An accelerated aging technique to evaluate the long term performance of high temperature insulating fluids for mobile transformers

Mobile transformers are designed to have the largest electrical capacity in the smallest, lightest, and most economical package available. As such, these mobile units tend to operate at significantly higher temperatures than conventional transformers with hot spot temperatures reaching 250C. This investigation looks at the use of a novel technique to study the long-term aging characteristics of high temperature insulating fluids and evaluate the performance of these fluids. Initially the work centered around the development of an aging container that would be capable of handling the materials necessary to emulate the ratio in an actual unit and still provide the volume of fluid necessary for testing. The next phase required a means of effectively drying out the components and impregnating them with the insulating fluids. The final phase involved the actual aging of the systems, the evaluation of the fluid performance, and the results of the aging of both hydrocarbon and Silicone fluids.