天广工程直流线路突变量保护误动作分析

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

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。

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.