Stresses of Circuit-Breakers: Effects of Grounding and Types of Applications

Circuit-breakers are one of the most important equipment in power systems. They serve as interrupting devices which interrupt the operating and short-circuit currents. Circuit-breakers are subject to electrical stresses during operation. These stresses are composed of stress of over-voltages across circuit-breakers, stress of rate of rise of recovery voltages and stress of interrupting currents. Such electrical stresses depend on types of applications, types of system grounding and rating of systems. The aim of this study is to investigate electrical stresses of circuit-breakers in respect of types of system grounding: isolated, compensated and solidly grounded systems and interrupting applications, for example, interruption of no-load transmission lines/cables, capacitor bank switching, interruption of shunt reactors and interruption of short-line faults. The simulation of circuit-breaker stresses in 110 kV system is carried out and the results in any applications are then compared