Effect of Voltage Recovery Rates on Interrupting Performance of Air-Blast Circuit Breakers [includes discussion

Abstract

Recovery rate is the term applied to the rate at which voltage rises across a circuit breaker immediately following interruption. Before high-voltage air-blast circuit breakers can be economically applied, a thorough knowledge of the relationships between circuit-breaker duties and recovery rates on systems is necessary. Whereas the performance of the modern oil circuit breaker is relatively unaffected by circuit recovery rate, the authors have found that this factor has a very significant effect on the performance of the radial-type air-blast circuit breaker. Using the minimum pressure required to produce successful interruption as a measure of circuit severity on the circuit breaker, an empirical relationship correlating the influence of both current and recovery rates has been found. As shown by this relationship, reduction of the inherent recovery rates by using linear resistors may be desirable in those circuits possessing unusually high rates. Until the relationships between system recovery rates and circuit-breaker duties have been correlated, it is advisable to apply these circuit breakers only where these factors and the circuit-breaker characteristics are both understood.