Analysis of vehicle body over-voltage under Ground´s automatic electrical phase

The switching of vacuum breakers will produce instability transient over-voltage when an electric multiple unit (EMU) passes the Ground´s automatic electrical phase. In order to study the propagating characteristic of over-voltage in the vehicle body, this paper introduced the operating principle of Ground´s auto-passing neutral section and analyzed the cause of over-voltage theoretically. Subsequently, the car-network coupling circuit model for EMU passing neutral section with on-board was built by utilizing ATP-EMTP power system electromagnetic transient analysis software, this paper proposed corresponding suggestions regarding suppression measures of over-voltage according to the vehicle body over-voltage´s influencing factors and distribution law in the length direction of EMU, which were obtained via simulation. The analytic result is significant for engineering practice.