抄録
The newly developed flashover voltage test methods are proposed in this paper. These methods estimate the mean value of the distribution efficiently and stably by using breakdown and non-breakdown responses when the flashover voltages follow a normal distribution with known coefficient of variation. Electrical engineers have long been using the up-and-down method developed by Dixon & Mood to assess the flashover voltage distribution when both the mean and the standard deviation are unknown. However, the method is numerically unstable in obtaining the mean value when the sample size is extremely small, e. g. 5 to 10. The proposed methods, "the mean-shooting method" and "the modified up-and-down method", are extremely effective in a numerical stability sense comparing to the ordinary up-and-down method when the mean is unknown but the coefficient of variation is assumed to be known in advance. As for the estimating error of the mean value of the flashover voltage, the error obtained by the mean-shooting method is seen to be superior to that obtained by the ordinary up-and-down method; for instance, 15 shots in the mean-shooting method is equivalent to 20 shots in the iln-and-clown method
