基于MMC的配电网电力电子变压器故障特性分析

Fault characteristic analysis of power electronic transformer based on MMC in distribution network

介绍了配电网电力电子变压器输入级、隔离级和输出级通常采用的拓扑结构;选取了半桥子模块型模块化多电平换流器、双有源桥和三相逆变器作为研究对象,基于PSCAD仿真平台,搭建了10k V配电网电力电子变压器仿真模型;对电力电子变压器中可能出现的故障类型,包括交流输入侧故障、中压直流侧故障、低压直流侧故障以及功率开关元件故障等进行了理论分析与仿真验证;对各类故障下电力电子变压器的过电压、过电流水平进行了分类统计,指出了对配电网电力电子变压器影响较大的故障类型。

The topology structures of the input stage,isolation stage and output stage of power electronic transformer in distribution network were introduced. Using the type of half bridge modular multilevel converter sub-module, the dual active bridge and three-phase inverter as the research object, the simulation model of 10kV distribution network power electronic transformer was built based on PSCAD simulation platform. The theoretical analysis and simulation verification of the possible fault types in power electronic transformer were carried out,including AC input fault, me- dium voltage DC side fault,low voltage DC fault and power switch component fault, etc. The overvohage and over- current level of power electronic transformer under various faults were classified and tallied. The fault types which have greater impact on power electronic transformer in distribution network were pointed out.