Torque prediction and maximization strategies for bifilar-wound hybrid step motors

A method to predict torque-speed characteristics of the bifilar-wound hybrid step motor with the inverse-diode-clamped drive circuit is presented. The phase excitation control strategies that maximize and minimize average torque production are found. A closed-form expression for average torque produced by the motor is found by representing the flux linkages and model parameters as Fourier series. The predicted average torque function is compared to other methods and experimentally measured results. Inclusion of the drive circuit model is shown to significantly improve prediction of torque speed characteristics