Abstract: Pantograph and catenary off-line brings great harm to the safe and reliable operation of subway vehicles. The equivalent process during off-line and the off-line equivalent circuit of subway vehicles was proposed. Taking a metro vehicles powered auxiliary inverter system as an example, the off-line transient analysis was carried out, and a simulation test was conducted. As shown in the results, the useful signal during off-line greatly reduced in vehicle system and the harmonics of Insulated Gate Bipolar Transistor (IGBT) voltage was greatly increased. The questions about heat-resistant and insulation arose, which caused the inverter module to damage and greatly reduced the metro vehicle operation safety and reliability. Important reference for IGBT selection, protection and pantograph-catenary structure improvement was provided.

Key words: arc, pantograph and catenary off-line, transient process, harmonic analysis, metro auxiliary inverters