Characterization of Electrical Breakdown of On-Board High-Voltage Combinations Under Lightning Transient Conditions

The high-voltage system of the Fuxing train set adopts the form of combined electrical appliances, which has a high probability of insulation breakdown under the action of frequent over-voltage in the operation process. In view of this problem, the electric field simulation model of the high-voltage combined electrical system was established, the electric field distribution of the electrodes of the high-voltage box was analyzed under the operating over-voltage conditions, and the air breakdown characteristics were investigated under the action of the field. The study shows that under over-voltage conditions, the electric field strength near the small-sized electrode of the combination appliance is higher than the air breakdown field strength, and the statistical time delay is about 5.94us when applying a voltage of 150 kV. When doubling the size of the connection electrode and applying a voltage of 150 kV, the statistical time delay is about 7.20 us, and the probability of discharge is reduced, and the results of the study provide theoretical support for the miniaturization of the high-voltage electrical appliances for vehicles with high-reliability design support.