Studies of the condition of thermally aged transformer board insulation by electrical and chemical techniques

The paper considers the assessment of the ageing condition of transformer board. Samples of two types of thermally aged transformer board and the accompanying oil samples were obtained from the H. Weidmann Ltd, Switzerland. Electrical, mechanical and chemical tests were applied to these samples. Results from these tests are presented in this paper. Comparisons of the two different transformer board based on their measured properties are also examined in this paper