XLPE/<i>h</i>-BN Nanocomposites With Enhanced DC Insulation Properties
Shihang Wang, Jianying Li, Shengtao Li
Abstract
Nanocomposites have been developed as the third-generation insulating materials. This article introduces the crosslinked polyethylene (XLPE) nanocomposite dielectric doped with a small amount of nano-hexagonal boron nitride ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${h}$ </tex-math></inline-formula> -BN), which exhibits excellent insulation properties under high dc voltage. The test results show that XLPE/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${h}$ </tex-math></inline-formula> -BN nanocomposites possess significant improvements in dc breakdown strength and 0.1 wt% nano <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${h}$ </tex-math></inline-formula> -BN doping can actually increase the dc breakdown strength by 39%. The space charge properties of the XLPE/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${h}$ </tex-math></inline-formula> -BN obtained by the pulsed electro-acoustic (PEA) measurements and the direct current integrated charge [DCIC- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${Q}({t})$ </tex-math></inline-formula> ] measurements show that the positive homocharge injection under dc voltage is obviously suppressed, and the electrical conductivity under relatively high electric field decreases. The thermally stimulated current results show that the nano <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${h}$ </tex-math></inline-formula> -BN doping introduces only deep charge traps (above 1 eV) to the XLPE matrix. The trap energy is deeper than that of the original traps, and this is the main factor leading to the improvement of the dc insulation properties. Besides, the doping of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${h}$ </tex-math></inline-formula> -BN does not introduce impurities or change the crystallinity of XLPE. This article presents the novel XLPE/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${h}$ </tex-math></inline-formula> -BN nanocomposites with excellent dc insulation properties and indicates the large potential of the nano <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${h}$ </tex-math></inline-formula> -BN-doped insulation materials.