Health diagnostics of water-cooled power generator stator windings using a Directional Mahalanobis Distance (DMD)

A power generator, one of the most critical components in power plant, could experience unexpected series system failures, resulting in substantial maintenance and societal cost. This paper proposes a new health diagnostics method for water-cooled power generator windings against moisture absorption. The main idea of the proposed diagnostics method is a Directional Mahalanobis Distance (DMD) based on the correlation matrix of health data. In this study capacitance data measured from a winding insulator is referred to as health data. It is an indirect measure of moisture absorption in power generator windings by water leakage. Data from ten generators, of which each has 42 windings, are used for demonstration of the proposed health diagnostics method for power generator windings.