An application of metal oxide surge arresters in the elimination of need for closing resistors in EHV breakers

At Florida Power & Light Co., a large percentage of the 500 kV circuit breakers were found to have broken or failing closing resistor mechanisms. A simulation study using the EMTP program for the statistical evaluation of switching surge flashover rates in the absence of breaker closing resistors is described. The stress on the metal oxide (MOV) surge arresters at the line ends is also evaluated. The conclusion is that with the MOV surge arresters at the 500 kV line terminals, breaker closing resistors are not required for the system studied