Investigation on the Microscale Interaction Characteristics of POSS-Modified Vegetable Insulating Oil Under Nonuniform Temperature and Electric Fields

Nano-additives can improve the physicochemical and electrical properties of insulating oil by enhancing the microscopic interaction. In this article, the microscale interaction characteristics of cage polysilse- squioxane (POSS)-modified insulating oil under nonuniform electric field and nonuniform temperature field and its influence on molecular diffusion are studied. The results indicate that under nonuniform temperature field, the interaction energy between POSS and insulating oil molecules in the high electric field strength area is higher and has better mutual solubility, and the high-temperature area under nonuniform temperature field cannot promote the mutual solubility between POSS molecules and insulating oil molecules. In addition, displacement vector data show that the increase of electric field strength can promote the displacement of insulating oil and POSS molecules, and the molecular displacement at the boundary of nonuniform electric field is higher. The high-temperature region under the nonuniform temperature field can increase the molecular kinetic energy, but the higher viscosity of the insulating oil molecule prevents heat transmission. Furthermore, the mean square displacement (MSD, nonlinear increase) under the nonuniform temperature field is far less than the MSD (linear increase) under the nonuniform electric field strength. This is mainly because the energy of the system under the nonuniform electric field is always at the same level, but the low-temperature area of system under the nonuniform temperature field continuously absorbs energy from the high-temperature area. This article can provide the microscale interaction of Nano-modified vegetable insulating oil under nonuniform electric field and nonuniform temperature field.