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Showing papers on "Precision rectifier published in 2012"


Journal ArticleDOI
TL;DR: In this article, a finite control set model predictive controller for closed-loop control of an active front-end rectifier is presented, which operates in discrete time and does not require additional modulators.
Abstract: In this paper, a finite control set model predictive controller for closed-loop control of an active front-end rectifier is presented. The proposed method operates in discrete time and does not require additional modulators. The key novelty of the control algorithm presented lies in the way dynamic references are handled. The control strategy is capable of providing suitable references for the source active power and the rectified voltage, without requiring additional control loops. Experimental results show that fast and accurate tracking of dynamic dc voltage and reactive power references can be achieved, while respecting the restrictions on maximum power levels of the rectifier.

219 citations


Journal ArticleDOI
TL;DR: In this article, a theoretical analysis of harmonically terminated high-efficiency power rectifiers and experimental validation on a single Schottky-diode rectifier and a class-F-1 GaN transistor rectifier are presented.
Abstract: This paper presents a theoretical analysis of harmonically terminated high-efficiency power rectifiers and experimental validation on a class-C single Schottky-diode rectifier and a class- F-1 GaN transistor rectifier. The theory is based on a Fourier analysis of current and voltage waveforms, which arise across the rectifying element when different harmonic terminations are presented at its terminals. An analogy to harmonically terminated power amplifier (PA) theory is discussed. From the analysis, one can obtain an optimal value for the dc load given the RF circuit design. An upper limit on rectifier efficiency is derived for each case as a function of the device on-resistance. Measured results from fundamental frequency source-pull measurement of a Schottky diode rectifier with short-circuit terminations at the second and third harmonics are presented. A maximal device rectification efficiency of 72.8% at 2.45 GHz matches the theoretical prediction. A 2.14-GHz GaN HEMT rectifier is designed based on a class-F-1 PA. The gate of the transistor is terminated in an optimal impedance for self-synchronous rectification. Measurements of conversion efficiency and output dc voltage for varying gate RF impedance, dc load, and gate bias are shown with varying input RF power at the drain. The rectifier demonstrates an efficiency of 85% for a 10-W input RF power at the transistor drain with a dc voltage of 30 V across a 98-Ω resistor.

187 citations


Journal ArticleDOI
TL;DR: In this paper, an efficiency-optimized, 98.8% efficient, 5-kW three-phase buck-type PFC rectifier with 400-V output is presented.
Abstract: In telecom applications, the vision for a total power conversion efficiency from the mains to the output of point-of-load (PoL) converters of 95% demands optimization of every conversion step, i.e., the power factor correction (PFC) rectifier front-end should show an outstanding efficiency in the range of 99%. For recently discussed 400-V dc distribution bus voltages, a buck-type PFC rectifier is a logical solution. In this paper, an efficiency-optimized, 98.8% efficient, 5-kW three-phase buck-type PFC rectifier with 400-V output is presented. Methods for calculating losses of all components are described and are used to optimize the converter design for efficiency at full load. Special attention is paid to semiconductor losses, which are shown to be dominant, with the parasitic device capacitance losses being a significant component. The calculation of these parasitic capacitance losses is treated in detail, and the charge-balance approach used is verified. A prototype of the proposed rectifier is constructed which verifies the accuracy of the models used for loss calculation and optimization.

177 citations


Journal ArticleDOI
TL;DR: A new full-wave CMOS rectifier dedicated for wirelessly-powered low-voltage biomedical implants using bootstrapped capacitors to reduce the effective threshold voltage of selected MOS switches achieves a significant increase in its overall power efficiency and low voltage-drop.
Abstract: We present, in this paper, a new full-wave CMOS rectifier dedicated for wirelessly-powered low-voltage biomedical implants. It uses bootstrapped capacitors to reduce the effective threshold voltage of selected MOS switches. It achieves a significant increase in its overall power efficiency and low voltage-drop. Therefore, the rectifier is good for applications with low-voltage power supplies and large load current. The rectifier topology does not require complex circuit design. The highest voltages available in the circuit are used to drive the gates of selected transistors in order to reduce leakage current and to lower their channel on-resistance, while having high transconductance. The proposed rectifier was fabricated using the standard TSMC 0.18 μm CMOS process. When connected to a sinusoidal source of 3.3 V peak amplitude, it allows improving the overall power efficiency by 11% compared to the best recently published results given by a gate cross-coupled-based structure.

126 citations


Proceedings ArticleDOI
17 Jun 2012
TL;DR: In this paper, an improved analytical model for diode efficiency in microwave rectifier is presented, which provides a simple calculation routine to determine the input power level at which the peak reverse voltage across the diode starts to exceed the DV voltage when the DV efficiency starts to decrease.
Abstract: In this paper, an improved analytical model for diode efficiency in microwave rectifier is presented. This model provides a simple calculation routine to determine the input power level at which the peak reverse voltage across the diode starts to exceed the diode breakdown voltage when the diode efficiency starts to decrease. After studying the origins of the power losses in a shunt connected diode rectifier carefully, closed-form equations are derived to calculate the diode efficiencies at various input power levels. A 2.45 GHz microwave rectifier is designed and measured. The experimental results agree well with the proposed model prediction.

115 citations


Proceedings ArticleDOI
09 Mar 2012
TL;DR: In this paper, a buck-type unity power factor rectifier is proposed for high-power electric vehicle battery charging mains interfaces, which is based on the Swiss Rectifier.
Abstract: This paper introduces a novel three-phase buck-type unity power factor rectifier appropriate for high power Electric Vehicle battery charging mains interfaces. The characteristics of the converter, named the Swiss Rectifier, including the principle of operation, modulation strategy, suitable control structure, and dimensioning equations are described in detail. Additionally, the proposed rectifier is compared to a conventional 6-switch buck-type ac-dc power conversion. According to the results, the Swiss Rectifier is the topology of choice for a buck-type PFC. Finally, the feasibility of the Swiss Rectifier concept for buck-type rectifier applications is demonstrated by means of a hardware prototype.

93 citations


Journal ArticleDOI
TL;DR: In this article, an active full-bridge rectifier is proposed for PE vibration energy harvesting systems, which solves the dc-offset problem of comparator-based active diode, minimizes the voltage drop along the conduction path, and extracts more power from the transducer, all of which lead to better power extraction and conversion capability.
Abstract: In this letter, a highly efficient active full-bridge rectifier is proposed for piezoelectric (PE) vibration energy harvesting systems. By replacing the passive diodes with an operational amplifier-controlled active counterpart and adding a switch in parallel with the transducer, the proposed rectifier solves the dc-offset problem of the comparator-based active diode, minimizes the voltage drop along the conduction path, and extracts more power from the transducer, all of which lead to better power extraction and conversion capability. The proposed rectifier, implemented in 0.18-μm CMOS technology, shows 90% power conversion efficiency and 81 μW output power, with values corresponding to 1.5 times and 3.4 times the values for a conventional full-bridge rectifier.

78 citations


Journal ArticleDOI
TL;DR: In this article, the authors proposed a current-driving scheme for a synchronous rectifier (SR) in an LLC resonant converter with a voltage-doubler rectifier.
Abstract: This paper proposes a current-driving scheme for a synchronous rectifier (SR) in an LLC resonant converter with a voltage-doubler rectifier. In the proposed scheme, only one current transformer (CT) with one secondary winding is used to drive two SRs in the voltage-doubler rectifier. Also, the sensed current from the CT can be fed to the output with an energy-recovery circuit. Compared to the conventional center-tapped rectifier, the CT count for the SR drive circuit is reduced, which saves both cost and space. Although the current rating of the SR in the voltage-doubler rectifier is doubled, the voltage rating is well reduced and a lower voltage rating device with lower ON-state resistance can be used to compensate the increased current rating. Furthermore, the SR voltage stress is well clamped to the output voltage under any condition which improves the reliability of the circuit. A prototype with 16 V/5.6 A output was built to verify the theoretical analysis.

78 citations


Journal ArticleDOI
TL;DR: The proposed AGC consists of a folded Gilbert variable gain amplifier, a dc offset canceller, inductorless post amplifiers, a linear open-loop peak detector, an integrator, a symmetrical exponential voltage generator, and a compensation block for temperature stability.
Abstract: This paper presents an automatic gain control (AGC) amplifier with temperature compensation for high-speed applications. The proposed AGC consists of a folded Gilbert variable gain amplifier (VGA), a dc offset canceller, inductorless post amplifiers, a linear open-loop peak detector (PD), an integrator, a symmetrical exponential voltage generator, and a compensation block for temperature stability. The novel temperature compensation scheme ensures the AGC stability and accuracy over -20°C-200°C by predicting the integrator biasing voltage based on the crucial blocks duplication technique. The proposed linear open loop PD combined with the linear-in-dB VGA manages the dB-linear error of less than 0.3 dB for the received signal strength indication (RSSI). The AGC chip is fabricated using a 0.13-μm SiGe BiCMOS technology. Consuming a power of 72 mW from a 1.2-V supply voltage, the fabricated circuit exhibits a voltage gain of 40 dB and a 3-dB bandwidth of 7.5 GHz. With a 215 - 1 pseudo-random bit sequence at 5-Gb/s, the measured peak-to-peak jitter is less than 40pspp across the -20°C-200°C temperature range. The low linear-in-dB error and the wide operating temperature range achieving the high-speed data input signal indicate the suitability of the proposed techniques for high-speed AGC amplifiers.

74 citations


Patent
17 May 2012
TL;DR: In this paper, an apparatus and method of protecting a power receiver of a wireless power transmission system is presented. But the authors do not specify the mechanism to protect the rectifier and/or the capacitor.
Abstract: An apparatus and method of protecting a power receiver of a wireless power transmission system are provided. A wireless power receiver includes a rectifier comprising an input and an output, and configured to receive a signal through the input, to rectify the signal to produce a rectified signal, and to output the rectified signal through the output, and a capacitor connected to the output of the rectifier and to ground. The wireless power receiver further includes a direct current-to-direct current (DC/DC) converter connected to the output of the rectifier and to a load, and configured to convert the rectified signal to a power, and to provide the power to the load, and a device configured to create a short circuit to protect the rectifier and/or the capacitor when a voltage greater than a threshold voltage is applied to the input of the rectifier and/or the output of the rectifier.

71 citations


Patent
Mingde Pan1, Weiqi Ding, Sergey Shumarayev, Peng Li, Masashi Shimanouchi 
31 Jan 2012
TL;DR: In this article, a receiver circuit for multi-level amplitude signaling with at least three amplitude levels for each symbol period is described. But the receiver circuit includes a peak detector, a reference voltage generator, and a comparator circuit, and the peak detector is arranged to detect a peak voltage of the multilevel amplitude signal.
Abstract: One embodiment relates to a receiver circuit for multi-level amplitude signaling which includes at least three amplitude levels for each symbol period. The receiver circuit includes a peak detector, a reference voltage generator, and a comparator circuit. The peak detector is arranged to detect a peak voltage of the multi-level amplitude signal, and the reference voltage generator uses the peak voltage to generate multiple reference voltages. The comparator circuit uses the multiple reference voltages to detect an amplitude level of the multi-level amplitude signal. Other embodiments and features are also disclosed.

Journal ArticleDOI
TL;DR: It is shown that the three-phase -switch rectifier (comprising three -connected bidirectional switches) is well suited for this application and a novel PWM current controller modulation concept is presented, where all three phases are controlled simultaneously.
Abstract: In the course of the More Electric Aircraft program frequently active three-phase rectifiers in the power range of several kilowatts are required. It is shown that the three-phase -switch rectifier (comprising three -connected bidirectional switches) is well suited for this application. The system is analyzed using space vector calculus and a novel PWM current controller modulation concept is presented, where all three phases are controlled simultaneously; the analysis shows that the proposed concept yields optimal switching sequences. Analytical relationships for calculating the power components average and rms current ratings are derived to facilitate the rectifier design. A laboratory prototype with an output power of 5 kW is built and measurements taken from this prototype confirm the operation of the proposed current controller. Finally, initial EMI-measurements of the system are also presented.

Journal ArticleDOI
TL;DR: An inherent shortcoming of rectifiers designed using standard CMOS devices is poor low input power performance but it is shown that this can be overcome through the use of intrinsic devices with close to zero-threshold voltage available in a 0.25 μm silicon-on-sapphire CMOS process.
Abstract: An inherent shortcoming of rectifiers designed using standard CMOS devices is poor low input power performance. It is shown that this can be overcome through the use of intrinsic devices with close to zero-threshold voltage available in a 0.25 μm silicon-on-sapphire (SOS) CMOS process. A novel complementary bridge rectifier structure based on a combination of cross-connected and diode bridge rectifier topologies is introduced to avoid the excessive leakage current incurred through the use of intrinsic devices. A design strategy which maximizes efficiency and produces an input impedance which will interface well with the inductive coil type antennas used in biomedical implants is presented for this new rectifier type. The fabricated rectifier achieves a 1 μW DC output power for an input power of -26.5 dBm at 100 MHz. A peak measured power conversion efficiency of 67% is achieved at 100 MHz, but more importantly >;30% PCE is attained for a wide output power range which reaches as low as -40 dBm. At the target 1 μW output power a PCE of 44% was achieved.

Journal ArticleDOI
TL;DR: In this paper, a hybrid driving scheme for full-bridge-type synchronous rectifier (SR) in LLC resonant dc/dc converter is proposed, which combines voltage-driving and current-driving methods to drive the SRs with simple circuit structure.
Abstract: The LLC resonant converter with a full-bridge rectifier can achieve two balanced outputs with a simple balancing capacitor, which is quite attractive for LED driver application. To further improve the efficiency, synchronous rectification is an effective way to reduce the conduction loss of the rectifier. In this paper, a new hybrid driving scheme for full-bridge-type synchronous rectifier (SR) in LLC resonant dc/dc converter is proposed. The proposed hybrid driving scheme combines voltage-driving method and current-driving method to drive the SRs with simple circuit structure. The high-side SRs are driven by one auxiliary winding of the transformer and the low-side SRs are driven by a current transformer with only one secondary winding. Furthermore, the proposed method can be operated in discontinuous conduction mode and continuous conduction mode conditions. The detailed operation principles and design considerations are presented. Finally, the experimental results from a 200-kHz 100-W prototype verify the theoretical analysis.

Journal ArticleDOI
TL;DR: Steady-state and transient analyses of the rectifier with the diode described by an exponential I-V characteristic are presented and formulas for the dc output voltage level, the output voltage ripple, and the power conversion efficiency are provided.
Abstract: This paper describes a simple analytical model of the rectifier circuit valid down to very low voltage operation (input voltage below the thermal voltage). Steady-state and transient analyses of the rectifier with the diode described by an exponential I-V characteristic are presented. We provide formulas for the dc output voltage level, the output voltage ripple, and the power conversion efficiency. We also give a compact expression for the charging time of the load capacitor. The models of the rectifier and the voltage doubler for input voltages down to the thermal voltage are verified with simulations and measurements using circuits built with off-the-shelf 1N4148 diodes.

Proceedings ArticleDOI
Fan Xu1, Ben Guo1, Leon M. Tolbert1, Fred Wang1, B. J. Blalock1 
09 Mar 2012
TL;DR: In this paper, the switching characteristics of a 1200 V, 33 A SiC MOSFET and a SiC schottky barrier diode (SBD) were tested by a double pulse test (DPT) based on a current-source structure at voltage levels up to 680 V and current up to 20 A.
Abstract: This paper presents the characteristics of a 1200 V, 33 A SiC MOSFET and a 1200 V, 60 A SiC schottky barrier diode (SBD). The switching characteristics of the devices are tested by a double pulse test (DPT) based on a current-source structure at voltage levels up to 680 V and current up to 20 A. In addition, based on these devices, a 7.5 kW, three-phase buck rectifier for a 400 V dc architecture data center power supply is designed. The total loss of this rectifier is calculated full load. The results show that the SiC based buck rectifier can obtain low power loss and smaller weight and volume than a Si based rectifier.

Journal ArticleDOI
TL;DR: In this paper, the similarity between RF power amplifiers and rectifiers is discussed and it is shown that the same high-efficiency harmonically-terminated power amplifier can be operated in a dual rectifier mode.
Abstract: The similarity between RF power amplifiers and rectifiers is discussed. It is shown that the same high-efficiency harmonically-terminated power amplifier can be operated in a dual rectifier mode. Nonlinear simulations with a GaN HEMT transistor model show the time-reversal intrinsic voltage and current waveform relationship between a class-F amplifier and rectifier. Measurements on a class-F-1 amplifier and rectifier at 2.14 GHz demonstrate over 80% efficiency in both cases.

Journal ArticleDOI
TL;DR: In this article, the amplitude of the voltage oscillation is varied according to design parameters, parasitic components, and operation regions, i.e., below-resonant region and above resonance region.
Abstract: The LLC resonant converter employing a center-tap rectifier can suffer from a high voltage oscillation across rectifier diodes owing to a leakage inductance of a transformer secondary. The amplitude of this voltage oscillation is varied according to design parameters, parasitic components, and operation regions, i.e., below-resonant region and above-resonant region. To reduce the diode voltage stress, this paper analyzes the voltage oscillation mechanism and presents the design consideration.

Journal ArticleDOI
TL;DR: In this paper, a new type of Class E rectifier that can regulate the output voltage or power is proposed, which is composed of a conventional Class E zero-voltage-switching rectifier and the controlled shunt capacitor whose capacitance is variable according to the state of the active switches.
Abstract: A new type of Class E rectifier that can regulate the output voltage or power is proposed. The proposed rectifier is composed of a conventional Class E zero-voltage-switching rectifier and the controlled shunt capacitor whose capacitance is variable according to the state of the active switches. With turning the active switches ON or OFF, the shunt capacitance of the rectifier can be changed, which enables the rectifier to vary the output voltage or power. This paper presents an analysis, experimental results, and simulation results in the steady state.

Journal ArticleDOI
Zhiyuan Ma1, Dehong Xu1, Rui Li1, Chengrui Du1, Xu Zhang1 
TL;DR: A modified minimum-loss space vector modulation (SVM) strategy suitable for the novel zero-voltage switching (ZVS) rectifier is proposed in this paper and the design guidelines of the soft switched circuit parameters are described in detail.
Abstract: A novel active clamping zero-voltage switching three-phase boost pulsewidth modulation (PWM) rectifier is analyzed and a modified minimum-loss space vector modulation (SVM) strategy suitable for the novel zero-voltage switching (ZVS) rectifier is proposed in this paper. The topology of the novel ZVS rectifier only adds one auxiliary active switch, one resonant inductor, and one clamping capacitor to the traditional hard-switched three-phase boost PWM rectifier. With the proposed SVM strategy, the novel ZVS rectifier can achieve ZVS for all the main and auxiliary switches. In addition, the antiparallel diodes can be turned OFF softly, so the reverse recovery current is eliminated. Besides, the voltage stress of all the switches is equal to the dc-link voltage. The operation principle and soft-switching condition of the novel ZVS rectifier are analyzed. The design guidelines of the soft switched circuit parameters are described in detail. A DSP controlled 30 kW prototype is implemented to verify the theory.

Proceedings ArticleDOI
17 Jun 2012
TL;DR: In this paper, a class-C 2.45 GHz Schottky-diode rectifier with short-circuit 2nd and 3rd harmonic terminations is designed using source-pull measurements, and demonstrates a maximum RF-DC conversion efficiency of 72.8% when matched to 50Ω.
Abstract: In wireless powering, the rectifier efficiency has a large effect on overall system efficiency. This paper presents an approach to high-efficiency microwave rectifier design based on reduced conduction angle power amplifier theory. The analysis for an ideal rectifying device is derived to predict efficiency dependence on optimal dc load. A class-C 2.45 GHz Schottky-diode rectifier with short-circuit 2nd and 3rd harmonic terminations is designed using source-pull measurements, and demonstrates a maximum RF-DC conversion efficiency of 72.8% when matched to 50Ω. The approach is applied to integration of a rectifier with a dual-polarization patch antenna in a non 50Ω environment and free-space measurements demonstrate a lower bound on efficiency of 56% at 150 µW\cm2 power density which includes matching circuit and mismatch losses.

Patent
11 May 2012
TL;DR: In this paper, a driver for an LED lamp assembly includes a rectifier configured to receive an AC power and produce the first DC power and a switching regulator coupled to the rectifier.
Abstract: A driver for an LED lamp assembly includes a rectifier configured to receive an AC power and produce a first DC power and a switching regulator coupled to the rectifier. The switching regulator is configured to receive the first DC power and produce an output DC power. The driver also includes a current controller coupled between the rectifier and the switching regulator. The current controller is configured to damp and stabilize an electric current flowing between the switching regulator and the rectifier.

Journal ArticleDOI
TL;DR: A model for a voltage source rectifier which is connected to a PM generator in a micro turbine unit, where Virtual Flux based Direct Power Control strategy is used to control the mentioned rectifier.

Journal ArticleDOI
TL;DR: In this article, the average inductor current of a power factor correction (PFC) rectifier operating in the continuous conduction mode (CCM) under average current mode control was calculated using two paired saw-toothed waves compared with the sensed signal, without the use of any ADCs.
Abstract: As is generally acknowledged, the main drawback of a fully digitalized power factor correction (PFC) rectifier is that too many analog-to-digital converters (ADCs) are used, and hence, the corresponding cost is high. Consequently, in this paper, the information on the desired signal is obtained from two paired saw-toothed waves compared with the sensed signal, without the use of any ADCs. For the PFC rectifier operating in the continuous conduction mode (CCM) under average current mode control, the two proposed formulas used to calculate the average inductor current, together with the strategy for changing sampling points, are applied to accurately sample the average inductor current of the PFC rectifier. At the same time, based on the slope value of the inductor current obtained from the proposed average current calculation formula, another related formula is derived to obtain the input voltage information used to feed the partial feedforward controller. As for the sinusoidal current command, it is generated by a sinusoid table along with a zero-crossing detector. Furthermore, the information on the output voltage is obtained by one simple approximate formula. Therefore, there is no ADC required to realize the full digital control of the PFC rectifier operating in CCM.

Patent
25 Sep 2012
TL;DR: In this paper, a wireless power receiver with a rectifier and a band-stop filter is described, where the filter circuit is connected between the coil and the rectifier circuit.
Abstract: This disclosure provides systems, methods, and apparatus for filtering of a rectifier in a wireless power receiver. In one aspect a wireless power receiver apparatus is provided. The receiver apparatus includes a coil circuit configured to wirelessly receive power via a wireless field. The receiver apparatus further includes a rectifier circuit configured to provide direct-current (DC) based at least in part on the received power. The receiver apparatus further includes a first filter circuit electrically connected between the coil and the rectifier circuit and configured to reduce emissions from the rectifier circuit and configured to maintain a first impedance presented by the rectifier circuit substantially equal to a second impedance presented to the coil circuit. The receiver apparatus further includes a band-stop filter circuit configured to electrically isolate emissions from the rectifier circuit.

Proceedings ArticleDOI
20 May 2012
TL;DR: The rectifier targets fully integrated power harvesting biomedical implant and lab-on-chip applications that use on-chip or mm-sized near-field inductively coupled wireless power transfer receivers and achieves the highest measured efficiency in its class.
Abstract: Design and measurement results are presented for a 0.18 µm CMOS full-wave rectifier architecture with 85.8% measured power efficiency at 40.68 MHz. The rectifier targets fully integrated power harvesting biomedical implant and lab-on-chip applications that use on-chip or mm-sized near-field inductively coupled wireless power transfer receivers. The rectifier uses feedback from the output to lower the voltage drop and increase the power efficiency. The rectifier achieves the highest measured efficiency in its class.

Journal ArticleDOI
TL;DR: In this paper, a low-drop diode equivalent, which mimics a diode using linear region-operated MOSFET, was used to replace the four diodes in a full-wave bridge rectifier, which is a part of the more advanced rectifiers like switch-only and bias-flip rectifiers.
Abstract: Piezoelectric-device-based vibration energy harvesting requires a rectifier for conversion of input ac to usable dc form Power loss due to diode drop in rectifier is a significant fraction of the already low levels of harvested power The proposed circuit is a low-drop-diode equivalent, which mimics a diode using linear region-operated MOSFET The proposed diode equivalent is powered directly from input signal and requires no additional power supply for its control Power used by the control circuit is kept at a bare minimum to have an overall output power improvement Diode equivalent was used to replace the four diodes in a full-wave bridge rectifier, which is the basic full-wave rectifier and is a part of the more advanced rectifiers like switch-only and bias-flip rectifiers Simulation in 130-nm technology and experiment with discrete components show that a bridge rectifier with the proposed diode provides a 30-169% increase in output power extracted from piezoelectric device, as compared to a bridge rectifier with diode-connected MOSFETs The bridge rectifier with the proposed diode can extract 90% of the maximum available power from an ideal piezoelectric device-bridge rectifier circuit Setting aside the constraint of power loss, simulations indicate that diode drop as low as 10 mV at 38 μA can be achieved

Proceedings ArticleDOI
28 May 2012
TL;DR: In this article, an analysis on suitable topologies for the generator-side converter (rectifier) of the back-to-back converter arrangement is presented, where the two most popular rectifier systems, namely, the passive diode bridge rectifier and the active six-switch two-level rectifier are taken as two extremes to evaluate other topologies presented in this paper.
Abstract: The drive towards high efficiency wind energy conversion systems has resulted in almost all the modern wind turbines to operate in the variable speed mode which inevitably requires back-to-back power electronic converters to decouple generator dynamics from the grid. The aim of this paper is to present an analysis on suitable topologies for the generator-side converter (rectifier) of the back-to-back converter arrangement. Performance of the two most popular rectifier systems, namely, the passive diode bridge rectifier and the active six-switch two-level rectifier are taken as two extremes to evaluate other topologies presented in this paper. The other rectifier systems considered in this study include combinations of a diode bridge rectifier and electronic reactance(s), a combination of a rectifier and a dc-dc converter and a half controlled rectifier. Diode-clamped and capacitor-clamped three-level active rectifier topologies and their possible switch reductions are also discussed in relation to the requirements of modern high power wind energy conversion systems (WECSs). Simulation results are presented to support conclusion derived from this analysis.

Patent
09 Feb 2012
TL;DR: In this paper, an auxiliary circuit that reduces switching loss and countermeasure circuit for a surge voltage generated in a rectifier diode are provided in a DC power supply including a transformer for making a semiconductor switch operate with a high frequency.
Abstract: In a DC power supply including a transformer, for making a semiconductor switch operate with a high frequency, an auxiliary circuit that reduces switching loss and a countermeasure circuit for a surge voltage generated in a rectifier diode are provided. In a DC power supply in which a DC power source 101 and a transformer T are connected via a power conversion circuit and a secondary winding of the transformer T is connected to a load RL via a rectifier diode bridge and a filter circuit to supply power to the load RL, a resonance reactor Lz is provided on an output side of the transformer T, a resonant switch circuit 103 including a parallel circuit of a diode Dz and a semiconductor switch Qz and a resonant capacitor Cz is connected in parallel to the rectifier diode bridge and a snubber circuit including a snubber capacitor Cs, a snubber diode Ds1 and a diode Ds2 for discharge is connected to a serial resonant circuit including the resonance reactor Lz and the resonant capacitor Cz in the resonant switch circuit 103 to absorb a surge voltage.

Journal ArticleDOI
TL;DR: In this article, a three-phase motor drive system supplied with a single-phase AC-DC diode rectifier is investigated in order to reduce shaft voltage in a threephase AC motor drive systems.
Abstract: Common-mode voltage generated by a power converter in combination with parasitic capacitive couplings is a potential source of shaft voltage in an AC motor drive system. In this study, a three-phase motor drive system supplied with a single-phase AC-DC diode rectifier is investigated in order to reduce shaft voltage in a three-phase AC motor drive system. In this topology, the AC-DC diode rectifier influences the common-mode voltage generated by the inverter because the placement of the neutral point is changing in different rectifier circuit states. A pulse width modulation technique is presented by a proper placement of the zero vectors to reduce the common-mode voltage level, which leads to a cost-effective shaft voltage reduction technique without load current distortion, while keeping the switching frequency constant. Analysis, simulations and experimental implementation have been presented to investigate the proposed method.