Arc Modeling to Predict Arc Extinction in Low-Voltage Switching Devices

Arc modelling is one of the most effective tools to evaluate switching performance of low-voltage switching devices (LVSDs), reducing the testing requirements of real devices; however, there is still a limitation on the ability to predict re-ignition. It has been shown that re-ignition in LVSDs is strongly dependent on the exit arc voltage (the value of arc voltage just prior to the current zero point) and the ratio of the recovery voltage to exit arc voltage at the current zero point. In order to predict re-ignition reliably, it is necessary to improve the ability to predict the exit arc voltage from arc modelling.In previous modelling studies of the arc in the splitter plates, a relationship between the potential drop and current density (V-J curve) in the arc root region (a thin layer between the arc column and the metal surface of the cathode or anode) was proposed to consider the effect of the arc root formation in the splitter plates. The paper presents a modified method to improve the ability to predict the exit arc voltage. The arc voltage waveform and the exit arc voltage are simulated, based on the modified V-J curve and the effectiveness of the arc model is evaluated by comparing the simulated result with experimental data.