Development of Zinc Oxide Ceramic Energy Absorbers for DC Thyristor Circuit Breakers

The performance and the overall bulk of low-voltage DC thyristor power circuit breakers explained in this article tend to be determined by the media in which circuit interruption is performed. The zinc oxide ceramic energy absorber is an extinguishing medium with capabilities beyond the counterparts used in the conventional high-speed circuit breakers. The withstand-voltage, the interrupting time and the surge energy to be extinguished during interrupting are considered, together with parameter values specified in JEC Standard. Each energy absorber for the prototype DC 1500V-3000A thyristor circuit breaker consists of twenty four 115 mmo 15 mm thick zinc oxide ceramic elements and is capable of absorbing 400 kJ. The performance of these assembled devices in an energy absorber and incorporated with a thyristor circuit breaker as well as in the discrete form have been verified.