Average lightning failure trip ratio of ±500kV Jiang-Cheng HVDC is 0.370 time per 100km·year

in which 84.2% happened at positive pole.Based on databases of Hunan lightning location system and sampling data from Jiang-Cheng fault tower

lightning movement parameters of 500kV Jiang-Cheng transmission line corridor were statistically analyzed and the results indicated that it is appropriate to set the length of side at 20km.Lightning densities of line corridor can vary much

but lightning current magnitude distributions are similar.Middle current of lightning magnitude is between 19.5kA and 24.6kA.Calculation results from rule method

multi-surge impedance method

and circuit method showed that shielding failure is the main cause for Jiang-Cheng HVDC lightning failure.