Mathematical Modeling of an Induction Motor for Vehicles

Abstract

It has been proposed, in order to model an induction motor for vehicles, to employ a system of differential equations recorded in the «inhibited coordinates». To improve the algorithm robustness, the number of the system's equations was reduced by expressing the phase currents through the phase flux linkage. The parameters of the prototype engine have been defined in line with the classical procedure. An algorithm has been constructed in order to account for the mechanical losses and power losses in the engine steel. An induction motor with symmetrical windings has been simulated in the MATLAB programming environment. The basic technical parameters for the engine were determined using the simulation model. The simulation results have been compared with the results of classic calculations. The error in determining the parameters based on the model and those calculated did not exceed 7 %. This indicates a high convergence between the simulation results and the results of calculations. It has been proposed, in order to study an induction motor with the asymmetrical stator windings, to apply the algorithm that implies accounting for a change in the mutual inductance at a change in the integrated resistance in the single or several phases of engine windings. The proposed algorithm for managing the asymmetric regime of stator windings could make it possible, without changing the structure of the model, to investigate the dynamic processes in an induction motor in case of the asymmetry of stator windings phases when they are damaged. Taking into consideration the losses of power in steel, as well as the mechanical losses, would improve the reliability of the results obtained. The error of determining the parameters of an induction motor at asymmetrical stator windings, obtained at modeling, and acquired experimentally, did not exceed 3 %, which testifies to the adequacy of the model.That would make it possible to apply the proposed simulation model of an induction motor when studying the dynamic processes in the engines used in the transportation infrastructure, in case of such a defect as the interturn short circuit in the stator windings