A novel direct torque control based on variable structure control in Hybrid Electric Vehicle induction machine drive

According to the requirements of the HEV for frequent start-stop, power feed-back, low speed high torque in climbing, boosting in accelerating and high efficiency, this paper proposes a motor drive system based on variable structure control. During different running states, three different DTC methods are applied. In middle and high speed, the traditional DTC is used; in the sub-low-speed, increasing the density of the regional division of flux linkage and optimizing the choice of the switch vector is used; in super-low-speed, the predictive control based on the DTC is used to decrease torque ripple, meantime, genetic algorithm is used to optimize the control parameters of the system in order to efficiently weaken the shock in switching between the different algorithm. The simulation results shows, this control strategy can meet the performance requirements of HEV well.