A Novel Time Varying Dynamic Modeling for Hysteresis Motor

Abstract

Hysteresis motors are used in special applications such as gyroscope, and gas centrifuge due to their unique features such as synchronism, self-starting and developing smooth torque. Dynamic modeling of hysteresis motors is essential to predict of the transient performance, studying the dynamic stability, development of modern closed-loop control and estimation strategies. This paper develops a new time varying dynamic model for a high-speed, circumferential-flux type hysteresis motor, in which the parameters of equivalent circuit of rotor’s material are adjusted based on operational B-H loop. For this purpose and based on elliptical assumption for B-H loops, the hysteresis lag angle β is updated due to the applied stator voltage and available load torque. Developed mathematical model satisfies many theoretical aspects of hysteresis motor behavior in transient and steady-state situations. The model offers a tool for studying the start-up of hysteresis motor, change of stator voltage, variation of load torque, frequency tracking for variable-speed applications and transient-state response to design parameters. Some simulations are provided to demonstrate the validity of developed model in Matlab/Simulink and are verified via some experimental results. Proposed results verify the advantages of this model rather than previous works.