Energy Optimization Strategy of Induction Motor for Electric Vehicles in High-Speed Constant Power Region

The problem of poor efficiency under light load also exists in high speed constant power region of induction motor (IM) drives for electric vehicles, which directly restrict the electric vehicles´ travel distance. The operation characteristics of IM in the ECE urban drive cycle are analyzed at first. Then the losses of induction motor are discussed and so is the effect on IM´s control caused by the voltage and current constraints in the high-speed constant power region. An energy optimization strategy suitable for electric vehicle based on loss model, by the means of regulating flux level, was given. Experiments were carried out based on DSP TMS320LF2407A experimental system. The results show that the optimization strategy improves the motor efficiency in high speed region markedly, and fast optimization, small torque and speed fluctuation are achieved. It provides a sound solution for the electric vehicle´s propulsion system