柔直旁路开关误动试验

Misoperation Test of Flexible DC Bypass Switch

柔性直流换流阀运行时,因旁路开关误动引起的故障例如不能触发IGBT短路保护或IGBT短路保护失效,会造成直流输电系统换流阀旁路开关瞬间承受短路电流。此处根据乌东德工程换流阀的研制过程,首次提出一种利用换流阀旁路误动试验验证旁路开关承受瞬间短路电流后能够长期稳定通流,实现柔直旁路开关误动防爆和稳定通流。首先阐述了柔直换流阀旁路开关误动故障机理及其带来的危害,在此基础上提出了旁路开关误动换流阀试验验证方法,并通过试验原理分析和换流阀试验验证,评估了旁路开关耐受短路电流的能力。最后,设计试验电路进行了试验验证,成功在乌东德工程中实现工程化应用。

When the flexible DC converter valve is operating,if the fault caused by bypass switch misoperation,such as the IGBT short-circuit protection or the failure of IGBT short-circuit protection,it will cause the bypass switch of the DC transmission system converter valve to bear the short-circuit current instantaneously.According to the development process of the converter valve in Wudongde project,a kind of converter valve bypass misoperation test is proposed for the first time,to verify the long-term stable flow of the bypass switch under the transient short-circuit current,so as to realize the flexible DC bypass switch misoperation explosion protection and stable flow.Firstly,the fault mechanism of bypass switch misoperation of flexible DC converter valve and its harm are described.On this basis,the test verification method of bypass switch misoperation converter valve is proposed,and the ability of bypass switch to withstand short-circuit current is evaluated by the test principle analysis and converter valve test verification.Finally,the test circuit is designed and the proposed method is verified,the engineering application is successfully realized in Wudongde project.