AC Breakdown Characteristic Investigation and Analysis of Several TiO2 Nano-modified Insulation Fluids

Mineral oil as the main insulation and cooling material in electrical power industry provide a good performance. However Increasingly stringent environmental protection and industry safety requirements promote more and more research focus on finding potential substitution which should be environmental friendly, bio-degradable, low toxicity and nonflammable. Many researchers have indicate that the ester fluid could be considered as the potential insulation fluids to replace the mineral oil by their bio-degradable, low toxicity, and excellent flame retardant performance. But mineral oil generally provide better insulation performance and economy advantage. Meanwhile, Nano-modification technique has been observed to be an effective method to enhance the mineral oil insulation performance. Thus using Nano-modifieication technique to improve the ester fluids insulation performance could be a feasible method to find the potential alternative insulation fluids. AC breakdown voltage is a key parameter which was used to evaluated insulating material dielectric properties. In this paper, the sample prepared by the mineral oil, synthetic ester, and the food grade natural ester. The AC breakdown voltage experimental results of several nano-fluid samples which can be classified with six concentrations and base on three types insulating liquids have been record and comparison. Beside that, the Weibull distribution analysis has been preform to evaluate the average probability breakdown voltage and low probability breakdown voltage. The results show that TiO 2 nano-modified samples provide higher breakdown voltage than the pure sample. The nanoparticle concentration influence show that with the concentration increasing, the breakdown voltage would reach crest and then start to decrease. The optimal concentration occur at the 0.0006% (b/w) which provide the highest breakdown voltage. The results indicate that the phenomenon of nanoparticle enhancement on the ester fluids dielectric breakdown voltage exist.