Design of Vernier Motor Considering PM Irreversible Demagnetization for Abnormal Operating Condition

This study investigates the design of a flux modulation pole (FMP)-type vernier motor considering irreversible demagnetization in a permanent magnet (PM). The FMP-type vernier motor, which has a distinct configuration compared to the conventional vernier motor, is taken into account because the PM placed at its stator is vulnerable to irreversible demagnetization. The demagnetization ratio of the PM is analyzed and compared using two different types of flux barrier, namely the bar- and delta-type barriers with varying design parameters. To guarantee reliability of the motor performance, both normal and abnormal operating conditions are considered for each type of flux barrier. Finally, selected models are compared to the base FMP-type vernier motor model in terms of demagnetization ratio and output torque.