Torque prediction for efficient commutation strategy of bifilar hybrid step motors

Novel phase-energization strategies are proposed to optimize energy consumption of closed-loop controlled step motors. A method to predict torque-speed characteristics of the bifilar hybrid step motor is presented. The phase energization control strategy that optimizes efficiency for a required average torque is found. The strategy is achieved by controlling both the position and the conduction interval of the input voltage waveform for each phase