Resonance effects in stepping motors

The mechanism of resonance-induced maloperation of stepping motors is studied, and a simple analytical method is presented enabling resonance frequency bands, and the damping factors necessary to suppress resonance, to be predicted. Emphasis is placed on the determination of the equivalent linearised torque/displacement characteristic for practical use. Experimental results for the bands of resonance-induced maloperation of a 3-stack stator, variablereluctance type of motor confirm the approach. The occurrence of reverse running in a highly stable, double-speed mode at certain, nonresonant frequencies is reported and briefly commented on.