Performance Evaluation of Additive Manufacturing Based Test Samples for Studies of Defects in Electrical Insulation

Electrical insulation is an important part of power equipment. Aging and degradation of the insulation due to operational and environmental stresses is inevitable and limits the lifetime of the components' insulation. Cavities and cracks inside the insulation lead to threatening discharges that can cause failure of the components. While several studies have been conducted, the mechanism of the insulation defect progression is still not well understood. Construction of the test samples is a critical task in order to conduct reliable practical studies on the insulation behavior. Considering conventional ways of sample construction, accuracy of the sample development is a major challenge. This paper proposes additive manufacturing as an improved methodology of the sample construction for internal defects in solid insulation. Number of test samples with and without cavity are developed using 3D printing. Performance of these samples has been evaluated considering inception of the partial discharge in the defects unto the breakdown. The response of the physical dimensions of the insulation sample and the defects is studied in terms of degradation properties. The factors that may affect the observed properties are highlighted. Gaining excellence in 3D printing of insulation based test samples will enable to conduct the experimental studies with increased accuracy.