Research on Arc Ignition Characteristics of Cables’ Insulation Under Different Temperatures Considering Thickness

Abstract

Internal arc faults in cables are a significant cause of cable fires, with the cable temperature being time-dependent due to varying loading levels. Thus, it is necessary to study the characteristics of arc-induced cable ignition considering the influence of temperature, which have been rarely addressed in previous studies. In this paper, an experimental platform for alternating current arc generation is established. This platform records and analyses the arc development's morphological characteristics, the voltage and current waveform changes at both electrode ends, and the electrodes' temperature distribution. Moreover, two types of cable insulation materials, i.e. cross-linked polyethylene (XLPE) and polyvinyl chloride (PVC) with different thickness and temperature, are tested to study the arc-induced ignition characteristics of cables. By comparing ignition times and combustion intensities within the same time frame, the characteristics of arc-induced ignition are analysed. It can be concluded that the insulation temperature accelerates the arc-ignition process significantly. For XLPE, the ignition time under 70°C can be reduced around 11%. Thick XLPE (1.6 mm) can delay the ignition time up to 1.5 times compared with thin one (0.8 mm). PVC exhibits similar behaviour but demonstrates greater resistance to arc-induced ignition than XLPE.