随机时滞电力系统稳定性分析

Stability Analysis for Stochastic Time Delay Power System

随着电力系统的大规模互联,可再生能源发电和电动汽车等并网规模的扩大,时滞及随机因素对电力系统稳定性的影响不容忽略。建立了随机时滞电力系统的数学模型,仿真分析了不同随机激励强度、不同随机激励分布下时滞电力系统的稳定性,并基于Pade近似计算了时滞系统的特征根。分析表明:当随机激励的强度较大时,基于Pade近似的时滞系统特征根结果与随机扰动下的仿真结果有较大的差异。这是因为基于Pade近似的时滞系统特征根结果只能反映系统在平衡点附近的动态特性。

With the large-scale interconnection of power system,and also with the massive grid connection of renewable energy power generation and electric vehicles,the effects of time delay and stochastic excitation on power system stability should be taken into account.This paper established the model of stochastic system with time delays,made simulation analysis under different excitation intensities and different time delays,and calculated the characteristic root of time-delay system based on Pade approximation.The results show that there will be great difference between eigenvalues and simulation results when the excitation intensities are much high because the eigenvalues can only reflect the stability of equilibrium point when the system′s nonlinearity is much strong.