Online Overshoot Suppression Method for EV Propulsion Motor Considering Cross-Coupled Inductance

Abstract

The effects of cross-coupled inductance are significant in high power density motors. It is observed here that the cross-coupled inductance causes current and voltage overshoots in the high-speed region. As the required voltage exceeds the voltage limit, the system becomes unstable. Here, the current dynamics are analyzed with a reduced model that incorporates a cross-coupled inductance, L-qd. Further, it is shown that L-qd makes an uncanceled zero in the current transfer function, which invokes the overshoot. It can be compensated with an estimate (L) over cap (qd). However, it is not easy to obtain correct estimates of L-qd in a wide current range. In this paper, an online overshoot suppression algorithm is proposed by using a high-pass filter. The simulation and experimental results provide some evidence for the effectiveness of the proposed algorithm. Finally, it is shown experimentally that the proposed algorithm cured the vehicle hunting problem after tapping off the gas pedal in a high-speed operation.