In order to improve the insulation ability of the three media interaction area of basin insulator, the reasons of the accumulation of foreign body, and the flashover along the basin insulator surface induced by the structure design defect of the three media interaction area was analyzed from the composition of three media interaction area, the movement characteristics of foreign body and the typical discharge phenomenon. Through electric field simulation, the influence of grounding shielding electrode, the flange thickness of basin insulator, and the distance between the grounding shielding electrode and the busbar cylinder flange on the electric field intensity in the low potential three interaction area were studied, the variation law of electric field in the high potential three interaction area with tilting angle and three media interaction area width of basin insulator were given. The calculation method of the thickness of the high voltage side of grounding shield electrode to prevent resin through failure and the criterion of electric field check in the three media interaction area were presented. The results show that the reasonable structure design of three media interaction area with high and low potential can effectively inhibit the surface flashover induced by foreign matter accumulation.

On the basis of the crystal structure of piezoelectric effect of polyvinylidene fluoride (PVDF) polymer, the effects of different annealing temperatures (60-160℃) on the surface crystal morphology, crystal size, crystallinity, and key dielectric parameters including polarization response curve and piezoelectric coefficient of PVDF film samples were studied. The results show that the sample crystal size and crystallinity increase with the increase of annealing temperature in the range of 60-140℃. The polarization curves show higher residual polarization intensity and hysteresis, and the piezoelectric coefficient increases from 11 pC/N to 27 pC/N with the increase of annealing temperature. When the annealing temperature reaches 160℃, cracks appear on the surface of sample, and consequently the breakdown is easy to occur in the polarization process, and the dispersity of piezoelectric coefficient is large.

The thermal conductivity mechanism and common thermal conductive fillers of thermal conductive silicone composites for electronic packaging were presented, the preparation strategies and research progress of filled-type high thermal conductive silicone composites were reviewed, and the future research direction of thermal conductive silicone composites for electronic packaging was prospected.

Aiming at the high risk factor of manual fault detection of strut insulators, this paper proposes a real-time fault diagnosis of strut insulators based on thermal imaging technology. The binarized segmentation of the infrared image of the strut insulator was taken as the feature extraction, and the grayscale median filter was introduced for preprocessing, then a Gaussian kernel support vector machine classification architecture was built. At last, the fault diagnosis of the strut insulator was realized. The results show that the diagnosis method can not only complete the fault monitoring of the strut insulator, but also improve the efficiency and accuracy.

In this paper, a novel semi-interpenetrating network material PVP/p(HEMA-co-BA) was synthesized by free radical polymerization of 2-hydroxyethyl methacrylate (HEMA), butylacrylate (BA), polyvinyl pyrrolidone (PVP), and host-guest interaction complex which was synthesized by recognition and free radical copolymerization using cyclodextrin modified aluminium oxide nanoparticles (CD-Al₂O₃NPS) as host molecules and acrylate containing adamantane as guest molecules. The microstructure and properties of PVP/p(HEMA-co-BA) were characterized and tested. The results show that the material has self-repairing property by the interaction of host and guest materials. And the introduction of two reversible non-covalent interactions host-guest interaction and hydrogen bond gives the material excellent shape memory function. With the shape memory and self-repair capability, the material can repair by itself and recover the original property when the distance between the two sections of the crack is large. In addition, PVP/p(HEMA-co-BA) has good thermal stability and can be used at 200℃ in high temperature environment.

In order to further improve the insulation performance of meta-aramid paper, we modified nano-TiO₂ by four kinds of silane coupling agents KH550, KH560, KH580, and KH151, respectively, and then prepared modified nano-TiO₂/PMIA composite paper. The influence of coupling agent types on the electrical properties of composite paper, including electrical strength, bulk conductivity and charge-trap characteristics were mainly studied. In addition, the changes in thermal and mechanical properties of different paper were also concerned. based on the molecular dynamic method, the TiO₂-PMIA interface grafted with different silane coupling agents was simulated, and the improvement effect of silane coupling agents on the filler-matrix interface was expounded. The results show that with the electrical insulation performance as the main concern index, the modification effect is ranked as KH550, KH151, KH560, KH580 from the optimal order. The suitable type of silane coupling agent can effectively improve the dispersion of nano-fillers in the matrix, enhance the breakdown voltage and volume resistivity of composite materials, and maintain the temperature resistance and mechanical strength of PMIA fibers.

Epoxy resin is used as the main material for insulated packaging of electronic device and motors, it is urgent to improve its thermal conductivity to meet more demanding use requirements. In this research, epoxy resin was modified by filling irregular alumina (i-Al₂O₃), and the effects of irregular i-Al₂O₃ with different volume fraction on the thermal conductivity and other properties of EP were studied. The results show that with the increase of the mass fraction of i-Al₂O₃, the viscosity of the composite mixing system gradually increases, the tensile strength increases at first and then decreases, the thermal stability and thermal conductivity gradually increase. When the volume fraction of i-Al₂O₃ is 45%, the epoxy composite material shows good the overall performance, its thermal conductivity coefficient reaches to 1.44 W/(m·K), which is 585.7% higher than that of pure epoxy resin with the thermal conductivity of 0.21 W/(m·K), at the same time, the volume resistance of the composite remains at the 10¹⁴ Ω·cm quantitative level.

In order to study the influence of semi-conductive shielding materials on the charge transport behavior in insulation, we selected three different types of semi-conductive shielding materials made in and out of China to cooperate with the same insulation, and trial-produce a shield-insulation-shield sandwich structure sample by simulating the actual cable structure, and conducted high-field conductance tests and space charge measurements. The results show that the introduction of the shielding layer changes the conduction mode inside the insulation. Compared with the pure insulation sample, the charge injection of the insulation sample with shielding layer increases significantly. The insulation-shielding interface of the imported shielding material sample has a stronger ability to inhibit charge injection, and the charge injection degree is weaker. The measurement of the space charge of each sample shows the impact of charge injection on the degree of space charge accumulation inside the insulation, the space charge accumulation of the shielding material sample made in China is more serious, while that of the imported sample is lower. It is needed to concern the impedance mismatch problem caused by the particularity of the sample structure in the measurement of space charge.

In order to study the causes of dehydration of silicone oil for high voltage cable terminal in closed environment, and investigate its characterization parameters after deterioration, we built an experimental platform with closed environment for thermal ageing and electrical ageing, and tested the physical, chemical, and electrical properties of silicone oil under different ageing states. The results show that both thermal ageing and electrical ageing can cause the dehydration of silicone oil. The thermal ageing at 90℃ and low energy partial discharge have less effect on the deterioration of the physical, chemical, and electrical properties of silicone oil, while the intermittent spark discharge and continuous arc discharge have great effect on that. The breakdown voltage, dielectric loss factor, and volume resistivity have larger correlation with the water content, so that they can effectively represent the deterioration degree of silicon oil.

The interface charge characteristics of oil-paper insulation under DC voltage is a huge challenge in the design of the insulation structure of converter transformers. The traditional resistance-capacitance (RC) model only considers the interface polarization charges due to the different dielectric constants and electrical conductivity of oil and paper materials, ignoring other forms of charges and their effects on the space electric field. In this paper, based on Kerr electro-optic effect, a non-contact, real-time measurement platform for space electric field characteristics in oil of oil-paper insulation was built. Aimed at the composite insulation structure consist of transformer oil-electrical insulation paper and transformer oil-transformer paperboard, the space electric field characteristics in the oil under DC voltage with different polarity and different amlitude were obtained. The difference between the total interface charge density and the polarization charge density calculated by the RC model was analyzed. The results show that when the electric field intensity in the oil is low, the total interface charge is dominated by polarization charges. With the increase of the electri field intensity in the oil, the difference between the total interface charge density and the polarization charge density calsulated by RC model increases gradually, indicat other forms of charge accumulates and its proportion in total charge increases gradually, the effect of it on the electric field increases gradually.