Optimising performance at Trattberget: Addressing winter challenges and enhancing operational efficiency

The Challenge

Trattberget wind farm is owned by NTR in Sweden and has an output capacity of 69MW. The farm faced challenges, including heightened turbine vibrations and frequent alarms, especially during the winter months. These issues threatened to impact long-term reliability and operational efficiency, and NTR sought to understand the root causes of these performance fluctuations.

The Solution

NTR reached out to RES to conduct a comprehensive Site Performance Assessment (SPA). A key component of this solution was the installation of AnemoLive, our remote diagnostic services and performance optimisation tool. Unlike previous instances where the Anemo edgebox was shipped, installed by a technician, and activated remotely, this deployment marked the first time RES installed it on-site in person, showcasing RES’ commitment to hands-on, innovative solutions and tailored customer service. During the SPA, RES gained access to a static dataset of full-spectrum high frequency data and performed a detailed diagnostic service of the entire wind farm to identify and mitigate performance issues for each turbine. 

As an optional service, the customer could opt for live data access to high-frequency data, which would help them identify and resolve additional issues, further enhancing their performance.

Mass Imbalance Correction
The SPA revealed a notable issue with the distribution of mass of the rotating parts in two turbines . This imbalance could cause the turbines to operate less efficiently than expected and potentially lead to mechanical problems or increased wear and tear.

The resolution of the mass imbalance was achieved through a coordinated effort between RES, NTR and the operation and maintenance (O&M) partner. RES conducted a thorough data review, while NTR’s local team performed on-site inspections that revealed incorrect weight installations during construction. Following this identification, the O&M partner’s local team contributed to the correction of the issue.

This correction significantly reduced the mass imbalance, with observable results within one to two weeks after implementation.

Generator Overspeed Monitoring
In addition to the mass imbalance, NTR reported frequent alarms, indicating potential generator overspeed issues, where the rotational speed of the generator exceeded its design limit. This can lead to severe mechanical stress, overheating, and potential damage to the turbine blades, generator components, or bearings.

At this point, NTR asked RES to implement the ongoing live data service, to help them understand and resolve the issue. By utilising this high-frequency data access, the engineering team could accurately monitor the generator, determining whether alarms indicated real problems or false triggers due to sensor inaccuracies.

The Impact

The mass imbalance correction significantly reduced vibrations and uneven fatigue loads on the turbines, leading to less wear and tear of the equipment, with an expected reduction in future maintenance cost over time, contributing to long-term financial benefits for NTR.

While the resolution of generator overspeed alarms is still ongoing, the interventions to date, particularly the mass imbalance correction, have enhanced stability and efficiency, contributing to a more sustainable operational model.

This case study highlights the importance of proactive performance assessments and innovative solutions in optimising wind farm operations, particularly in challenging winter conditions. Although the precise return on investment (ROI) is yet to be measured, the initial results indicate promising improvements in operational efficiency and cost savings.