Research on New Coreless Axial Flux High Speed Permanent Magnet Synchronous Motor for Flywheel Energy Storage

A typical flywheel energy storage system (FESS) has a complex structure and suffers from high cost, unstable axial electromagnetic force, and high self-discharge loss. This article presents the new axial flux coreless alternative pole permanent magnet synchronous motor (AFCA-PMSM) for flywheel energy storage system. Firstly, the topology and worling principle of AFCA-PMSM were introduced. Secondly, the design of flywheel rotor energy storage and mechanical strength are considered. Further, the suspension magnetic circuit of the structure is established, and the independence of the suspension and excitation magnetic circuits is analyzed. Finally, the performance indexes such as torque, suspension force, no-load back electromotive force and loss are comprehensively analyzed by finite element method. The AFCA-PMSM flywheel energy storage system has the advantages of high torque density, low cost, low self-discharge rate, high-energy storage and stable suspension force.