开绕组无刷双馈风力发电机的直接功率控制研究

STUDY ON DIRECT POWER CONTROL OF OPEN-WINDING BRUSHLESS DOUBLY-FED WIND POWER GENERATOR

为了提高无刷双馈风力发电机系统的控制灵活性和故障冗余能力,进一步减小所需变频器容量,实现最大功率跟踪,提出一种具有开绕组结构的无刷双馈风力发电机及其直接功率控制系统。将无刷双馈发电机(brushless doubly-fed generator,BDFG)的控制绕组端设计为开绕组结构,采用双端供电式级联型两电平逆变器与控制绕组两端连接对开绕组BDFG(open-winding BDFG,OW-BDFG)进行励磁,可对各相控制绕组电流进行独立控制。针对该种由双逆变器馈电的OW-BDFG,提出采用混合矢量直接功率控制(direct power control,DPC)方法以实现最大功率跟踪,该种控制方法结构简单,计算量小,且无需观测磁链大小,实时性好。最后,通过仿真研究验证所提出OW-BDFG直接功率控制系统的有效性和可行性。

A brushless doubly-fed wind power generator with open-winding structure and its direct power control system were proposed to improve the control flexibility and fault redundancy ability of brushless doubly-fed wind power generator system, to make the needed inverter capacity smaller and to implement the maximum power tracking. The control winding of brushless doubly-fed generator （BDFG） is designed as open-winding structure, and the double-power-supply cascade two-level inverter connected with the two ends of control winding is adopted to excite the open-winding BDFG （OW-BDFG）, which each phase current of control winding can be controlled independently. For this OW-BDFG fed by the double inverter, the hybrid vector direct power control （DPC） method is employed to implement the maximum power tracking. This control method has simple structure, small computational amount, and good real-time performance without observing the flux amplitude. Finally, the effectiveness and feasibility of the proposed OW-BDFG DPC system is verified through the simulation study.