Deterioration diagnosis of insulators for breakers using chemical evaluation and Mahalanobis-Taguchi (MT) method

We have developed a deterioration diagnostic technique of the insulators for power distribution equipments such as breakers using the chemical evaluation and the Mahalanobis-Taguchi (MT) method. It is possible to diagnose the deterioration degree with great accuracy and nondestructively on-site without the effect of humidity and external noise such as electromagnetic wave. The chemical evaluation items are ion concentration, coloration, and gloss, etc. The measurement of the nitric acid ion concentration and the sulfuric acid ion concentration was especially effective for diagnosis. It was clarified that the deterioration degree of the insulators could be diagnosed by this technique because the linear relationship existed between the results judged by MT method and the actual measurement results of surface resistivity. This technique has been applied to the diagnosis of power distribution equipment since April, 2003