CFD Simulation of the Flow Reversal Transient in a High Voltage Circuit Breaker

In a high voltage circuit breaker (HVCB) the current interruption process has different phases: high current phase, before current zero phase and after current zero phase. As a result, the gas flow reverses typically 1-3 ms before current zero (CZ) and the arc is blown when the current approaches zero. The flow reversal transient has an impact on the cooling of arc around CZ and thus on the interruption performance for both higher and lower currents. In this work, the flow reversal phenomenon is investigated numerically by simulating all current phases. Flow reversal transients, as observed in the simulation, are confirmed by the measurement. Numerical evaluations are carried out to understand the flow reversal transients and influencing parameters.