April 6, 2018
Control of Wind Turbines and Wind Farms
Wind energy is recognized worldwide as cost-effective and environmentally friendly and is among the world's fastest-growing sources of electrical energy. However, science and engineering challenges still exist. For instance, in order to further decrease the cost of wind energy, wind turbines are being designed at ever-larger scales, especially for offshore installations. We will overview a two-bladed downwind morphing rotor concept that is expected to lower the cost of energy more at wind turbine sizes beyond 13 MW compared to continued upscaling of traditional three-bladed upwind rotor designs. We will highlight some of the control systems issues for such wind turbines at these extreme scales and outline selected advanced control methods we are developing to address these issues. In the second part of the talk, we will discuss the growing interest in the coordinated control of wind turbines on a wind farm. Most wind farms currently operate in a simplistic “locally greedy” fashion where each turbine optimizes its own power capture. Due to wake interactions, however, this locally greedy control is actually suboptimal to methods in which the collective wind farm is considered. We will overview recent work in wind farm control and show selected results that demonstrate the performance improvements possible when carefully accounting for the wake interactions in coordinating the control of the wind turbines on the farm. We shall close by discussing continuing challenges and on-going and future research avenues that can further facilitate the growth of wind energy.
Lucy Pao is a Professor in the Electrical, Computer, and Energy Engineering Dept. at U. Colorado Boulder. She has completed sabbaticals at Harvard U. (2001-2002), the U. California, Berkeley (2008), the US National Renewable Energy Laboratory (2009), the Hanse-Wissenschaftskolleg Institute for Advanced Study in Delmenhorst, Germany (2016-2017) and the ForWind Center for Wind Energy Research at Oldenburg U. (2016-2017). She earned B.S., M.S., and Ph.D. degrees in Electrical Engineering from Stanford U. Her research has primarily focused on combined feedforward and feedback control of flexible structures, with applications ranging from atomic force microscopy to disk drives to digital tape drives to megawatt wind turbines and wind farms. She is a Fellow of the International Federation of Automatic Control (IFAC) and the Institute of Electrical and Electronics Engineers (IEEE). Selected recent awards include the 2012 IEEE Control Systems Magazine Outstanding Paper Award (with K. Johnson), the 2015 SIAM Journal on Control and Optimization Best Paper Prize (with J. Marden and H. P. Young), the 2017 Control Engineering Practice Award from the American Automatic Control Council, and the Scientific Award 2017 from the European Academy of Wind Energy. Selected recent and current professional society activities include being a Fellow of the Renewable and Sustainable Energy Institute (2009-present), General Chair of the 2013 American Control Conference, member of the IEEE Control Systems Society (CSS) Board of Governors (2011-2013 and 2015), IEEE CSS Fellow Nominations Chair (2016-present), and member of the IFAC Executive Board (2017-2020).