Use of integral arc models in circuit breaker testing and development

The extended Mayr equation for the electric arc was used to develop an evaluation technique for determining the relevant arc parameters separately for each single short line fault (SLF) test. Thus it is possible to calculate the results expected from these tests under changed circuit conditions. The main advantage is an increase of the information gained from the tests. Special care was taken to choose measurement and calculation methods that are sufficiently robust for application in power tests. Only the arc voltage before current zero, the applied inherent dI/dt, and the circuit elements are needed as input data. The validity of the technique was tested by a sensitivity analysis and several comparisons between calculated and measured results. The method is already being routinely applied for full-scale SF₆ breaker testing and development