风电机组中双馈异步发电机(DFIG)恒电压运行时具备一定无功调压能力。为了准确评估含DFIG风电机组的电力系统电压稳定性,得到更为精确的临界功率或负荷裕度的统计信息,构建了考虑DFIG风电机组恒电压运行的无功极限的静态电压稳定概率分析模型,并采用蒙特卡罗法结合内点法加以求解。模型中将风电场接入节点作为PV节点,考虑了风机网侧变换器的注入无功功率,分析了风速随机性和相关性对风电机组注入无功功率和系统电压稳定性的影响。IEEE 118和300节点标准系统的计算结果验证了所提模型和方法的有效性。
The wind power generation unit with DFIG( Doubly- Fed Induction Generator) has a certain capability of reactive voltage regulation when it operates in constant voltage mode. In order to precisely evaluate the voltage stability of power system with DFIG and obtain more accurate statistical information of critical power or load margin,a probabilistic evaluation model of static voltage stability is constructed,which considers the reactive power limit of DFIG operating in constant voltage mode and combines Monte Carlo method with interior point method to obtain the solution. The model takes the connecting node of wind farm as a PV node and considers the injecting reactive power of grid-side converter. The impacts of wind speed randomness and correlation on the injecting reactive power of DFIG and the voltage stability of system are analyzed. The calculated results for IEEE 118-bus and 300-bus systems indicate the proposed model and method are effective.