New safety dielectric coolants for distribution and power transformers

This article offers a summary of the development of dielectric fluids based on edible natural seed oils. We also include a discussion of the history of liquid dielectric coolants for distribution transformers. Additionally, we examine ester-based fluids; a key-properties comparison between new, natural ester-based fluids and other major dielectric coolant types; and details of field trials with transformers designed to use the new fluids.