A Theoretical Analysis of Dynamic Arcs and Test Results of Model Synchronous Air Blast Circuit Breakers

This paper reported analyzed results of the transient dynamic arc around current zero of air blast circuit breakers on the basis of Mayr arc model. It was proved that an arc time constant and arc power loss were determined by boundary layer flow analysis just around current zero. By these arc constants, max. RRRV P1-5/(di/dt)20 (P: Pressure, (di/dt)o : current derivative without arc). These proprieties were confirmed by experimental results of the model synchronous air blast circuit breaker. Moreover, the water flow with open surface was applied to analyze dependence of time constant on the geometrical form and arrangement of arc quenching nozzles.