Influence of grading capacitors on the breaking capacity of two vacuum interrupters in series

Series coupling of two vacuum interrupter (VI) is used in special applicati ons to double the current breaking capability. Grading capacitors are usual ly added to guarantee essentially equal voltage distribution in each interr upter and to lower the fate of rise of the transient recovery voltage. Othe r solutions are designed without the use of grading capacitors due to aspec ts such as lack of space and the need to reduce cost. The aim of this paper is to show the influence of grading capacitors on the breaking capacity. A comparison of the performance with a non-equal voltage distribution is pre sented, considering the case of self grading arrangements without any addit ional grading means. The focus is on the transient behavior of both eases w hen reignitions occur in the vacuum interrupters.