南方电网连锁故障大扰动及应对措施

南方电网大容量、远距离、交直流并联送电,结构性稳定问题十分突出。基于南方电网的特点和运行经验,分析了南方电网目前主要面临的4类连锁故障风险:特高压、高压直流双极闭锁扰动引发的连锁故障风险,极端天气导致的多重线路故障风险,主设备故障叠加继电保护隐性障碍引发的多元件跳闸风险和低频振荡引发的连锁故障风险;提出了三道防线协同配合防御策略,以及在线安全稳定控制技术、基于WAMS的稳定控制技术、RTDS大规模电网仿真技术和直流孤岛运行技术等新技术研发方向。

Analysis of the Large Disturbances Caused by Cascading Failures and Defense Schemes in CSG

Due to long distance, bulk power transmission, and complex parallel operation of multiple AC and DC transmissionsystems, the strutural stability issue remains a big challenge to China Southern Power Grid CSG. According to CSG's system feature and operation experience, there are mainly four types of large disturbance risks threating system security from cascading failures. They are bipolar block of HVDC/UHVDC, multiple AC transmission line trippinga induced by bad weather, multiple 500 kV equipment trippings caused by main device failure and following relay's latent faults, and interarea oscillations. Based on analysis of these risks, this paper proposed a defence strategy with three coordinated defense lines for CSG. In addition, several new researchfields related to securitystability control are discussed, including online dynamic security assessment and control DSA&C technology, multiple HVDC coordinated damping control based on WAMS, realtime digital simulation technology for large scale AC/DC hybrid systems, and the control technology for HVDC/UHVDC transmission systems in islanding operation mode.