Multi-objective optimization design of a PM-less synchronous motor using simplified response surface method

For cost-effective concern, how to reduce the usage amount of the rare-earth permanent-magnet (NdFeB) in an IPMSM has become an important research issue. Fortunately, the less permanent-magnet synchronous motor (PM-Less SM) with confusing rotor flux barriers and clever permanent-magnet arrangement has the potential to become high-performance motor. The main advantage is through ingenious geometric structure design, the PM-Less SM can have larger inductance difference (L_d-L_q) and torque angle (δ_e) to enhance the reluctance torque component that is shown, thus the output torque of the PM-Less SM is able to meet the requirement of load. Hence, under cost-effective concern, the PM-Less SM gradually has become a hot research topic. In this paper, a simplified response surface method (SRSM) with the shuffled frog leaping algorithm (SFLA) is proposed to find the most suitable shape of rotor flux barriers and the PM usage amount to improve the motor´s performances, such as lower torque ripple and higher power factor. Experimental results show that the proposed method can rigorously and effectively obtain optimal geometric parameters of a PM-Less SM machine for enhancing the motor performances.