DC breakdown and flashover characteristics of direct fluorinated epoxy/Al₂O₃ nanocomposites

Effect of different surface treatment agents on the physical chemistry and electrical properties of polyethylene nano‐alumina nanocomposites

“…This shows all three kinds of chosen coupling agents have been proved to be effective options to modify the surface of the nanoparticle, which increases both the density and energy of deep traps. The changes of deep traps increase the DC breakdown strength [24]. In conclusion, the composite samples using surface‐treated nanoparticles exhibit higher breakdown strength than the base polymer, which means adding nano‐alumina into PE has a positive impact on insulation performance.…”

“…Before the intrinsic breakdown happens, local breakdown exists between each individual particle and base polymer. However, due to the limited size of nano‐particles and reduced spherulite size, the total length of the breakdown path increases, which enhances the breakdown strength of the composite system [7, 24, 31, 32]. When the loading content is 0.5 phr, all the surfaced modified samples exhibit higher DC breakdown strength compared with the virgin LDPE sample.…”

“…The trap distribution is tightly linked with the electrical performance of nanocomposites. The deep trap is believed to have the ability to capture more charge carriers and therefore reduce the carrier charge mobility [22][23][24][25][26][27][28][29][30][31][32][33][34]. This can also be verified by the enhanced DC resistivity of LDPE/nano-alumina with surface modification.…”

“…Deep traps could lead to the increase of breakdown strength as they reduce the charge mobility and the mean-free path of electron acceleration through capturing the charge carriers [20,21]. Moreover, the trap density and shallow traps also have an effect on breakdown strength but the relationship between these parameters is not fully clear yet [6,7,[22][23][24].…”

Improvement of surface flashover in vacuum

“…Numerous studies have shown that surface fluorination is an effective way to improve the surface flashover performance in vacuum of insulator materials [85][86][87][88][89][90][91][92][93][94], including epoxy and its composite [85,93], high-density polyethylene (HDPE) [93], polystyrene (PS) [94] and other materials. Authors apply the fluorination treatment method in low-density polyethylene (LDPE) to improve the surface flashover voltages and the surface potential decay (SPD) to characterise properties of insulator surface [95].…”