基于广域测量系统的发电机强励控制方案

Forced excitation control scheme based on wide-area measurement system

基于扩展等面积准则(EEAC),分析了发电机强励控制对电力系统暂态稳定性的影响机理和作用规律,并指出:强励机组、强励控制量、强励启动和退出时刻是发电机强励控制效果的主要影响因素;如果不能选择合适的机组进行强励控制或者未能在恰当的时机启动和退出强励控制,则强励控制将有可能反而不利于系统稳定。在此基础上,提出了一种基于广域测量系统的发电机强励控制方案,以克服传统强励控制方案对上述因素考虑的不足。基于实际南方电网系统的仿真结果表明当通信时延在0.3s以内时,上述广域强励控制方案可以保持良好的控制性能,有效提升系统的暂态稳定性。

The mechanisms and effects of the generator forced excitation control on the transient stability of power systems are analyzed based on EEAC. It is pointed out that the selection of the generators to be forced excited, the control quantity, the activating and deactivating time play important roles on the effect of the forced excitation control; it may even bring negative effects on the stability of the system, if the generators or the activating/deactivating time are not properly selected. Since the traditional generator forced excitation control schemes have difficulties in solving these aforementioned problems, a novel forced excitation control scheme based on the wide-area measurement system is proposed. The simulation result of China Southern Power Grid shows that the transient stability of the system can be improved significantly with the proposed wide-area forced excitation control when the commutation delay is less than 0.3 s.