Design and Optimization of a Pole Changing Flux Switching Permanent Magnet Motor
Yi Mao, Yi Du, Feng Xiao, Xiaoyong Zhu, Li Quan, Dao Zhou
Abstract
A flux switching permanent magnet (FSPM) motor is designed and optimized in this article to achieve high torque density and expanded speed regulation range from a design viewpoint of pole-changing (PC). Based on the field modulation theory, the PM field in the FSPM motor is modulated by the stator and rotor teeth, generating rich harmonics with different pole-pair numbers in the air-gap flux density. By adopting an appropriate slot pole combination, working harmonics with different slot pitch angles are obtained to establish a basis for the PC-FSPM motor. Then, different working harmonics can be used to achieve different energy conversions with different winding configurations, so the PC operation can be performed to realize the high torque and wide speed regulation range by switching the working modes. Based on the field modulation theory, the operation principle of conventional and PC-FSPM motors is analyzed and compared. Then, according to the design principle of the PC-FSPM motor, a 24/22-pole PC-FSPM motor with the E-core is designed and optimized by a multilevel optimization method. Finally, the electromagnetic performances are analyzed by finite-element analysis and the test results of the prototype have verified the feasibility of the motor.