中文摘要：

在Matlab环境下，借助电力系统分析工具箱（PSAT）实现了包含三级电压控制系统的大电网动态时域仿真，并分析其对广东电网暂态电压安全性的影响。结果表明该系统的二级电压控制紧急动作模式虽然有利于广东电网故障后的暂态电压恢复，但不能阻止暂态电压不安全事故的发生。进而，建立了针对暂态电压不安全故障的紧急切负荷控制优化模型，通过采用轨迹灵敏度法将动态优化模型转化为线性规划模型以获得紧急切负荷控制策略，动态仿真结果验证了所得控制策略能够使广东电网在严重故障后恢复暂态电压安全。

英文摘要：

In Matlab environment and using power system analysis tools （PSAT） software, the dynamic time-domain simulation of large-scale power grid with three-level voltage control system is implemented, and the influences of three-level voltage control system on transient voltage security of Guangdong power grid are analyzed. Analysis results show that the emergency action mode of secondary voltage control in the three-level voltage control system contributes to the post-fault transient voltage recovery of load buses in Guangdong power grid, however it cannot prevent the occurrence of transient voltage insecurity. For this reason, in allusion to transient voltage insecurity accident an optimal control strategy for emergency load shedding, in which the trajectory sensitivity is utilized to turn the dynamic optimal model into linear programming model to achieve emergency load shedding control strategy, is established, and it is verified by dynamic simulation that after serious fault the transient voltage security of Guangdong power grid can be recovered by the achieved control strategy.