应用场路结合法设计了一台2 MW直驱外转子永磁同步风力发电机,建立二维电磁场仿真模型,研究发电机在空载、额定负载、短路工况下的磁链、反电势等电磁性能。为削弱发电机齿槽转矩,基于能量法和傅里叶级数分解法,给出齿槽转矩的解析表达式,通过分析极弧系数对齿槽转矩和输出电压正弦畸变率的影响,提出最佳极弧系数的确定方法。仿真结果验证了理论分析的正确性,为电机参数的优化提供依据。
A 2 MW direct drive permanent magnet wind generator was designed by equivalent magnetic circuit method,and the simulation model of 2D Electromagnetic Field of generator was established. The magnetic flux and the back EMF curve of the generator were analyzed and calculated under no load,rated load and short circuit conditions. To reduce cogging torque in generator,an analytical expression of cogging torque was proposed based on energy method and Fourier expansion. The method to determine the optimal pole arc coefficients was proposed with analyzing the influence of pole arc coefficient on cogging torque and sinusoidal distortion rate of output voltage. The simulation results verify the correctness of the theory analysis.