Low-Vibration Design and Investigation of a Consequent-Pole PM Motor Utilizing Composite MMF and Subarea Permeance

In this article, an unequal Halbach consequent pole permanent magnet (PM) motor is proposed, where the research efforts are focused on effectively realizing low-vibration guidance design. With the guidance of deduction and analysis of the magnetic motive force (MMF)-permeance-based model, the even-order airgap flux harmonics characteristics and vibration sources generation mechanism of the consequent pole motor are investigated in detail. Then, the dominant harmonics related to radial force and torque ripple are determined and functioned as design objectives. By introducing a concept of composite MMF, a targeted unequal Halbach PM array is proposed to effectively regulate the MMF characteristics of the motor, thereby achieving even-order PM MMF harmonic suppression. On this basis, the subarea permeance design is further proposed, aiming to effectively weaken the high torque ripple contribution harmonics while further suppressing even-order harmonics. In addition, the performances of the proposed unequal Halbach consequent pole motor are evaluated, including the airgap harmonic analysis, torque, torque ripple, vibration characteristics, and so on. Finally, theoretical analysis and simulation experiments have verified the effectiveness of the proposed unequal Halbach consequent pole motor and its low-vibration design method.