Analysis of fault detection in the electrical insulation system of rotating machines

A new approach for fault detection and analysis in the electrical insulation system of generator winding bars is used for visual investigation. This paper presents two series of measurements, each with two bars, under simultaneous electrical, thermal and mechanical stress. A mechanically dominated aging mechanism is investigated in combination with a variation in temperature, which has a high influence on the lifetime. As a result of the complex structure of the insulation system, structural changes are difficult to detect with terahertz technology.