Multiobjective Optimization Design of Outer Rotor Coreless Bearingless Permanent Magnet Synchronous Motor

The outer rotor coreless bearingless permanent magnet synchronous motor (ORCBPMSM) is suitable for flywheel energy storage systems because of the advantages of no core loss and high efficiency. To improve the output torque and suspension forces of the motor, a Taguchi-response surface method (T-RSM) is proposed to conduct multiobjective optimization design of the motor. First, the basic structure and working principle of the proposed motor are expounded, and the basic design parameters of the motor are given. Then, the orthogonal matrix is established according to the number of factor levels, and the finite element analyze (FEA) is conducted to obtain each set of test results. After that, the sensitivity analysis is conducted and the best combination of variables can be achieved. Aiming at improving the accuracy of the Taguchi method, the fitting functions are established among the targets and conflicting variables, and the optimal solution is obtained by RSM. Finally, the optimal motor is manufactured, and the performance of the motor is verified. The experimental results show that stable operation can be obtained and the operating performance of the proposed motor is improved after optimization.