Inside Success Story: Early Generator Bearing Vibration Detection at a Combined-Cycle Plant

A European power generation company serving residential, commercial, and industrial markets uses GE Vernova’s SmartSignal™ predictive analytics to detect early equipment failures across several combined-cycle power plants. They selected SmartSignal along with GE Vernova’s Industrial Managed Services (IMS) to enhance reliability, reduce unplanned downtime, and optimize maintenance operations. Recently, SmartSignal issued an alert to the assigned IMS engineer, signaling a potential issue with a generator bearing.

A generator bearing in a combined-cycle plant is a critical mechanical component that supports the generator’s rotor shaft, allowing it to spin smoothly at high speed. The generator converts mechanical energy from the turbine into electrical energy, and its rotor spins at thousands of RPM. Bearings keep the rotor aligned and rotating with minimal friction. Monitoring these components with advanced predictive analytics is essential because:

Using SmartSignal predictive analytics to monitor for early signs of issues, this European utility was able to prevent significant equipment damage and maintain operational reliability.

SmartSignal’s digital twin blueprint, a prebuilt model incorporating known failure modes, flagged a subtle but critical trend: a gradual rise in vibration levels on generator bearing 1. The digital twin continuously compares real-time sensor data against expected behavior, and in this case, it revealed a reading climbing from 60 µm to 71 µm, surpassing the maximum threshold of 68 µm.

This was an early warning of potential bearing distress. Acting on the alert, the IMS team immediately notified the customer’s Center of Excellence (CoE) and recommended a detailed vibration analysis. To ensure proactive follow-up, a formal monitoring case was created, enabling engineers to track the anomaly and prevent escalation.

Generator bearings operate under extreme conditions, as mentioned above, they support rotors spinning at thousands of RPM. Even small changes in vibration can signal:

If left unchecked, rising vibration can lead to bearing seizure, rotor damage, and unplanned outages. Predictive analytics helps catch these subtle shifts early, giving operators time to act before damage occurs.

Following the notification, the site team began closely monitoring the vibrations of the affected bearing and scheduled a comprehensive inspection of both the bearings and the rotor during the next planned outage. During the generator inspection, engineers discovered that several distance pieces within the rotor end winding had loosened. The site team implemented a repair solution to secure the distance pieces.

Thanks to the early notification from GE Vernova’s IMS team, the customer was able to proactively prepare for an extended inspection of the generator and ultimately identify the root cause of the developing issue.

In the worst-case scenario, complete loosening of the distance pieces could have damaged the end winding, potentially necessitating a full rotor replacement. Following the generator restart after the outage, both the customer and the IMS teams confirmed that the corrective actions were effective, as vibration levels stabilized and subsequently decreased to the values predicted by the model. The customer estimated that approximately $3,800,000* in costs were avoided.

*Avoided costs are based on North American average production loss