High voltage high-current commutator based on series-connected triggered vacuum switches

The 80 kV, 250 kA commutator consisting of two series-connected triggered vacuum switches (of type TVS-43) has been manufactured and tested. The measurements have shown that the voltage distribution on series connected switches was nonuniform. Breakdown voltages of each TVS and the commutator breakdown voltage as a whole were measured. The experimental distribution function of breakdown voltage of the commutator was constructed on the basis of measurement results. The tests results have allowed to check the used method for breakdown probability account of the commutator, in which the experimental distribution function of breakdown voltage of each TVS is used. The comparison of a calculated distribution function of commutator breakdown voltage with the experimental distribution function showed good agreement. The proposed method allowed estimation of the dielectric strength of the commutator depending on the degree of nonuniformity of voltage distribution between series connected TVSs.