Jumper Fitting Corona Characteristic for EHV High Altitude Transmission Line

Problems of electromagnetic environment are getting more and more attention nowadays for design and operation in power system. Corona discharge of jumper spacers for 750 kV transmission line in some northwest part areas of China is relatively severe and need to be optimized. In this paper finite element method is used to simulate the distributions of electric field on the surface of jumper spacer under the actual transmission line and influences of electric distribution are also discussed. According to the simulation results, corona discharge test is performed. By using the anti-corona ball on the clamp of jumper spacer can reduce the electric field strength from 35.4 kV/cm to 29.2 kV/cm (ball diameter 100 mm) and 22.5 kV/cm (ball diameter 150 mm). The inception voltage and extinction voltage are raised more than 23.5% and 19.4% respectively. The method discussed in this paper can be taken as the reference in optimization and design for the jumper spacer of 750 kV transmission line.