励磁控制器中电流测量量对电力系统低频振荡的影响

Effect of Current Measurement Value in Excitation Controller on Low Frequency Oscillation of Power System

低频振荡的频繁发生严重影响电力系统安全稳定运行。为了分析导致电力系统低频振荡加剧的原因,通过研究发现,发电机励磁调节器调差单元中电流测量值可能是加剧低频振荡的原因之一。针对发电机励磁调节器调差单元中电流测量值的变化特性和发电机功角震荡特性进一步分析,运用戴维南等效电路分析方法证明电流测量值与发电机功角具有同幅震荡特性,且它的引入在一定程度上比电压测量值的引入对低频振荡的影响大,运用MATLAB仿真建模验证结果表明,低频振荡的加剧在一定程度上是由于调差单元电流测量值对发电机励磁系统的助增效果造成的。

The frequent occurrence of low frequency oscillation seriously affects the safe and stable operation of pow- er system. By analyzing the cause of the aggravation of the low frequency oscillation of power system, it is found that the current measurement value of adjustment unit of the generator excitation regulator may be one of the reasons for intensifying the low frequency oscillation. This paper for the generator excitation adjustment regulator difference vari- ation characteristic of unit current measurements are analyzed, using the Thevenin＇ s equivalent circuit analysis method that current measurement and power angle of generator has the same amplitude oscillation characteristics, and its introduction influenced greater than that of the voltage measurement value on the low frequency oscillation. The simulation results based on MATLAB show that the low frequency oscillation is increased to a certain extent due to the effect of the adjustment unit current measured value on the excitation system of the generator.