Effect of silane‐grafting on water tree resistance of XLPE cable insulation

Abstract

Water treeing is one of the main deterioration phenomena observed in the polymeric insulation of extruded crosslinked polyethylene (XLPE) cables, which can affect the service life of power cables. In this work, we investigated the effect of grafting of a silane (vinyl trimethoxysilane, VTMS) on the resistance of XLPE to water treeing. A series of water-treeing tests, the mechanical and dielectric measurements indicated that the silane-grafting could significantly improve the water tree resistance of the conventional XLPE cable insulation with little influences on its dielectric properties, e.g., the dielectric breakdown strength, dielectric constant and loss tangent, and its mechanical performance. It was found that there exists an optimum value of VTMS concentration (about 0.6 phr) corresponding to the minimum water tree length. The water tree resistance mechanism of silane-grafted XLPE was proposed on the basis of the process of silane hydrolysis and crosslinking.

Copper diffusion in cable-insulating materials by chemiluminescence and DSC techniques

“…Different substances, such as peroxides [7], silanes [8][9][10] or ionizing radiations [11][12][13][14], are regularly used as crosslinking agents. The resulted crosslinked materials have widely applied in cable industry due to their excellent dielectric properties, better water-tree resistance and suitable thermo-mechanical behavior [5,15]. However, the long-term performances of these materials are affected by oxidative degradation which is induced by combined environmental actions (heat transfer, photooxidative or high energy radiation exposures, mechanical loadings) which have energy transfer reasons usually accompanied by electrical stresses during the service life.…”

“…Coil insulations of electromagnets, power transformers or electrical cables are common examples through many other industrial applications. High-energy cables with crosslinked polyethylene (XLPE) insulation are largely used for electric power transmission since 1960s [1,2] due both to the high performances of this material and to the economic efficiency of its production [3][4][5][6]. Different substances, such as peroxides [7], silanes [8][9][10] or ionizing radiations [11][12][13][14], are regularly used as crosslinking agents.…”

On-line monitoring and analysis of the dielectric loss in cross-bonded HV cable system

“…It was noted in [2] and [18] that, as a result of moisture deterioration in XLPE insulation, DL factor shows an increasing trend due to the decrease of the insulation resistance. In other insulation deterioration, such as thermal deterioration [19], mechanical deterioration [25], oxidation deterioration [24], radiation deterioration and electrical deterioration [23], the indications are that insulation capacitance does not change much during the deterioration. Increase in the DL angle results from decrease in the insulation resistance, such as in the case of water tree aging due to moisture deterioration.…”

Effect of Nanoparticle Surface Modification and Filling Concentration on Space Charge Characteristics in TiO2/XLPE Nanocomposites

“…In recent years, the tremendous development of nanotechnology has provided a new direction for researching on properties of polymer. Domestic and foreign scholars have carried out extensive studies on the space charge characteristics of polymer nanocomposites, mainly focusing on the following aspects: (1) how the electrode materials, the thickness of samples, the aging types, and so on impact the distribution of space charge in nanocomposites [6]; (2) the space charge behaviors and inhibition mechanism of nanocomposite [7,8]; (3) the electrical conductivity and conductance mechanism of nanocomposite [9,10]; (4) the inhibition behaviors and inhibition mechanism of electrical and water branches in nanocomposites [11][12][13].…”