Development of switching performance evaluator and arc modelling tool for low-voltage switching devices

Abstract

Purpose The purpose of this paper is to investigate a reliable evaluator of arc re-ignition and to develop a numerical tool for accurate prediction of arc behaviour of low-voltage switching devices (LVSDs) prior to empirical laboratory testing of real products. Design/methodology/approach Two types of interruption tests have been carried out in the investigation of re-ignition evaluators. Arc modelling tool coupled with the load circuit has been developed to predict arc characteristics based on conventional magnetohydrodynamics theory, with special attention given to Lorentz force acting on the arc column and surface phenomena on the splitter plate. The model assumptions have been validated by experimental observation of arc motion and current and voltage waveforms. Findings It is found that the exit-voltage across the switching device and the ratio of system to exit-voltage at the current zero point are reliable evaluators for prediction of re-ignition. Where the voltage ratio is positive, instantaneous re-ignition does not occur. Further, the probability of re-ignition is very low if the voltage ratio is in the rage of −1.3 to 0. Originality/value It is observed that the voltage ratio can be considered as a reliable global evaluator of re-ignition, which can be used for various types of LVSD test conditions. In addition, it is shown that arc modelling allows a good prediction of the current and voltage waveforms, arc motion as well as the exit-voltage, which can be used to obtain the evaluator of re-ignition.

Experimental Study of Relationship Between Arc Light Intensity and Temperature in Low-Voltage Switching Devices

“…It was observed that arc motion greatly influences the probability of re-ignition; the better arc entry into the splitter plates leads to a reduction in the re-ignition probability. Shin et al developed arc modelling to predict arc characteristics, based on magnetohydrodynamic theory, with special attention given to the Lorentz force acting on the arc column and the arc root area on the splitter plate [11] - [12]. Arc images measured by the AIS were compared with the simulated temperature distribution to validate the model.…”

Analysis of Erosion Resistance of CuC Arcing Contacts Manufactured by Plasma Spraying Technology

“…An increase of the lifetime of the low-voltage highcurrent switching devices (LVSD) requires the guaranty that the arc transfers from the main contacts to arcing contacts. One of the main factors affecting the erosion of arcing contacts during arc burning are plasma jets [1], which starts from in the arc roots [2]. The arc movement under the action of electromagnetic forces can be analysed both by experiment and modelling.…”

Experimental Study of Reignition Evaluators in Low-Voltage Switching Devices

“…It was found that the evaluator of the exit arc voltage is a simple tool; however, its reliability has not been rigorously tested. Shin et al [10] proposed an additional evaluator, the ratio of the system voltage to the exit arc voltage at the current zero point, through the switching test results of the miniature circuit breakers (MCBs) and molded case circuit breakers (MCCBs). Chen et al [11] studied the correlation between the arc motion and reignition in magnetic contactors by using optic fiber arc imaging technology and found that the better the arc entry into the splitter plates, the less likely the reignition.…”