The power generated by wind turbines can fluctuate rapidly, sometimes by as much as 50%, which poses challenges for both power grids and the turbines themselves. A recent study conducted by researchers from the University of Oldenburg and the Sharif University of Technology in Tehran offers a potential solution to mitigate these power fluctuations.
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The highly fluctuating power output of wind turbines results partly from the reactions of the control system. Image Credit: Jaroslaw Puczylowski
The study suggests that the control systems of wind turbines are primarily responsible for these short-term variations in electrical output. It also provides insights into how these control systems can be improved to make the energy output from wind turbines more stable and consistent. The findings from this research have been published in the science journal PRX Energy.
Dr. Pyei Phyo Lin, leading a research team at the University of Oldenburg, conducted an analysis using data from multiple turbines within a wind farm.
Because wind turbines operate under turbulent wind conditions – similar to a plane landing in strong winds—all the measured data display multiple fluctuations and no clear signal can be detected. We refer to this as ‘noise.’
Dr. Pyei Phyo Lin, University of Oldenburg
The physics engineers and colleagues, employed stochastic methods to analyze time series data related to variables such as wind speed, electrical output from the turbines, and the rotational speed of the generator.
Noise as a Source of Information
With this groundbreaking mathematical approach, they successfully untangled the data noise, distinguishing it into two distinct components: one stemming from wind effects and the other arising from the turbine's control system responses.
Noise is often considered an unpleasant effect that interferes with measurements.
Dr. Pyei Phyo Lin, University of Oldenburg
“Now the noise provides us with new information about the system – that’s a new quality,” adds co-author Dr. Matthias Wächter, who heads the Stochastic Analysis research group at the University of Oldenburg.
As the team explains, the results of its study indicate that the reactions of wind turbine control systems to abrupt wind fluctuations are often suboptimal: these systems tend to switch control strategies, which can lead to the observed strong fluctuations in electrical output. The new findings pave the way for turbulent wind phenomena to be decoupled from the control systems’ reactions.
“In this way, it will be possible to refine the control systems to ensure that wind turbines generate power more consistently,” notes turbulence expert Professor Dr Joachim Peinke from the University of Oldenburg, who was also involved in the research. Additionally, implementing these improvements could enhance the efficiency of wind turbines and prolong their operational lifetimes.
Currently, Dr. Mohammad Reza Rahimi Tabar serves as a Fellow at the Hanse-Wissenschaftskolleg Institute for Advanced Study in Delmenhorst.