中文摘要：

分析了特高压交流运行初期银东直流闭锁故障对系统稳定性的影响,提出直流双极闭锁后通过切除山东电网内部分负荷以减少特高压联络线北送功率来防止系统失稳。设计了切负荷控制系统,依据电网运行状态及时计算刷新银东直流双极闭锁后的切负荷量,并根据各子站负荷性质和负荷量合理选择切负荷站点。相比于对分法,基于弦割法的临界切负荷量搜索策略能够快速找到银东直流双极闭锁后山东电网内的临界切负荷量。

英文摘要：

The influence of Yindong 660 kV DC block fault on power system stability in the initial stage of UHV AC project is analyzed. It is proposed to shed part of Shandong Power Grid loads after the DC bi-polar block to reduce the power transmission from Central China Power Grid to North China Power Grid for system instability prevention. The corresponding load shedding control system is designed,which computes the loads to be shed in real time according to the operating condition of power grid and selects the proper substations for load shedding based on the nature of loads. Compared with the bisection method,the critical shedding load search based on the string cut method more rapidly determines the loads to be shed in Shandong Power Grid after DC block fault.