Helicopter Live-Line Work on 1000-kV UHV Transmission Lines

Live-line work methods using helicopters in the vicinity of 1000-kV transmission lines were simulated with finite-element modeling of the electric-field distributions. The effect of the approach path of the helicopter live-line work platform toward the energized conductor was computed. Predicted electric fields on the line worker head, body, arms, and legs were compared with measured results from a single-phase ultra-high-voltage (UHV) mock-up, and with calculation results from the simulation of an extra-high-voltage (EHV) 500-kV transmission-line geometry. The UHV conductor-to-work platform discharge occurred at a distance of about 2 m, in line with standard flashover models. Additional shielding efficiency of about 4 dB is recommended for the electrically conductive clothing when working on the UHV lines in China, compared to EHV lines.