Experimental study of the effect of using phase change material to improve electrical insulation of power distribution transformers

In this article, the effect of using phase change materials to improve heat transfer in power distribution transformers has been investigated experimentally. To enhance the cooling of the transformer, a new method has been proposed, which involves adding paraffin inside aluminium containers that are sealed to the transformer oil. The test setup includes an electric transformer filled with transformer oil, two electrical heaters, a power regulator, a thermal camera, oil insulation measuring device, and temperature sensors placed at various locations. The experimental results demonstrated that the addition of phase change materials to the electronic transformer oil led to a decrease in the temperature of the transformer, particularly in summer weather conditions. Additionally, the mean temperature of the transformer oil was reduced from 46.7 to 42.5 degrees Celsius by adding 8 kg of paraffin. However, it was observed that when the temperature increases suddenly and rapidly within an hour, these materials are ineffective in dissipating the heat and reducing the temperature of the transformers. Additionally, the research examines the impact of continuous and high-temperature increases on the oil electrical insulation. The results revealed that using phase change materials increased the voltage that the oil could withstand as an electrical insulator from 56.8 kV to 61 kV.