Molecular Simulation on a New Type of Two-Element Mixed Natural Ester Insulating Oil with Upgraded Fluidity and Oxidative Stability

Natural ester is an environmentally friendly insulating medium, which is regarded as a potential alternative to mineral oil. Improving the fluidity and oxidative stability of natural ester is essential for its application in power equipment. Mixed modification can ameliorate the performance shortcomings of natural esters and, in comparison to methods such as nanomodification or antioxidants, it does not suffer from issues like agglomeration or environmental contamination. Therefore, the best-modified short-chain saturated triglyceride is selected by molecular dynamics, and then the oxidative stability of the mixed-insulating oil is evaluated by quantum chemistry. Results exhibit that glyceryl triacetate has the best viscosity-reducing effect, which can improve the free volume and diffusion ability of the mixed-insulating oil and decrease the entanglement and friction between the carbon chains of the oil molecules. DFT calculations indicate that the oxidative stability of mixed insulating oil can be improved with glyceryl triacetate. This study can contribute to the development of high-performance insulating oil for power equipment by providing theoretical references and computational support.