Dissection of stator winding insulation HVRM, VPI insulation

This paper focuses on the dissection coils/bars of stator winding manufacturing from ONLY VPI insulation (vacuum pressure impregnation). It outlines the preparation process and essential inspection tools required for dissection, accompanied by discussions and photographs illustrating the typical appearance of VPI insulation and failure modes for coils. This paper will share the experience of those involved in visual evaluations of dissected coil samples within high voltage stator windings and to manufacturers and owners of electrical generators engaged in assessing test reports and results.