Research on EMI of Traction Network Transient Current Pulse on Shielded Cable Terminal Load

Abstract

The transient current pulse (TCP) caused by the traction network short-circuit fault (TNSF) will produce a high-strength transient electromagnetic field (TEMF). The electromagnetic field will interfere with nearby weak current equipment through the shielded cable. In this paper, a transient circuit model (TCM) for the short-circuit traction network is proposed to calculate the transient current. The short circuit is equivalent to a ring, and the TEMF transient electromagnetic field is calculated based on the magnetic dipole. The current response of the TEMF transient electromagnetic field on the shielded cable is deduced based on the transmission line theory and verified by experiments. The electromagnetic interference (EMI) of a TEMF transient electromagnetic field to the shielded cable terminal load were was studied under various incidence angles, azimuth angles, and polarization angles. The results demonstrate that the greater the incident angle and azimuth angle, the greater the EMI on the terminal load. The horizontal distance between the shielded cable head and the short-circuit point should be greater than 6 m, and the incident angle should be greater than 45∘. This method can provide a theoretical basis for the electromagnetic compatibility research of traction power supply systems and their nearby weak current equipment.