A time-stepping coupled finite element-state space model for induction motor drives. I. Model formulation and machine parameter computation

A time-stepping coupled finite element-state-space model for induction motor drives is developed. The model utilizes an iterative approach to include the effects of magnetic nonlinearities, and space harmonics due to the machine magnetic circuits' topology and discrete winding layouts. Model formulation and development, which include an improvement in the layout of the cage circuit representation, are given in this paper. This improvement leads to an enhancement of the "well-posedness", that is, reduction of ill-conditioning in the overall numerical convergence of the model. Meanwhile, in a companion paper results of induction motor performance simulation are compared with no-load and load tests for sinusoidal and inverter operating conditions. Particular attention is given to comparison between sinusoidal and inverter operating losses obtained from this generalized model.