Research On Lightning Overvoltage Of Cable-Overhead Line

Lightning overhead lines have occurred.As Cable buried in the ground,lightning can not directly hit the cable.However,when the cable is connected to the overhead line,the overvoltage is generated in the transmission line,which will eventually cause the overvoltage in the cable to cause damage to its insulation.At first,the structural model of the submarine cable was introduced,and the advantages and disadvantages of the two different cables of the oil-filled cable and the cross-linked polyethylene cable were compared.The submarine oil-filled cable was used in Hainan networking project.Secondly,combined with the actual working conditions of Hainan networking project,the ATP(Alternative Transient Program)simulation software was used to simulate the submarine cable.The maximum attack and counterattack overvoltage of the submarine cable was 911 kV and 890 kV respectively,and both occur at the end of the sea cable line.At the last of the paper,the influence of different factors such as arrester,line length,lightning point position and power phase on the overvoltage of submarine cable were studied,and the measures to reduce lightning level and lightning strike probability were discussed.It is found that the overvoltage of the front submarine cable is mainly affected by the attenuation effect,and the overvoltage amplitude is decreasing.The last submarine cable over-voltage is mainly affected by the wave reflection process,affected by the arrester.When there is no lightning arrester,the maximum overvoltage along the line appears at the end of the line.When there is a lightning arrester,the maximum overvoltage along the line appears near the end of the line.The results of this paper provide a good theoretical analysis and date support for the submarine cable insulation of Hainan network engineering,which also provide a reference for the improvement of lightning protection level.