Simulation of thickness controlled DC breakdown of XLPE regulated by space charge & molecular chain movement

• Published in: IEEE transactions on dielectrics and electrical insulation Vol. 27; no. 4; pp. 1143 - 1151
• Main Authors: Bhutta, M. Shoaib, Yang, Lijun, Ma, Zhipeng, Nazir, M. Tariq, Akram, Shakeel, Mehmood, M. Ali, Faiz, Nouman
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Carrier mobility; Chain mobility; charge transport; Computer simulation; dc breakdown; Direct current; Electric breakdown; Electric potential; Electrical faults; Electrodes; Enlargement; Experiments; free volume; Insulation; insulation thickness; molecular chain movement; Molecular chains; Permittivity; Polymers; Simulation; Space charge; Thickness
• ISSN: 1070-9878; 1558-4135
• DOI: 10.1109/TDEI.2020.008742

In this study, XLPE electrical breakdown depending on insulation thickness is analyzed by simulations and experiments. The bipolar space charge and molecular chain displacement models are investigated to explain the experimental results. The results from experiments indicate that the electrical DC breakdown field decreases with increasing insulation thickness. For simulations, carrier mobility and trapping parameters are obtained from experiments. The simulation results of both models present an inverse power relationship between the DC breakdown strength and insulation thickness. The simulation results of molecular chain mobility model show consistency with experimental results as compared to a bipolar space charge model. The movement of polymer chain containing deep traps expands the free volume and this enlargement in free volume can be a major reason for the variation in the DC electrical breakdown strength of XLPE with insulation thickness.