Universal approach to gas flow and pressure rise calculation in HV circuit breaker chambers

Abstract

Interruption of short circuit currents in high voltage circuit breakers requires high SF6 gas pressure, which can be generated by compression of SF6 gas and/or energy transfer from the arc. The pressure difference between circuit breaker chambers causes SF6 gas flow. The rise of pressure in the chambers is highly dependent on the design of the circuit breaker. This paper presents a universal approach to modeling of gas flow and pressure rise, which is based on a real gas model and implemented into computer software for high voltage circuit breaker interruption simulation. The approach allows simulation of SF6 and alternative media circuit breakers with any number of chambers and different types of valves and connections between chambers. The calculated pressure rise is validated by comparison with experimental measurement results from high power laboratory.