Ablation Gas Concentration Distribution with Opening Process of Electrodes Using Three-Dimensional Numerical Simulation

The role of circuit breakers is to disconnect the accident point from the power system. The reduction in the duration of instantaneous voltage drops after the accident is the important issue for circuit breakers. For this purpose, it is necessary to prevent the re-ignition after the current zero point. The current interruption using the ablation gas from the nozzle of circuit breakers has been studied in order to reduce the amount of SF₆ gas consumption. The ablation gas mixing amount into the arc is important with opening process of electrodes in order to effectively utilize the interruption performance of ablation gas. Making the weak point that makes it difficult to maintain the arc will prevent the re-ignition even when the transient recovery voltage is applied. However, the physical phenomenon of ablation gas contamination during the opening process of electrodes has not been elucidated. In this paper, the ablation gas concentration distribution with the opening process of electrodes using the three-dimensional numerical simulation was calculated. As a result, the ablation gas was generated with the opening electrodes. In addition, the temperature transition caused by the contamination of ablation gas and the amount of ablation gas for each temperature range was obtained.