Effects of inorganic fillers on withstanding short‐time breakdown and long‐time electrical aging of epoxy composites

Abstract

Inorganic fillers were added to epoxy resin for preparing micro and nano filler/epoxy composite, and then the breakdown strengths, depths of erosion caused by partial discharge, and electrical tree experiments of composites were investigated. It was found that the loading of micro fillers usually decreases the short-time breakdown strength (breakdown under a continuously rising voltage) of the composites. On the contrary, it increases the ability to withstand long-time electrical aging (erosion or breakdown caused by electrical tree under a discontinuously rising voltage or constant voltage) of the composites. The effect of inorganic fillers in suppressing the electrical tree or erosion channel propagation in the composite is different during the process of withstanding short-time breakdown and long-time electrical aging. Defects are introduced during the mixing of fillers and epoxy resin, which play a role to decrease the short-time breakdown strength and accelerate long-time electrical aging. It is concluded that micro and nano inorganic fillers can suppress the electrical tree channel propagation and erosion caused by partial discharge, whereas defects play the opposite role in composites. Two opposite effects of inorganic fillers and defects exist simultaneously during the process of electrical aging and breakdown; whereas inorganic fillers play a primary role in long-time electrical aging, defects play a primary role in short-time breakdown.

Achieving High Energy Density and Low Loss in PVDF/BST Nanodielectrics with Enhanced Structural Homogeneity

“…Most interestingly, the maximum E b values of the three series of composites are found at the filler loading content of 10 wt %. In the previous reports, the maximum E b values of various polymer-based composites, such as P­(VDF-CTFE)/BaTiO 3 , PVDF/ZnO, P­(VDF-CTFE)/Ta 2 O 5 , epoxy/Al 2 O 3 , and so on, were detected within the range of 2–10 wt % filler content as well. − When the filler loading is low (ca. <10 wt %), the rigid fillers in the nanoscale might fill the free volume space and increase the Young modulus of the composites.…”

The influence mechanism of nanoparticles on the dielectric properties of epoxy resin

“…Epoxy resin is widely used in ultra-high voltage power equipment and the aerospace eld due to its excellent short-time breakdown and long-term damage performance. 1 With the development of UHV engineering, pure epoxy resin can no longer meet the needs of the power industry. Seeking new materials or modifying existing materials has become a research hotspot at home and abroad.…”

Complex Permittivity and Electromagnetic Interference Shielding Effectiveness of OPEFB Fiber-Polylactic Acid Filled with Reduced Graphene Oxide

“…When the concentration of rGO filler increases, the particles’ interaction within the matrix increased. The average polarization correlated with a cluster of particles is more robust than an individual particle due to improved composite inclusion dimensions and thus greater interfacial area [ 37 ], this results in higher average polarization, and hence, a higher contribution to the dielectric properties. However, it is observed that even at 8% rGO, the obtained permittivity values were lower than values obtained by Kashi et al [ 38 ], where and attained values of 11.17 and 0.87, respectively, for 6% GNP.…”