Analysis and optimization of a novel brushless compound-structure permanent-magnet synchronous machine

A novel brushless compound-structure permanent-magnet synchronous machine (CS-PMSM) is proposed in this paper. The structural characteristics are described and the operation principle is introduced. The equivalent magnetic circuit of the BDRM is established, and the electromagnetic torque is deduced by analytical method. The new type of brushless CS-PMSM consists of one stator machine (SM) and one brushless double rotor machine (BDRM). Using 3D finite element method (FEM), a BDRM prototype is designed and evaluated. Some characteristics including air gap flux density, no-load flux linkage, back-EMF, and torque behavior are obtained.