Case Story – Hyötytuuli Oy

How TCM ® became the key to controlled and smooth preventive maintenance at the Tahkoluoto offshore pilot turbine

The company
Finnish wind energy producer Suomen Hyötytuuli Oy invests in preventive maintenance, including vibration monitoring of  turbines. The company has three wind farms in Finland, and two new wind farms to be commissioned during 2017, and several projects under development.

Suomen Hyötytuuli Oy has a TCM® Enterprise Server with two sites connected, with a total of 10 wind turbines (WTG’s), all of with the TCM® System installed. Kuljunniemi wind farm in Raahe with five 2.3 MW Bonus WTG’s completed in 2004 and four 2.3 MW Siemens WTG’s completed in 2010.

The company will build 10 offshore wind turbines, and the new offshore wind farm will also be connected to the TCM® Enterprise Server. The existing pilot offshore turbine is located in the middle of the new wind farm. Siemens will supply 10 wind turbines for the new site, each with a capacity of 4.2 megawatts and a rotor diameter of 130 meters, and each installed with the TCM® system. Siemens will also be responsible for servicing the wind turbines during the first two years. The installation of the wind turbines is scheduled for summer 2017, and the Tahkoluoto Offshore wind farm will produce energy during autumn 2017.

TCM® Ocular Pro
Suomen Hyötytuuli Oy has a TCM® Ocular Pro license in connection to the TCM Enterprise Server. With the TCM® Ocular Pro license, the company has the ability to analyze WTG’s, and  diagnose incoming alarms. TCM® Ocular is a diagnostic platform providing useful tools for supporting daily workflow using TCM® Monitoring. It provides a data-mining and visualization platform for analyzing vibration data. Based on the drivetrain model, build from kinematic data, fault signatures and indicators in the data are easily identified using TCM® Ocular.

TCM® caught abnormal vibration activity
In September 2016, the TCM® system caught abnormal vibration activity in the 2.3 MW Siemens offshore pilot turbine in Pori. An unexpected main bearing damage was noticed. Using TCM® Ocular Pro, the fault was diagnosed, and the severity and expected remaining lifetime were assessed. Based on this a recommended action was determined.

Recommended actions
In this case, the recommendation was to verify the fault through visual inspection within the next month and schedule the repair of the bearing within four months, while running curtailed until then.

“Vibration measurement is an important part of our preventive maintenance strategy. Now we  are always up to date and can notice possible damage earlier. It was important for us to be able to make the required curtailment procedures to keep the offshore pilot turbine running and avoid shutting it down. This has resulted in remarkable savings in time and money,” 

-Jaakko Kleemola,Technology Manager, Suomen Hyötytuuli Oy.

Conclusion
Gram & Juhl’s TCM® Enterprise Server combined with TCM® Ocular enabled Suomen Hyötytuuli Oy to plan offshore turbine maintenance for the next summer season in a cost-efficient way, and prevent further damage well in advance. The system allows to make analyses on the condition of the turbine, and therefore produce energy in a safe manner until to the planned maintenance, despite of the damage.

At sea outside Tahkoluoto in Pori at the Reposaari wind farm, there is one 2.3 MW Siemens offshore WTG, which was completed in 2010. This is the first and currently also the only offshore wind turbine in Finland.

Conditions for offshore wind power production in Finland are different compared with, for example, the North Sea, since the cold and icy conditions require special technical solutions. Wind power production is expected to keep expanding to the sea due to better wind conditions, and the possibility of building large-scale offshore wind farms.