Computational Model and Experimental Validation of the Influence of Grain‐Boundary Parameters on the Electrical Performance of Arrester Varistor

ABSTRACT From a materials‐computation perspective, this study integrates the electron‐excitation model of double Schottky‐barriers with a Voronoi network to characterize the microscopic electrical and structural properties of ZnO varistors. The quantitative influences of two pivotal barrier parameters—the grain donor density N d and the grain‐boundary interface‐state density N i —on macroscopic electrical performance metrics such as voltage gradient, leakage current, and current‐withstand capability are systematically investigated. The reliability of the model is corroborated by accelerated aging tests on samples featuring a graded Y 2 O 3 doping profile, which also elucidate the effects of yttrium incorporation on varistor performance and aging resistance. The findings furnish a theoretical foundation for the design and fabrication of high‐performance ZnO varistors and are of significant value for the development of surge arresters.