Dynamic stator-flux-oriented induction machine control for electric vehicle application

Induction machines are affordable and robust, presenting a valid option for electric vehicles. Many control schemes for such machines are known and have been published. With regard to fast torque dynamics and robustness against parameter variation, stator-flux-oriented control is a very favorable option. This paper presents a stator-flux oriented control which bases on a comprehensive model of the induction machine. A sophisticated compensation of non-ideal converter behavior further enhances the results obtained. These results are documented by measurements and verify excellent performance: Fast response without current overshoot uses the rating of the converter optimally. Dynamic field weakening keeps excellent torque response in the field-weakening range without any voltage margin, too. Fast torque dynamics are not required for fulfilling the commands issued by the driver but for efficient disturbance rejection and additional features like slip-slide control and maximum-traction-point detection. For such features, the underlying torque control defines the performance - consequently, fast and precise reaction is requested.