Mechanical degradation of hydro generator stator core: advanced diagnostics, on-site remediation, and engineering insights from a field case

Hydro generators are critical assets in hydropower plants, playing a central role in ensuring energy availability, grid reliability, and operational efficiency. With the global shift toward increased penetration of variable renewable energy sources, the dependable performance of synchronous machines becomes even more vital. While electrical failures are well-documented as the predominant cause of forced outages in rotating electrical machines, mechanical deterioration of stator core assemblies—though comparatively infrequent—can result in severe operational disruptions, long lead-time repairs, and significant financial losses.