负荷随机扰动对电力系统电压稳定性的影响

对一个典型的电力系统动态模型进行了分析 ,在考虑了负荷随机性基础上 ,建立了随机扰动的电压稳定模型。通过对引入无功负荷随机扰动项的系统进行数值仿真和理论分析 ,提出了负荷随机效应引起的电力系统电压失稳新的模式——当系统处于负荷水平比较紧张情况下 ,负荷的小幅波动的正向累积 ,会使得系统电压突然失稳 ,在电压骤降的同时发电机端相角基本维持恒定。此外 ,还给出了数值仿真结果理论上的解释 ,表明了仿真结果的合理性。

Effects of stochastic load model on power system voltage stability

The random load characteristics in a sample power system were considered to develop a stochastic model for voltage stability. Theoretical analysis and numerical simulation of the model lead to a new pattern of voltage collapse where the voltage instability is induced by the positive accumulation of stochastic load disturbances in a heavy loaded power system. At the moment of collapse, the voltage drops sharply while the generator angle maintains fairly constant, which is supported by the simulation results. So a system which is stable under the deterministic model may become unstable when random disturbances of load are taken into account, which shows the need to use the stochastic load model.