Study On Methods To Improve The Performance Of Resisting The Water Tree In XLPE

With the rapid development of national economy of our country,the whole demand of our country for electricity is growing.As a main electricity transmission carrier in the medium voltage distribution transmission system,the usage amount of crosslinking polyethylene cable is also increasing.Water tree is occurred in crosslinking polyethylene insulation in the role of water and electronic field.when water tree grow to a certain length at its tip.it may lead to an electrical tree,causing the cable insulation breakdown.So an electricity accident occurred.However,because the durable years are too long,the aging problem of some cable insulation increases seriously,which affects the cable's life 1.Water tree aging is one of major reason for the damage of cable's insulation.Therefore,to develop a good water-tree-retardant cross-linked polyethylene insulation cable material is significant.Adding some polar copolymer,nucleating agent,inorganic nanomaterials into polymer,we prepare the modified crosslinked polyethylene insulation materials.Making some study of water tree's growing in the material in the environment of high frequency and high voltage.Making observations on water tree's shape and length in different time.Analysising the mechanism of various organic and inorganic modified materials.The survey's results show that water tree resistant in crosslinked polyethylene capacity was significantly better than low-density polyethylene.Added ethylene-vinyl acetate copolymer(EVA),ethylene-ethylacrylate copolymer(EEA)and nucleating agents ZC-3 in material can inhibit the growth of water trees in XLPE.On the whole,the performance of resisting the water tree of the material containing nucleating agent is the best.By comparison,the performance of resisting the water tree in the material containing 2%nucleating agent is obviously,better than the imported finished water-tree-retardant insulating product.Hydrophilic and hydrophobic silica having improved resistance to water trees XLPE performance effect,wherein the hydrophobic silica has more water tree resistant properties.the performance of resisting the water tree in the material containing 5%imported SiO2 is obviously better than the two finished water-tree-retardant product.