Dynamic analysis of induction machine driven electric vehicles based on the nonlinear accurate model

The complexity of electric vehicles (EVs) as electromechanical systems make their simulation and analysis a difficult but challenging task, especially in the case studied in this paper where the EV is driven by an induction machine (IM). While IM performance is simple enough, its dynamic model introduces a variety of significant nonlinearities. Hence a main innovation of the present paper is the integration of the IM model into the entire system in a manner that enables a rigorous stability analysis. Particularly, each part of the EV, such as the battery storage system, the IM, the power converters and finally the dc loads are all taken into account and nonlinear Lyapunov based techniques are applied to prove stability. The cumbersome task of constructing suitable Lyapunov storage functions that are used to prove input-to-state stability (ISS) of the whole system, with respect to the external mechanical torque on the car wheels and the internal battery voltage, is precisely presented. ISS property ensures robustness and as it has been recently shown it can guarantee convergence to a nonzero equilibrium for any feasible bounded duty-ratio signals. As it is proven by the simulation results the theoretical analysis is confirmed by a very satisfactory system performance without contradictions and adverse impacts between the several responses of the electric and electromechanical part.