特高压串补线路负序方向高频保护行为分析

PERFORMANCE OF NEGATIVE SEQUENCE DIRECTIONAL PROTECTION ON SERIES COMPENSATED ULTRA-HIGH-VOLTAGE TRANSMISSION LINE

特高压输电技术和串联电容补偿技术部是提高输电线路传输容量、改善电力系统稳定性的有效措施,同时又都给输电线路继电保护提出了新的更高的要求。文中对带串补的特高压线路采用负序方向高频保护作为主保护方式进行了研究。结果表明负序方向高频保护适用于带串补的特高压输电线路,但是应克服串补不对称击穿和负序LC谐振带来的不正确动作。

Both ultra-high-voltage (UHV) transmission technology and series compensation are effective measures to improve the transmission capability of transmission line and stability of power system. At the same time, both of them put forward more requirements for transmission line protection. This paper studies the negative sequence directional protection (NSDP) as the primary protection of series compensated UHV transmission line. The results show that NSDP can be applied to series compensated UHV transmission line, and proper measures must be taken to avoid the incorrect operations which might be caused by unsymmetrical bypass of series capacitor and negative sequence LC resonance.