Transient recovery voltage and thermal performance of an airblast circuit breaker

This paper examines the way in which the current-interrupting ability of a gas-blast circuit breaker is influenced by the initial transient recovery voltage (t.r.v.). Theoretical relationships are explored between t.r.v. waveshape, circuit-breaker are parameters and performance. Limitations which may result from the presence of high-frequency oscillations of the recovery voltage in the first few microseconds after current zero are also calculated. Encouraging agreement is obtained between calculations and the results of systematic experiments on an air-blast interrupter in a synthetic test plant. Possible applications of the work to the rating and testing of circuit breakers are discussed.