The analysis of paper degradation by-products as a tool for monitoring fault conditions in oil-filled electric apparatus

Cellulosic materials are used for electrical insulation and mechanical support in power apparatus such as transformers and reactors. In order to evaluate the condition of the insulation system of this type of equipment, it is necessary to determine if the cellulosic materials are being degraded excessively. Several experiments were performed to determine the content of indicator by-products generated from the degradation of cellulosic materials under electrical, thermal, and oxidative stress. Several variables were explored to determine their influence on by-product generation and subsequent degradation. Case histories from service-aged insulation provided evidence to corroborate laboratory results