压气式高压SF6断路器喷口结构对非对称短路开断性能的影响规律OA

This study investigates the interruption performance of puffer-type high-voltage SF6 circuit breakers under asymmetric short-circuit current with high DC components.Based on T100a type tests,an arc enthalpy-flow physical simulation model is established to study the influence of nozzle structural parameters on interruption performance.Key parameters,including nozzle throat length,throat diameter,and nozzle-to-auxiliary-nozzle distance,are examined for a 252 kV/50 kA puffer-type SF6 breaker,focusing on their effects on arc-extinction voltage spikes,compression chamber pressure and gas mass flow during asymmetric current interruption.The results reveal that nozzle throat diameter critically affects interruption performance,where enlargement causes nonlinear reductions in extinction spikes and chamber pressure while undersized diameters induce gas flow deficiency due to arc blockage.The throat length effects strongly coupled with downstream divergence angles,with increased divergence enhancing chamber pressure by about 4％though stabilizing overall.The nozzle-to-auxiliary distance significantly modulates gas mass flow,where both insufficient and excessive dimensions disrupt gas-blast balance at current zero.The study elucidates the intrinsic mechanism whereby nozzle geometry governs interruption capability through gas-blast regulation,theoretically supporting optimized SF6 breaker nozzle design.