An AC arc discharge model for ice-covered FRP live-line tools

Four separate FRP hot-stick flashover incidents have occurred in Canada during live-line working under steady-state system conditions at the peak of the voltage negative half-cycle during cold and freezing conditions. The incidents were reported at 500-kV AC line voltage working stress (95–96 kV/m) in 1997 and 2002 in Manitoba, and at 230-kV AC line voltage working stress (71 kV/m) twice in the neighbouring province, Saskatchewan, in 2012. To the best of our knowledge, the most reliable reproduction of these incidents has been achieved at UQAC Laboratories 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
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Equivalent Salt Deposit Density (ESDD) during a series of “true” cold fog tests. In this paper, suitable mathematical models for predicting the AC flashover voltage of ice-covered insulators are studied by considering a 1-mm ice layer covering an FRP hot stick. To the best of our knowledge, such modeling for FRP hot stick under cold and frozen conditions has never been attempted so far.