Sample Projects

This page gives examples of my recent and ongoing projects in control systems as applied to wind energy systems, both individual turbines and wind farms. This page is not intended to be all-inclusive and should be considered a work-in-progress.

Segmented Ultralight Morphing Rotor (SUMR) for a 50 MW Wind Turbine

This ARPA-E-funded, 7-institution collaboration is a highly multi-disciplinary endeavor that will result in a design of a novel rotor for a massive 50-MW wind turbine as well as a scaled demonstration test at the National Renewable Energy Laboratory's National Wind Technology Center near Boulder, CO. The control systems team is working closely with experts in aerodynamics, structural dynamics, cost modeling, and field testing to design and test the rotor, which is expected to significantly lower the cost of energy from wind.

Wind farm control

When turbines are grouped together in farms, areodynamic interaction between turbines results in energy loss and increased turbulence compared to the same number of turbines in the same wind conditions without other turbines nearby. In this research, we have used the high-fidelity modeling tool SOWFA to examine methods for redirecting turbine wakes to improve performance. Funding provided by DOE.
Figure from P. Fleming, P. Gebraad, S. Lee, J.W. vanWingerden, K. Johnson, M. Churchfield, J. Michalakes, P. Spalart, and P. Moriarty, "Evaluating techniques for redirecting turbine wake using SOWFA," Renewable Energy, Wind turbine wake redirection

Wind turbine fault detection and protection

Fault detection and protection schemes are necessary to ensure safe turbine operation, and this project will help to determine what strategies and sensors are necessary. Pictured are a block diagram showing the hierarchy of fault detection compared to operational and subsystem control (top) and a "before" and "after" set of data from a detected fault in the blade pitch system. Before the fault was detected, a pitch gear box oil problem was causing the pitch actuator to respond slowly even at its current limit. After the fault was detected and corrected, the blade pitch was better able to follow its commanded pitch angle.
Fault detection

Lidar-based wind turbine control

Advanced sensor technology such as Lidar (Light Detection and Ranging) enable more advanced wind turbine control, including feedforward control for load reduction. Many different strategies are possible, including the FX-RLS feedforward technique for which these results are shown. The Lidar measures the wind speed at one or more points in front of the turbine and the FX-RLS algorithm adapts the coefficients in a FIR filter in the feedforward path. In the results shown, the four feedforward control cases (with various parameters) mitigate overspeed caused by a wind gust as compared to the PI feedback only case, with load reduction also apparent in several components. Funding provided by DOE/NREL.
Feedforward control
Feedforward control