Incorporating the thermal effects and flux setting in the vehicular drive system

The fact that the drive system of an electric vehicle (EV) and hybrid electric vehicle (HEV) is powered by the battery and cooled by car coolant increases the importance of machine operation at an optimal operating point both with respect to efficiency and thermal considerations. This paper investigates the temperature effect on the machine's performance and suggests a fuzzy logic controller to optimize the machine operation with respect to drive system efficiency and insulation degradation. The paper also includes a simple strategy for the flux setting of induction machine to optimize its efficiency. The machine is operated at various loads and data is collected for the machine's efficiency. This data is then used in the controller design for operating the machine at various loads.