Lightning is the main reason for the trip of transmission line

however

the lightning flashover criterion based on standard lightning impulse has some limitations in back flashover criterion calculation

thus it is necessary to research the simulation and experiments on the short-tail voltage wave under transmission line back flashover. Based on the PSCAD/EMTDC simulation software

we established a back flashover model of the 110 k V double-circuit transmission line.Meanwhile

we simulated and analyzed the influences of the tower height

lightning current model（double exponential wave and heidler wave） and gro

unding resistance on the waveforms. Based on the present impulse voltage generator in the laboratory

the impulse voltage circuit that meets the requirement of different short-tail voltage waveform was designed

and the experiment was carried out. The results of simulation show that the wavefront of short-tail voltage wave is shorter if towers are higher. The peak

the wavefront

and the wavetail decrease obviously with the decrease of grounding resistance

and the short-tail voltage wave generated by double exponential current is different from that generated by heidler current. In addition

the wavefront is between 0.2

2

.0 μs and the the wavetail mainly focuses on 5

1

0 μs. The experimenal results show that the insulator U50% under short-tail voltage wave is higher than that under standard lightning wave by 25%

3

0%

which shows that the backflashover criterion under these two kinds wave has a large difference

thus the waveform of impulse voltage greatly influences the backflashover withstand calculation result.