Effects of tower, phase conductors and shield wires on the electrical field around a tower window during live-line work

Abstract

The three-dimensional FEM electric field calculation model of a fiber glass-reinforced plastic (FRP) hot stick during live-line work, which was elaborated in a previous study, could well explain some features of the flashovers that occurred during a series of cold fog tests at CIGELE. These tests have achieved the most reliable reproduction of four separate FRP hot stick flashover incidents in Canada at a voltage stress of 105 kV/m at -1.04°C, Relative Humidity (RH) of 109 % with visible fog and 2.8 μg/cm 2 Equivalent Salt Deposit Density (ESDD). However, at the incident site, the geometry is different from that of the laboratory tests. In this paper, a three-dimensional electric field calculation model of a FRP hot stick during live-line work based on the finite element method is proposed to account for the geometry of the Manitoba site incidents at 500-kV. Moreover, the influence of the tower, phase conductors and shield wires on the potential and electric field distribution around an FRP hot stick during live-line work is studied.