模块化多电平换流阀子模块旁路方案设计

模块化多电平电压源型换流阀（Modular Multi-level Converter, MMC）作为±800kV特高压柔性直流输电系统中的关键设备，其子模块的可靠性直接影响到整个系统的安全稳定运行。本文系统设计了基于永磁双驱动旁路开关的主动旁路方案，设计了基于双向转折晶闸管的被动旁路方案。结合主动旁路的经济性和被动旁路的可靠性，设计了分级旁路方案。试验结果表明，主动旁路方案能主动下发旁路命令可靠旁路故障子模块；在主动旁路方案失效的情况下，被动旁路方案可靠旁路故障子模块，解决了因子模块单一故障引起换流系统跳闸的难题，为±800kV特高压柔性直流换流阀工程实施提供了设计指导。#$NL关键词：柔性直流;模块化多电平;换流阀;旁路方案 #$NL中图分类号:TM711 文献标志码:A 文章编号:

Bypass scheme design for value sub-module of modular multi-level converter

As the key equipment of high voltage direct current(HVDC) flexible transmission system, the reliability of modular multilevel converter sub-module operation directly affects the safety and stability of the whole system. A sub-module bypass scheme is fully proposed. An active bypass scheme based on a permanent magnetic dual-drive bypass switch is designed. A passive bypass scheme based on breakover bidirectional thyristor is designed. Considering the economics of active bypass and the reliability of passive bypass, a hierarchical bypass scheme is designed. The test results show that fault sub-module can be reliable bypassed by command from the active bypass scheme. Meanwhile, in the case of the failure of active bypass scheme, the passive bypass scheme can reliably bypass the fault sub-module. The hierarchical bypass solves the problem that a single faulty sub-module causes the transfer system tripping. Design guidance for the implementation of HVDC-flexible valve is provided.