Overview of Test Methods for Electric Strength of Vacuum Interrupter using Lightning Impulse Voltage

This paper outlines different test methods for investigating electrical strength with lightning impulse voltage. The test methods are compared and contrasts for application to vacuum interrupters. In addition to the procedures for determining the withstand voltage according to standards, the up-and-down method for determining statistical withstand voltage and 50 % breakdown voltage as well as the step-up method are described. For determination of breakdown probability distributions, a classic method and the new always breakdown method are explained. The minimization of the influence of the conditioning effect on the results of the different methods is discussed. Characteristic parameters for the test methods used to generate the breakdown probability distribution are indicated. Thus, the basics of an evaluation procedure for test methods for electric strength using lightning impulse voltage are presented.