Improved Method for Direct Black-Box Arc Parameter Determination and Model Validation

Black-box models are a valuable tool to simulate dynamic arc-network interactions, such as those that occur during fault current interruption in ac or HVDC circuit breakers. However, accurate determination of characteristic arc parameters from voltage and current measurements is very challenging. This paper aims to improve the accuracy in arc characterization. A new arbitrary current source is used to simplify arc parameter determination through a more complex current waveform, for example, a series of staircase-like increasing steps. With this, the stationary and transient arc characteristics can be measured independently from each other. Therefore, current steps are well suited to: 1) validate the choice of a specific black-box model and 2) determine the arc parameters of the chosen model with higher accuracy. In principle, the source is also well suited to fill a table of the arc voltage response U, U̇ at various current levels and slopes I, İ. Thus, it would be possible to characterize arcs independent of any black-box model, but it would not be well suited to compare different arcs. Therefore, this paper focuses on an improved black-box parameter determination and the experimental validation of the Schwarz model, with P and τ being free functions of g.