A time-stepping coupled finite element-state space model for induction motor drives - Part 2: Machine performance computation and verification

In a companion paper, a Time-Stepping Coupled Finite Element State-Space algorithm for 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 power condition (inverter) operation. In this paper, the model is used in the computation of the parameters and prediction of performance characteristics of a 3-phase, 2 pole, 1.2-hp, 208 Volts squirrel-cage case-study induction motor. In addition, emphasis is laid on comparison between sinusoidal and inverter operations, with regard to effects on ohmic and core losses, as well as torque ripples. Furthermore, this includes harmonic breakdowns of selected inductance profiles and developed torque profiles. Numerical simulations were verified by comparison to test data with excellent correlation between both sets of results.