Calculation And Analysis Of Over-voltage 500kV Xinhuan Line

For the transmission of power system,500 kV extra-high voltage transmission line is an important part of whole power transmission network.From years of operation experience,power frequency overvoltage and switching overvoltage are main reasons causing damages of high voltage equipment.If lack of efficient research and analysis and related protection action,it is highly possible to affect stable operation of the network.In addition,500 kV ehv transmission lines are easily be struck by thunderbolt because they are exposure to natural environment,which can damage the stable operating of the network too.So in order to ensure the network transmission system stabilization,the research and analysis focusing on 500 kV ehv transmission lines are necessary and useful.This article is focusing on Xinhuan Line.In Xinhuan Line situations,such as frequent inspection operation,changing the operation methods and lighting disaster.It is using ATPEMTP to establish power frequency overvoltage,switching overvoltage and lighting overvoltage modules based on Xinhuan Line data.It is calculating power frequency overvoltage and switching overvoltage under four different working conditions,analyzing electric reactor's effect on power frequency overvoltage,the relationship between neutral reactor and secondary arc current and lighting protector inhibitory influence on switching overvoltage.In order to calculate Xinhuan Line lighting withstand level and analysis how fundamental frequency power supply,ground resistance and tower high influence on it,it establishes lighting current,tower,transmission line and insulator string modules to simulate actual situation.From the results,we can see power frequency overvoltage rise after electric reactor out of service under different working conditions.It is easy can tell the electric reactor has inhibitory effect on power frequency overvoltage.Lines without lighting protectors have significant voltage values comparing which with lighting protector.For lighting overvoltage,changing towers' ground resistance,fundamental frequency power supply and tower height have different effects on lighting withstand level.This article is considering Xinhuan Line different overvoltage conditions and calculating and analyzing its prevention and control work systematically.