Predicting the pullout torque/speed curve of variable-reluctance stepping motors

An efficient numerical technique for predicting the pullout torque of variable-reluctance (VR) stepping motors is described. The method takes account of magnetic saturation and of nonlinearities in the drive circuit, and thus permits reliable prediction of the torque/speed curve to be achieved at the design stage. This is particularly valuable in studying the behaviour at high stepping rates where, hitherto, the influence of the motor and drive parameters has not been properly understood.