一种具有直流故障闭锁能力的新型子模块

A Modified Sub-module Topology With DC Fault Blocking Capability

对于传统基于半桥子模块(HBSM)的模块化多电平变换器(MMC)而言,由于HBSM结构不具有直流故障闭锁能力,因此,当MMC直流侧发生短路故障时,过大的电流将会损坏器件。为了解决该问题,提出一种改进型半桥子模块结构,该结构在正常运行时,工作原理与HBSM结构类似;而当直流侧发生短路故障时,通过闭锁该结构内的全部IGBT,能够实现故障电流的闭锁,并搭建仿真模型以及实验平台。实验结果表明,所述子模块结构能够良好地实现直流故障闭锁。

Due to lack of the DC fault blocking capability in the half bridge sub-module(HBSM)structure,the device in the modular multilevel eonverter(MMC)based on the traditional HBSM will be damaged when the MMC DC fault current is too large.In order to solve this problem,an modified HBSM structure is proposed.When the proposed strueture works normally,its working prineiple is similar to that of HBSM strueture.When the DC side short-circuit fault occurs,all IGBTs will be turned off to block the fault current.The simulation model and the experimental platform are built,the results show that the proposed sub module structure can achieve the DC fault ride-through well.