永磁同步电机因使用磁钢提供磁通,简化了电机转子结构从而提高了电机的运行可靠性;另外,因无需励磁电流省去了励磁损耗,从而具有高效率、高功率密度等优点.但传统永磁同步电机由于存在齿槽转矩和磁阻转矩,存在电机输出转矩脉动较大的问题.针对该问题,以提高电机平均输出转矩、降低电机输出转矩脉动和减小电机气隙磁密总谐波失真为优化多目标,建立一种分段磁钢永磁同步电机模型.选择电机转子关键结构参数为优化参数,通过田口算法优选出对优化目标影响较大的结构参数,再采用响应面法拟合优化目标曲线确定最优参数组合,实现分段磁钢永磁同步电机多目标优化,并通过仿真验证了有效性.最后试制了一台三相48/8极的样机并进行了试验,试验结果验证了电机结构及优化方法的合理性.

针对传统分块转子磁通切换发电机在低励磁电流时,空载电动势过轴线对称且正负半周期幅值不相等的问题.提出了一种在定转子上增加气隙磁障的方法以削弱空载电动势中的谐波,改善电动势波形的方法,并且利用电机学公式从理论上分析了其谐波削弱的原理.通过有限元仿真软件对新型分块转子磁通切换发电机静态特性进行了分析,包括磁场分布、空载电动势、磁链等.仿真结果表明,优化后电机空载电动势的电压波形正弦性畸变率降低了83.1％.

针对偶数极分块转子磁通切换发电机存在偶数次谐波,导致感应电动势正负半周期波形不对称问题.建立了解析数学模型并推导出不同时刻、不同位置转子磁导引起的定、转子磁势的变化,进而达到削弱偶数次谐波的目的.提出了一种在分块转子内增加气隙磁障的新型拓扑以削弱感应电动势中的偶数次谐波.通过有限元仿真得到了传统的和带磁障的两种电机的磁链和感应电动势,并通过傅里叶分析得到各次谐波含量,证明了解析方法的正确性.依据上述理论试制了样机并进行实验,仿真和实验结果表明:加入气隙磁障后,12/8极分块转子感应电动势正负半周期波形近乎对称,相比于传统分块转子磁通切换发电机,虽然感应电动势基波幅值减小了14.9％,但是电压波形畸变率降低了88.2％,验证了所提方法的正确性,从而为偶数极分块转子谐波的削弱提供了一种新的解决方式.

The voltage harmonics of the six-phase doubly salient electro-magnetic generator (DSEG) are large, and the electromagnetic isolation is poor due to the mutual inductance of the armature winding. An optimization scheme for the stator non-uniform air gap structure is proposed. By establishing a non-uniform air gap angle function model, the analytical expression of the induced electromotive force in the non-uniform air gap structure is derived. Using finite element and mathematical model to verify that the stator tip is changed from circular arc to linear structure can increase power and reduce voltage high harmonics, improve the power quality of the generator. Based on the equivalent magnetic circuit, the influence of the winding method of the excitation winding on the mutual inductance of the armature winding is studied. When the field winding is wound interval every two stator poles, the mutual inductance is small. The electromagnetic properties of the new six-phase electric excitation double salient pole are analyzed by two-dimensional finite element analysis. The rationality of the proposed motor structure is verified by experiments.