Simulation of High-Frequency Arc Extinction on SF₆ Gas Circuit Breaker

Abstract

Investigations are made on the simulation of reignition high-frequency arc extinction that occur during interrupting inductive currents with SF₆ gas circuit breakers. This simulation was conducted by employing a combination of the Mayr-type arc equation and the circuit equation. The simulations conventionally conducted by using the Mayr-type arc equation of large short-circuit current interruption pertained in most cases to the period in the neighborhood of one current zero point. In this report, however, simuiation was made on high-frequency current which passed the zero point a number of times.
The gist of our report can be summarized as follows: (1) A test circuit was prepared by simulating reignition and high-frequency arc extinction, and tests are conducted by using a 300 kV SF₆ gas model circuit breaker. (2) High-frequency current and arc conductance were measured, and from the measurement results, the arc parameters (arc time constants and arc losses) of the Mayr-type arc equation were read. (3) The phenomenon of high-frequency arc extinction was calculated through simulating the test circuits, by applying the obtained arc parameters to the Mayr-type are equation. The occurrence limits of high-frequency arc extinction were found to closely correspond to the actual measurement results. (4) Studies were made on those clarified arc parameter values as well as on respective effects on high-frequency arc extinction by frequency of high-frequency current, transient recovery voltage, and attenuation of high-frequency current.