一起高压大容量柔性直流输电换流器子模块故障分析

Analysis on Convertor Sub-Module Fault of Flexible HVDC Transmission

阀控系统是柔性直流输电控制系统的中间桥梁,在功能上联系着极控制保护设备(PCP)和换流阀一次设备。以此为研究对象,针对一起柔性直流输电阀控系统子模块过电压旁路故障问题进行了深入分析研究。介绍了模块化多电平换流器的基本结构、运行原理、数学模型、控制策略等,为后面的分析研究提供理论基础。其次,根据阀控系统故障现象,经过对各类故障原因的排查分析定位了故障点。最后通过模拟试验复现故障现象,验证了分析结论。

The valve control system is the intermediate bridge of the flexible HVDC transmission control system,which is functionally connected with the pole control protection equipment(PCP)and the primary equipment of the converter valve.Taking it as the research object,this paper conducts an in-depth analysis and research on a sub module overvoltage bypass fault in a flexible DC transmission valve control system.The paper first introduces the basic structure,operation principle,mathematical model,control strategy,etc.of the modular multilevel converter,which provides a theoretical basis for the subsequent analysis and research.Secondly,according to the failure phenomenon of the valve control system,the fault point is located through the investigation and analysis of various fault causes.Finally,the fault phenomenon is reproduced through simulation test,and the analysis conclusion is verified.