Evaluation of various dynamic modeling methods of a circumferential-flux hysteresis motors

To analyze hysteresis motor performance from startup to synchronism, we need to a valid dynamic model. This paper studies and evaluates various dynamic modeling methods for hysteresis motor. Modeling based on constant impedance for the rotor, variable impedance based on load angle for the rotor, and variable impedance as well as dependent voltage source for the rotor is assessed. These models are implemented in Simulink for a given high-speed, circumferential-flux hysteresis motor and their dynamic responses, attributes and defects are explored. Unlike the hysteresis motor with constant impedance modeling for the rotor, the hysteresis motor with variable impedance modeling based on hysteresis delay angle and equivalent voltage source for the rotor will reach the synchronism at full load condition. Also we discover by this model the variation of lag angle would stay under 90 degree (ideal degree of hysteresis lag angle) and at the synchronism would be equal to nominal value of the typical motor. The simulation results obtained by variable impedance modeling based on load angle for the rotor will show us the motor reaches synchronism but the value of load angle is beyond 90 and almost equal to 180°. Finally, some suggestions are given to improve of dynamic model.