Recent Advances in Cross-linked Polyethylene-based Nanocomposites for High Voltage Engineering Applications: A Critical Review

Abstract

Scientific advancements in the field of high-power transmission and distribution of electrical energy revolutionized the field of high-performance polymer-based electrical insulation systems. Cross-linked polyethylene (XLPE) and its nanocomposites have gained substantial attention in the area of insulation, and these materials play a prodigious role in the arena of cable insulation. This paper includes various strategies for cross-linking PE coupled with different nanofillers to enhance the electrical insulation properties to attain high power transmission. It summarizes the significance of SiO 2 -, alumina-, TiO 2 -, and MgO-based XLPE nanocomposites as potential candidates for insulation in high voltage cables, electrical chips, and transistors and boron nitride-based XLPE nanocomposites for thermal insulation applications. Major challenges in dielectric insulation for cables, like partial discharge, space charge accumulation, water trees, volume resistivity, and DC breakdown strength, are addressed.

Effects of modified hexagonal boron nitride on electrical insulation properties of LLDPE/EAA nanocomposites

“…Charges are generated near the cathode and anode in the pure LLDPE sample, and the depth of charge injection material increases with the polarization time, and the charge density increases greatly when the polarization time is 1800 s. There was still charge near the anode in A 2 blend, but the charge near the cathode in A 2 blend reduced obviously, and the charge density was basically unchanged during a polarization time of 1800 s. In sum, the polar groups (carboxyl groups) of EAA would introduce deep traps in the blends, thereby inhibiting the accumulation of space charge.Inorganic nanoparticles can form a great deal of deep traps at the interface between nanoparticle and matrix, thus capturing space charge to improve electrical insulation properties of the matrix. 3,35 The h-BN is an excellent filler for nanocomposites because of its excellent electrical properties, but the uneven dispersion of h-BN in a matrix limits its application. 18 Therefore, in the work reported in this paper, a new modification method was used to etch h-BN with thionyl chloride, which could introduce active groups on its surface, and then h-BN was covalently modified by etching with succinic acid.…”

“…1,2 Whereas, the addition of certain nanoparticles can inhibit the accumulation of space charge to enable even higher voltages than currently used. 3 Ever since nanometric dielectrics were reported to have a significant effect on suppressing space charge, 4,5 improving electrical insulation properties of polymers by introducing nanoparticles has gradually become a research focus. Nanoparticles form a great deal of traps in a polymer, which could capture space charge and inhibit its movement, thus improving the electrical insulation performance of a nanocomposite, such as increasing the breakdown strength, reducing space charge density and DC conductivity, etc.…”

“…13 Such modified nanoparticles can obviously improve the electrical insulation properties of nanocomposites. 3 Zhang et al found that SiO 2 surface modified by vinylsilane (VI) coupling agent had good dispersion in crosslinked polyethylene (XLPE) and inhibited the movement of space charge, which increased DC breakdown strength of the nanocomposite. 14 In addition, γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) coupling agent was used to modify the surface of TiO 2 to prepare XLPE/TiO 2 -KH560 nanocomposites, which improved the dispersion of TiO 2 in XLPE, thus better inhibiting space charge to improve DC breakdown strength.…”

Significantly Improved Electrical Properties of Crosslinked Polyethylene Modified by UV-Initiated Grafting MAH

“…The polymer dielectric nanocomposites (nanodielectrics) have manifested substantially improved dielectric properties, such as inhibited space charge accumulation and reduced electrical conductance, and enhanced breakdown strength in comparison to neat polymer material, which originates from the numerous deep traps for charge carriers caused by polar molecular groups at nanofiller/matrix interfaces [7,8]. Thomas reported various strategies for XLPE coupled with different nanofillers to enhance the electrical insulation properties for high power transmission, and comprehensively summarized the significance of SiO 2 , Al 2 O 3 , TiO 2 , MgO and BN-based XLPE nanocomposites as potential candidates for various applications in high voltage cables, electrical transistors and thermal insulation [9]. However, the modification efficiency relies greatly on the dispersivity and surface states (impurities and defects) of nanofillers in the polymer matrix, which cannot be facilely controlled due to the infinitely large surface/volume ratio [10,11].…”

Preface to the Mohamed El-Aasser Festschrift

“…Pelton et al developed improved substrates for lateral flow biosensors by printing precipitated calcium carbonate inks incorporating latex binders. Thomas et al have reviewed the application of cross-linked polyethylene-based nanocomposites as insulators in high-voltage applications.…”