Aspects of statistical treatment of electrical breakdown behaviour in gas-insulated apparatus

The knowledge of stochastic breakdown behaviour of environmental friendly gas mixtures become more and more important with respect to the required replacement of SF₆ - insulated apparatus. To obtain the necessary withstand values of breakdown voltage at the variety of desired parameters a statistical treatment of the measured data is required. The paper deals with the estimation of these values typical for such type of gas- insulated systems e.g. the approximation by a theoretical distribution function and necessary conditions. Problems at estimation will be discussed as non-conventional statistical treatment including some recommendations for their overcoming.