Arc modelling for switching performance evaluation in low-voltage switching devices

Arc modelling is an efficient tool for predicting the switching performance of low-voltage switching devices (LVSDs) prior to testing real products. Moreover, it offers a valuable design aid in the improvement and optimization of LVSDs. This paper focuses on the investigation of evaluators that predict re-ignition phenomena and the numerical simulation of arc characteristics in LVSDs. It is found that the probability of re-ignition depends strongly on the ratio of the system voltage to the exit-voltage. The implemented 3-D arc model is based on conventional magnetohydrodynamics theory and takes into account the properties of air that vary with temperature and pressure, motion of the contact, arc root formation and plasma radiation. The simulated results are compared with experimental data to validate the proposed arc model and the voltage trends show agreement.