Design of a brushless compound-structure permanent-magnet synchronous machine for HEV propulsion system

Compound-structure permanent-magnet synchronous machine (CS-PMSM), which is composed by two electric machines, is a new type of machine developed these years. It has a wide application prospect on hybrid electric vehicle (HEV). One of the main disadvantages of this machine is that as one of the rotors has armature winding in it, a brush and slip rings must be used. Some research work has been done to solve this problem and a novel brushless scheme is proposed in this paper. The new type of brushless CS-PMSM consists of one stator machine (SM) and one brushless double rotor machine (BDRM). As the BDRM has a new claw-pole structure, the equivalent magnetic circuit is drawn, then the model is built and optimized by using 3D finite-element method (FEM), the results of the optimization show both the back electromotive forces (BEMFs) and torque meet the requirements.