Abstract :
The observed effect of restriking-voltage rates of rise on the performance of various types of circuit breaker is given, and high rates are shown to increase greatly the severityof the interrupting duty independently of kVA, and consequently to be a factor of consierable importance in the choice of circuit breakers. An indication is made as to where severe conditions are likely to occur on a system. The causes of the high-frequency oscillations consequent to interrupting fault power are analysed, the rate of rise of restriking voltage is defined, and the effect on this rate of different factors which cannot normally be controlled, such as asymmetry and arc characteristics, are discussed. The physical constants and factors inherent to the type of system and fault affecting these oscillations, and formulae for the rate of rise for simple circuits, are given. A method of solution for multi-frequency circuits, based on lumped constants, is described, and in the Appendix the principles for solving long lines employing distributed constants are outlined.
