Study On Thermal Properties Of Fully Insulated Type Enclosed Bus Based On The Type Of Modified Epoxy Resin

As a large-current transmission device bus is always used to connect a variety of motors and electrical current to transmit current and power,which is widely used in power plants and substations of the power system.However,it will generate a lot of heat when it works,if the heat cannot be dissipated in time the bus will be affected by the continuous high temperature,insulating material is accelerated aging,life bus bar insulating portion is reduced,there may even cause accidents in production.So the heat analysis has become one of the most concerns of each enclosed bus manufacturers and major transformer substation.In this paper,based on the type of solid insulation enclosed bus,by modifying bus insulating layer material?epoxy?,researched the rise of temperature of the modified bus bar and the ANSYS finite element simulation software were used to simulate the bus temperature rise.The temperature rise of the enclosed bus was studied on the basis of the study of development status of the Insulating thermal conductivity materials both at home and abroad.And it was concluded that one of the causes of bus bar temperature rise is the poor thermal conductivity of bus bar insulation?epoxy?.In order to improve the thermal conductivity of the epoxy resin,SiO₂ filler was added in liquid epoxy;then added accelerators,curing agents and coupling agent for modifying filler surface and other chemical reagents;the filler particles were sufficiently dispersed in the epoxy resin material by using the ultrasonic dispersion apparatus and mixer;then the aspirator was used to vacuum degassing;and finally placed in an oven for curing process to obtain SiO₂/EP composite sample preparation.The FD-TC-B type thermal conductivity tester was used to test samples' thermal conductivity,the impact of SiO₂ filler ratio and particle size on the thermal conductivity of the composite material was analyzed.Analysts believe micron SiO₂ and nano-SiO₂ can enhance the thermal conductivity of the epoxy resin and the former than the latter can enhance the thermal properties of the composites.At the same time,the dielectric loss,dielectric constant and partial discharge inception voltage of the composites were tested and the results was that the electrical properties of micron SiO₂ of epoxy resin modified worse than SiO₂ nano particles and 5%nano filler is the best filler amount.Based on the comprehensive analysis of electrical properties and thermal properties of modified epoxy,the optimal ratio was selected out,as a final insulating layer material was applied to the bus entity.Finally,the thermal conductivity of the resulting experimental data as a basis was used to simulate the bus bar temperature rise by using of ANSYS software.The influence of different modified epoxy insulating material on bus bar temperature rise was theoretically analyzed.