Unified theory of torque production in switched reluctance and synchronous reluctance motors

A method is proposed for calculating the average and instantaneous torque of the synchronous reluctance motor from a knowledge of the trajectory of the phase flux-linkage versus phase current [i-Ψ] waveform, i.e., the same method as used with the switched reluctance motor. This allows a direct comparison between torque production in the two motors to be made. Analytical and finite-element analysis both show that the [i-Ψ] loci of the synchronous reluctance motor are ellipsoidal in shape and are not limited to the first and third quadrants as in the switched reluctance motor