无刷双馈异步电机潮流建模和收敛性研究

针对并网无刷双馈异步电机(BDFM)风电机组潮流计算问题,发现在最大功率点跟踪(MPPT)方式下,BDFM有功出力与电网运行条件有关;提出BDFM与电网联立求解潮流模型。对于受功率调度的BDFM,发现有功参考值在低风速下可能得不到满足,将导致潮流发散;提出两阶段潮流模型:首先判断功率调度是否有效,然后选择BDFM潮流约束和求解方法。为改善潮流收敛性,提出基于转差率或支路功率的BDFM初值算法。给出IEEE RTS系统中BDFM参数计算结果,以验证所提BDFM潮流算法的可行性和正确性。

Power flow modeling and convergence analysis to brushless doubly-fed induction machines

To the power flow modeling of the brushless doubly-fed induction generators (BDFMs), it is found that their active output under the maximum power point tracking (MPPT) mode is related to the power system operation condition, thus simultaneous solution to power flow constraints of the BDFMs and the power system is newly proposed. For the BDFMs under power dispatch, it is found that the reference power may not be satisfied by low wind speed, yielding divergence of power flow solution. A two-stage power flow model is newly proposed. Effectiveness of power dispatch object is judged to choose the power constraints and solution procedure for the BDFMs. To improve power flow convergence, the initial setting to the BDFMs set by the rotor slips or branch powers is newly proposed. The numerical results on IEEE RTS test system are provided, which validate the feasibility and accuracy of the proposed models.