Study On Electrical Characteristics Of Extremely Low Temperature Toughened Epoxy Resin Insulation Material

Since the discovery of superconductivity,superconductivity technology has been developing rapidly.With the research and development of high temperature superconductivity,the application of superconductivity technology is more extensive.The application in the field of electrical engineering is of great significance to the development of power industry,and has also attracted great attention.Superconducting technology and electrical technology have gradually combined to produce a new technology with broad application prospects,namely superconducting power technology.Insulating materials play an important role in superconducting power equipment.However,because superconducting magnets work in very low temperature environment,insulating materials used in normal temperature environment may produce air gap,cracking and other insulation defects in very low temperature environment,resulting in insulation failure and even serious accidents.Therefore,insulating materials need to have good low temperature resistance.In order to study the electrical characteristics of toughened epoxy resin in extremely low temperature environment,this dissertation presents a design scheme of electrical performance test device.According to the requirements of electrical performance test,the device structure is designed,and the device material and sealing structure are selected.The device meets the structural strength design requirements through theoretical calculation.At the same time,the ANSYS finite element analysis software is used to analyze the structural strength and structural stability.Finally,the analysis and calculation results show that the designed electrical performance test device meets the structural strength,and no instability will occur under the working condition.In order to study the influence of electrode shape and electrode spacing on the distribution of dielectric electric field strength in the electrical performance test device,the finite element analysis of electric field is carried out under the condition of different electrode shape and spacing,and the comparison results show that the electric field strength in nitrogen decreases with the increase of electrode spacing,and the sharp electrode will produce significantly greater electric field strength,so in order to prevent the concentration of electric field,sharp structure should be avoided as far as possible.In order to study the influence of insulation defects on insulation performance,through the electric field analysis of air gap defects at different positions,compared with the results of defect free sample model,it is concluded that the air gap defects will increase the maximum field strength in the sample model,and the air gap defects on the outer surface will increase the electric field strength most obviously.Then,the 16 kA HTS current lead is taken as the research object,and the model is established to analyze the electric field.The comparison results show that the parts with large changes in the insulation structure are prone to generate electric field concentration,and the air gap defects or uneven material mixing will also significantly increase the electric field strength at the defects,which may cause partial discharge and eventually lead to insulation failure.Therefore,in the structural design of HTS current leads,the tip structure should be avoided.At the same time,the manufacturing process of the insulation structure can be improved,the air gap rate of the material can be reduced,and the phenomenon of uneven mixing of each component of the material can be avoided.Figure [76] table [14] reference [66]...