Generator winding fault
Stator-winding temperature anomalies are one of the clearest SCADA signatures of an electrical fault in the generator — typically a frequency-converter failure, insulation degradation, cooling system problem, or developing inter-turn short. Early detection turns a costly emergency rewind into a planned converter swap.
Reviewed by Michael Tegtmeier, Founder & Managing Director · Last reviewed: May 10, 2026
What happens
The generator's stator windings convert rotor torque into electrical power; their temperature is set by current load, cooling-system performance, and insulation condition. When something goes wrong electrically — a faulty IGBT in the frequency converter, an inter-turn insulation breakdown, a cooling-fan malfunction, or sustained derating that loads the windings asymmetrically — winding temperatures climb above what wind speed and power output can explain, often with simultaneous power-output instability or curtailment. Catching the deviation against the model-expected temperature buys months of planning time.
Signs to look for
Stator winding temperatures rise above the model-expected envelope at a given wind/power operating point.[1,2]
Power output becomes unstable — fluctuating between rated and lower setpoints — or the turbine is silently derated by the control system.[1,3]
Cooling-system temperatures (coolant, ambient outlet) shift in tandem.[2]
Status-code patterns shift: more derating events, more frequency-converter warnings.[3]
Root causes
- Frequency-converter (IGBT) faults causing irregular phase loading and excess winding heat.[1,3]
- Insulation degradation — moisture, partial discharge, thermal aging — leading to inter-turn or turn-to-ground shorts.[2,4]
- Cooling-system failures — clogged radiators, failed fans, low coolant flow.[2]
- Operating outside the design envelope — sustained over-temperature operation or inadequate slip-ring contact in DFIG generators.[3]
How Turbit detects this
Per-turbine neural networks learn each generator's normal winding-temperature behaviour as a function of wind speed, power, ambient temperature, and grid conditions. Deviations against the predicted value catch developing electrical faults months before status codes escalate to a forced shutdown. The relevance-prediction layer correlates winding-temperature anomalies with frequency-converter status codes to point at the most likely root cause.
From the Turbit fleet
Generator winding-temperature anomalies in the Turbit fleet typically resolve to one of three causes — frequency-converter faults, cooling-system issues, or insulation degradation — in roughly that frequency order. Detection-to-resolution windows depend on parts availability for the converter or cooling component, but the AI-detection-to-OEM-engaged step is consistently under a month.
On a 50-turbine portfolio, the typical converter exchange is EUR 30–60k. Catching the developing fault while the turbine still produces — instead of after a forced trip — is the difference between a scheduled exchange and a crane-and-crew emergency.
References
- Fault detection of a wind turbine generator bearing using interpretable machine learning — Frontiers in Energy Research (2023)
- Wind turbine generator failure analysis and fault diagnosis: A review — Liu et al. (2024)DOI: 10.1049/rpg2.13104
- Wind Turbine Generator Reliability Analysis To Reduce Operations and Maintenance Costs — NREL (2023)
- Monitoring and Identifying Wind Turbine Generator Bearing Faults Using Deep Belief Network and EWMA Control Charts — Frontiers in Energy Research (2021)
See Turbit on your fleet
Backtest Turbit on the turbines where you already know something happened — or read how operators like VSB, Energiequelle, Enercity and Teut use Turbit on their fleets today.