Analysis of the Synchronous Torques in a Split Phase Induction Motor

This paper puts forward a method for calculating the synchronous torque dips in a split-phase induction machine. First it derives the equivalent circuits so that the torque speed/curve can be obtained over a full speed range (including asynchronous torque oscillations). When the currents are resolved these are used to calculate the synchronous torques from a set of interactions between the machine MMFs and the slot permeances. This gives the synchronous torques (speed and magnitude) which can be superimposed onto the torque/speed curve. The method is tested experimentally and found to give reasonable results.