Wind turbines

Improving bolt tightening procedures

In the dynamic realm of wind turbine manufacturing, where every bolted flange connection plays a crucial role in ensuring reliability and longevity, our customer faced a challenge. Seeking to enhance the efficiency and precision of their tightening procedure for a new generation of turbine models, they had the goal to preload bolts faster and more reliably with a new tightening procedure. That would achieve cost-effectiveness, and, above all, introduce a level of precision that would minimize retightening during future maintenance, significantly reducing operational costs for their customers.

However, this quest for improvement came with a caveat: without in-field validation, the potential consequences of deploying this enhanced tightening method could be both financially and operationally catastrophic. It was against this backdrop that Sensorise came to help.

Validation with preload monitoring

To evaluate the effectiveness of the new tightening method, the customer’s measurement team wanted to evaluate how the bolt preload changes over time from the point of installation and during operation. The flanges connecting the blades to the hub are one of the most critical bolted connections in wind turbines. Introducing our Sensorise SmartScrew System, we seamlessly captured vital data on preload loss. To accomplish this, we installed eight SmartScrews per flange, complemented by an 8-channel IO-Link master per blade. However, navigating the challenges presented by the confined installation space within the hub while enabling 360-degree blade pitching required a wireless energy transfer to the blade. The solution involved leveraging inductive energy transfer from the hub to the blade, coupled with wireless data transfer from the blade to the nacelle, ensuring seamless communication and data transmission across the wind turbine system. Equipped with 32 measurement channels, the system featured one sensor group per blade, ensuring continuous high speed data capture, while the acquired data was transferred via CANbus to the customer’s system.

This data-driven approach allowed the customer to make well-informed decisions regarding the validation of the new method.

Insights from bolted connections: more uptime

Our pioneering solution extends beyond conventional preload monitoring by enabling the measurement of dynamic bolt loads in real time. By capturing load cycles and unlocking invaluable insights, our team not only verified the accuracy of FEM simulations and numerical calculations but also provided a pathway to guide wind turbine operations.

We discovered that higher wind speeds do not always correlate with increased bolt loads. As a result, rules governing emergency shut-downs due to high-velocity winds could be recalibrated, allowing turbines to increase uptime while ensuring the safety of load-carrying components such as blade bolts.

With advanced tightening methods and data-driven insights, our customer achieved lower operational costs and higher reliability, as well as new opportunities for increased uptime, solidifying their pioneering role in wind energy.

Join us on this journey of innovation as we make critical machine components bring value to your business, one force measurement at a time.