Study on the hunting in high speed hysteresis motors due to the rotor hysteresis material

Hysteresis motors behave very much like to classical synchronous motors, except that the motor magnetic pole definition varies slightly with torque. This paper presents a study on the hunting of a radial-flux type, high speed hysteresis motor caused by the hysteresis material of the rotor. Firstly, a nonlinear dynamic model of the PWM-controlled hysteresis motor drive is developed in d-q axis. Then the effects of magnetic properties of hysteresis rotor materials are investigated. Experimental results verify that B-H curve of hysteresis material have significant effect on the rotor hunting in steady state rather than other parameters.