RB-IGBT矩阵变换器传动系统中的一种新颖两步换流策略

本文基于600V/100A逆阻式IGBT(RB-IGBT)研制了一台三相/三相矩阵变换器样机.实验中采用间接空间矢量调制算法,实现了该样机对一台异步电机的转差频率闭环恒压频比控制.提出了一种新颖的两步换流策略实现了双向功率开关间的可靠换流.该换流策略不需要任何电流电压传感器,仅依靠本文为RB-IGBT设计的驱动保护电路中的集-射电压检测单元即可获取换流所需信息.文中最后给出了样机照片和在不同负载条件下系统的实验结果.实验结果表明,所提出的换流策略是有效的,用于矩阵变换器-异步电机系统,具有较好的驱动性能.     

逆阻式IGBT的驱动保护电路及换流策略的研究)

针对逆阻式IGBT的开关特性，提出了数模混合式三段驱动电路。该驱动电路引入了可控的充、放电电流源，加快器件的开、关速度，而不增加开关过程产生的 与 。基于新颖的Vce电压检测方法，设计了过流保护电路，解决传统Vce检测方法不适应于逆阻式IGBT的问题。为了验证驱动保护电路的有效性以及逆阻式IGBT在矩阵变换器中应用的可行性，本文构建了一套AC-AC Buck斩波器，对双向开关的换流策略进行了研究与实验比较。     

一种简单的IGBT驱动和过流保护电路

讨论了IGBT驱动电路对其静态和动态特性的影响以及对驱动电路与过流保护电路的要求。利用IGBT的通态饱和压降与集电极电流呈近似线性关系的特性,设计了一个具有完善的过流保护功能的IGBT驱动电路。经分析和实验表明,该电路具有简单、实用、可靠性高等优点。     

应用逆阻型IGBT的移相控制电流型全桥零电流开关DC/DC变换器

介绍了一种使用新型的逆阻型IGBT(RB-IGBT)的电流型移相控制的全桥ZCSDC/DC变换器。介绍了逆阻型IGBT结构和特点,和普通IGBT不同,此新型IGBT具有双向阻断能力,适用于电流型电路。在该文所提到的电路中,通过引入谐振元件和利用电路中原有的寄生参数如变压器漏感,同时加入开关管的开关重叠时间,可以使得IGBT获得零电流关断条件,消除由于IGBT关断时候拖尾电流造成的关断损耗。该文分析了变换器的工作原理以及零电流关断条件,最后通过一个4kW实验装置的实验结构验证了前面的分析。     

直流断路器用IGBT正向恢复特性实验建模

直流断路器是柔性直流电网故障清除的主流手段。混合式直流断路器动作前,转移支路IGBT处在正栅极电压的零电压零电流状态,当转移支路电流开始上升时,由IGBT正向恢复过程产生的集-射极电压过冲一旦满足IGBT过流监测判据,将会引起保护误动进而降低装备运行可靠性。针对直流断路器工况下IGBT出现的正向恢复现象,通过建立的IGBT大电流开通实验平台获取了不同电流上升过程中IGBT集-射极电压波形,基于分阶段数学表征建立了能够反映IGBT正向恢复特性的I-U映射关系。与实测结果相比,该模型计算所得的集-射极电压峰值相对误差小于10%,高于过流监测阈值电压的持续时间相对误差小于15%,可支撑直流断路器所用IGBT的过流监测判据的合理制定。     

A Novel Commutation Method of Matrix Converter Fed Induction Motor Drive Using RB-IGBT

This paper gives an overview of a collector-emitter voltage sign-based commutation method. This method is implemented based on the output current sign and commutation voltage polarity signals of matrix converter. All these signals are acquired by a simple unit in the drive and protection boards designed for reverse blocking insulated gate bipolar transistors (RB-IGBTs) of the matrix converter in test. Therefore, no current and/or voltage sensor is required to obtain any other commutation signals. The RB-IGBT samples used are newly developed, and one important feature is that its reverse leakage current is mostly affected by nu_ge. Under the same temperature condition, when nuce is negative, a positively biased nu_ge results in a distinct decrease of the reverse leakage current. The proposed commutation method can supply the reverse-blocked RB-IGBTs with positively biased nu_ge . Hence, the power losses caused by the reverse leakage current can be reduced using the proposed method. Experimental results have proved the feasibility and effectivity of this method     

基于逆阻式IGBT的三相/单相矩阵式变换器

针对三相/单相矩阵式变换器系统,提出一种平均电压脉宽调制方法,通过实时检测三相输入相电压,经过简单计算即可对输出进行正弦调制.采用新型开关器件逆阻式IGBT(RB-IGBT)实现了一台3kW的三相/单相矩阵式变换器样机,并针对RB-IGBT独特的漏电流特性,提出一种基于输入电压大小检测、适用于RB-IGBT的两步换流方法.实验结果表明,该样机可以实现正弦的输出波形.从而证明了本文提出的控制策略和换流方法的有效性和可靠性.     

Research on optimal configuration strategyof energy storage capacity in gridconnectedmicrogrid

To coordinate the protection of PMSG (permanent magnet synchronous generator), collector circuits and outgoing lines, a comprehensive and improved protection method of PMSG based wind farms with LVRT (low voltage ride through) capability is proposed. The proposed method includes adding a short time delay to the collector network current protection zone I and a directional protective relaying to the collector network protection, installing grounding transformers and zero sequence current protection, and generator low-voltage protection action improvement. A LVRT scheme consisting of variable resistance dumping circuit, grid side dynamic reactive power control and reactive power compensation control is proposed. The fault characteristics of PMSG based wind farms are analyzed, and a PMSG based wind farm in Dabancheng, Xinjiang, is used as an example to analyze typical wind farm protection configuration, the setting values considering LVRT requirements, and the coordination problems. Finally, an improved wind farm protection coordination methodology is proposed and its validity is verified by simulation.     

Configuration and operation combinedoptimization for EV battery swappingstation considering PV consumptionbundling

Integration of electric vehicles (EVs), demand response and renewable energy will bring multiple opportunities for low carbon power system. A promising integration will be EV battery swapping station (BSS) bundled with PV (photovoltaic) power. Optimizing the configuration and operation of BSS is the key problem to maximize benefit of this integration. The main objective of this paper is to solve infrastructure configuration of BSS. The principle challenge of such an objective is to enhance the swapping ability and save corresponding investment and operation cost under uncertainties of PV generation and swapping demand. Consequently this paper mainly concentrates on combining operation optimization with optimal investment strategies for BSS considering multiscenarios PV power generation and swapping demand. A stochastic programming model is developed by using state flow method to express different states of batteries and its objective is to maximize the station’s net profit. The model is formulated as a mixed-integer linear program to guarantee the efficiency and stability of the optimization. Case studies validate the effectiveness of the proposed approach and demonstrate that ignoring the uncertainties of PV generation and swapping demand may lead to an inappropriate batteries, chargers and swapping robots configuration for BSS.     

逆变器驱动电机系统中的耦合电流

针对由于逆变器驱动电机系统中的PWM电压具有高频和高dv／dt的特性，在电机内部产生共模耦合效应，并产生共模耦合电流流过电机内部的寄生电容这一特点，通过建立的分布参数电路模型和等效的集总参数电路模型，研究了电机内部高频情况下的共模耦合效应，分析了共模耦合电流的基本特性，给出了共模耦合电流的计算方法，对三相系统中的耦合电流进行了试验研究，并讨论了耦合电流对系统性能的影响。结果表明，耦合电流伴随电压的跳变而产生。呈双频振荡，引起电压和电流的畸变，并将引起电机绕组的过电压。     

Series connection of IGBT's with active voltage balancing

This paper describes an active gate drive circuit for series-connected insulated gate bipolar transistors (IGBTs) with voltage balancing in high-voltage applications. The gate drive circuit not only amplifies the gate signal, but also actively limits the overvoltage during switching transients, while minimizing the switching transients and losses. In order to achieve the control objective, an analog closed-loop control scheme is adopted. The closed-loop control injects current to an IGBT gate as required to limit the IGBT collector-emitter voltage to a predefined level. The performance of the gate drive circuit is examined experimentally by the series connection of three IGBTs with conventional snubber circuits. The experimental results show the voltage balancing by an active control with wide variations in loads and imbalance conditions     

小开距下直流真空断路器介质恢复试验及分析

介绍了一种能在小开距下分断高上升率短路电流的方法,并就其真空介质恢复特性展开试验研究。设计了等效真空介质恢复试验方案,从燃弧能量与零电压恢复时间两方面对真空介质恢复过程进行分析,得到直流真空断路器短路分断控制方法的设计依据。研制了额定1 000V/800A直流真空断路器试验样机,可在小于1ms内成功分断上升率约为20A/μs的短路电流,并将电流峰值限制在8kA以内。试验结果证明了所提出的小开距下分断高上升率短路电流的方法有效、可行。     

Flexible dv/dt and di/dt control method for insulated gate power switches

Active gate control techniques are introduced in this paper for flexibly and independently controlling the dv/dt and di/dt of insulated gate power devices during hard-switching events. In the case of dv/dt control, the output voltage dv/dt can be controlled over a wide range by electronically adjusting the effective gate-to-drain (-collector) capacitance (i.e., Miller capacitance). For di/dt control, similar techniques are applied for electronically adjusting the output current di/dt over a wide range using voltage feedback from a small inductor connected in series with the switch's source (emitter) terminal. Both techniques are designed to maximize their compatibility with power module implementations that combine the power switch and its gate drive, including integrated circuit gate drives. Simulation and experimental results are included to verify the desirable performance characteristics of the presented dv/dt and di/dt control techniques.     

Novel current‐source multilevel inverter driven by single gate drive power supply

This paper proposes a novel current‐source multilevel inverter, which is based on a current‐source half‐bridge topology. Multilevel inverters are effective for reducing harmonic distortion in the output voltage and the output current. However, the multilevel inverters require many gate drive power supplies to drive switching devices. The gate drive circuits using a bootstrap circuit and a pulse transformer can reduce the number of the gate drive power supplies, but the pulse width of the output PWM waveform is limited. Furthermore, high‐speed power switching devices are indispensable to create a high‐frequency power converter, but various problems, such as high‐frequency noise, arise due to the high dv/dt rate, especially in high‐side switching devices. The proposed current‐source multilevel inverter is composed of a common emitter topology for all switching devices. Therefore, it is possible to operate it with a single power supply for the gate drive circuit, which allows stabilizing the potential level of all the drive circuits. In this paper, the effectiveness of the proposed circuit is verified through experimental results. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(2): 88–95, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20475     

IGBT驱动及短路保护电路研究

首先讨论了对IGBT的保护以及对其驱动电路的基本要求，然后基于IGBT集电极退饱和原理，作提供了一个具有完善短路保护功能的IGBT驱动电路。分析及试验结果表明，该电路简单、实用、可靠性高。     

一种新颖的逆变器输出无源滤波器的研究

提出了一种新颖的可以同时降低差模dv／dt和共模电压的逆变器输出无源滤波器。该滤波器由一LC低通滤波器和一共模变压器构成。其主要特色是将两种结构的滤波器集合在一起，简化了滤波器的结构和设计。通过理论分析，仿真和实验方法验证了该滤波器在满足降低差模dv／dt使差模电压正弦化的同时可以最大程度的消除共模电压，从而有效延长电机的电气寿命。详细地分析了滤波器的共模等效电路，然后给出了滤波器的设计方法。进行了传统的LRC滤波器的相关实验，与所提滤波器进行了效果对比，验证了所提滤波器的有效性。     

Single-Phase SRM Drive With Torque Ripple Reduction and Power Factor Correction

In a single-phase switched reluctance motor (SRM) drive, the dc voltage source is generally supplied by a circuit consisting of a bridge rectifier and a filter capacitor connected to an ac line. The charging time of the capacitor is shorter from the ac source as capacity increases. The bridge rectifier draws pulsating current from the ac source, which results in a degraded power factor (PF) and lower system efficiency. A single-phase SRM drive system is presented in this paper, which includes the realization of a drive circuit for the reduction of torque ripple and PF improvement with a novel switching topology. The proposed drive circuit adds one switch and one diode, which can separate the output of the ac/dc rectifier from the large capacitor and supply power to the SRM alternately. This allows the drive system to realize torque ripple reduction and PF improvement through the switching scheme. The validity of the proposed method is analyzed by mathematical modeling and tested by simulations and experiments.     

大功率电机直接起动的逆变器控制模式切换策略

在冲击性负荷下(如短路故障)要保证逆变器可靠地运行,采用两种控制模式:正常情况下,逆变器输出恒定电压,工作于电压控制模式;异常情况下(如短路、冲击性负载),逆变器输出电流恒定,工作于电流控制模式。两种控制模式的切换成为逆变器可靠运行的关键技术之一。常用的切换策略:故障的负载电流值大于电流阈值和故障消除的负载电压恢复到额定电压进行模式切换。但是,为解决冲击性负载下可靠地保护,希望进入电流控制模式的电流阈值较低,而在特定的负载下安全地直接起动大容量电机(电机的起动电流一般是额定电流的几倍甚至上十倍),则希望电流阈值较高。针对二者矛盾,文中利用大功率电机起动与故障工况的差异,再引入电压阈值作为判断条件解决了电机起动误入电流控制模式的问题,两台400kV.A、50Hz的样机实验验证了该策略的有效性。     

A New Five-level Single-phase Inverter Employing a Space Vector Current Control

This article introduces a new five-level single-phase voltage source inverter. The proposed configuration employs two bidirectional switches. Since some switches share the same gate signals, the proposed circuit significantly contributed in reducing the utilized power electronics components, gate drive circuits, and system complexity. A novel space vector current control strategy was employed to maintain the desired number of voltage levels based on load current. With the proper selection of the redundant inverter switching states, the deviation in neutral-point voltage was considerably minimized. The proposed work was simulated and its hardware was manufactured.     

一种混合9电平电压源逆变器及其变频脉宽调制

介绍了一种应用于中高压变频调速装置的9电平输出电压源逆变器，逆变器的主电路由2种不同拓扑结构的逆变电路组成，分别使用不同参数的开关器件实现，可以综合利用阻断电压高的器件和开关速度快的器件的优点。分析了逆变器主电路的拓扑结构及特点，研究了主电路的开关模式后提出了一种基于载波调制的适合于任意电平数目混合逆变器的PWM(脉宽调制)算法，最后仿真研究了混合9电平逆变器在变速驱动场合中的应用，并验证了算法的有效性。对线电压的频谱分析表明，混合9电平逆变器有很好的输出波形，输出谐波含量少，在高频段输出线电压的总谐波畸变率小于5％，输出电压的dv／dt小，可用于驱动大容量的中高压异步电动机。