Fault Surge Versus Switching Surge A Study of Transient Overvoltages Caused by Line-to-Ground Faults

Abstract

When the improvements in extra-high- oltage power circuit breakers now being studied are realized in practice, over- voltages caused by energization or reenergization of lines can be made so low that the limiting factor determining how much the line insulation may be reduced might become the overvoltage produced by single line-to-ground faults. On lines insulated for levels below twice the normal line-to-ground crest voltage, such faults could develop into double line-to-ground faults, which would be particularly objectionable if single-pole switching were to be employed.