Simulation and research on Direct Torque Control of Asynchronous Traction Motor

The paper, based on deeply analysis of the traditional Direct Torque Control (DTC), established a model of the traditional DTC strategy in the base of Asynchronous Traction Motor with circular flux track and hexagon flux track. The features and shortcomings of the traditional DTC switching frequency are analyzed, so an approximation constant frequency method based on variable torque tolerance is adopted. At last, both of the two methods are compared by Matlab/simulink, the modified results show a state of approximately constant frequency. The control method takes full advantage of the terminate frequency of inverter and decreases the torque pulse in the setup stage, so as to prevent driving wheel effectively from slipping at setup stage for the power-intensive high-power locomotives.