Simulations of an improved operating mechanism for high voltage SF6 GIS circuit breaker

High voltage SF6 circuit breaker simulations based on an integral-physical enthalpy flow arc model are very powerful tool in designing and optimization of high voltage SF6 circuit breakers. This is especially important in case when full correlation between the electric arc, interrupter unit and operating mechanism parameters is needed. This paper presents computer simulations of an improved operating mechanism proven on a 123/145kV 31.5/40 kA GIS circuit breaker and verified using experimentally obtained data. The optimum value of the opening energy for rated short-circuit current interruption of the analyzed circuit breaker is estimated by using an improved operating mechanism model. In addition, several analyses have been made in order to investigate how some interrupter parameters affect the contact travel and breaking performance.