Simulation and experimental analysis of corona loss of 1000 kV and 500 kV AC transmission lines on same tower

In order to obtain data of corona loss of AC multi-circuit transmission line with double-circuit 1000 kV and double-circuit 500 kV on the same tower, we performed both test and simulation studies. The finite element method was used to calculate the field strength on the surface of wires in a corona cage and wires for the future East China towers. An optical digital corona loss measurement system was adopted to measure the corona loss of a 4×LGJ-630 wire and an 8×LGJ-630 wire in the corona cage under dry/rain conditions. The corona loss of the towers under rain condition was calculated by using the corona loss equivalent method. The result shows that, under the dry condition, both 4 bundled and 8 bundled conductors in the corona cage haloed all over when their voltages were 350 kV and 400 kV, respectively; however, there was no inflection point in the voltage which would induce all-over halo under the rain condition. According to the calculations, under the heavy rain condition, the corona losses of 1 km double-circuit 1000 kV and double-circuit 500 kV were 300.99 kW and 80.92 kW, respectively.