Study on identification of electrical aging of epoxy laminate by fuzzy mathematics

In this paper a new identification technique based on fuzzy mathematics is proposed to classify the aging process of epoxy laminate. In order to select proper aging characteristic parameters, the variation of the partial discharge (PD) parameters of the epoxy laminate is investigated during the entire process of an aging test. Fortunately it is found in this study that four PD parameters, Mn, Q, Span+, and Span-, are sensitive to aging and all increase with aging time; especially Span+ and Span- are more obvious. Because the conception of “aging” is not precise but vague in nature, it is helpful to introduce fuzzy mathematics, good at dealing with uncertain information, into the aging identification. The new identification technique classifies the entire aging process into five levels. A, B, C, D, and E, which respectively represent five insulation situations: better, good, medium, bad, and worse. The identification result is effective and encouraging