Evaluation of Surge Suppression Resistors in High-Voltage Circuit Breakers

The switching surge insulation level of steel tower and wood pole transmission lines operating at system voltage levels of 115 through 500 kV are compared with the switching surge magnitudes that can occur on these systems. High-side and low-side switching with and without surge suppression resistors is considered. The results indicate that at 345 kV and above surge suppression resistors should be used, while below 345 kV these resistors cannot, in general, be justified.