Unidirectional Accelerated Lifetime Investigations of Mechanically Dominated Aged Electrical Insulation System used in Generator Winding Bars

This paper investigates the influence of electrical, thermal and in particular mechanical stress on the electrical insulation system of generator stator bars. For this purpose, accelerated ageing tests are performed in order to analyze the ageing behavior with experimental results. As the focus is on mechanically dominated ageing, there is a defined variation of the mechanical load. Previously, studies have been performed on alternating stress, which is fully reserved. In this work the unidirectional stress is investigated.