Misha Sinner, a PhD candidate in the Department of Electrical, Computer and Energy Engineering, presented a paper at the International Federation of Automatic Control World Congress in July 2020 on wind turbine control.
A finalist for the Application Paper Prize at that conference, the work summarized findings from an international partnership that tested a control method on a model wind turbine operating in a state-of-the-art wind tunnel.
We asked him about his findings and what it is like working with Professor Lucy Pao at CU Boulder.
Question: How would you describe the work and results of this paper?
Answer: This work developed and demonstrated a control method that can make use of measurements of the incoming wind ahead of a wind turbine. Typically, wind turbine control systems rely only on rotor speed measurements (of how fast the blades are rotating). Adding in measurements of the wind ahead of it allows us to anticipate incoming gusts and produce a smoother power output.
Previously, computer simulations have demonstrated the value of including the upstream measurements, but there have not been many physical tests. With a group of collaborators at the ForWind Center for Wind Energy Research at the University of Oldenburg, in Germany, we tested this control method on an 8-foot-tall model wind turbine operating in a state-of-the-art wind tunnel and compared the results to the same controller without the upstream wind measurements. Ultimately the method includes the information from the upstream measurements in a way that hadn't been tested before, and we verified that including the upstream wind measurements in this way can help significantly in regulating the wind turbine operation.
Q: What are potential applications of this work? How will this impact someone’s daily life?
A: Improving the operation of wind turbines can lower the cost of wind energy, which means that it can be more economically viable in more places. As we know, there is still a lot of work needed to transition our energy system from relying heavily on fossil fuels to a system where the majority of electricity comes from renewable resources and fossil fuels are used only sporadically. This is a small piece of that complicated puzzle!
Q: Was there a problem or something you didn't expect during the course of the work? What was the hardest part of completion?
A: Running experiments is never easy. Although I had visited the test facility in Germany, I was not actually present when the tests were run, so there was a significant amount of communication that had to be carried out over email to get everything ironed out in a short period of time. It was something of a miracle that the experiment worked out so well.
Q: It sounds like this has been a really strong and ongoing partnership. What questions are still left to be answered?
A: Partly based on the success of this work early on, I was awarded a grant by the German Academic Exchange Service to conduct a follow-up study. So I spent two months in the fall of 2019 at ForWind in Oldenburg, developing a more complex version of the controller we eventually presented in this paper and testing it on the scaled wind turbine with a larger set of inflow conditions. The results of that follow-up work have now been published in the IEEE Transactions on Control Systems Technology as well. But there are still many interesting problems to be tackled in wind energy – I am particularly interested in strategies for coordinating the control of turbines within a wind farm environment.
Q: What is it like working with Professor Lucy Pao? Why did you decide to study here for your PhD?
A: I came to CU Boulder specifically because I wanted to be advised by Lucy on wind energy-related control problems, and it has been a pleasure getting my degree here and working in her research group. Lucy has been a fantastic advisor, giving me the flexibility to follow my own research directions while always being available to answer questions, help work through problems and provide feedback. I've thoroughly enjoyed working with colleagues, both within Lucy's research group and in external collaborations. My classes in CEAS, most of which have been in the ECEE department, have also been of very high quality and have informed my ongoing research interests.
"Wind Tunnel Testing of an Optimal Feedback/feedfoward Control Law for Wind Turbines" was a result of ongoing collaborative efforts on wind turbine control systems between the University of Colorado and the ForWind Center for Wind Energy Research at the University of Oldenburg in Germany. This study was funded in part by the German Academic Exchange Service, the Hanse-Wissenschaftskolleg in Delmenhorst, and the German state of Lower Saxony within the project "ventus efficiens." Misha's work has been supported by the National Renewable Energy Laboratory, a Palmer Endowed Chair at CU Boulder, and Envision Energy. Other authors include Lucy Pao, Vlaho Petrović, Frederik Berger, Lars Neuhaus and Martin Kühn.