云广特高压直流线路孤岛运行方式过电压保护方案

Implementation Scheme of Over-voltage Protection for Islanding Operation of Yun-Guang UHVDC

云广直流孤岛运行方式下发生直流双极闭锁时将在送端换流站交流系统产生幅值很高的过电压,孤岛运行过电压水平控制是决定能否孤岛运动的关键闪素。基于此,利用EMTDC计算了不同运行方式下楚雄换流站交流侧的过电压水平、避雷器工况、交流滤波器断路器断口暂态恢复电压及容性开断电流等,并根据过电压计算结果对A型避雷器、交流滤波器断路器等电气设备和安稳控制保护系统提出了相关要求,设计了过电压保护实施方案。仿真计算结果表明,该实施方案可行、有效,可确保孤岛运行方式下系统和设备安全。

Based on the calculation of the over-voltage level, energy of MOA and transient recovery voltage of AC filter breaker after the bipole is blocked under the islanding operation of Yun-Guang UHVDC, the requirements on MOA, AC circuit breakers as well as DC control and protection system etc were presented, and implementation scheme of overvoltage protection was also designed. The simulation results show that the implementation scheme is effective, and the safety of the system and equipment can be guaranteed under islanding operation mode.