An overview of potential liquid insulation in power transformer

The dielectric performance of mineral oil and natural esters is still a challenge that has been studied for many years to attain the best liquid insulation for power transformer. With the continued need for power transformers, the use and reuse of mineral oil in transformers has reached several thousand tonnes across the world. Therefore, industries are compelled to resolve the problem of pollution and non-biodegradability of petroleum-based mineral oil. Typically, there is no right solution; to that end researchers have recently shifted their focus towards edible oil markets to find the alternative insulating fluid. Although edible oils are a better choice over mineral oil, they still exhibit several detrimental properties as with mineral oil. The purpose of this survey is to contrast mineral oil-based transformer oils in the power industry and its alternatives. The review makes use of several research articles over a period of 32 years, covering and uncovering the facts on mineral oil, silicone oil and natural esters. In this view, the technology utilisation, efficiency improvement and inferences are accessible for current and future authors to select the right technology for the development of new insulating fluid.