PM-Assisted Synchronous Reluctance Machine Flux Weakening Control for EV and HEV Applications

In this paper, a novel robust torque control strategy for permanent magnet assisted synchronous reluctance machine drives applied to electric vehicles and hybrid electric vehicles is presented. Conventional control techniques can highly depend on machine electrical parameters, leading to poor regulation under electrical parameters deviations or, in more serious cases, instabilities. Additionally, machine control can be lost if field weakening is not properly controlled and, as a consequence, uncontrolled regeneration is produced. Thus, advanced control techniques are desirable to guarantee electric vehicle drive controllability in the whole speed/torque operation range and during the whole propulsion system lifetime. In order to achieve these goals, a combination of a robust second-order current-based sliding mode control and a look-up table/voltage constraint tracking based hybrid field weakening control is proposed, improving the overall control algorithm robustness under parameter deviations. The proposed strategy has been validated experimentally in a full-scale automotive test bench (51-kW prototype) for being further implemented in real hybrid and electric vehicles.