直驱式电励磁双凸极风力发电机的极数研究

针对低速直驱风力发电应用场合，对电励磁双凸极电机的极数进行了研究。双凸极电机属变磁阻电机，存在2个气隙且电枢绕组为集中绕组，常规电机数学模型已不再适用。该文分析了电机的气隙磁密和极对数的特点，并在此基础上推导了单匝绕组电动势和相绕组电势的表达式，从理论上证明了在定子内径和转速不变时，单匝绕组电动势与极数无关，而相电势与极数成正比关系。有限元仿真和实验结果验证了理论分析的正确性。给出1 MW直驱式电励磁双凸极风力发电机设计实例，并进一步分析了极数对电机有效材料的影响，为低速直驱式电励磁双凸极电机的极数选择提供参考。

Pole Analysis of Doubly Salient Electromagnetic Generator for Direct Driven Wind Turbine

The goal of this paper is to analyze the pole number of the doubly salient electromagnetic generator (DSEG) for direct driven wind turbine. As a variable reluctance generator, the doubly salient electromagnetic generator has two air gaps and concentrated phase windings, so the traditional mathematical method is no more effective. In this paper, the features of air gap flux density and the pole pair number are analyzed firstly. Based on that, the relations between poles and electromotive force (EMF) are derived. And it is validated theoretically that the EMF per turn has no relationship with the pole number while the EMF of phase is proportional with pole number. Then the results of finite element analysis (FEA) simulation and experiment are given to show the validity of the researches in this paper. Finally, the effective material weights with different pole number of the 1 MW doubly salient electromagnetic generators are estimated and the research results presented by the paper are useful for pole number chosen in the DSEG.