Feng Huo

Study on the electromagnetic environment of 1000 kV AC double-circuit transmission lines in China

The electromagnetic environment problems of three typical towers (two proposed in China, one in Japan) 1000 kV AC double-circuit transmission lines were analyzed in this paper. Successive images method was applied in calculating the conductor surface voltage gradient and power frequency electric field intensity (EFI) at the level of 1 m above the ground surface. Corona loss (CL), radio interference (RI) level and audible noise (AN) were calculated and the values at typical altitudes were calculated by using empirical formulas respectively. The minimum distance of the lowest phase conductor to the ground, corridor width (CW), RI level and AN were discussed according to the proposed electromagnetic environment control criteria in China. The correlation of a linear function between the RI level and the average maximum bundle gradient was discussed. CL, RI and AN variation with the bundle spacing were also discussed. Calculation and discussion results show that the two typical tower lines can satisfy electromagnetic environment control criteria at different altitudes by selecting suitable line parameters.

Study on parameters design and corona characteristics test equivalent of grading rings for 1000kV UHV AC compact transmission line

In order to give reference for the study of 1000kV ultra high voltage (UHV) AC compact transmission line grading ring design and corona characteristics, based on the 1000kV UHV AC compact transmission line pre-designed parameters, 3D electrostatic field finite element numerical analysis whole model to calculate the electric field distribution of composite insulator and grading ring was built, and the influence of pipe diameter, ring diameter, installation position and small grading ring to the maximum electric field strength on the surface of the grading ring was analyzed. Based on the numerical analysis results, four kinds of grading rings with different parameters were preliminary selected for true type test. 3D electrostatic field finite element model according to the corona test arrangement was built, the electric field of four kinds of grading rings were analyzed and compared with the whole model, and the correction coefficients were obtained between the whole model and corona testing simulation model. The research results can be a reference for the optimization design and following corona characteristics test parameters correction for 1000kV AC compact transmission line grading rings.