October 19, 2022, VIRTUAL SENSING
HBK, along with experts in the fields of wind turbine research and development, manufacturing, energy provision and testing, are collaborating on a major, three-year, research project, funded by the Danish Energy Technology Development and Demonstration Programme (EUDP).
With increased focus on climate change and the scarcity of resources, there is a growing need for sustainable and smart solutions. Wind energy, one of the fastest-growing and most important sources of renewable energy, is already driving the world towards a cleaner, healthier and fossil-free future.
In addition to keeping up with the fast pace of technology, wind turbine manufacturers, like all manufacturers, are under pressure to deliver continuous innovation, while constantly facing the engineering challenges of shorter product development cycles and reduced costs – all without compromising the highest standards of quality, reliability and safety.
One way of achieving this is by collaborating with external partners. Collaboration not only provides access to technological resources, rare skills and competencies but also instigates agility and efficiency, potentially shortening time to market for new products. Blatigue-2 is one such collaboration.
The project, BLATIGUE-2: Fast, Smart and Efficient Fatigue Testing of Large Wind Turbine Blades, is led by the Danish Technical University (DTU), involves ten partners and is a follow up to Blatigue-1 where a fatigue test method – better than current standard tests – was developed along with an exciter that could actually test wind turbine blades. That initial work continues with Blatigue-2, where the exciter and software will be combined to make a smart exciter solution that will increase the quality of blade testing, not only reducing unplanned blade repairs by an estimated 10% but also significantly reducing the time to market for new blade designs.
Project Manager Kim Branner from DTU Wind explains, “The project’s vision is to create a fast, smart method to perform tests. We will develop new tools and software, which the industry needs. When the tests of the blades are improved, fewer errors will occur, they will become more reliable, and this will also increase the wind energy’s competitiveness.”
The project focuses on developing and demonstrating four technologies, which are key parts of the overall solution. These technologies will be commercialized and brought to the market by four of the partners. HBK’s representative is Senior Research Engineer, Dmitri Tcherniak, who is responsible for developing virtual sensing algorithms for the project. This technology will significantly reduce the need for physical sensors and data acquisition channels, which will reduce CAPEX for hardware and sensor investments and reduce man-hours and testing time.
Dmitri has a long history of cooperation with DTU Wind Energy in the field of wind turbine vibration, modal analysis, and structural health monitoring. He explains how HBK got involved in the project, “It was actually just due to good personal relations. Someone at DTU mentioned BLATIGUE-2, and I suggested developing ‘virtual sensing’ in the frame of the project, as it is good for the project and it is good for HBK, as we need to master this technology.”
So what is virtual sensing? Dmitri, explains, “Virtual sensing is a relatively new technique. It is a hybrid technique based on the synthesis of computational and experimental methods. Combining high-definition mode shapes originating from finite element analysis with the experimental data from a few measurement points, one can reconstruct the full-field dynamic displacement of the blade. In other words, one can ‘measure at virtually any point on the structure, even if there is no sensor there’. This is how the term ‘virtual sensing’ was coined.”
Example of virtual sensing: full-field displacement and surface strain reconstruction based on readings from a few accelerometers
So what are the next steps? “We are only eight months into the project,” says Dmitri, “but we already have some interesting results. It looks like we can reconstruct the full-field acceleration with reasonable confidence. The next step is to try to reconstruct the full-field strain.”