Statistical determination of minimum breakdown voltage for GIL and GIS

The paper deals with the problem of the optimum test procedure for investigating the dielectric properties of gas-insulated switchgear and transmission lines (GIS and GIL). For large GIS and GIL the test procedure becomes more significant, owing to a reduction of the statistical withstand voltage of the whole construction, due to the area effect. However physically there cannot occur a discharge below a minimum breakdown voltage. This fact is taken into account by a Weibull distributed breakdown probability. In order to determine the minimum breakdown voltage a suitable withstand voltage test procedure is considered. Calculations and Monte Carlo simulations were performed for different shape parameters of the Weibull distribution.