Controlling Switching Surges on 1100-kV Transmission Systems

At 1100 kV, transient overvoltages caused by switching transmission lines pose the greatest stress to system insulation. These overvoltages must be limited to realistic values to make 1100- kV transmission economically attractive. Various altematives for limiting switching surges including controlled and uncontrolled multistep resistor breakers are investigated under many different system conditions. Several of these altematives are found to be capable of limiting surge magnitudes to acceptable values.