The Effect of the Number of Spacer Insulators on the Breakdown Voltage of Vacuum Insulation

It was shown that when extended high voltage vacuum insulation is being considered, the effect of the number of spacer insulators on the breakdown voltage of the system has to be taken into account. Two cylindrical electrode systems with a variable number of spacers were investigated. A very distinct decrease of the breakdown voltage with the increase in the number of insulators was noted. This effect was much greater than could be predicted when the normal distribution of the flashover voltages of a single insulator was assumed. A much better approximation was obtained when the Weibull distribution was used.