风电次同步振荡的多工况分析

Multi-Working-Condition Analysis of Subsynchronous Oscillations in Wind Power Systems

针对风电运行条件或工况时变对次同步振荡稳定性的影响,提出了一种基于变工况阻抗模型的SSO定量评估方法,通过将阻抗矩阵的元素表达成工况(即基波电压、电流)二次型的商,可计算不同工作点的聚合阻抗频域特性,进而分析不同运行方式下的SSO稳定性。以新疆哈密风电系统为原型进行算例研究,运用所提方法对两种典型工况下的振荡稳定性进行了定量分析,并进行电磁暂态仿真验证,结果表明,实际系统中风电机组在线数量和单机出力等运行条件的改变均会对系统振荡稳定性产生影响,所提方法可有效评估不同工况下系统的振荡风险。

As the operation of wind power or time-varying working condition has some effects on subsynchronous oscillation stability,the paper puts forward a SSO quantitative assessment method based on the variable condition impedance model.It expresses impedance matrix elements into the quotient of quadratic form of working conditions(i.e.fundamental voltage and current)to calculate the frequency characteristics of aggregated impedance under different operating points,analyzing SSO stability under various operating conditions.The proposed method,taking Xinjiang Hami wind power system as an example,makes quantitative analysis of oscillation stability of two typical operating conditions,and verifies them through electromagnetic transient simulation.According to the results,the change of operating conditions such as the wind turbine number and unit power output will affect the system oscillation stability.This method can effectively evaluate the system oscillation risk under different operating conditions.