage applications requiring high power quality and minimal size and weight. Another distinct advantage of this topology is the ability to supply the main NPC converter with a

James A. Ulrich; Ashish R. Bendre

2009-01-01

353

Ac-dc converter firing error detection  

SciTech Connect

Each of the twelve Booster Main Magnet Power Supply modules consist of two three-phase, full-wave rectifier bridges in series to provide a 560 VDC maximum output. The harmonic contents of the twelve-pulse ac-dc converter output are multiples of the 60 Hz ac power input, with a predominant 720 Hz signal greater than 14 dB in magnitude above the closest harmonic components at maximum output. The 720 Hz harmonic is typically greater than 20 dB below the 500 VDC output signal under normal operation. Extracting specific harmonics from the rectifier output signal of a 6, 12, or 24 pulse ac-dc converter allows the detection of SCR firing angle errors or complete misfires. A bandpass filter provides the input signal to a frequency-to-voltage converter. Comparing the output of the frequency-to-voltage converter to a reference voltage level provides an indication of the magnitude of the harmonics in the ac-dc converter output signal.

Gould, O.L.

1996-07-15

354

GraphicConverter  

NSDL National Science Digital Library

GraphicConverter goes beyond the ability to convert a large number of graphic file formats. It provides tools for the creation and/or editing of graphics, animations, movies, and slide presentations; it also supports Adobe Photoshop compatible plug-ins. Currently, GraphicConverter can import 96 different graphic file formats and export 38. Conversion of several files (graphic or text) at a time is also possible through the "convert more..." feature. The tools offered for graphic editing are Photoshop-like. Detailed documentation is provided. This Macintosh shareware is provided by Lemke Software.

355

PWM converter topologies  

NASA Astrophysics Data System (ADS)

Dc to dc converters using an electrical switch to control power flow between a dc source and a dc load are discussed. Only Pulse Width Modulation (PWM) type converter topologies are considered. A basic three element, three terminal converter topology is defined followed by two universal rules allowing for derivation of a wide variety of different topologies. A summary of different topology types is provided with steady state and small signal relations given for each. The survey shows 46 converter topologies of which 18 are known and 28 are new (under, patent application). The number of topologies could be increased to 68 if negative input voltages are considered.

Meerman, E. R. W.; Spruyt, H. J. N.

1989-08-01

356

4. View of bridge deck from northeast approach (bridge deck ...  

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

4. View of bridge deck from northeast approach (bridge deck from southwest approach is virtually identical - Big Cottonwood River Bridge No. 246, Spanning Big Cottonwood River at Cottonwood Street (City Road No. 165), New Ulm, Brown County, MN

357

4. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...  

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

4. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shoreof Clark Fork River showing 4 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

358

3. View of Clark Fork Vehicle Bridge facing southwest. Bridge ...  

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

3. View of Clark Fork Vehicle Bridge facing southwest. Bridge from north shore of Clark Fork River. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

359

2. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...  

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

2. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

360

7. View of Clark Fork Vehicle Bridge facing northwest. Bridge ...  

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

7. View of Clark Fork Vehicle Bridge facing northwest. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

361

SULPHITE BRIDGE FROM DOWNSTREAM, BEARING NORTHEAST 25 DEGREES. THE BRIDGE ...  

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

SULPHITE BRIDGE FROM DOWNSTREAM, BEARING NORTHEAST 25 DEGREES. THE BRIDGE ONCE HAD VERTICAL BOARD SIDING BUT VANDALS BURNED IT OFF IN 1981 - Sulphite Railroad Bridge, Former Boston & Maine Railroad (originally Tilton & Franklin Railroad) spanning Winnipesautee River, Franklin, Merrimack County, NH

362

46. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE ...  

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

46. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE NO. 13. LOOKING NORTH-NORTHEAST. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

363

45. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE ...  

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

45. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE NO. 10. LOOKING SOUTH. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

364

47. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE ...  

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

47. TRANSFER BRIDGE CONTROL ROOM ON SECOND LEVEL OVERLOOKING BRIDGE NO. 11 IN OPERATION. LOOKING NORTH. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

365

1. VIEW OF SWING BRIDGE FROM KEDZIE AVENUE BRIDGE, LOOKING ...  

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

1. VIEW OF SWING BRIDGE FROM KEDZIE AVENUE BRIDGE, LOOKING EAST. - Chicago, Madison & Northern Railroad, Sanitary & Ship Canal Bridge, Spanning Sanitary & Ship Canal, east of Kedzie Avenue, Chicago, Cook County, IL

366

APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...  

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

APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM ENTRY. VIEW FACING NORTHWEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream East Range, Wahiawa, Honolulu County, HI

367

APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...  

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

APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM BELOW, SHOWING VALVE TOWER TO RIGHT. VIEW FACING NORTH - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream East Range, Wahiawa, Honolulu County, HI

368

Sulphite Railroad Bridge1896, Title Sheet Sulphite Railroad Bridge, Former ...  

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

Sulphite Railroad Bridge-1896, Title Sheet - Sulphite Railroad Bridge, Former Boston & Maine Railroad (originally Tilton & Franklin Railroad) spanning Winnipesautee River, Franklin, Merrimack County, NH

369

Bridge Engineering: Volume 1.  

National Technical Information Service (NTIS)

The 34 papers in this report deal with the following areas: development of a computerized bridge inventory for a state road authority; the New Mexico bridge inspection program; precepts of the evaluation of facilities for human use and the application to ...

B. L. Richards K. White J. Minor J. C. Porter A. M. Shirole

1978-01-01

370

1.2 MW dc-dc converter  

NASA Astrophysics Data System (ADS)

A dc-dc converter has been developed to charge capacitors to 16 kV from a 400 V battery bank. It is designed to charge an 8.5 MJ bank nine times in 3 min. The converter is comprised of six modules, each producing 12.5 A of charging current, and an enclosure which houses the modules and provides control power and a master controller. The six 200 kW modules have a combined power rating of 1.2 MW. The pulse width modulation converter system operates at 24 kHz and contains inverters with power MOSFETs as the principal inverter components, 200 kW transformers and inductors, and full bridge rectifiers with fast recovery diodes. The converter modules have a volume power density of 1.0 MW/cu m and a mass power density of 1.2 kW/kg. The converter design and test results are described.

Homeyer, W. G.; Callanan, R. J.; Bowles, E. E.; Nerem, A.

1993-01-01

371

Thermionic converters for ISUS  

Microsoft Academic Search

Eight alkali metal thermionic power converters were produced for a ground-based design verification test of a bimodal power and propulsion system. The effort provided a significant development step toward a spaceflight demonstration of the Integrated Solar Upper Stage (ISUS). The converters are electrically connected in series to produce a nominal eight (8) volt, 250 Watt output. In the power mode

Edmund L. James; William D. Ramsey; Gregory J. Talbot

1997-01-01

372

Analog to Digital Converter.  

National Technical Information Service (NTIS)

An analog-to-digital converters, finding particular application in a multichannel pulse height analyzer, with a means for digitizing the analog input in two conversion steps is presented. To digitize the input to 13 bits, a 7-bit digital to analog convert...

C. H. Lucas

1974-01-01

373

Respectful Type Converters  

Microsoft Academic Search

In converting an object of one type to another, we expect some of the original object's behavior to remain the same and some to change. How can we state the relationship between the original object and converted object to characterize what information is preserved and what is lost after the conversion takes place? We answer this question by introducing the

Jeannette M. Wing; John Ockerbloom

2000-01-01

374

The Real Time Digital Simulation of a Single Phase Voltage Source Converter and its Application  

Microsoft Academic Search

Voltage Source Converters (VSCs) use Gate Turn- Off (GTO) devices and Pulse Width Modulation (PWM) technology to control the operation of the converter bridge. This paper presents a new fully digital model of a single phase VSC. The unique improved firing algorithm (a numerical algorithm for compensating discrete time step firing error) allows the simulation time step to be in

Ming Yu; Hiroo Konishi

375

An isolated DC-DC converter using two zero current switched IGBTs in a symmetrical topology  

Microsoft Academic Search

A symmetrical, current-fed DC-DC boost converter was investigated theoretically and experimentally on a 300 W prototype in the frequency range: 40 to 110 kHz. The converter is built around an L-type half-bridge IGBT inverter. Zero-current-switching is achieved by a series resonant LC-network placed between the collectors of the IGBTs

Gregory Ivensky; Igor Elkin; Sam Ben-Yaakov

1994-01-01

376

Building Our Bridge to Fun!  

NSDL National Science Digital Library

Students identify different bridge designs and construction materials used in modern day engineering. They work in construction teams to create paper bridges and spaghetti bridges based on existing bridge designs. Students progressively realize the importance of the structural elements in each bridge. They also measure vertical displacements under the center of the spaghetti bridge span when a load is applied. Vertical deflection is measured using a LEGO® MINDSTORMS® NXT intelligent brick and ultrasonic sensor. As they work, students experience tension and compression forces acting on structural elements of the two bridge prototypes. In conclusion, students discuss the material properties of paper and spaghetti and compare bridge designs with performance outcomes.

Applying Mechatronics to Promote Science (AMPS) GK-12 Program,

377

Tapped inductor filter-assisted soft-switching PWM DC-DC power converter with high frequency transformer link for automotive AC power supply  

Microsoft Academic Search

This paper presents a novel voltage source full-bridge type soft-switching phase-shift PWM controlled DC-DC power converter with a high frequency transformer link, which can operate under ZVS transition of leading bridge leg and ZCS transition of lagging bridge leg. This power converter can be used as power conditioner for small-scale solar photovoltaic cell and fuel cell power generation systems and

Serguei Moisseev; Y. Ishigami; K. Soshin; M. Nakaoka

2004-01-01

378

MSPWM & MTPWM techniques for asymmetric H-bridge multilevel inverter  

Microsoft Academic Search

Multilevel inverter is a new breed of power converter which is suited for high power applications. The various topologies of multilevel inverter are diode - clamped, capacitor clamped and cascaded H-bridge inverter. It is an effective solution for increasing the number of levels in output waveform with reduced dc sources and switching elements, thereby dramatically reduces harmonics without increasing the

P. Jamuna; C. Christober Asir Rajan

2012-01-01

379

Application of time series analysis for bridge monitoring  

Microsoft Academic Search

Despite recent considerable advances in structural health monitoring (SHM) of civil infrastructure, converting large amounts of data from SHM systems into usable information and knowledge remains a great challenge. This paper addresses the problem through the analysis of time histories of static strain data recorded by an SHM system installed in a major bridge structure and operating continuously for a

Piotr Omenzetter; James Mark William Brownjohn

2006-01-01

380

Bay Bridge 360  

NSDL National Science Digital Library

This website was created by the various California transportation agencies that are involved in the enormous job of retrofitting the San Francisco-Oakland Bay Bridge to protect it from being damaged by seismic activity. It is an extremely well thought out website, with an interactive aerial graphic of the Bridge on its homepage that introduces visitors to their work. If you click on the colored circles on the bridge, you can see a slideshow of the construction on that section of the Bridge, and some of the Bridge sections include a time-lapse video of the construction. Additionally, there is a short film visitors can watch to get an overview of the project, by clicking on the blue circle above "Bay Bridge Overview" in the right-hand corner of the homepage. Clicking on the arrow in the left-hand corner of the homepage takes you inside the website where you can find links to "Closures and Detours", "Environmental Issues", for the Final Environmental Impact Statement, detailed explanations of the construction methods under the "Information Center" link, and even "Construction Cams". If you just can't get enough of traffic where you live, just click on "Construction Cams" and see Bay Bridge traffic.

2009-06-08

381

A novel topology family of single stage ACDC converter with PFC  

Microsoft Academic Search

A circuit topologies family of single-stage parallel uninterruptible AC\\/DC converter with high power factor are presented. The topology includes four sections, i.e. full bridge rectifier, parallel converter with power factor correction(PFC), uninterruptible power supply and fast output voltage regulation. The converter has lots of advantages such as: single stage power conversion, uninterruptible power supply, high power factor, electrical isolation between

Jinhua Liu; Xuejun Ma

2010-01-01

382

A novel multicell DC-AC converter for applications in renewable energy systems  

Microsoft Academic Search

This paper presents a novel DC-AC converter for applications in the area of distributed energy generation systems, e.g., solar power systems, fuel-cell power systems in combination with supercapacitor or battery energy storage. The proposed converter is realized using an isolated multicell topology where the total AC output of the system is formed by series connection of several full-bridge converter stages.

Hans Ertl; Johann W. Kolar; Franz C. Zach

2002-01-01

383

A new ZVS bidirectional DC-DC converter for fuel cell and battery application  

Microsoft Academic Search

This paper presents a new zero-voltage-switching (ZVS) bidirectional dc-dc converter. Compared to the traditional full and half bridge bidirectional dc-dc converters for the similar applications, the new topology has the advantages of simple circuit topology with no total device rating (TDR) penalty, soft-switching implementation without additional devices, high efficiency and simple control. These advantages make the new converter promising for

Fang Z. Peng; Hui Li; Gui-Jia Su; Jack S. Lawler

2004-01-01

384

Converters dedicated to long-term monitoring of strain gauge transducers  

Microsoft Academic Search

This paper presents two new strain gauge bridge-to-pulse position modulation (PPM) converters. They have been developed in 2-?m BiCMOS technology. The first one uses a chopper amplifier and a voltage-to-time converter associated in a feedback loop. This topology mainly exhibits an automatic offset cancellation capability, a ratiometric transfer function, and 10-b accuracy. The second one is a voltage-to-frequency converter using

Jean-Baptiste Begueret; Mohammed Reda Benbrahim; Zhiqun Li; Francis Rodes; Jean-Paul Dom

1997-01-01

385

5. View of Clark Fork Vehicle Bridge facing east. Bridge ...  

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

5. View of Clark Fork Vehicle Bridge facing east. Bridge from south shore of Clark Fork River-southernmost span. 1900-era Northern Pacific Railway Bridge in background. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

386

Circuit bridging of components by smoke  

SciTech Connect

Smoke can adversely affect digital electronics; in the short term, it can lead to circuit bridging and in the long term to corrosion of metal parts. This report is a summary of the work to date and component-level tests by Sandia National Laboratories for the Nuclear Regulatory Commission to determine the impact of smoke on digital instrumentation and control equipment. The component tests focused on short-term effects such as circuit bridging in typical components and the factors that can influence how much the smoke will affect them. These factors include the component technology and packaging, physical board protection, and environmental conditions such as the amount of smoke, temperature of burn, and humidity level. The likelihood of circuit bridging was tested by measuring leakage currents and converting those currents to resistance in ohms. Hermetically sealed ceramic packages were more resistant to smoke than plastic packages. Coating the boards with an acrylic spray provided some protection against circuit bridging. The smoke generation factors that affect the resistance the most are humidity, fuel level, and burn temperature. The use of CO{sub 2} as a fire suppressant, the presence of galvanic metal, and the presence of PVC did not significantly affect the outcome of these results.

Tanaka, T.J.; Nowlen, S.P.; Anderson, D.J. [Sandia National Labs., Albuquerque, NM (United States)

1996-10-01

387

Catalytic converter efficiency monitoring  

SciTech Connect

This patent describes a method for monitoring an internal combustion engine on-board catalytic converter efficiency. It comprises: establishing predetermined test entry conditions; transferring fuel control system input to an EGO sensor located downstream of a converter; measuring a characteristic of a first air/fuel ratio limit cycle with a first set of fuel controller parameters; changing fuel controller parameters; measuring a characteristic of a second air/fuel ratio limit cycle with a second set of fuel controller parameters; calculating a transport time delay and a time constant of a converter as a function of the first and second limit cycles; and determining catalytic converter efficiency from a predetermined catalytic efficiency characterized as a function of a transport time delay and a time constant.

Gopp, A.Y.

1992-10-27

388

Template Converter Program.  

National Technical Information Service (NTIS)

The computer program represents one of three FORTRAN IV programs necessary to generate perspective views of highways from design data. The Template Converter Program performs essentially a bookkeeping function for the Perspective Plot Program. It accepts ...

J. P. Penzien

1971-01-01

389

Wirephoto Standards Converter.  

National Technical Information Service (NTIS)

A standards converter that translates simultaneously between the United States and European wirephoto networks has been developed. Items of noncompatibility include picture duration, lines per minute, lines per inch, and scanning direction. The system ope...

D. E. Troxel W. F. Schreiber C. L. Seitz

1968-01-01

390

Cascaded thermionic converters  

NASA Astrophysics Data System (ADS)

A combination of experimental results and analytical work indicates the feasibility of a cascaded thermionic converter comprised of a barium-cesium stage with an emitter temperature of 2000 K and a cesium close-spaced stage with a collector temperature of 740 K having an overall lead efficiency of 27%. This cascaded converter has potential beneficial applications to space nuclear power, space terrestrial solar power and topping cycles in fossil or nuclear central stations.

Fitzpatrick, Gary O.; Allen, Daniel T.; McVey, John B.

1992-01-01

391

PDF to HTML Converter  

NSDL National Science Digital Library

If you're looking for a way to convert pdf files to html, this helpful application can do just that. Visitors just need to click the browse button here to locate the pdf that they wish to transfer. After doing this, they will supply their own email, and seconds later, they will have the converted file. This version is compatible with all operating systems.

2010-01-01

392

Analog to digital converter  

Microsoft Academic Search

An analog-to-digital converter, finding particular application in a multichannel pulse height analyzer, includes means for digitizing the analog input in two conversion steps. To digitize the input to 13 bits, a 7-bit digital to analog converter with a 7-bit up-down counter is used. During the first conversion step which is a coarse conversion, the input V sub i is compared

C. H. Lucas

1976-01-01

393

Transcutaneous battery charger using a half bridge SRC controlled by resonant current phase  

Microsoft Academic Search

A transcutaneous battery charger based on a half-bridge series resonant converter (SRC) and controlled by resonant current phase is presented. One of the main problems of these kind of converters is the large (and variable) air gap in the transformer. On the other hand, the batteries used are mainly Li+, due their energy density; the main problem of this kind

J. Diaz; J. M. Lopera; M. J. Prieto; A. Martin; J. A. Esteban

2002-01-01

394

Probabilistic-based Bridge Management Implemented at Skovdiget West Bridge  

Microsoft Academic Search

This paper describes the implementation of a probabilistic-based bridge management plan for the Skovdiget West Bridge, Denmark in 1998-99. Skovdiget West bridge is a 30 year old 220 m long post-tensioned concrete box-girder bridge with serious deterioration of both concrete, reinforcement and cables. By use of deterministic load carrying calculations combined with traditional lifetime estimates, the bridge would either require

F. M. JENSEN; A. KNUDSEN; I. ENEVOLDSEN; E. STOLTZNER; Niels Juels Gade

395

Build Your Bridge  

NSDL National Science Digital Library

These interactive learning modules and simulations allow students to explore the science, technology and people involved in building the New Bay Bridge, which is intended as a replacement for the historic San Francisco-Oakland Bay Bridge that was damaged in the 1989 Loma Prieta Earthquake. In the interactive module "Quake Country," students investigate plate tectonics as the driving force behind the faulting and resulting earthquakes in the Bay area. In the "Engineering for Earthquakes" simulation, students act as engineers, design their own bridges, and test them against the Maximum Credible Earthquake (MCE), the worst earthquake that might hit the Bay area every 1500 years. In the module "Two Miles and 2,000 Hands," students learn about the people who perform a large variety of jobs in building the new bridge.

396

CyberBridge  

NSDL National Science Digital Library

CyberBridge, a website from Harvard University, features tutorials and quizzes that teach concepts from AP Biology and AP Chemistry that are fundamental to success in introductory college or university life sciences courses.

Ernie Chang (Harvard University;Life Sciences); Amanda Simons (Harvard University;Life Sciences); Akiko Okusu (Harvard University;Life Sciences); Tara Mann (Harvard University;Life Sciences); Evan Lau (Harvard University;Life Sciences); Nancy Huang (Harvard University;Life Sciences)

2010-05-27

397

Bridging a cultural gap  

NASA Astrophysics Data System (ADS)

There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes—aimed at bridging the gap between high-school mathematics and tertiary mathematics—is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a potential bridging programme, this paper aims at demonstrating that the gap can be bridged, by presenting an ongoing modular bridging programme especially designed for the diverse types of student populations in teachers training colleges. We also present here some innovative teaching and assessment methods that were judged essential for the success of these programmes—focusing mainly on the "Questionnaire Based Instruction Method". Finally we suggest directions of follow up and research.

Leviatan, Talma

2008-09-01

398

Hillsboro Canal Bridge Monitoring.  

National Technical Information Service (NTIS)

This report describes the implementation of a testing and monitoring program for bridge 930338 in Belle Glade. Glass-fiber reinforced polymer (GFRP) deck panels and plates were installed over an existing steel superstructure using grouted steel studs. Thi...

A. P. Singh H. R. Hamilton J. L. McCall X. Peng

2011-01-01

399

DC\\/DC converter for high input voltage: four switches with peak voltage of Vin\\/2, capacitive turn-off snubbing and zero-voltage turn-on  

Microsoft Academic Search

A new four-switch full-bridge DC\\/DC converter topology is especially well-suited for power converters operating from high input voltage: it imposes only half of the input voltage across each of the four switches. The two legs of a full-bridge converter are connected in series with each other, across the DC input source, instead of the usual topology in which each leg

Ivo Barbi; Roger Gules; R. Redl; N. O. Sokal

1998-01-01

400

Bridge Management and Nondestructive Evaluation  

Microsoft Academic Search

The City and County of Denver (CCD) Public Works Department owns, inspects, and maintains 531 bridges in its inventory of which 264 are considered major structures spanning over 6.1 m in length. In this paper, a methodology using the CCD major bridge network for the application of nondestructive evaluation (NDE) methods in bridge inspections is explained. The methodology, called Bridge

Kevin L. Rens; Carnot L. Nogueira; David J. Transue

2005-01-01

401

A current-fed HF link direct DC\\/AC converter with active harmonic filter for fuel cell power systems  

Microsoft Academic Search

This paper describes a current-fed high frequency (HF) link direct DC\\/AC converter suitable for fuel cell power source. The proposed current-fed HF link direct DC\\/AC converter consists of a current-fed full-bridge inverter with an active harmonic filter, a HF link transformer, and a simple cycloconverter. The high frequency full-bridge inverter at the primary generates sinusoidally PWM modulated current pulses with

Yu Jin Song; Se-Kyo Chung; Prasad N. Enjeti

2004-01-01

402

A high-efficiency soft-switched AC\\/DC converter with current-doubler synchronous rectification  

Microsoft Academic Search

An improved ac\\/dc converter based on asymmetrical half-bridge topology is proposed in this paper. To substantially enhance the efficiency for low-voltage\\/high-current output applications, a current-doubler synchronous rectifier is combined with a modified asymmetrical half-bridge converter that retains the inherent zero-voltage-switching property. The power losses in the secondary rectification stage and the primary switches can be significantly reduced. The proposed architecture

Huang-Jen Chiu; Li-Wei Lin

2005-01-01

403

Vector generator scan converter  

DOEpatents

High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardware for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold. 7 figs.

Moore, J.M.; Leighton, J.F.

1988-02-05

404

A single-stage electronic ballast with emergency lighting features  

Microsoft Academic Search

This paper presents a single-stage electronic ballast with emergency lighting features. The ballast can function as a regular ballast, emergency ballast, battery charger or discharger and power failure detector, achieving regular and emergency lighting features. The single-stage converter used in the ballast is an integration of a bidirectional flyback converter and two half-bridge series-resonant parallel-loaded inverters. Derivation and operating principle

Y.-K. Chen; Y.-C. Wu; T.-F. Wu; Y.-E. Wu

2003-01-01

405

Fluorometer to spectrophotometer converter  

Microsoft Academic Search

A simple accessory has been constructed that will convert a standard laboratory spectrofluorometer into a spectrophotometer. This attachment fits within the sample compartment of a spectrofluorometer and consists of a cuvette holder, two mirrors, and two collimators. Light is redirected from the excitation lamp through the cuvette and then into the emission detector to measure absorbance instead of fluorescence. One

H. R. Garner

1996-01-01

406

4. VIEW OF SILVER BRIDGE (ST. MARY'S BRIDGE), CARRYING COUNTY ...  

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

4. VIEW OF SILVER BRIDGE (ST. MARY'S BRIDGE), CARRYING COUNTY ROAD OVER SOURIS RIVER NEAR SOUTH END OF REFUGE, LOOKING NORTHEAST - Upper Souris National Wildlife Refuge Dams, Souris River Basin, Foxholm, Ward County, ND

407

198. SPOUT RUN ARCH BRIDGE AND SPOUT RUN WESTBOUND BRIDGE ...  

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

198. SPOUT RUN ARCH BRIDGE AND SPOUT RUN WESTBOUND BRIDGE FROM POTOMAC RIVER LOOKING SOUTHWEST. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

408

22. BRIDGE CREEK BRIDGE, AVENUE OF THE GIANTS, OLD HIGHWAY ...  

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

22. BRIDGE CREEK BRIDGE, AVENUE OF THE GIANTS, OLD HIGHWAY 101. HUMBOLDT COUNTY, CALIFORNIA. LOOKING E. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

409

Full Range ZVS Phase Shifted Power Converter with \\  

Microsoft Academic Search

The study and development of a quasi-resonant power converter, with Full Bridge - PhaseShifted - Pulse Width Modulation (FB-PS-PWM) topology is presented. The originality of thepaper is the adding of resonant networks (poles) on each leg to get soft commutation (ZeroVoltage Switching ZVS) over the full range of the output current. The design of the polestructure and the component ratings

Frederick Bordry; A Dupaquier

1998-01-01

410

Bridge Types: Suspension Bridge Spans, Section AA; Cantilever Truss Spans, ...  

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

Bridge Types: Suspension Bridge Spans, Section A-A; Cantilever Truss Spans, Section B-B; Through Truss Spans, Section C-C; Deck Truss Spans, Section D-D - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

411

Application of a Modular Multilevel Cascade Converter (MMCC-SDBC) to a STATCOM  

NASA Astrophysics Data System (ADS)

This paper presents the application of a modular multilevel cascade converter based on single-delta bridge-cells (MMCC-SDBC) to a STATic synchronous COMpensator (STATCOM), particularly for negative-sequence reactive-power control. The SDBC is characterized by cascade connection of multiple single-phase H-bridge (or full-bridge) converter cells per leg, which facilitates flexible circuit design, low voltage steps, and low electro-magnetic interference (EMI) emissions. However, there is no published report on such a STATCOM with experimental verification or a control strategy. This paper designs, constructs, and tests a 100-V 5-kVA PWM STATCOM based on the SDBC with focus on the operating principle and performance. Experimental results confirm that this converter can control not only the positive-sequence reactive power but also the negative-sequence reactive power and low-frequency active power intended for the flicker compensation of arc furnaces.

Hagiwara, Makoto; Maeda, Ryo; Akagi, Hirofumi

412

Uncontrolled Concrete Bridge Parapet Cracking.  

National Technical Information Service (NTIS)

The Ohio Department of Transportation has recently identified the problem of wide-spread premature cracking of concrete bridge parapets throughout its District 12 region (Northeast Ohio). Many of the bridge decks that contain these prematurely cracked par...

A. Kalabon J. Bazzo N. Delatte

2013-01-01

413

New control scheme for AC-DC-AC converter without DC link electrolytic capacitor  

Microsoft Academic Search

A novel concept for a static three-phase to three-phase power converter for an AC motor drive with unity power factor and reduced harmonics on the utility line is presented. The power circuit consists of two back-to-back connected six-pulse bridges having only a 5-?F ceramic capacitor in the DC link. By controlling the active power balance between two bridges, the DC

J. S. Kim; S. K. Sul

1993-01-01

414

A Soft-Switched Three-Port Bidirectional Converter for Fuel Cell and Supercapacitor Applications  

Microsoft Academic Search

This paper presents a zero-voltage-switching (ZVS) three-port bidirectional converter for fuel cell and supercapacitor applications. A simple and effective method to extend the soft-switching range is proposed, especially for the three-port active-bridge topology. By continuously adjusting the duty cycle on the supercapacitor side H-bridge according to the supercapacitor voltage level, soft-switching conditions are achieved over the full operating range due

H. Tao; A. Kotsopoulos; J. L. Duarte; M. A. M. Hendrix

2005-01-01

415

A Data Selection System Based on Field-Programmable Gate Array in Cascaded Voltage Sourced Converter  

Microsoft Academic Search

There are many identical cascaded power units in voltage sourced converter (VSC) based on cascaded H-bridge or cascaded half-bridge, and the capacitor voltage balance is an important issue in them. The capacitor voltage in every power unit should be monitored on-line, which needs a versatile system to collect capacitor voltage. This paper proposes an on-line data collection system which can

Yuebin Zhou; Daozhuo Jiang; Jie Guo; Pengfei Hu

2012-01-01

416

7Level Medium Voltage Inverter System with PWM Converter for Regenerating Operation  

Microsoft Academic Search

In medium voltage drives, no standard converter topology exists to feed induction motors. So far, various topologies have been introduced to overcome limited voltage capacity of power switching devices. In market, Neutral Point Clamped(NPC) 3-level drives and H-Bridge cascaded multi-level drives are the main stream at high voltage and large capacity inverter drives. Power module, in H-Bridge cascaded multi-level topology,

Kwang-Seob Kim; Byung-Ki Kwon; Byung-Hun Yang; Chang-Ho Choi

417

High Input Voltage Step-Down DC-DC Converters for Integration in a Low Voltage CMOS Process  

Microsoft Academic Search

A cascode bridge circuit for monolithic switching DC- DC converters operating at high input voltages is pro- posed in this paper. The proposed circuit can also be used as an I\\/O buffer to interface circuits operating at signifi- cantly different voltages. The circuit technique permits the full integration of the active and passive devices of a switching DC-DC converter with

Volkan Kursun; Siva Narendra; Vivek De; Eby G. Friedman

2004-01-01

418

A 1.6 kW, 110 kHz DC-DC converter optimized for IGBTs  

Microsoft Academic Search

A full-bridge DC-DC converter using zero-current and zero-voltage switching techniques is described. This circuit utilizes the characteristics of the IGBT to achieve power and frequency combinations that are much higher than previously reported for this device. Experimental results are included for a 1.6 kW, 110 kHz converter with 95% efficiency

Keming Chen; Thomas A. Stuart

1991-01-01

419

A 1.6kW, 110kHz DC-DC converter optimized for IGBT's  

Microsoft Academic Search

A full bridge DC-DC power converter using a zero current and zero-voltage switching technique is described. This circuit utilizes the characteristics of the IGBT to achieve power and frequency combinations that are much higher than previously reported for this device. Experimental results are included for a 1.6 kW, 110 kHz converter with 95% efficiency

Keming Chen; Thomas A. Stuart

1993-01-01

420

Bridge Deck Drainage Guidelines.  

National Technical Information Service (NTIS)

The document presents criteria to determine if bridge drainage scuppers and drains are required. A design nomograph allows a rapid decision to be made. A key variable, design rain intensity, is analyzed: the rational method is reviewed and new methods for...

G. K. Young J. Phillippe S. J. Bellomo J. Normann W. E. Hughes

1986-01-01

421

Bridging the Gap?  

ERIC Educational Resources Information Center

|The political context of the conversion of the Historic Tramway Bridge, adjacent to Sandon Point in Bulli (NSW, Australia), and how this was exploited to serve predetermined ends, illustrates that technologies can be designed to have particular social (and political) effects. Through reflection on this relatively small engineering project, this…

Salter, Colin

2009-01-01

422

Virtual Bridge Design  

ERIC Educational Resources Information Center

|The West Point Bridge Design (WPBD) building project engages students in project-based learning by giving them a real-life problem to solve. By using technology, students are able to become involved in solving problems that they normally would not encounter. Involvement with interactive websites, such as WPBD, assists students in using…

Bisogno, Janet; JeanPierre, Bobby

2008-01-01

423

Bridging the Gap.  

ERIC Educational Resources Information Center

|Describes interdisciplinary activities with real-world applications ranging from science to mathematics to technology. Cites the study and construction of model bridges as a way for students to learn about engineering concepts and some of their relationships. States that the exercise enhanced teacher cooperation between the different fields. (RT)|

Kroto, Joseph J.

1988-01-01

424

Building Migratory Bridges  

ERIC Educational Resources Information Center

The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

Roy, Michael; Doss, Laurie K.

2007-01-01

425

Bridging a Cultural Gap  

ERIC Educational Resources Information Center

|There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes--aimed at bridging the gap between high-school mathematics and tertiary mathematics--is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a…

Leviatan, Talma

2008-01-01

426

Virtual Bridge Design  

ERIC Educational Resources Information Center

The West Point Bridge Design (WPBD) building project engages students in project-based learning by giving them a real-life problem to solve. By using technology, students are able to become involved in solving problems that they normally would not encounter. Involvement with interactive websites, such as WPBD, assists students in using…

Bisogno, Janet; JeanPierre, Bobby

2008-01-01

427

Design Squad: Suspension Bridge  

NSDL National Science Digital Library

In this video segment adapted from Design Squad—a PBS TV series featuring high school contestants tackling engineering challenges—students employ the concepts of tension and compression to build a suspension bridge without the aid of power tools.

Foundation, Wgbh E.

2007-08-09

428

Design Squad: Truss Bridge  

NSDL National Science Digital Library

In this video segment adapted from Design Squad—a PBS TV series featuring high school contestants tackling engineering challenges—students employ the concepts of tension and compression as they build a truss bridge without the aid of power tools.

Foundation, Wgbh E.

2007-08-09

429

The Bridge to Somewhere  

ERIC Educational Resources Information Center

|Since its inception in 2000, Pan-Asian American Community House's (PAACH's) education mission has bridged Asian-American studies to student life. PAACH initiatives have helped spread Asian-American diaspora to thousands of students at the University of Pennsylvania. They have also helped students determine for themselves what it means to be a…

Lum, Lydia

2009-01-01

430

CMOS Bridging Fault Detection  

Microsoft Academic Search

The authors compare the performance of two test generation techniques, stuck fault testing and current testing, when applied to CMOS bridging faults. Accurate simulation of such faults mandated the development of several new design automation tools, including an analog-digital fault simulator. The results of this simulation are analyzed. It is shown that stuck fault test generation, while inherently incapable of

Thomas M. Storey; Wojciech Maly

1990-01-01

431

Building Bridges to Reading.  

ERIC Educational Resources Information Center

Reading aloud to kindergarten children makes good educational sense. For this group, teachers should emphasize the aspects of reading aloud that promote a love of story listening as a bridge to future reading. To read aloud well, teachers should: (1) use stories with strong plots, vivid characters, and interesting settings; (2) select a book they…

Krolikowski, Sue

432

Building Migratory Bridges  

ERIC Educational Resources Information Center

|The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

Roy, Michael; Doss, Laurie K.

2007-01-01

433

Delaware Memorial Bridge  

Microsoft Academic Search

The Delaware Memorial Bridge was built in two spans. The first, completed in 1951, is on the left in this photograph, is now used to carry New Jersey bound traffic on Interstate Highway 295. Originally it carried traffic in both directions, but within a decade a second span was added because of large amounts of traffic from the newly constructed

Chet Smolski; Othmar Ammann

1970-01-01

434

JHU Bridge Designer  

NSDL National Science Digital Library

The Bridge Designer is a web-based program that allows the user to design and analyze 2-Dimensional statically determinate trusses. The user can specify support types (fixed or rolling) and locations, as well as the locations of various truss nodes and members.

Karweit, Michael

435

A Bridge to Consciousness  

ERIC Educational Resources Information Center

|Article describes how music, being a system of logical thought and a bridge to consciousness, can help the gifted child who cannot always handle his emotions in a culture where the function of the school in furthering the socialization process has been vastly oversold. (Author/MM)|

Vaughan, Margery M.

1972-01-01

436

BUILDING BRIDGES IN HEALTHCARE  

Microsoft Academic Search

or those who have not been in the Charleston area for several years, 2005 has marked the opening of a fabulous new span that links Charleston with Mount Pleasant. In mid July, the entire region turned out to stroll over the new bridges and celebrate their completion with a monumental fireworks display. The two dilapidated structures that had offered an

Bill Hueston

437

Evaluating vehicular-induced bridge vibrations for energy harvesting applications  

NASA Astrophysics Data System (ADS)

Highway bridges are vital links in the transportation network in the United States. Identifying possible safety problems in the approximately 600,000 bridges across the country is generally accomplished through labor-intensive, visual inspections. Ongoing research sponsored by NIST seeks to improve inspection practices by providing real-time, continuous monitoring technology for steel bridges. A wireless sensor network with a service life of ten years that is powered by an integrated energy harvester is targeted. In order to achieve the target ten-year life for the monitoring system, novel approaches to energy harvesting for use in recharging batteries are investigated. Three main sources of energy are evaluated: (a) vibrational energy, (b) solar energy, and (c) wind energy. Assessing the energy produced from vehicular-induced vibrations and converted through electromagnetic induction is the focus of this paper. The goal of the study is to process acceleration data and analyze the vibrational response of steel bridges to moving truck loads. Through spectral analysis and harvester modeling, the feasibility of vibration-based energy harvesting for longterm monitoring can be assessed. The effects of bridge conditions, ambient temperature, truck traffic patterns, and harvester position on the power content of the vibrations are investigated. With sensor nodes continually recharged, the proposed real-time monitoring system will operate off the power grid, thus reducing life cycle costs and enhancing inspection practices for state DOTs. This paper will present the results of estimating the vibration energy of a steel bridge in Texas.

Reichenbach, Matthew; Fasl, Jeremiah; Samaras, Vasilis A.; Wood, Sharon; Helwig, Todd; Lindenberg, Richard

2012-03-01

438

Construction of an Experimental Segmental Bridge.  

National Technical Information Service (NTIS)

Concrete segmental bridge construction seems to offer many advantages over other types of bridge construction both in bridge replacement programs and in new bridge programs. This report discusses the construction process of the experimental segmental brid...

R. M. McClure H. R. Thomas J. E. Kehler

1980-01-01

439

Cracks in Concrete Bridge Decks.  

National Technical Information Service (NTIS)

A study of cracks in bridge decks as reported in the literature and observed in NSW shows that certain types of cracks are predominant in particular bridge types. Cracks in composite bridges and in cast-in-place kerbs and cantilever deck slabs are shown t...

D. Campbell-Allen B. Lau

1978-01-01

440

Self-balancing resistance bridge  

Microsoft Academic Search

An automatically balanced resistance bridge with below-picowatt dissipation in the measured resistance has been developed. The bridge, capable of measuring resistances between 20 ? and 10 k? with an accuracy of 5%, was specifically designed to allow resistance measurements to be made at low temperatures without introducing an appreciable heat source to the cryostat. It consists of a Wheatstone bridge

Alvaro Kaplan; George O. Zimmerman; Dean S. Edmonds

1986-01-01

441

Fiber optic power converter  

NASA Astrophysics Data System (ADS)

High-efficiency, narrow-band fiber optic power converters have been produced under pilot line conditions. Power conversion efficiencies as high as 30 percent are obtained for devices illuminated with 50 mw from a 1060 nm Nd:YAG laser. The devices have an average power conversion efficiency in excess of 23 percent and fill factor greater than 74 percent. These devices can be used in remote locations to provide power for a variety of uses.

Eide, John; Mueller, Chip; Leonard, Ted

1989-09-01

442

Purplemath: Cancelling / Converting Units  

NSDL National Science Digital Library

This page contains a step-by-step tutorial in converting between units. It begins with one-step conversions, progressing to problems requiring multiple unit conversion. Areas of frequent student difficulty are given extra attention by the author, who presents the tutorial in an informal writing style designed to engage high school students. This tutorial is part of an award-winning collection of free resources developed to promote understanding and confidence in algebra.

Stapel, Elizabeth

443

Free FLV Converter  

NSDL National Science Digital Library

Taking Flash files from the web can be a bit cumbersome, so this application will definitely be a most welcome find. This free Flash converter (the second to last link on the left) allows users to take Flash files and transfer them to formats appropriate for portable devices and other items. The site is available in both French and English and this particular version is compatible with computers running Windows 2000, XP, 2003, and Vista.

2007-01-01

444

Electrothermodynamic (etd) power converter  

Microsoft Academic Search

These inventions relate to novel advances in Electrothermodynamics (ETD), also known as charged aerosol, heat\\/electric power generators: (1) A new more efficient, compact converging\\/diverging configuration comprising a torus of revolution (TORON) used with a gas flywheel. (2) A ''Method II'' two-fluid mixed flow ejector\\/converter in a gas flywheel loop employing a primary steam or a high molecular weight driver jet

1983-01-01

445

Multilevel converters -- A new breed of power converters  

SciTech Connect

Multilevel voltage source converters are emerging as a new breed of power converter options for high-power applications. The multilevel voltage source converters typically synthesize the staircase voltage wave from several levels of dc capacitor voltages. One of the major limitations of the multilevel converters is the voltage unbalance between different levels. The techniques to balance the voltage between different levels normally involve voltage clamping or capacitor charge control. There are several ways of implementing voltage balance in multilevel converters. Without considering the traditional magnetic coupled converters, this paper presents three recently developed multilevel voltage source converters: (1) diode-clamp, (2) flying-capacitors, and (3) cascaded-inverters with separate dc sources. The operating principle, features, constraints, and potential applications of these converters will be discussed.

Lai, J.S. [Oak Ridge National Lab., TN (United States). Engineering Technology Div.; Peng, F.Z. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States)

1995-09-01

446

A three-phase soft-switched high power density DC\\/DC converter for high power applications  

Microsoft Academic Search

The authors present three DC\\/DC converter topologies suitable for high-power-density high-power applications. All three circuits operate in a soft-switched manner, making possible a reduction in device switching losses and an increase in switching frequency. The three-phase dual-bridge converter proposed is seen to have the most favorable characteristics. This converter consists of two three-phase inverter stages operating in a high frequency

R. W. De Doncker; D. M. Divan; M. H. Kheraluwala

1988-01-01

447

A three-phase soft-switched high-power-density DC\\/DC converter for high-power applications  

Microsoft Academic Search

Three DC\\/DC converter topologies suitable for high-power-density high-power applications are presented. All three circuits operate in a soft-switched manner, making possible a reduction in device switching losses and an increase in switching frequency. The three-phase dual-bridge converter proposed is shown to have the most favorable characteristics. This converter consists of two three-phase inverter stages operating in a high-frequency six-step mode.

Rik W. A. A. De Doncker; Deepakraj M. Divan; Mustansir H. Kheraluwala

1991-01-01

448

A novel winding layout strategy for planar transformer applicable to high frequency high power DC-DC converters  

Microsoft Academic Search

High power isolated full bridge DC\\/DC converters are used widely in electric vehicles (EVs) and hybrid electric vehicles for battery charging purpose. Such DC\\/DC converters use planar magnetic components to minimize their size and weight and to increase their ability to withstand mechanical vibrations. Typical planar transformers (PT) in DC\\/DC converters have high inter-turn and inter-layer capacitances that cause them

Majid Pahlevaninezhad; Pritam Das; Josef Drobnik; Praveen Jain; Alireza Bakhshai; Gerry Moschopoulos

2011-01-01

449

A novel single stage step up\\/down AC\\/DC converter for small BLDC wind power generators  

Microsoft Academic Search

In this paper, a novel single stage step up\\/down AC\\/DC converter is proposed for small wind power BLDC generators. Basically, the proposed converter is derived by integrating a brushless DC generator (BLDCG), a full diode bridge, and a C'uk DC to DC converter to achieve same robustness as a traditional diode rectifier but without incurring large torque ripple trouble. Also,

Ching-Tsai Pan; Ting-Yu Chang; Emily Fang

2011-01-01

450

Analysis and design of a soft-switched and isolated bi-directional DC-DC converter  

Microsoft Academic Search

A new scheme adopting bi-directional converter is proposed to function both a DC-DC boost converter and a battery charger simultaneously in on-line UPS. The detail analysis of the proposed bi-directional soft-switched DC-DC full-bridged converter is given, this paper also gives the scheme of realizing soft-switching, the experimental setup is built and the results verify the feasibility of the proposed topology.

Lin Xinchun; Liu Fangrui; Duan shanxu; Kang Yong

2008-01-01

451

Thyristor converter simulation and analysis.  

National Technical Information Service (NTIS)

In this paper we present a simulation on thyristor converters. The simulation features nonlinearity, non-uniform firing, and the commutations. Several applications such as a current regulation, a converter frequency characteristics analysis, and a power l...

S. Y. Zhang

1991-01-01

452

Bridged ferrocenes. 10. Structural phenomena  

SciTech Connect

The structures of 1,1',2,2'-bis(tetramethylene)ferrocene, I, 1,1',2,2',4,4'-tris(tetramethylene)ferrocene, II, and 1,1',2,2',4,4'-tris(pentamethylene)ferrocene, III, are given and are compared to the previously determined structure of 1,1',2,2',4,4'-tris(trimethylene)ferrocene, IV. The iron-to-ring distances are consistent with the reported Moessbauer spectra and redox potentials. The cyclopentadienyl rings are eclipsed in the compounds with trimethylene and pentamethylene bridges but are staggered by 12-14 in the compounds with tetramethylene bridges. In compounds with tetra- and pentamethylene bridges the presence of staggering or eclipsing is attributed to the need to avoid eclipsing of the protons in the bridges. In the compound with three trimethylene bridges, the shortness of the bridges is of primary importance. The staggered conformation observed in I and II may be the source of the apparent anomalies observed in the ring-proton region of the NMR spectra of bridged ferrocenes. The bridge-proton region of the NMR spectra at 360 MHz are given for I and other bridged ferrocenes. Disorder of the bridge carbons observed in the crystals are correlated with the flipping of the bridges observed in the NMR spectra. 30 references, 8 tables.

Hillman, M.; Fujita, E.; Dauplaise, H.; Kvick, A.; Kerber, R.C.

1984-01-01

453

Model Predictive Control of Multilevel Cascaded H-Bridge Inverters  

Microsoft Academic Search

This paper presents a model predictive current control algorithm that is suitable for multilevel converters and its application to a three-phase cascaded H-bridge inverter. This control method uses a discrete-time model of the system to predict the future value of the current for all voltage vectors, and selects the vector which minimizes a cost function. Due to the large number

Patricio Cortes; Alan Wilson; Samir Kouro; Jose Rodriguez; Haitham Abu-Rub

2010-01-01

454

Cost of Impressed Current Cathodic Protection for Coastal Oregon Bridges  

SciTech Connect

The State of Oregon is using arc-sprayed zinc coatings for anodes in impressed current cathodic protection (ICCP) systems on reinforced concrete coastal bridges. The two lowest bids for four ICCP projects were averaged and converted to 1997 dollars. The total average cost for the ICCP projects was $51.63/ft2 ($555.51/m2) of protected concrete. The cathodic protection part of the ICCP projects average $14.08/ft2 ($151.47/m2), while zinc anode installation cost an average of $7.13/ft2 ($76.67/m2). Oregon's rugged and beautiful coastline is graced with a series of historical arched bridges designed by Conde B. McCullough. McCullough is the internationally recognized architect who designed many of the Oregon Coast Highway (U.S. 101) bridges in the 1920s and 1930s. Many are listed on the National Historic Register. After the expense ($45m) and public outcry associated with the replacement of the historic Alsea Bay Bridge in Waldport, Oregon, the Oregon Department of Transportation began using impressed current cathodic protection (ICCP) to extend the service life of reinforced concrete bridges. Figure 1 visually illustrates the need for such remediation. It shows exposed rebar from underneath the Brush Creek Bridge, which is very representative of the conditions found underneath many coastal Oregon bridges. Four ICCP projects have been funded, put out for bid, and completed. The four projects, their bid closing dates, and their completion dates are the Cape Creek Bridge (1990- 1992), the Yaquina Bay Bridge south arches (1991-1995), the Depoe Bay Bridge (1993-1997), and the Yaquina Bay Bridge south approach (1995-1997). The Cape Creek, Yaquina Bay, and Depoe Bay Bridges are shown in Figs. 2-4. Other ICCP projects are underway on the Oregon coast. In the ICCP systems, arc-sprayed zinc coatings on the concrete surface are anodes that protect the steel rebar. Accelerated laboratory studies at the Albany Research Center have predicted zinc anode service lives of approximately 27 years based on long-term bond strength measurements.1-3 Experience in California4 has documented zinc anode service lives of over 11 years. Both indicate a substantial savings in project costs compared to bridge replacement. For example, the replacement cost of the arc-sprayed sections of the three Oregon bridges is estimated to be $57m, while the four ICCP projects on those bridges have cost $20m. (The $45m to replace the Alsea Bay Bridge was more than simply the replacement cost--it included expanding the bridge to four lanes and making the bridge ''ICCP ready'' by ensuring electrically continuous rebar).

Holcomb, Gordon R.; Cryer, Curtis B.

1998-07-01

455

Climbing techniques for bridge inspection  

NASA Astrophysics Data System (ADS)

California has about 24,000 publicly owned bridges that require routine structural evaluations to comply with National Bridge Inspection Standard (NBIS) mandates. Of these, about 800 are identified as possessing fatigue prone or fracture critical details requiring thorough tactile investigations. Gaining access to bridge elements to perform these investigations has become increasingly difficult and costly. The traditional uses of under bridge inspection trucks, lift equipment and rigging are economically and practically limited by bridge size, structure type, traffic demands and support costs. In some cases, bridges that have become damaged by earthquakes cannot safely support the loads of heavy personnel lift equipment. The California Department of Transportation (Caltrans)'s Office of Structural Materials and Office of Structure Maintenance and Investigations evaluated the use of rock climbing and mountaineering techniques as an alternative means of gaining access for bridge inspections. Under a small research grant, a bridge climbing training course was developed through a local University of California outdoor recreation group and 7 engineers and technicians were initially trained. A comprehensive Code of Safe Practices was created and standards of training, procedures and equipment required for bridge inspections were established. A successful climb investigation on a large, previously inaccessible arch bridge was completed at the end of the training that proved the techniques safe, economical and effective. Within one year, 20 bridge maintenance engineers were trained, and a formal program was established to organize, schedule, equip and certify engineers and technicians for bridge climbing. Several other offices within Caltrans as well as the California Department of Water Resources have since adopted these techniques for specialized structural inspection tasks. Climbing techniques are now used routinely in California as an alterative means of gaining access to bridges and structures, and over 100 bridges have been identified as those where climbing is the only means available to perform structural investigations.

Kaslan, Erol C.

1998-03-01

456

Electrothermodynamic (etd) power converter  

SciTech Connect

These inventions relate to novel advances in Electrothermodynamics (ETD), also known as charged aerosol, heat/electric power generators: (1) A new more efficient, compact converging/diverging configuration comprising a torus of revolution (TORON) used with a gas flywheel. (2) A ''Method II'' two-fluid mixed flow ejector/converter in a gas flywheel loop employing a primary steam or a high molecular weight driver jet such as a fluorocarbon containing charged aerosol water droplets and a low molecular weight carrier gas such as hydrogen or helium with an electro-negative gas additive, in a Rankine cycle including a vapor/gas and liquid separator with a bypass to the ejector/converter loop. (3) A ''Method III'' two-fluid mixed flow comprising a supersonic jet expanding conically within a subsonic flow, separated by a boundary layer in which the charged aerosol forms downstream of the orifice, at a cross section of at least 100 times the orifice section; and in which the electric charge density of the charged aerosol decreases along the jet axis, whereby substantially all of the kinetic power of the jet is converted to electric power within the jet, there being no ejector. (4) An array of supersonic jets utilizing Method III. (5) An array of supersonic jets utilizing Method III without separating duct walls in which ''convection cells'' provide return flows, forming a plurality of TORON configurations. (6) A supercritical Rankline cycle in a single stage employing Method III. (7) A method IV two-fluid cycle uses charged aerosols in an inert gas and operates on an Ericsson-type cycle. (8) Optimum operating conditions are defined for Methods II, III, and IV. (9) A high potential emitter is employed with a grounded body, and a sapphire tube sealed to metal by a new technique provides an insulating duct for the high temperature, high pressure vapor.

Marks, A.M.

1983-07-26

457

Unidirectional energy converter  

SciTech Connect

Thermal energy is converted into rotational energy by using the expansion of a fluid medium to propel a plurality of pistons within at least one continuous, closed-loop passageway mounted on a rotatable platform. In at least one region of the passageway, the pistons must move inwardly against centrifugal force as the platform rotates. In at least one other region of the passageway, the pistons are moved outwardly under the influence of centrifugal force. Means are provided for imparting force to successive ones of the pistons to propel them against centrifugal force in said one region; while means are provided for converting the energy of pistons moving outwardly under the influence of centrifugal force in said other region into rotational energy. This rotational energy is used to drive gears mounted on the platform which mesh with a stationary gear carried beneath the platform to cause rotation of the platform about its rotational axis. The energy used to accelerate the pistons is thereby converted into rotational energy of the platform. In one embodiment of the invention, at least two continuous, closed-loop passageways are used on the platform in order to prevent an unbalanced condition. In another embodiment of the invention, a single passageway is used on the platform comprising two essentially straight portions on opposite sides of the axis of rotation of the platform interconnected at their opposite ends by curved portions, also on opposite sides of the axis of rotation of the platform. By forcibly rotating the platform in reverse, the invention can be used as a compressor.

Anno, J.N.; Fawcett, S.L.

1981-07-28

458

Plastic molded torque converter turbine  

Microsoft Academic Search

A turbine disposed within a torque converter is described, the torque converter disposed between an engine and a transmission within a vehicle, the turbine rotatively fixed to a converter output element, the turbine comprising: a hub, formed of ferrous material, including: a flange portion, having a first side and a second side, having a complement of projections protruding from the

R. R; T. E. Hojna

1993-01-01

459

Rupee Convertibility and Exit Policy  

Microsoft Academic Search

The successful of partial convertibility of rupee and adequate foreign reserves have boosted confidence of the government. It is more than likely that we are going to see a convertible rupee on trade account before the end of this year. In official quarters it is believed that fiscal imbalance is only stumbling block in the path of a fully convertible

Rastogi A B

460

BATS IN AMERICAN BRIDGES  

Microsoft Academic Search

Bridges and culverts were evaluated as bat roosting habitat in 25 U.S. states at elevations from sea level to 10,000 feet. Field surveys were conducted at 2,421 highway structures. Scientific literature was reviewed, and local biologists and engineers were interviewed, leading to the discovery of approximately 4,250,000 bats of 24 species living in 211 highway structures. Only one percent of

Brian W. Keeley; Merlin D. Tuttle

461

Build a Bridge  

NSDL National Science Digital Library

In this activity, learners use recycled materials to build a bridge that holds as many potatoes as possible. They investigate weight, height, strength, and measurement as they seek design solutions. The activity instructions include ways to adjust the level of challenge for learners of different ages. Try this at family events or to engage all ages. Available as a web page and a downloadable PDF. Students should have the ability to use tape and scissors.

2010-01-01

462

Bridge-NOAA Collection  

NSDL National Science Digital Library

The Bridge-NOAA Collection is a selection of exemplary resources from the National Oceanic and Atmospheric Administration (NOAA) that have been reviewed by educators and found to be well-suited for educational purposes. The collection also emphasizes professional-development opportunities for teachers. There is a strong focus on research data and its use in teaching. The collection provides educators with accurate and useful information on global, national, and regional ocean-science topics.

2007-10-19

463

Nanoparticle bridge DNA biosensor  

Microsoft Academic Search

A new DNA sensing method is demonstrated in which DNA hybridization events lead to the formation of nanoparticle satellites that bridge two electrodes and are detected electrically. The hybridization events are exclusively carried out only on specific locations, the surfaces of C-ssDNA modified 50 nm GNPs. The uniqueness of this work is that only a small number of T-ccDNA molecules

Hong-Wen Huang

2010-01-01

464

Bridging the gap  

Microsoft Academic Search

Engineers are applying the results of the scientific method to achieving solutions for real world problems. The QFT robust\\u000a design technique was utilized in this paper to illustrate how the bridging of the gap between the scientific and engineering\\u000a methods can be achieved. As an example, an aerospace firm has stated to Professor M. Grimble, University of Strathcldye, the\\u000a following:

C. Houpis

465

164 Currencies Converter  

NSDL National Science Digital Library

Olsen and Associates of Zurich, Switzerland, a "developer of online forecasting technology for business and finance" has made this simple and fun service available. Simply enter the amount of currency for any of 164 currencies, the currency to be converted to, and the date of the exchange rate (back to January 1, 1990, in day/month/year format) into an online form, and presto, an exchange rate (which is then reversible) is obtained. As this is a demonstration product, neither multiple currencies nor multiple dates are allowed. Users should also read the FAQ to understand why the rate they get might be slightly different from the one their bank advertises.

1997-01-01

466

Cycloidal Wave Energy Converter  

SciTech Connect

This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will exceed this initial performance estimates. In advancing the Technology Readiness Level (TRL) of this type of wave energy converter from 3 to 4, we find the CycWEC to exceed our initial estimates in terms of hydrodynamic performance. Once fully developed and optimized, it has the potential to not just outperform all other WEC technologies, but to also deliver power at a lower LCOE than competing conventional renewables like wind and solar. Given the large wave power resource both domestically and internationally, this technology has the potential to lead to a large improvement in our ability to produce clean electricity at affordable cost.

Stefan G. Siegel, Ph.D.

2012-11-30

467

Reduction of voltage stress in the full bridge BIBRED by duty ratio and phase shift control  

Microsoft Academic Search

A new control scheme is presented which provides simultaneous control of the output voltage and the energy storage capacitor voltage in the full-bridge boost integrated with buck rectifier\\/energy storage\\/DC-DC power converter (full-bridge BIBRED). The new control scheme solves the problem of wide voltage excursions for the energy storage capacitor voltage under variable load conditions. A low frequency, large signal AC

M. A. Johnston; R. W. Erickson

1994-01-01

468

Isolated half-bridge gate driver with integrated high-side supply  

Microsoft Academic Search

Half-bridge gate drivers have been widely used in a variety of applications, such as motor drives, power supplies, and plasma display panels. However, they are difficult to use because of the need for isolation and the need to provide isolated power supply for high-side gate drive. Here I will describe an isolated half-bridge gate driver with an integrated DC\\/DC converter

Baoxing Chen

2008-01-01

469

A novel SVM algorithm for reducing oscillations in cascaded H-bridge multilevel inverters  

Microsoft Academic Search

Cascaded H-bridge inverters have been selected as one of the preferred power converter topologies for high-voltage, high-power applications. However, undesired oscillations could occur in the H-bridge inverter drive system particularly under light load conditions, which would cause high voltage or current stress on the motor and inverter. In this paper, the mechanism of the oscillations is analyzed and a novel

Sanmin Wei; Bin Wu; R. Cheung

2003-01-01

470

Cascaded H-Bridge Multilevel Boost Inverter without Inductors for Electric\\/Hybrid Electric Vehicle Applications  

Microsoft Academic Search

\\u000a This paper presents a cascaded H-bridge multilevel boost inverter for electric vehicle (EV) and hybrid EV (HEV) applications\\u000a implemented without the use of inductors. Currently available power inverter systems for HEVs use a dc–dc boost converter\\u000a to boost the battery voltage for a traditional three-phase inverter. A cascaded H-bridge multilevel boost inverter design\\u000a for EV and HEV applications implemented without

S. Dhayanandh; A. P. Ramya Sri; S. Rajkumar; N. Lavanya

471

Control of cascaded H-bridge inverters using an FPGA-based platform  

Microsoft Academic Search

Cascaded H-bridge multilevel inverters are highly modular converters particularly suitable for generating high output voltages and connecting independent dc sources like solar arrays or fuel cells. Three-phase multilevel inverters based on cascaded H-bridge inverters require a large number of control signals, particularly if the number of levels is high. In this case, Field-Programmable Gate Array appears as the right solution

Emanuel C. Meireles; Antonio P. Martins

2011-01-01

472

DC link balancing and ripple compensation for a cascaded-H-bridge using space vector modulation  

Microsoft Academic Search

This paper presents a modulation scheme for the cascaded H-bridge multi-level converter based on space vector modulation. The method is modified from other implementations in two ways. Switching states are chosen to keep the d.c. link voltages on each bridge equal and a modified co-ordinate transformation is employed to compensate for d.c. link voltage ripple. A constraint for minimal switching

John Vodden; Pat Wheeler; Jon Clare

2009-01-01

473

High-power galvanically isolated DC\\/DC converter topology for future automobiles  

Microsoft Academic Search

This paper presents a 2 kW three-phase dual active bridge converter (DAB3) which converts power between 42 V and 300 V and is easily scalable up to 20 kW. The DAB3 has been selected for this application based on detailed simulations comparing different suitable topologies. The circuits investigated in this paper can operate in a soft-switching manner enabling a reduction

Jorg Walter; Rik W. De Doncker

2003-01-01

474

An improved soft-switching PWM FB DC\\/DC converter for reducing conduction losses  

Microsoft Academic Search

An improved soft-switching topology of a full-bridge (FB) pulsewidth-modulated (PWM) DC\\/DC converter is described. The new topology employs an energy-recovery snubber to minimize a circulating current flowing through the transformer and switching devices. By using an energy-recovery snubber instead of adding a tapped inductor and a saturable reactor to reduce RMS current stress, the converter achieves zero-current switching (ZCS) for

Eun-Soo Kim; Kee-Yeon Joe; Moon-Ho Kye; Yoon-Ho Kim; Byung-Do Yoon

1999-01-01

475

A Novel Control Scheme for Current-Source-Converter-Based PMSG Wind Energy Conversion Systems  

Microsoft Academic Search

A novel control scheme for permanent-magnet synchronous generator is proposed in this paper, where a current-source converter is employed as the bridge between the generator and the grid for high-power wind energy conversion systems. In these medium voltage (2.3-13.8 kV) level applications, current-source converters not only have inherent advantages, but also present some challenges for controller design due to the

Jingya Dai; Bin Wu

2009-01-01

476

Sinusoidal line current rectification at unity power factor with boost quasi-resonant converters  

Microsoft Academic Search

A sinusoidal line current rectifier is considered at unity power factor, where the conventional boost converter, usually utilized between the diode rectifier bridge and the DC bus capacitor, is replaced with a boost zero-current switching quasi-resonant converter (boost ZCS-QRC). The zero-current switching quasi-resonant rectifier (ZCS-QRR) is analyzed theoretically. Normalized curves are plotted, and equations that allow high flexibility in design

Ivo Barbi; S. A. Oliveira da Silva

1990-01-01

477

The three-level ZVS-PWM DC-to-DC converter  

Microsoft Academic Search

A novel high-frequency DC-to-DC power converter for high voltage and high power is introduced which features zero voltage switching (ZVS), operation at constant frequency, regulation by pulse width modulation (PWM), and low RMS current stress upon power switches. Its greatest attribute, in comparison with the full-bridge (FB-ZVS-PWM) converter, is that the voltage across the switches is half of the input

J. R. Pinheiro; I. Barbi

1993-01-01

478

Low-loss DC to AC converter system for stand alone photovoltaic applications  

Microsoft Academic Search

A composite converter with a high-frequency link was investigated for stand alone DC-to-AC-conversion applications such as batteries charged by photovoltaic panels. The secondary converter was a supply-commutated high-frequency bridge, while the primary inverter was investigated further. A center-tap transformer inverter was chosen, and two approaches were used to minimize switching losses. The first approach was to implement regenerative snubbers. The

C. J. Simpson; J. D. van Wyk; J. J. Schoeman

1992-01-01

479

Converting Biomass to Products  

SciTech Connect

For nearly 30 years, PNNL has been developing and applying novel thermal, chemical and biological processes to convert biomass to industrial and consumer products, fuels and energy. Honors for technologies resulting from this research include the Presidential Green Chemistry Award and several Federal Laboratory Consortium and R&D 100 Awards. PNNL’s research and development activities address the complete processing scheme, from feedstock pretreatment to purified product recovery. The laboratory applies fundamental science and advanced engineering capabilities to biomass conversion and processing to ensure effective recovery of optimal value from biomass; carbohydrate polymer systems to maximize energy efficiencies; and micro-technology systems for separation and conversion processes. For example, bioproducts researchers in the laboratory’s Institute for Interfacial Catalysis develop and demonstrate the utility of new catalyst formulations for production of bio-based chemicals. This article describes a sampling of current and recent catalysis projects for biomass conversion.

Graybeal, Judith W.

2006-06-01

480

Ion bridges in microfluidic systems  

Microsoft Academic Search

Recently many microfluidic systems are increasingly equipped with functional units for ionic controls for various applications.\\u000a In this review article, we define an ion bridge as a structure that controls current or distribution of ions in a microfluidic system, and summarize the ion bridges in the\\u000a literature in terms of characteristics, fabrication methods, advantages and disadvantages. The ion bridges play

Taek Dong Chung; Hee Chan Kim

2009-01-01

481

EARTHQUAKE RESPONSE OF SUSPENSION BRIDGES  

Microsoft Academic Search

Suspension bridges represent critical nodes of major transportation systems. Bridge failure during strong earthquakes poses\\u000a not only a threat of fatalities but causes a substantial interruption of emergency efforts. Although wind induced vibrations\\u000a have historically been the primary concern in the design of suspension bridges, earthquake effects have also gained importance\\u000a in recent decades. This study involves ambient vibration testing

Mustafa Erdik; Nurdan Apayd?n

482

Field Performance of Timber Bridges  

Microsoft Academic Search

Abstract In September 1989, the Ciphers bridge was constructed within the Beltrami Island State Forest in Roseau County, Minnesota. The bridge superstructure is a two-span continu- ous stress-laminateddeck that is approximately12.19 m long, 5.49 m wide, and 305 mm deep (40 ft long, 18 ft wide, and 12 in. deep). The bridge is one of the first to utilize red pine

Stress-Laminated Deck Bridge; Michael A. Ritter; Paula D. Hilbrich Lee; Gregory J. Porter; Richard Hebert

483

Digital generator assisted impedance bridge  

Microsoft Academic Search

A manually-operated prototype wide-range four-terminal-pair universal impedance bridge has been constructed in order to test ideas for an automated bridge. The least relative uncertainty is 2×10-5 at 1 kHz and about 20×10-5 at 100 kHz. A two-phase digital voltage generator provides convenient sources for the two voltages required to bring the bridge to near but not exact balance. The detector

A. C. Corney

2002-01-01

484

Virtual Bridge Design  

NSDL National Science Digital Library

The West Point Bridge Design (WPBD) building project engages students in project-based learning by giving them a real-life problem to solve. By using technology, students are able to become involved in solving problems that they normally would not encounter. Involvement with interactive websites, such as WPBD, assists students in using higher-level thinking skills and problem solving (NSTA 2006). It is important that we keep our students engaged in learning science, as the scientific society of tomorrow depends upon the science students of today.

Jeanpierre, Bobby; Bisogno, Janet

2008-09-01

485

West Point Bridge Design Contest  

NSDL National Science Digital Library

The second annual West Point Bridge Design Contest concluded in May 2003. Although it is uncertain whether the contest will receive funding for future competitions, its Web site has a number of educational resources for middle and high school students. The main feature is the bridge design software, which allows the user to "model, test, and optimize a steel highway bridge, based on realistic specifications, constraints, and performance criteria." Completed designs can be submitted online for unofficial judging. The book, Designing and Building File-Folder Bridges, can also be freely downloaded. [CL

486

47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.  

Code of Federal Regulations, 2011 CFR

...Telecommunication 5 2011-10-01 2011-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section...SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge Act § 80.1007...

2011-10-01

487

47 CFR 80.331 - Bridge-to-bridge communication procedure.  

Code of Federal Regulations, 2012 CFR

...Telecommunication 5 2012-10-01 2012-10-01 false Bridge-to-bridge communication procedure. 80.331 Section 80...Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a)...

2012-10-01

488

47 CFR 80.331 - Bridge-to-bridge communication procedure.  

Code of Federal Regulations, 2011 CFR

...Telecommunication 5 2011-10-01 2011-10-01 false Bridge-to-bridge communication procedure. 80.331 Section 80...Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a)...

2011-10-01

489

47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.  

Code of Federal Regulations, 2012 CFR

...Telecommunication 5 2012-10-01 2012-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section...SERVICES Radiotelephone Installations Required by the Bridge-to-Bridge Act § 80.1007...

2012-10-01

490

77 FR 53251 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation  

Federal Register 2010, 2011, 2012, 2013

...Annual Materials Report on New Bridge Construction and Bridge Rehabilitation AGENCY...Federal Register a report describing construction materials used in new Federal-aid bridge construction and bridge rehabilitation...

2012-08-31

491

76 FR 55160 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation  

Federal Register 2010, 2011, 2012, 2013

...Annual Materials Report on New Bridge Construction and Bridge Rehabilitation AGENCY...Federal Register a report describing construction materials used in new Federal-aid bridge construction and bridge rehabilitation...

2011-09-06

492

75 FR 62181 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation  

Federal Register 2010, 2011, 2012, 2013

...Annual Materials Report on New Bridge Construction and Bridge Rehabilitation AGENCY...Federal Register a report describing construction materials used in new Federal-aid bridge construction and bridge rehabilitation...

2010-10-07

493

1. GENERAL VIEW OF LIFT BRIDGE FROM 18TH STREET BRIDGE, ...  

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

1. GENERAL VIEW OF LIFT BRIDGE FROM 18TH STREET BRIDGE, LOOKING SOUTHWEST. - Pennsylvania Railroad, South Branch Chicago River Bridge, Spanning South Branch of Chicago River Bridge east of Canal Street, Chicago, Cook County, IL

494

Single stage AC\\/DC converter with input power factor correction  

Microsoft Academic Search

The full-bridge converter with isolation transformer is the preferred topology for medium and high power SMPS. A simple topology modification, i.e. the addition of two input inductors, and appropriate control methods permit to control simultaneously and accurately the output voltage and the input current, performing a new single stage SMPS. The circuit behaviour is strongly dependent on the output power

Victor Anunciada; Hugo Ribeiro

2003-01-01

495

Analysis, Design, and Experimentation of a Double Forward Converter With Soft Switching Characteristics for All Switches  

Microsoft Academic Search

The study of a topology resulting from the combina- tion of two forward structures attached to a single transformer core is presented in this paper, as a dual active bridge converter is obtained. In order to reduce the switching losses and the elec- tromagnetic interference, a soft commutation cell, which provides zero-voltage commutation of the main switches for the entire

Demercil de Souza Oliveira Jr.; Carlos Elmano de Alencar e Silva; René Pastor Torrico-Bascopé; Fernando Lessa Tofoli; Carlos Augusto Bissochi Jr.; João Batista Vieira Jr.; Valdeir José Farias; Luiz Carlos de Freitas

2011-01-01

496

Influence of the modulation method on the conduction and switching losses of a PWM converter system  

Microsoft Academic Search

The authors explore the dependency of the conduction losses of a bridge leg of a pulsewidth modulation (PWM) power converter system with a high pulse rate on the shape of the phase modulation functions. This is done for modulation methods that are optimized with respect to minimum harmonic current RMS values. The results are compared to the results gained for

Johann W. Kolar; Hans Ertl; Franz C. Zach

1991-01-01

497

Harmonic Propagation in Power Lines due to Converter Loads and Nonlinear Resistors  

Microsoft Academic Search

This paper describes the propagation of harmonic voltages and currents, generated by solid state power converters and nonlinear resistive loads in power systems. After establishing accurate harmonic models for a six pulse bridge rectifier and a nonlinear resistor supplied from non sinusoidal sources, a harmonic power flow technique, \\

J. P. Tamby; V. I. John

1986-01-01

498

An expert system for concrete bridge management  

Microsoft Academic Search

The importance of bridge repair versus new bridge construction has risen in recent decades due to high deterioration rates that have been observed in these structures. Budgets both for building new bridges and keeping the existing ones are always limited. To help rational decision-making, bridge management systems are presently being implemented by bridge authorities in several countries. The prototype of

P. Thoft-Christensen; J. D. Sørensen; J SORENSEN

1997-01-01

499

Extended bridge algorithms for large networks  

Microsoft Academic Search

A network bridge is a device that operates at the ISO data link level and routes packets across extended networks, commonly composed of multiple local area networks (LANs) and bridges. A set of algorithms that greatly extends the application of the network bridge is presented. This multitree bridge algorithm allows networks of arbitrary topology and capacity to use bridge routing.

W. D. Sincoskie; C. J. Cotton

1988-01-01

500

5. North side of throughtruss bridge over railroad tracks (bridge ...  

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

5. North side of through-truss bridge over railroad tracks (bridge #U182512605). View to southwest. - South Omaha Union Stock Yards, "O" Street Viaduct, "O" Street Spanning Hog Pens; South Omaha Terminal Railway Company Tracks & Union Pacific Railroad Tracks, Omaha, Douglas County, NE