Research on the Real-Time Simulation of the Traction Drive System in Electric Multiple Units

A discrete mathematical model of the traction drive system,including a traction transformer,two four-quadrant converters,an intermediate DC circuit,a PWM inverter and a traction motor,is established based on Simulink through analyzing the structure and the working principle of the traction drive system of an electric multiple unit.Combined with a real-time simulator named dSPACE,a real-time simulation platform of the traction drive system is established.The platform,which includes a virtual traction drive system,a real traction controller and their connect box,can simulate the changes of physical variables of the traction drive system.And it's the first time that a virtual driver's console and a virtual central control unit join the real-time platform to simulate the response of the traction drive system to the drivers' actions.An on-vehicle TCU program is tested on the platform,the output traction characteristic curve is similar to the designed one,and the voltages and the currents of the four-quadrant converters and the traction motors under the traction and the brake conditions meet the traction and the brake control requirements.All the results show that the real-time traction drive simulation platform can accurately simulate the real traction drive system,so the virtual traction drive system in the platform can be used to study and test the traction control unit instead of a real one.