级联H桥变换器IGBT开路故障分析与冗余方法研究  

IGBT Open-Circuit Fault Analysis and Fault-Tolerant Method for Cascaded H-Bridge Converter

作　　者：赵楠[1] 郑泽东[1] 刘建伟 李驰[1] 李永东[1] Zhao Nan;Zheng Zedong;Liu Jianwei;Li Chi;Li Yongdong(State Key Laboratory of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University,Beijing 100084,China)

机构地区：[1]电力系统及大型发电设备安全控制和仿真国家重点实验室(清华大学电机工程与应用电子技术系),北京100084

出　　处：《电工技术学报》2023年第6期1608-1619,共12页Transactions of China Electrotechnical Society

基　　金：广东省重点领域研发计划资助项目(2020B0909030003)。

摘　　要：级联H桥变换器包含了大量的开关器件,往往面临严峻的可靠性问题。该文从电路特性和调制过程两方面对级联H桥变换器IGBT开路故障的影响规律进行分析,并提出一种基于调制重构的级联H桥变换器IGBT故障冗余方法。该故障冗余方法通过重构变换器调制过程,使H桥从故障中恢复运行,且发生开路故障的单元依然具有部分功率传输能力,提高了级联H桥变换器开路故障的处理能力。Cascaded H-bridge(CHB)converters are a type of common topology for high-voltage high-power power conversion and reliability,especially fault tolerant control,is a key issue because a CHB converter consists of many converter submodules and power devices.There are two levels of fault tolerant control for CHB converters,namely system level,which makes use of redundant or hot standby converter submodules,and converter level,that enhances the fault-tolerant performances for a converter submodule.The system level control usually bypasses faulty submodules completely and needs extra components which introduce increased costs and decreased efficiency,and thus the converter level control is also important to enhance the fault tolerant performance of one submodule before being bypassed.This paper focuses on the converter level and proposes a modulation reconstruction method to output reduced power for H-bridge submodules with open-circuited power switches,which requires no additional redundant switches or changes in topology.For open-circuit faults in a H-bridge,it is found and analyzed that one open-circuit switches only affects its corresponding output voltage in half of a line cycle,either positive or negative,depending on whether upper or lower switches are open-circuited and on the polarity of its current.In the affected half line cycle,the faulty H-bridge can only output half of its nominal voltage with a dc offset of half of its dc bus voltage,which will result in distortion in the output current.In the other half of a line cycle,the faulty H-bridge can operate like normal H-bridges.It is possible to modulate the faulty H-bridge to work in the unaffected half line cycle and to be bypassed in the other half,instead of bypassing the H-bridge at all times.Thus,a modulation method is proposed to enhance the power transfer capability of a CHB converter with faulty H-bridge submodules,based on which switch is open-circuited and the polarity of the current,and the modulation waveforms for the faulty and other healthy H-bri

关 键 词：级联H 桥变换器 开路故障分析 冗余方法 调制重构 

分 类 号：TM461[电气工程—电器]