Constant-power operation performance improvement of the induction machine drives for hybrid electric vehicle applications

Torque decline problem is analyzed when the induction machine is at the constant-power operation. The influence of the leakage reactance on the torque is analyzed. Under the condition of variable frequency driving, it is qualitative analyzed how the slot combination and the rotor slot shape affect the constant-power operation performance of the induction machine. Constant-power operation performance of the induction machine is improved by optimizing these two parameters. Finally, finite element method is used to validate the optimization result. The constant-power performance of the sample induction machine is improved through the finite element method.