A time-stepping coupled finite element-state space model for induction motor drives. II. Machine performance computation and verification

In a companion paper, a time-stepping coupled finite element state-space algorithm for the modeling of induction motor drives was developed. The model formulation and algorithm allows one to rigorously model the effects of space harmonics caused by magnetic circuit nonlinearities, topology and winding layouts, as well as their interaction with time harmonics caused by the inverter operation. In this paper, the model is used in the computation of induction motor performance with emphasis on the comparison between sinusoidal and inverter operations, with regard to effects on ohmic and core losses, as well as torque ripples and drive input/output power relationships. This includes harmonic contents of various currents, flux linkages and voltages, etc. The model allows for future study of failure modes such as bar and end-ring breakages in the squirrel-cages of such machines