Effect Of Inorganic Nano-fillers On Electrical Treeing In LDPE

Electrical tree is one of the most primary factors causing the breakdown of insulation and eventually the insulation failure. Lots of studies have indicated that the generation and growth of electrical tree is unavoidable, and a variety of work has been done only to mitigate and inhibit generation and growth of electrical tree to some degree, but it can't be eliminated fundamentally.Lots of studies have indicated that nanometer material is a promising insulating material for power cable. At present, some scholars have proposed that it can improve the dielectric properties of polymers by use of ZnO and Al₂O₃ nanoparticles. However, the influence of ZnO and Al₂O₃ nanoparticles on the properties of polymer dielectric, such as electrical tree aging and corona aging and space charge resistance, have not been researched and analyzed in detail. So the dielectric properties of LDPE polymer dielectric mixing with ZnO and Al₂O₃ nanoparticles were studied in this article.First of all, both ZnO and Al₂O₃ nanoparticles were prepared by liquid phase precipitation, and parts of nanoparticles were made a decentralized treatment with silane coupling agent ZnO/LDPE (KH550) and Al₂O₃/LDPE (KH550) nanometer composite dielectric has been prepared by melt and mixed method. The dispersion of nanoparticles in the LDPE was observed with scanning electron microscopy. Subsequently, the characteristics of electrical tree aging, corona aging and surface morphology of corona aged film were researched.In addition, the space charge resistance of sample was researched. Finally, all experimental data was analyzed. It was discovered that the performance of ZnO/LDPE nanopolymers was superior to Al₂O₃/LDPE nanopolymers in the electrical tree resistance and space charge inhibition. Thus, ZnO/LDPE nanopolymers are more suitable for insulating materials with electrical tree aging resistance, while Al₂O₃/LDPE nanopolymers are not. From comparison, it was gotten that ZnO/LDPE nanopolymers had a good dielectric performance when the doping content was 1wt%, which was more appropriate for preparing insulating materials.