Insulating Properties of Low Density Polyethylene/Alumina Nanocomposites

Si-Jiao Wang,Hong-Da Yan,Zhi-Min Dang,Jun-Wei Zha,Yun-Hui Wu

doi:10.3844/ajeassp.2015.405.409

Abstract

High-Voltage Direct Current (HVDC) cable has become an important factor in the development of HVDC transmission. However, there are still difficulties such as space charge distribution in the development of HVDC cables. In this study, Low Density Polyethylene (LDPE) nanocomposites filled with nano alumina (nano-Al2O3) particles with or without modification were prepared by employing melting blend method. The results show that the modified nano-Al2O3 particles with vinyl silane coupling can be homogeneously dispersed in LDPE matrix. Space charge of the LDPE nanocomposites was tested by Pulsed Electro-Acoustic (PEA) method. The PEA spectrum indicated that decay charge effect of the LDPE/Al2O3 nanocomposites is better than that of neat LDPE. The space charge accumulated in the nanocomposites can be effectively decayed. The J-V curves show the nano-Al2O3 decrease the carrier mobility. The excellent insulation properties of the LDPE nanocomposites were attributed to the better interfacial adhesion between the surface-treated nano-Al2O3 particles and the matrix.

Highlights

Low Density Polyethylene (LDPE) is widely used as bulk insulation in extruded cables, but under HighVoltage Direct Current (HVDC) the space charge accumulated in the LDPE can greatly distort the electrical field and influence the aging property
The polarization currents curves of LDPE reach the equilibrium value at 100 s, while the Al2O3/LDPE nanocomposites filled with 1 wt% nano-Al2O3 only at 50 s
The carrier mobility μp are calculated from the fitting constants k, which have given as follows Equation 4: 9 k = 8d 3 ε rε0μp

Summary

Introduction

Low Density Polyethylene (LDPE) is widely used as bulk insulation in extruded cables, but under HighVoltage Direct Current (HVDC) the space charge accumulated in the LDPE can greatly distort the electrical field and influence the aging property. LDPE nanocmposites filled with the nano-Al2O3 particles with and without surface modification were prepared. Space charge characteristics in LDPE nanocomposites were measured using the Pulsed Electro Acoustic technique (PEA).

Results

Conclusion