The surge voltage of car body seriously affects the safe operation of vehicle electrical equipment

and disturbs the data acquisition and transmission of train control equipment in the process of rising pantograph of the high speed electric multiple unit（EMU）. Taking a car as an example

we established an equivalent model

including the overhead contact power supply

the high voltage cable

the carriages and the grounding system based on the PSCAD/EMTDC software

to analyze the characteristics of the surge voltage when rising pantograph with the existing connection mode. Moreover

we simulated the propagation characteristics of overvoltage on pantograph and car body at the moment of the pantograph rising

and analyzed the influences of the high voltage cable length

the equ

ivalent parameters of the overhead contact power supply and its voltage phase on the induced voltage. The results show that the transient voltage amplitude of the pantograph head is 60

7

0 kV

the oscillation decay time is about 25 μs

and the oscillation frequency is often between 0.86

1

.74 MHz. The surge voltage amplitude of car body decreases gradually along the direction of its propagation between different carriages. The maximum voltage amplitude of car body is up to 7.02 kV which is the voltage difference between the roof and bottom of car number 3. The research results show that the surge voltage is mainly affected by the length of high voltage cable

the equivalent parameters of the power supply

and voltage phase of the contact line at pantograph lifting moment.