Analysis and design of nanofluid-filled power transformers

To alleviate the adverse impact due to the deterioration of electrical insulation, this paper presents an electromagnetic-thermal-fluid analysis for the prediction of temperature distribution in transformers with oil-based nanofluids or pure oil. The core loss and copper loss are taken as the heat sources for the temperature analysis using computational fluid dynamics. To strive for computing the temperature distribution accurately in the nano-oil, an effective numerical method using finite volume method and improved physical parameter model are employed. Numerical simulation of the thermal performance of the nanofluid with different volumetric fractions with Al2O3 nanoparticles is compared with those using pure transformer oil in a 500 VA single-phase transformer. From the comparisons of the simulation results, it is found that the volumetric fraction 0.01% is an optimum concentration in reducing the transformer size for the same power rating. The observation is served as useful guidelines and detailed process for the design of oil-based power transformers.