Research Of Lightning Protection For High-speed Railway Traction Substation

With the rapid development of high-speed railway, the safe operation of the traction substation also becomes more and more important. Unlike ordinary substations, the traction substation of high-speed railway has two characteristics. One is that its external power mostly adopts220kV level and it allows the increase of lightning over-voltage which invades traction substation along overhead lines. The other is that it easily enhances lightning activity nearby in thunderstorm weather because the substation is mostly located in the vicinity of the railway and the rail has low resistance as reflux facility. Lightning accidents would pose a great threat to the stable operation of the device in the traction substation. So it is necessary to assess the lightning protection performance of the entire substation and take measures to reduce the lightning over-voltage of the devices.This paper mainly studies the lightning damage of the devices in the substation caused by lightning wave which invades the traction substation along220kV line. This paper takes the lightning protection performance of some the traction substation as engineering background and adopts PSCAD/EMTDC to establish model for major device. On this basis, the entire model which reflects the invasion of the lighting wave is established. This paper stimulates the lightning according to the tower and the central ground wire and shielding wire stroke by lightning. The insulation margin can be calculated according to the lightning over-voltage of major devices. On this basis, the lightning performance of the substation can be assessed. For lack of existing measures, new lightning protection methods are adopted. The ground wire in line side ends in the terminal tower and the lightning rod is installed on the substation and the terminal tower to jointly protect the line. The simulation results show that the latter can effectively reduce the lightning over-voltage of the device in the substation caused by the lightning wave and prevent the lightning between the terminal tower and substation. Finally, the results are verified by theoretical analysis. New methods can effectively enhance the insulation margin of the devices and improve the lightning protection performance of the traction substation.