高压电缆—架空线混合线路重合闸新判据

New Reclosing Criterion for Hybrid Lines of High-voltage Cables and Pole Lines

提出了基于两侧电流信息的新型电抗继电器,以及带并联电抗器线路的瞬时故障识别判据构成的全新的综合判据。新型电抗继电器利用线路两侧电流获得故障点的电流,进而利用故障点的电流作为极化构成的理想零序电抗器,由该电抗器来界定是架空线路段故障还是电缆线路段故障,与传统的基于单侧电流信息的电抗继电器相比更为精确。另外,结合带并联电抗器线路的瞬时故障识别判据,能确保带并联电抗器的混合线路在发生永久性故障时可靠闭锁重合闸,避免了重合于永久性故障对系统带来的冲击。基于上述两种判据的综合判据实现了电缆段故障及永久性故障闭锁重合闸的要求。EMTDC及RTDS实验验证了该综合判据的有效性。

A new reactance relay based on the current of both sides is proposed, which is more accurate than traditional reactance relay based on the current of one side. The current on fault point is obtained with currents of both line ends in new reactance relay. Further, the current on fault point is used to construct an ideal zero phase sequence reactor, which is used to determine the fault coming from power cable or pole line. It is more exact than traditional fault locating with single end current or reactor. It has self-adaptive compensation to avoid over-reaching and under-reaching due to current infeed from remote end and is immune to various system operation modes. In addition, combining with the recognition criterion of a transient fault for a line with shunt reactor, the auto-recloser can reliably be blocked whenever a permanent fault occurs on hybrid line with shunt reactor. Thus, the damage caused by permanent fault reclosing to cables and impact to power systems is avoided. The combining criterion based on both above criterions can implement requirements of reclosure block in case of cable and permanent faults. Finally, EMTDC and RTDS simulation tests are established and implemented. The test results show that this method can effectively distinguish the fault location, and auto-reclosure can work properly as desired.