I. Introduction
Epoxy resin is employed as a solid insulating material inside power apparatuses, such as generators, transformers, and switchgears [1]. Enhancing breakdown strength increases the operating electric field, thereby contributing to the development of high-efficiency generators and compact solid switchgears. One technology that improves the breakdown strength of epoxy resins involves the use of nanocomposites in which nano-sized ceramic particles are dispersed throughout the epoxy resin. Epoxy nanocomposites are recognized for their excellent insulation performance, including superior breakdown strength and resistance to partial discharges [2]. Application of epoxy nanocomposites in generators and solid switchgears has also been proposed [3], [4].