功率开关失效下的电力电子变压器故障特性分析与仿真

Fault characteristics analysis and simulation of power electronic transformer considering power switches failures

文中介绍了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;选取了具有直流故障闭锁功能的钳位双子模块型模块化多电平换流器、双主动桥和三相逆变器作为研究对象,对电力电子变压器输入级、隔离级和输出级换流器在功率开关短路故障和开路故障下的故障特性进行了理论分析;基于PSCAD仿真平台,搭建了10 k V电力电子变压器仿真模型,对所分析的故障类型进行了仿真验证,证明了理论分析的正确性;依据理论分析和仿真结果,对各类故障下的故障特性进行了统计,指出了对电力电子变压器影响较大的故障类型。

The topologies of input stage,isolation stage and output stage of power electronic transformer were introduced respectively in this paper. The type of clamp double sub-module modular multilevel converter which has the function of DC fault blocking,the dual active bridge and three-phase inverter were selected as the research objects,and the fault characteristics of the short-circuit and open-circuit faults occurred in the power switches included in the input stage,isolation stage and output stage of power electronic transformer were analyzed. Based on PSCAD simulation platform,the simulation model of 10 k V power electronic transformer was built. The analyzed fault types of power switches were simulated and verified,which proved the correctness of the theoretical analysis. The fault characteristics of all analyzed faults were statistically obtained according to the simulation results. The fault types under serious impacts on power electronic transformer were pointed out.