The Comprehensive Performance of ZnO Varistors Regulated by the Formulation System and Sintering Process

ZnO varistor is the core component of surge arrester, which plays a crucial role in suppressing overvoltage in transmission and distribution system. Optimization of multivariate regulation technology and improvement of sintering process are important means to develop high performance varistors, but there is a lack of systematic scientific research on the mechanism of its influence on both microstructure and macroscopic electrical properties. In this study, the change characteristics of macroscopic electrical performance were obtained through numerical calculation of varistor by establishing a Voronoi network. And the influence of formulation system and sintering process on the microstructure and macroscopic performance of varistor was obtained experimentally. Based on the experimental and calculation results, the following conclusions were obtained: Y3+ inhibits grain growth and forms surface states and traps at grain boundaries, increasing E1mA while causing α1mA and IL degradation; The increase of sintering temperature leads to the thickening and then thinning of the grain boundary layer, causing the U-shaped change of α1mA and IL. The research results can provide an important theoretical and experimental basis for the development of high performance varistors.