Dependence of internal pressure rise due to arc on current waveform and ignition position

Abstract

This paper describes an experimental study concerning the pressure rise due to high current arcs in a closed chamber. In this study, the arcs were ignited in certain chambers of varying size under the same conditions, namely, an arc current of 12.5 kA and an arc duration of 0.1 s. Moreover, the pressure rises in the chambers were measured while varying the current waveform, namely, the frequency of the AC power source and the DC component of the current, and the ignition position. Based on each measured waveform, not only the maximum value ∆P max but also the middle value ∆P mid , which was the midpoint of the amplitude around the time point of ∆P max , were extracted. As a result of the evaluation using both ∆P max and ∆P mid , it was shown that ∆P max / ∆P mid varied with both the current waveform and the ignition position, whereas ∆P mid was independent of them. Through FFT analysis of both the pressure rise and the arc power waveforms, it was verified that this experimental result was related to the resonance effect between the pressure rise and the arc power oscillations.

Pressure Rise and Propagation Phenomena Due to Fault Arc in Container with Opened Pipe

“…Consequently, our institute conducted experimental studies on pressure rise characteristics in closed chambers and developed simulations for pressure rise and propagation using a CFD (computational fluid dynamics) tool. We investigated the effects of various parameters on pressure rise and propagation and confirmed that the pressure rise and propagation can be predicted by appropriate setting of such parameters, especially the percentage of arc energy contributing to the heating of air inside the chamber.…”