多运行方式下含风电场电力系统的小干扰概率稳定性研究

Probabilistic Small Signal Stability Analysis of Power System Integrated With Large-Scale Wind Farm Considering Multi Operating Conditions

为了考虑系统的多运行方式,采用概率方法对风电场接入对系统小干扰稳定性的影响进行研究。首先采用插入式建模技术(plug-in modeling technique,PMT)建立适合小干扰稳定分析的完整的双馈感应风力发电机组(doubly-fed induction generator,DFIG)线性化模型;然后进行概率潮流计算,得到系统状态变量的概率描述,形成系统状态矩阵;最后应用概率特征根方法对系统进行求解分析,得到系统小干扰概率稳定性。以2个系统为例对风电场接入后的电力系统小干扰概率稳定性进行仿真分析,结果表明:风电场的加入使机电振荡模态特征值实部的概率分布变得相对分散;系统本地振荡模态稳定概率大幅下降,区间振荡模态稳定概率略有上升;通过加装电力系统稳定器(power system stabilizer,PSS),可提高系统小干扰概率稳定性。

The probabilistic method is applied in the research on probabilistic small-signal stability of power grid integrated with large-scale wind farm under multi operation conditions. Firstly, using plug-in modeling technique （PMT） a completer linearized model of doubly fed induction generator （DFIG） suitable to the analysis on small-signal stability is established; secondly, the probabilistic power flow calculation is performed to obtain probabilistic description of system state variables and the system state matrix is formed; finally, using probabilistic eigen-root method the established system is solved and analyzed to obtain probabilistic small-signal stability of the whole system. Taking the modified IEEE 3-machine 9-bus system and a modified 4-machine 2-area system for examples, the simulation and analysis on probabilistic small-signal stability of power grid integrated with wind farm are performed. Simulation results show that power grid integrated with wind power makes： A） the probabilistic distribution of the real part of modal eigenvalue of electromechanical oscillation becomes relatively dispersed; B） probability of modal stability of local oscillation is greatly decreased and probability of modal stability of inter-area oscillation is slightly increased;C） it is enable to enhance the probabilistic small-signal stability of the whole system by adding power system stabilizer （PSS）.