Corona Discharge Detection and Electric Field Analysis of Double-swinging Protectors in 1000 kV UHV Transmission lines

The double-swinging protectors are the key fittings of UHV transmission lines, which play a role to prevent bundle conductors from galloping in the wind. Corona discharge is prone to occur on its surface because of the structure of double-swinging protectors, which causes noise pollution and power loss. In this paper, ultraviolet imaging technology was used to detect corona discharge of the double-swinging protectors. And the position of corona discharge of the double-swinging protectors was obtained by analyzing ultraviolet images. In order to study the effects of the structure of the double-swinging protector on the electric field distribution and corona discharge suppression of the double-swinging protectors, a 3-D finite element model of the 1000 kV UHV transmission lines with double-swinging protectors was established by COMSOL Multiphysics. The model loaded with peak value of phase voltage was calculated and analyzed. The results show that shortening the effective pendulum length and increasing the pendulum radius can effectively reduce the maximum surface field strength of the double-swinging protectors and suppress corona discharge. In addition, a newly designed double-swinging protectors was proposed to optimize the maximum surface electric field strength of the double-swinging protectors and restrain corona discharge. The work in this paper could provide references for the design and manufacturing of line fittings in 1000 kV UHV transmission lines.