中文摘要：

为了提高双转子电机的转矩密度，实现其应用于混合动力汽车驱动系统的小型轻量化和平稳运行的需求，提出一种三相12／22／12极定子永磁式磁通切换双转子电机结构，其绕组和永磁体均位于外定子和内转子上，外转子上无绕组和永磁体，避免了外转子的冷却问题。对定子永磁式磁通切换双转子电机的拓扑结构及工作原理进行了介绍，采用有限元方法对电机磁场分布、气隙磁密、永磁磁链、空载反电动势、电感及转矩等电磁性能进行了分析。研究结果表明，提出的定子永磁式磁通切换双转子电机结构具有内外电机磁场耦合小、空载反电动势正弦性好、转矩密度大、转矩脉动小的特点，并通过原理样机实验结果验证了电机设计的有效性。

英文摘要：

In order to improve the torque density of double-rotor machine and meet the demand of small amount and steady running in its hybrid electric vehicle driving system, a 3-phase and 12/22/12-pole stator-permanent magnet（PM） flux-switching double-rotor machine is proposed. It consists of both arma- ture windings and PMs in the stator and inner rotor while no PMs in the middle rotor, which can avoid the middle rotor＇ s cooling problem effectively. The machine topology and operation principle were presented. By using finite element method （FEM）, the corresponding electromagnetic performances, in- cluding magnetic field distribution, PM flux linkage, back electromotive force（EMF）, inductances and torques were analyzed. The simulation results show that the proposed machine has the merits of little magnetic coupling exists between inner and outer machines, favorable sinusoidal feature of no-load back EMF, large torque density, and little torque ripple. And the designed machine＇s validity is verified by the tests on the prototype machine.