同塔双回线路准三相运行及改进跳合闸策略研究

Ｒesearch on Tripping and Ｒeclosing Strategy and Quasi － three － phase Operation of Double － circuit Transmission Lines on the Same Tower

摘要:

传统同塔双回线路保护为单回线配置，即按两回独立线路配置保护，因此跳合闸策略也多为独立配置，跨线 故障发生后将导致同塔双回线路全线跳闸。线路两侧系统电气联系中断，造成严重负荷损失，威胁电力系统安全稳 定运行。针对全程同塔双回的输电线路，重新定义了准三相运行，并对准三相运行的可行性进行了分析。在此基础上 提出了同塔双回线路改进跳合闸策略，降低故障后全线跳闸的概率，减少断路器的跳合闸操作次数。利用 PSCAD/ EMTDC 搭建了典型同塔双回线路模型，验证了准三相运行的可行性，并分析验证了改进跳合闸策略的优势。

Abstract:

Conventional protection of double － circuit transmission lines on the same tower trips and recloses the two circuits independently after the faults occurring in transmission line． The possibility of tripping all lines is high when inter － circuit faults occur． Large amount of load will be rejected and electrical link between two sides will be disconnected，which has negative effects on the stability of power system． A novel tripping and reclosing strategy is proposed which regards the double circuits as a whole． It can decrease the possibility of tripping all lines and reclose to permanent faults． The feasibility of quasi － three － phase operation ( QTPO) is analyzed． A typical model of double － circuit transmission lines on the same tower is established in PSCAD/EMTDC． Some important electrical indexes which can reflect the performance of QTPO are analyzed by simulation．