一种适用于高压线路非全相运行时的距离保护振荡闭锁的开放方案

摘要

When the high voltage transmission line is non-full-phases operation, the asymmetric element will be closed. While the healthy phases of the line have faults under such circumstances, if the voltage of swing center continuous low is the only criterion for fault detection, it needs long time-delay and will impact the speed of distance protection trip. Moreover, this scheme is not suitable for single-phase earth fault. The paper proposes a combining scheme that, single-phase fault can be detected through partition changes of phase selection by zero-sequence current and negative-sequence current phase selector, and phase-to-phase fault can be detected through the delta voltage of swing center, when power system is non-full-phases and swing operation. The simulation results show the effectiveness of the scheme.%电力系统高压输电线路非全相运行时，由于不对称开放元件退出，若此时再发生故障，如果仅依靠振荡中心电压持续低的长延时判据来开放振荡闭锁，则影响距离保护的动作速度。该方案不适用于单相接地故障。提出了一种采用零负序电流选相分区结果改变开放单相故障和健全相振荡中心电压突变检测开放相间故障相结合的方案，来解决非全相振荡再故障现有开放元件动作速度慢的缺陷。仿真结果证明了该方案的有效性。