Evaluating the effects of lower molecular weight acids in oil-paper insulated transformer

Paper insulation breakdown of a transformer will directly result in the failure of its operation. Temperature variation in transformer initiates cellulose chain scission. Studies indicate that carboxylic acids are formed due to this scission in an aged transformer. Organic acids that are produced as byproduct is one of the key factors for insulation degradation in an oil-paper insulated transformer. Low molecular weight acids that are water soluble, prefer to stay in paper, which eventually affects the paper insulation, whereas the higher molecular weight acids are known to be fat soluble and affect the oil insulation. Along with the traditional methods which are used for condition monitoring, initiatives must be taken to understand the influence of acids generated inside the transformer. With a view to look into the detrimental effects of acids on the insulation status, organic acids are mixed in a definite proportion with transformer oil and the experimental results on an insulation sample are reported. An attempt has been made to correlate the dielectric test results with type and concentration of organic acids present in the transformer insulation system.