The basic function of the train electric traction system is to absorb electrical energy and convert it into the mechanical energy required to drive the train, or convert the mechanical energy of the train into electrical energy, thereby implementing electric braking of the train. The form of traction power supply for city rail train is commonly DC750V, 500A or DC1500V, 250A. During electric traction, the DC power is converted into three-phase AC power by the inverter to supply power to the AC traction motor. At this point electrical energy is converted into mechanical energy. During electrical braking, the mechanical energy of the traction motor is converted into electrical energy, which is converted into DC by the three-phase inverter and fed back to the grid.

For rail transit conductor rail current carrying capacity and traction power supply system, ITECH builds a power supply system with a total power of up to 152KW by simply paralleling multiple power supplies of the same specification to meet high-power testing requirements. At the same time, it is equipped with an energy feedback type DC electronic load, which can not only simulate various load characteristics, but also feed excess electric energy back to the grid. It reduces the cost of electricity and heat dissipation for users, and saves energy and protects the environment.