Abstract: The traditional insulating oil can not play a satisfactory role because of its poor viscosity, low oxidative stability, and poor biodegradability. Oil-based titanium dioxide nanofluids have been widely developed for their excellent alterating current and pulse breakdown properties, high electrical conductivity and good ageing resistance. However, the stability of the nanofluids is still unsatisfactory and many mechanisms remain to be clarified. Therefore, it is systematically summarized including the preparation, characterization, stabilization mechanisms, and key performance parameters of titanium dioxide nanofluids. Further more, the advantages and disadvantages of oil-based titanium dioxide nanofluids are compared. This work can provide the reference for this kind of material's follow-up development.

Key words: high voltage transmission, modified insulating oil, titanium dioxide, nanofluid