Method of Evaluating Exhaust Characteristics of High-voltage Circuit Breaker

The exhaust characteristics at high current duty of a breaker terminal fault for a gas circuit breaker are evaluated. A method of designing the exhaust chamber so that the exhaust temperature is less than the threshold temperature is then proposed. The threshold temperature is the value at which the maximum electric field of the exhaust chamber coincides with the critical electric field. In the design, the initial value of the structure is determined so as to decrease the number of trials in the development process. The calculation time of the numerical analysis is reduced by combining a one-dimensional (1-D) arc simulation with a two-dimensional (2-D) gas flow simulation of only the exhaust parts. An optimal design of an exhaust chamber using this design method is described as an example. In the interruption test of 63 kA using the optimal structure, dielectric strength was ensured and no flashovers occurred in any opening area.