为了研究不平衡电网电压条件下永磁风力发电机系统增强运行能力的有效控制策略，提出了比例-谐振电流控制方案，并将该方案应用于并网逆变器的直接功率控制中，以实现直驱永磁风力发电系统无需正、负相序分解的统一控制.在PSCAD/EMTDC环境下建立基于背靠背IGBT变频器的1.5 MW永磁直驱风力发电系统仿真模型，仿真结果表明，在不平衡电网电压下，该系统能够实现最大风能跟踪，且新型的直接功率控制策略结构简单，能够实现单位功率因数控制，具有良好的动态性能，有效地抑制了直流母线电压的升高，增强不平衡电网电压故障下直驱永磁风力发电系统的不间断运行能力.%In order to investigate the enhanced control and operation of wind power generation systems based on permanent magnet wind generator(PMWG) when the network voltage is unbalanced,a proportional-resonant(PR) current control strategy is presented,meanwhile the control strategy is applied in direct power control(DPC) for grid-connected inverter(GCI) to simultaneously regulate the positive and negative sequence grid currents without involving any sequential-decomposition process. A 1.5 MW D-PMSG with back-to-back IGBT frequency converter is simulated in the PSCAD/EMTDC environment. Simulation results show that the maximum wind energy tracking is achieved in this system. The novel DPC strategy which is simple,could implement unity power factor control with excellent dynamic performance,inhibit the rise of DC voltage effectively,and enhance the ride-through capability of D-PMSG wind generation system under unbalanced network fault conditions as well.
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