<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>A major cause for failure of underground cables is due to formation of electrical trees in the cable insulation. A variety of tree structure can form from a defect site in cable insulation <italic>viz</italic> bush-type trees, tree-like trees, fibrillar type trees, intrinsic type, depending on the applied voltage. Weibull studies indicate that a higher applied voltage enhances the rate of tree propagation thereby reducing the life of cable insulation. Measurements of injected current during tree propagation indicates that the rise time and fall time of the signal is of few nano seconds. In the present study, an attempt has been made to identify the partial discharges caused due to inception and propagation of electrical trees adopting UHF technique. It is realized that UHF signal generated during tree growth have signal bandwidth in the range of 0.5-2.0 GHz. The formation of streamer type discharge and Townsend type discharges during tree inception and propagation alters the shape of the tree formed. The UHF signal generated due to partial discharges formed during tree growth were analyzed adopting Ternary plot, which can allow one to classify the shape of tree structure formed.</p></abstract>

A major cause for failure of underground cables is due to formation of electrical trees in the cable insulation. A variety of tree structure can form from a defect site in cable insulation viz bush-type trees, tree-like trees, fibrillar type trees, intrinsic type, depending on the applied voltage. Weibull studies indicate that a higher applied voltage enhances the rate of tree propagation thereby reducing the life of cable insulation. Measurements of injected current during tree propagation indicates that the rise time and fall time of the signal is of few nano seconds. In the present study, an attempt has been made to identify the partial discharges caused due to inception and propagation of electrical trees adopting UHF technique. It is realized that UHF signal generated during tree growth have signal bandwidth in the range of 0.5-2.0 GHz. The formation of streamer type discharge and Townsend type discharges during tree inception and propagation alters the shape of the tree formed. The UHF signal generated due to partial discharges formed during tree growth were analyzed adopting Ternary plot, which can allow one to classify the shape of tree structure formed.

Understanding Electrical Treeing Phenomena in XLPE Cable Insulation Adopting UHF Technique

Department of Electrical Engineering, IIT Madras, Chennai-600 036, India

Department of Electrical and Computer Engineering, Democritus University of Thrace, Xanthi, Greece

Journal of Electrical Engineering

A major cause for failure of underground cables is due to formation of electrical trees in the cable insulation. A variety of tree structure can form from a...

Understanding Electrical Treeing Phenomena in XLPE Cable Insulation Adopting UHF Technique

Published Online: Jun 07, 2011

Page range: 73 - 79

DOI: https://doi.org/10.2478/v10187-011-0012-4

Keywords
power cables, cable insulation, partial discharge, UHF signal, electrical breakdown, failure analysis, XLPE, ternary plot

This content is open access.

Understanding Electrical Treeing Phenomena in XLPE Cable Insulation Adopting UHF Technique

Published Online: Jun 07, 2011

Page range: 73 - 79

DOI: https://doi.org/10.2478/v10187-011-0012-4

Keywordspower cables, cable insulation, partial discharge, UHF signal, electrical breakdown, failure analysis, XLPE, ternary plot

This content is open access.

Keywords
power cables, cable insulation, partial discharge, UHF signal, electrical breakdown, failure analysis, XLPE, ternary plot