A Novel Axial Split Phase Bearingless Switched Reluctance Machine for On-Board Flywheel Battery

In this paper, a novel topology for the flywheel battery is proposed, based on the axial split phase (ASP) bearingless switched reluctance machine (BSRM) concept. The topology and operating principle of the ASP-BSRM are explained, the electromagnetic characteristics, torque, suspension force and coupling performance are analyzed by 3-D finite element analysis (FEA). In order to improve the torque and suspension force of the ASP-BSRM, the single variable method by FEA is adopt to screen out the sensitive structure parameters, and a new multi-objective optimization design mothed based on random forest regression (RFR) and differential evolution (DE) is proposed to optimize the key parameters. The 3-D FEA of the complete system is performed, and simulation results verify the proposed topology overcomes the dead zone of suspension force and realize the decoupling between torque and suspension forces. Besides, the optimized torque and suspension force are improved by 4.15% and 12.91%, respectively. An experimental prototype is built to provide an experimental basis for investigation of the actual operating characteristics. The experimental results of the system are evaluated under different operating conditions and compared with FEA results.