High-speed control strategy for permanent magnet synchronous machines in electric vehicles drives: Analysis of dynamic torque response and instantaneous current compensation

Flux-weakening control strategy of interior permanent magnet synchronous machines have a massive significance to enlarge the operational speed of electric vehicles (EVs) and to facilitate the power integration. However, how to keep the torque stability and achieve the fast response should be given the top priority. In order to facilitate the flux-weakening control application on EVs, a novel flux-weakening control strategy with fast transient current response is proposed. In detail, the change of dynamic voltage margin and its response are analyzed in this paper. Accordingly, the flux-weakening control is proposed through the collaborative control of the dynamic current compensation and the d-axis current-error adjustment. To fully evaluate effectiveness of proposed strategy, the traditional PI-based voltage-closed flux-weakening and the low-pass-filter method are constructed for comparison. The simulation and experimental results illustrate that the proposed strategy can achieve the fast torque response and also have the capacity to reduce the torque fluctuation of the stable state.