天广工程直流线路突变量保护误动作分析

笔者分析了天广直流控制保护系统改造完成后发生的3次双极线路保护动作事件,剖析其中直流线路突变量保护误动作的原因。根据天生桥换流站和广州换流站的实际录波和实际过程,结合厂家给出的突变量保护定值和整定思想,分析导致突变量保护误动作的因素。笔者给出了2个解决方案——降低低电压保护定值和增大突变量保护的动作延时,并经实践验证正确,为以后更好地实施直流控制保护系统国产化改造提供参考。

Analysis on the Fault Trip of Bipole DC Line Protection in Tianguang HVDC

This paper analyses three bipole line protection accidents after the completion of the Tianguang HVDC control and protection regenerated system.The reason of DC line dU/dt protection fault trip is given according to the transient fault record in Tianshenqiao convertor station and Guangzhou convertor station.The set value of dU/dt protection and the setting process are studied in order to understand the fault trip.Two corresponding methods,lowing the under voltage protection value and increasing the dU/dt protection value,are put forward which are proved by the field effect.When these methods are utilized in future China home-produced HVDC control and protection system,the HVDC can operate better.