Research on Electromagnetic Interference Characteristics of SiC MOSFET Traction System in Track Circuit Frequency Band and Its Impact on Signal Equipment

With the growing demand for lightweight design and energy efficiency in high-speed trains, SiC MOSFET power devices have demonstrated significant advantages in traction systems owing to their high-frequency operation and superior efficiency. In this paper, the electromagnetic disturbance characteristics of SiC MOSFET and IGBT power devices in traction system are compared by simulation, and the harmonic influence of track circuit working frequency band is analyzed emphatically, because this frequency band is directly related to the safety of train operation control. The results show that the harmonic of SiC MOSFET power device system is small in the working frequency range of track circuit. At the same time, a train-network co-simulation model is established to evaluate the harmonic distribution of the traction return current and the traction network under dynamic operating conditions (when the train runs to 6km from the traction substation). Finally, this paper verified that the harmonics of the SiC MOSFET system will not interfere with the action of the track relay.