附加励磁阻尼控制抑制次同步谐振研究

Studies on a Supplementary Excitation Damping Controller for Mitigating SSR

基于阻尼特性分析对抑制次同步振荡的附加励磁系统阻尼控制器(SEDC)进行了详细研究。首先基于IEEE次同步谐振第一标准测试系统及IEEEST1A型励磁系统设计相应的SEDC。采用测试信号法,通过计算发电机组的次同步电气阻尼特性,分析所设计的SEDC对发电机组次同步振荡的抑制效果。结果表明,SEDC在不采用带通滤波器的方式下,将转速偏差经适当移相及放大,通过对励磁电压的调节,可以提供足够的阻尼转矩抑制次同步谐振;采用带通滤波器可大大提高通带频率对应的电气阻尼,同时对多个模态采用带通滤波,可以同时提高各个扭振频率处的电气阻尼,有利于次同步谐振的抑制。

A supplementary excitation damping controller （SEDC） is designed on the IEEE SSR first benchmark model and the IEEE STIA type excitation system. By using test signal method, the sub-synchronous electrical damping characteristics of a generator and the impacts of the designed SEDC on the generator＇ s electrical damping are analyzed. The results show that when the generator speed deviation is used to modulate the outputs of the excitation system only by phase shifting and amplifying, enough positive damping can be achieved to suppress sub-synchronous resonances. Furthermore, when bandpass filters tuned to each torsional frequency are added in the SEDC, the electrical damping at all possible torsional frequencies are increased.