用于频率紧急控制的水电群精准控制策略

Accurate Control Strategies of Hydropower Group for Frequency Emergency Control

随着大规模水电集中开发,水电高占比大容量外送电网已具备一定规模,其频率安全问题越发凸显,现有离散的控制策略在控制精度上已难以满足控制需求。提出用于频率紧急控制的水电群精准控制策略,在电网发生故障出现较大功率盈余时采用传统离散切机和水电机组出力快速调节的协调控制策略,实现故障情况下对水电群的精准控制。提出了水电机组出力快速调节方法,通过安全稳定控制系统直接给水电机组调速系统下发水电机组出力快速调节指令,快速调节水电机组出力,代替部分离散切机量,可有效解决现有安全稳定控制系统存在的过控/欠控问题。算例仿真结果验证了所提控制策略的可行性与有效性。

With the large-scale centralized development of hydropower, the large-capacity power grid with high proportion of hydropower has a certain scale, and its frequency safety problem is more and more prominent. The existing discrete control strategy is difficult to meet the control demand in the control accuracy. A precise control strategy for frequency emergency control is proposed for hydropower units. When there is a large power surplus in the power grid with a fault, the coordinated control strategy of traditional discrete generator shedding and rapid output regulation of hydropower units is used to realize the precise control of hydropower group in the case of fault. This paper puts forward a fast regulation method for the output of hydropower units. Through the security and stability control system, the rapid adjustment command of the output of hydropower units is directly issued to the speed regulation system of hydropower units, which can quickly adjust the output of hydropower units instead of some discrete generator tripping. It can effectively solve the over control/under control problems in the existing security and stability control system. The simulation results show that the proposed control strategy is feasible and effective.