The Optimization of Entering Route for Live Working on 750 kV Transmission Towers by Space Electric-Field Analysis

Live working is important for the continuity of electricity supply in power system. Experiment results of 50% switching impulse sparkover voltages (U₅₀) for different live working entering routes on a real tower are presented. The potential and electric-field distribution around the 750 kV straight tower window with a line worker inside, was analyzed via an approach combing charge simulation method and indirect boundary element method. The comparison demonstrates the close relationship between electric-field distribution and U₅₀. The sparkover voltage and the maximum electric-field strength change synchronously for a specific structure. Generally speaking, the higher the electric filed strength is, the lower the sparkover voltage will be. Thus, the experiment procedure for deciding the best entering route can be simplified according to the electric-field distribution calculation.