Computer Simulation of an Induction Machine with Spatially Dependent Saturation

This paper presents a new analog computer model for the simulation of an induction machine which takes into account the spatially dependent main flux saturation effect. Using this model of saturation, an unstable operating region for a voltage fed induction motor with high source impedance has been calculated and has been correlated with both test results and the results predicted by the conventional linearized model. This study clearly demonstrates an improvement over the linearized model in predicting machine dynamic behavior. Because the simulation accurately models large signal as well as small signal behavior it should prove equally useful in predicting transient behavior. The manner of dealing with saturation of the magnetizing field presented in this paper can be readily implemented on a digital as well as an analog computer and can also be extended to the study of other electrical machines.