A Variational Approach to MTPA Control of Induction Motor for EVs Range Optimization

The paper presents a control strategy for induction motor which optimizes both efficiency and torque response in both transient and steady state. In the context of vectorial control of induction motor, the optimum problem is defined according to the calculus of variations for a given step change of the reference torque. This allows finding the closed-form analytical solution of the current reference trajectories which minimize the amplitude of the stator current. Simulation and experimental results confirm the validity of the proposed approach that allows getting significant improvements in the drive efficiency. As a consequence, if the induction motor is used in the powertrain of an electric vehicle, the proposed control strategy can determine an increase of the range per charge, as demonstrated by the analysis of a case study.