Mixed Insulating Liquids with Mineral Oil for High Voltage Transformer Applications: A Review

Due to the growing interest in environmental concerns, synthetic and natural esters have become key focus of picture last two decades as insulating fluids for high-voltage equipment. This is because, unlike mineral oil, ester liquids are biodegradable, nontoxic, safe environment human health. These derived from renewable sources high fire resistance. However, still used a rather limited number electrical equipment several reasons (high cost, viscosity density, increased tendency toward electrostatic charge, faster propagation streamers an inhomogeneous electric field, etc.). Besides, huge amount filled with oils. The massive replacement oil-filled or may be extremely expensive utilities transformer owners. In addition, event partial complete retrofilling oil fluid, evidently contain mixture fluids, therefore, demanding scope research on mixed liquids. intent this article present comprehensive review literature blend other alternative dielectric fluids. critical progresses, highlights, challenges related along significant tutorial elements well some analyses discussed. should useful researchers, utilities, owners concerned aspects.