Preparation And Dielectric Properties Of Y-Type Nano-Zeolite Modified Transformer Oil

Transformers play an important role in the power system,and transformer oil in transformers is the most critical insulation medium,and the good operation of transformers depends on their dielectric strength.As a porous hollow skeleton structure material,zeolite has a large specific surface area and large pore diameter structure,which makes it improve the insulation ability of the material and have better compatibility.In this thesis,NaY nano-zeolite was selected as the research object to explore its influence on the dielectric properties of transformer oil.In order to improve the dispersion of nano-zeolite particles in transformer oil,oleic acid modified NaY nano-zeolite(NaY-OA)and silane coupling agent(NaY-KH550)were modified on the surface of nano-zeolite on the basis of the original zeolite,and NaY nano-zeolite(NaY-KH550)modified by silane coupling agent were obtained.The successful surface modification of nano-zeolite and good dispersibility were proved by infrared spectroscopy analyzer and scanning electron microscope.The results of natural standing experiment and particle size analyzer show that the three kinds of nano-zeolite have good dispersion stability in oil.The effects of NaY,NaY-OA and NaY-KH550 nano-zeolite on transformer oil breakdown and conductivity characteristics were studied by comparative methods.The results show that nano-zeolite increases the breakdown voltage of transformer oil,the DC breakdown voltage of NaY-KH550 increases the transformer oil higher,and the AC breakdown voltage of NaY-OA on transformer oil is more stable.The influence of temperature on the conductivity of nano-zeolite modified transformer oil is obvious,and its conductivity increases exponentially with the increase of nanoparticle doping concentration at high temperature.The frequency domain dielectric spectroscopy was used to test the broad frequency permittivity and dielectric loss tangent of three nano-zeolite modified transformer oils.The results show that the dielectric constant of nano-zeolite modified transformer oil is slightly higher than that of pure oil,and its dielectric constant is less affected by temperature conditions.At low frequency,the dielectric loss of nano-zeolite modified transformer oil is significantly higher than that of pure oil,and the higher the temperature,the more obvious the increase in dielectric loss.Quantitative analysis showed that the dielectric loss value of nano-zeolite modified transformer oil increased with the increase of nanoparticle doping concentration,and increased exponentially with the increase of temperature.Based on Materials studio simulation software,nano-zeolite modified transformer oil was modeled and molecular dynamics simulation.The simulation results show that the two-phase interface of zeolite and oil molecules has better compatibility,and the interaction between the two can be verified.The results show that zeolite can reduce the diffusion capacity of water molecules in oil under different temperature conditions,and capture them by using the surface pore structure,which confirms the adsorption effect of zeolite on water in oil.