电力电子变压器公共冗余结构及容错控制策略

Communal redundant structure and fault-tolerant control strategy for power electronic transformer

电力电子变压器(PET)包含大量电力电子器件,其子模块故障率相对较高,严重影响了供电可靠性。为提高级联H桥型PET的可靠性及容错能力,针对级联H桥的结构及运行特点,提出了一种双子模块公共冗余结构。该结构通过双向开关切换阵列灵活切换2个冗余子模块之间的连接方式,能够在PET内部任意单子模块和双子模块故障情况下实现备用功能。基于该新型冗余结构,提出相应的容错控制策略及运行模式切换逻辑,并对比了PET采用不同冗余结构时的运行可靠性和制造成本。

PET(Power Electronic Transformer) contains many power electronic devices,the failure rate of its submodules is relatively high,which seriously affects the reliability of power supply.To improve the reliability and fault-tolerant ability of cascaded H-bridge PET,combining with the structural and operating characteristics of cascaded H-bridge,a dual-submodule communal redundant structure is proposed.This structure switches the connection mode between the two redundant submodules flexibly through bidirectional switches,and can realize the standby function in the case of any single-or dual-submodule fault inside PET.Based on the novel redundant structure,the fault-tolerant control strategy and mode switching logic of the redundant structure are proposed,and the operating reliability and manufacturing cost of PET with different redundant structures are compared.