考虑无功功率协调控制的优化低频减载

Optimal Under Frequency Load Shedding Considering Coordination Control of Reactive Powe

针对一个有较大无功功率剩余的受端孤立电网,分析在低频减载切除有功负荷时,发电机进相运行、电容器投切等无功控制手段对受端孤网低频减载的影响,提出在低频减载过程中使发电机适度进相运行的同时控制电容器投切,使用按电压切除电容器、按频率投入电容器的控制策略,配合低频减载使系统频率在满足要求的情况下尽快恢复稳定。仿真结果表明,对无功功率的适当控制能够有效提高孤立电网低频减载的有效性,更有利于维持系统频率稳定和孤立电网的安全稳定运行。

For an isolated receiving - end power grid with large surplus of reactive power, the influences of reactive power con- trol methods, such as the leading phase operation of generator and the switching of capacitor, on under frequency load shed- ding in isolated receiving - end power grid are analyzed when under frequency load shedding removes active power. It is pro- posed that during under frequency load shedding, the switching of capacitor should be controlled while the leading phase oper- ation of generator is moderate, and the control strategies in which the capacitor is removed according to voltage and the capaci- tor is put into operation according to frequency are used to cooperate with under frequency load shedding so that the system fre- quency can be resumed stable situation as soon as possible when it meets the requirements. The simulation results show that the proper control of reactive power can effectively improve the effectiveness of under frequency load shedding in isolated power grid and it is more useful to maintain the stability of system frequency and the safe and stable operation of isolated power grid.