New algorithm for determining critical flashover voltage and standard deviation from flashover probability data

Abstract

The paper deals with the determination of critical flashover voltage and standard deviation from flashover probability data. A new and simple algorithm is suggested for the analysis of flashover data. In this algorithm the critical flashover voltage and standard deviation of the flashover of a given insulation are determined by interpolation of the data assuming a cumulative normal distribution of variation. The algorithm uses very simple equations permitting much faster evaluation for the critical flashover and standard deviation. Computational difficulties that arise in the two methods (Maximum Likelihood and Graphical Method) are avoided. The algorithm has been applied to several examples, the calculated values are very close to those obtained by using the two methods, the degree of imprecision introduced is usually negligible. A computer program based on the new algorithm is presented to perform all the computations.