贵广Ⅰ回直流线路电压突变量保护逻辑的优化

针对一起广东500 kV砚都站开关故障导致直流保护误动作故障,对线路电压突变量保护的逻辑进行了分析,结合故障波形分析了突变量保护误动作的原因,提出了突变量保护逻辑的优化方案。利用贵广Ⅰ回直流PSCAD/EMTDC仿真模型进行不同运行工况下的故障模拟计算,佐证了电压突变量保护定值选取的合理性。按照优化方案对贵广Ⅰ回直流RTDS实时仿真系统的直流保护软件进行了修改,通过故障回放验证了优化后的保护逻辑在发生类似故障时,可以有效防止电压突变量保护的误动作。

Optimization of Undervoltage Sensing Protection Logic in Guizhou Guangdong HVDC Line I

Aiming at a fault of protection misoperation emerged from switches breakdown in the 500 kV Yandu station of Guang- dong, this paper analyses the logic of undervoltage sensing protection and the reasons of the protection misoperation according to the transient fault record, and proposes an optimization scheme of undervoltage sensing protection. Based on simulations on different working situations with the PSCAD/EMTDC simulation model for the HVDC Guizhou-Guangdong Line I, the rationality of protection threshold value selected in this paper is proved. With modified HVDC protection software of RTDS for the HVDC Guizhou-Guangdong Line I based on the proposed optimization scheme, the on-spot fault recorder playback experiment shows that the optimization protection logic can avoid the undervoltage sensing protection misoperation caused by AC exterior fault.