考虑随机激励的电力系统机电暂态过程模型

Stochastic models for study of electromechanical transient process in power systems

针对电力系统机电暂态过程,构建考虑随机激励的简化模型。给出单机无穷大系统和两机电力系统机电暂态过程随机模型,并基于EEAC理论构建多机电力系统机电暂态过程等效随机模型。结果表明,在较强假设下,多机电力系统机电暂态过程随机模型可以简化为等效的单机无穷大系统模型,模型参数分为常数和时变两种情况,随机激励可以表达为多频率随机激励的叠加。最后,给出仿真算例。算例表明,在随机激励下,功角曲线呈现出有规律的振荡,且其基本上是一个频率。

A simplified stochastic model considering stochastic excitation was developed for the study of the electromechanical transient process in power systems. First,stochastic models considering stochastic excitation were built for electromechanical transient processes in the one-machine infinite bus（ OMIB） system and the two-machine power system. Then,based on the EEAC theory,the stochastic models considering stochastic excitation for the multi-machine power system were deduced. The results show that under approximate conditions,the stochastic model of the multi-machine power system can be simplified as the model of the OMIB system,and the model parameters may be constant or time-varying according to different assumptions. The stochastic excitation may be considered the superposition of stochastic excitations that have different frequencies. Finally,simulations were performed. The simulation results show that,when affected by the stochastic excitation,the rotor angle curve exhibited regular oscillations with frequencies that were almost the same.