Effect of Thermal Aging on the mechanical Characteristic of Insulating Paper Impregnated with Different Insulating Oils

Transformers are critical components of the power grid. The energy transfer is highly dependent on the performance of the transformer. As the transformer operates, the paper insulation undergoes an aging process as a result of thermal, electrical, and mechanical stresses. The chemical and physical characteristics of the paper insulation change gradually. Paper insulation which mostly consists of cellulose degrades and the Degree of Polymerization decreases due to the decomposition of the inter-fiber bondings. This causes a reduced mechanical strength and will lead to tears, defibrillations and loss of stability. In this contribution, the mechanical behavior of paper insulation impregnated with uninhibited oil, and 2 different inhibited oils investigated. The observation focus is on the mechanical characteristics of paper insulation by considering and the degree of polymerization and the Tensile Strength.