An Integrated Converter for Rail Vehicles Based on Silicon Carbide

In order to realize the miniaturization and weight reduction of the traction drive system of rail vehicles and reduce the motor current distortion caused by the low switching frequency of the traditional converter during high-speed operation of the vehicle, an integrated converter consisting of a power electronic transformer and a sine wave traction inverter based on silicon carbide (SiC) is proposed. The system implementation scheme based on SiC MOSFETs, the design scheme of high-frequency, high-power and high-insulation voltage-resistant magnetic isolation, and the communication design scheme of low-latency system are given, and the input and output characteristics of the system are analyzed by simulation. The results show that the total harmonic distortion rate (THD) of the input current is less than 1 %, the power factor is greater than 0.99, and the output voltage THD is less than 3.50% when the rated power is 3.25 MVA. The system efficiency is greater than 97.5%, which is higher than the efficiency of the traditional traction drive system by 3 % ∼ 5%.