Multi-objective Optimization and Performance Analysis of Dual-Rotor Hub Motor Based on Comprehensive Sensitivity Stratification

To solve the shortcomings of the existing hub motors in the practical application of electric vehicles, an integrated dual-rotor hub motor (DRHM) was proposed, which can realize multiple drive modes to adapt to the vehicle's variable driving conditions. Aiming at the complex structure of the DRHM, a multi-objective optimization method of design variables stratification based on comprehensive sensitivity was proposed. The design variables with medium and high sensitivity were optimized by the response surface method and genetic algorithm, respectively. After overall weighing the optimization objectives of output torque, torque ripple, usage amount of permanent magnets and magnetic coupling coefficient, three candidate design were screened out. By the comprehensive performance evaluation of the motor, the optimal structural sizes were determined. Based on a two-dimensional model, the electromagnetic performances of the DRHM were analyzed. The simulation results show that the motor has a small cogging torque and low magnetic coupling degree, and the independent control and stable operation of the internal and external motors can be realized. Besides, the basic characteristics of the DRHM prototype were tested. The experimental results accords well with the simulation results, which show that the proposed motor structure is reasonable and the multi-objective optimization method is effective.