Study On Dielectric Properties Of Oil-Paper Modified By Nano Particles Under Composite Voltage

With the development strategy of strong transmission in our country,as the hub equipment of ionization transmission,the safety and stable operation of transformer is getting more and more attention.Insulating oil and insulating paper are important components of insulation in transformer.The insulation performance of insulating oil and insulating paper can improve the transformer capacity and ensure its stable operation.The development of nano science provides a new possibility for improving the performance of insulating materials.Therefore,this paper puts forward “Study on Dielectric Properties of Oil-Paper Modified by Nano Particles under Composite Voltage”.This article studies the modification mechanism model of nano-insulation oil and the typical nano particles structure and selects the TiO₂ and ?-Al₂O₃ as modified particles,using oleic acid surface modification of nano particles.Then I make stable nano modified insulating oil with the method of ultrasonic dispersion and make nano modified insulation paper with the method of dipping;Relying on classical dielectric theory,I set the DC breakdown test platform,communication dielectric test platform and electrical aging test platform to develop the modified insulating oil and modified insulating paper insulation structure breakdown,dielectric properties and electrical aging performance research.The following laws are obtained:?1?The addition of TiO₂ and ?-Al₂O₃ nano particles can improve the DC breakdown performance of insulating oil and insulating oil paper structure,and it can improve the starting voltage along the surface and dielectric properties of insulating oil-paper.Among them,TiO₂ nano particles improved the performance of the DC breakdown field of insulating oil,and improved by 26.1% compared with unmodified insulating oil when the mass concentration was 0.04g/L.In addition,it is better to improve the DC breakdown field of insulating oil-paper structure by using ?-Al₂O₃ nano particles,which is 23.1% higher when the mass concentration is 0.04g/L than the unmodified insulation paper.For the improvement of dielectric properties,the modification effects of TiO₂ nano particles is superior to the ?-Al₂O₃ nano particles in mass concentration is 0.05 g/L,TiO₂ nano particles modified relative dielectric constant of insulating paper and tan? than unmodified oiled paper insulation fell by 17.8% and 22.8%;?2?The electrical properties of TiO₂ and?-Al₂O₃ nano modified insulation paper with a mass concentration of 0.04g/L are better than those of unmodified insulating oil-paper.In the early stage of electrical aging test,the change rate of DC breakdown field strength,relative dielectric constant and tan? is less than that of unmodified insulating oil-paper,which can play a role in inhibiting the development of electric aging.?3?Under the combined voltage,the intensity of DC breakdown of the nano modified insulating oil-paper decreases with the aging time,and the relative dielectric constant and tangent function increase with the aging time.The research results of this paper provide some guidance for the application of nano modified insulating oil-paper in the design and manufacture of converter transformer.