A Study on Switching Performance Associated with Structure of Quenching Chamber in DC 1500V Air Circuit Breakers

It is a challenging work to develop the direct current (DC) air circuit breaker (ACB) with the rated voltage of 1500 V, which has a compact size. There are two main switching performances in the DC ACBs; one is the breaking characteristics of a small current and the other is the short-circuit interruption performance. In order to develop DC ACBs effectively with a short time and low cost, it is essential to evaluate two main switching performances in the early stage of the development process. This paper presents an empirical study of the small current switching and simulation investigation of the short-circuit interruption in the DC ACBs. It is observed that the switching performance of a small current is improved as the number of the arcing contact increases. In addition, it is found that both of the flow guide and upper flow path in the quenching chamber benefit the switching performance under the short-circuit condition.