Estimation of 80kA short-line fault interrupting capability in an SF6 gas circuit breaker based on arc model calculation

Interrupting performances of high-voltage circuit breakers have been quantitatively evaluated through current zero measurements during interrupting tests. The interrupting capability of circuit breakers can also be estimated by means of an arc model calculation, the parameters of which are determined through current zero measurement. An actual case where the arc model calculation was used for the development of an 80kA circuit breaker is discussed in this paper. We estimated the 80kA interrupting capability based on the current zero data measured during 50kA interrupting tests, which had already been carried out with a similar type of circuit breaker. We designed the necessary capacitance for short-line fault interruption by means of the arc model calculation. The test results agreed well with the predicted performance.