Electric-field-induced redistribution of BaTiO₃ particles in photocurable resin and its effects on gas-solid interfacial discharge

Gas-solid interfaces are among the most vulnerable regions in gas-insulated power equipment. Electric-field-assisted stereolithography (SLA) can induce the redistribution of high-permittivity fillers to form graded structures, thereby tailoring dielectric properties and interfacial electric-field distributions. However, the relationships among driving parameters, particle redistribution, surface charge dissipation, and discharge characteristics remain insufficiently understood. In this study, BaTiO₃/photocurable resin composites were fabricated, and the effects of filler volume fraction, driving voltage, and electric-field application time on particle distribution, dielectric properties, surface potential decay, and interfacial discharge characteristics were investigated. Increasing the driving voltage and application time enhanced the spatial non-uniformity of the BaTiO₃ particles, increased the relative permittivity, accelerated surface potential decay, increased the surface flashover voltage and partial discharge inception voltage (PDIV), and reduced partial discharge activity. For the 10 and 20   vol% composites, the maximum field strengths under the strongest assumed permittivity gradient were approximately 2.98% and 2.73% lower than those of the corresponding homogeneous cases, respectively.Compared with the 400   V and 1   min condition, the relative permittivity, surface flashover voltage, and PDIV increased by approximately 12.7%, 28.7%, and 65.6%, respectively, at 1200   V and 30   min. Under the same driving condition, the surface potential of the 10   vol% composite decayed by approximately 91.7% within 90   s. These results indicate that electric-field-induced particle redistribution can improve gas-solid interfacial discharge characteristics. The dielectric non-uniformity associated with particle redistribution may regulate the interfacial electric-field distribution and contribute to the observed improvements. Download: Download high-res image (266KB) Download: Download full-size image