Carlo L. Bottasso's web page

Cp-Lambda, a Code for Performance, Loads, Aeroelasticity by Multi-Body Dynamics Analysis. Cp-Lambda is a comprehensive aero-servo-elastic non-linear finite-element-based multibody dynamics solver, based on a geometrically exact formulation, scaled index-3 DAE approach, using a non-linearly stable energy preserving/decaying time integration scheme. Cp-Lambda uses aerodynamics models based on 2D sectional airfoil characteristics augmented with dynamic inflow, and implements turbulent and gusty wind models according to IEC rules. Cp-Lambda has models of sensors and actuators, and is easily coupled with routines or external codes implementing control laws and control logic supervisors. Coupling with an aero-acoustics code based on the permeable Ffowcs Williams-Hawkings formulation is in progress. The code has been extensively validated with respect to other wind turbine codes and to experimental data, and is currently in use by industry.

Selected references:
C.L. Bottasso, A. Croce, B. Savini, W. Sirchi, L. Trainelli, `Aero-servo-elastic Modeling and Control of Wind Turbines using Finite Element Multibody Procedures', Multibody Systems Dynamics, 16:291-308, 2006.

C.L. Bottasso, S. Cacciola, A. Croce, `Estimation of Blade Structural Properties from Experimental Data', Scientific Report DIA-SR 11-01, Dipartimento di Ingegneria Aerospaziale, Politecnico di Milano, April 2011. [report]

Cp-Max, a Code for Perfomance Maximization. Cp-Max is a code for the multi-disciplinary design optimization of wind turbines using high-fidelity comprehensive models. Cp-Max can perform: a) aerodynamic optimization of the rotor (e.g. twist and chord distribution for max Annual Energy Production (AEP), with noise constraints and max chord constraints); b) structural optimization of the blades (e.g. minimum weight configuration for given design load cases (IEC-61400 DLCs), placement of frequencies, stress/strain allowables, etc.); c) combined aerodynamic-structural optimization (e.g. for max AEP over weight). The code allows the user to define a large number of constraints and different combinations of cost function contributors for all design problems. The optimization is performed by means of a variety of global-local state-of-the-art techniques, using the Noesis Optimus^TM code. Evaluation of cost function and constraints is performed by running simulations (e.g. turbulent response, gust response, eigenanalysis, etc., as necessary) with a parametric high-fidelity aero-servo-elastic model implemented in Cp-Lambda.

Selected references:
C.L. Bottasso, F. Campagnolo, A. Croce, C. Tibaldi, `Optimization-Based Study of Bend-Twist Coupled Rotor Blades for Passive and Integrated Passive/Active Load Alleviation', Scientific Report DIA-SR 11-02, Dipartimento di Ingegneria Aerospaziale, Politecnico di Milano, December 2011. [report]

C.L. Bottasso, F. Campagnolo, A. Croce, `Computational Procedures for the Multi-Disciplinary Constrained Optimization of Wind Turbines', Scientific Report DIA-SR 10-02, Dipartimento di Ingegneria Aerospaziale, Politecnico di Milano, January 2010 (revised May 2011). [report]
C.L. Bottasso, `Holistic Design of Wind Turbines, using Aero-Servo-Elastic Multibody Models', Plenary lecture, The First Joint International Conference on Multibody System Dynamics IMSD10, Lappeenranta, Finland, May 25-27, 2010.
C.L. Bottasso, F. Campagnolo, A. Croce, `Multi-disciplinary Constrained Optimization of Wind Turbines', EWEC 2010, European Wind Energy Conference & Exhibition, Warsaw, Poland, April 20-23, 2010.

C.L. Bottasso, F. Campagnolo, A. Croce, `Software Procedures for the Multi-Disciplinary Constrained Optimization of Wind Turbines', TORQUE 2010, The Science of Making Torque from Wind, Forth, Heraklion, Crete, Greece, June 28–30, 2010. [poster]

Advanced Control Laws for Wind Turbines. The group is actively studying adaptive model predictive methods for pitch and torque controlled wind turbines. The focus is on adaptive schemes, which can adjust to varying operating conditions and can correct for unresolved or unmodelled physics, and on schemes which can enforce the presence of constraints (e.g. bounds on blade/tower loads, limitations on actuator authority, etc.). As part of this effort, the research group is studying a number of supporting technological solutions: on-line identification of wind turbine states (e.g. blade flapping/lagging, tower fore-aft and side-side motion) through Kalman filtering; on-line identification of turbulent wind states by extended Kalman filtering; on-line and off-line identification or reduced model parameters; implementation of control laws on real-time operating systems; implementation on embedded hardware (PC-104) and integration with wind turbine sensors and actuators.

Selected references:
C.L. Bottasso, A. Croce, D. Devecchi, C.E.D. Riboldi, Y. Nam,`Multi-Layer Control Architecture for the Reduction of Deterministic and Non-Deterministic Loads on Wind Turbines', Wind Energy, under review, 2010. Paper presented at EWEA 2011, Brusselles, Belgium, March 14-17, 2011. [paper]

C.L. Bottasso, A. Croce, Y. Nam, C.E.D. Riboldi, `Power Curve Tracking in the Presence of a Tip Speed Constraint', Renewable Energy, under review, 2009. [preprint]

C.L. Bottasso, A. Croce, S. Cacciola, S. Gupta, `Estimation of Damping for Wind Turbines Operating in Closed-Loop', EWEC 2010, European Wind Energy Conference & Exhibition, Warsaw, Poland, April 20-23, 2010. [pptx presentation, pdf presentation]

C.L. Bottasso, A. Croce, C.E.D. Riboldi, G.S. Bir, `Spatial Estimation of Wind States from the Aeroelastic Response of a Wind Turbine', TORQUE 2010, The Science of Making Torque from Wind, Forth, Heraklion, Crete, Greece, June 28–30, 2010. [paper]
C.L. Bottasso, A. Croce, ‘Advanced Control Laws for Variable-Speed Wind Turbines and Supporting Enabling Technologies’, Scientific Report DIA-SR 09-01, Dipartimento di Ingegneria Aerospaziale, Politecnico di Milano, January 2009. [report]
C.L. Bottasso, A. Croce, ‘Cascading Kalman Observers of Structural Flexible and Wind States for Wind Turbine Control’, Scientific Report DIA-SR 09-02, Dipartimento di Ingegneria Aerospaziale, Politecnico di Milano, January 2009. [report]

C.L. Bottasso, A. Croce, ‘Power Curve Tracking with Tip Speed Constraint using LQR Regulators’, Scientific Report DIA-SR 09-04, Dipartimento di Ingegneria Aerospaziale, Politecnico di Milano, March 2009. report]
C.L. Bottasso, A. Croce, B. Savini, `Performance Comparison of Control Schemes for Variable-Speed Wind Turbines', The Science of Making Torque from Wind, TWIND 2007, The Technical University of Denmark, Lyngby, Denmark, August 28-31, 2007. [paper, presentation]
C.L. Bottasso, A. Croce, B. Savini, Posters from the POLI-Wind Booth, EWEC 2007, European Wind Energy Conference & Exhibition, Milano, Italy, May 7-10, 2007. [poster1, poster2, poster3, poster4]
C.L. Bottasso, D. Leonello, B. Savini, `Adaptive Reference-Augmented Predictive Control, with Application to the Reflexive Control of Unmanned Rotorcraft Vehicles', IEEE Transactions on Automatic Control, under review. [preprint]

	< PC-104 hardware running Linux real-time OS. The hardware has enough computing power to support supervision, sophisticated active control laws and diagnostics on a single integrated platform. Code written in standard high level language (e.g. C, C++) can be readily run without modifications on board the actual wind turbine.
	< PC-104 box (bottom left corner of picture) on board the LeitWind 1.5 MW wind turbine
Wind turbine operating under the control of the PC-104 embedded hardware, running POLI-Wind control laws (Malles, 27/07/2007) >

(WT)², the Wind Turbine in a Wind Tunnel. With the support of industry, we are designing scaled aero-elastic wind tunnel models of a large multi-MW wind turbine. Scope of the models is the development, verification and comparison of control laws for wind turbines, as well as the testing of extreme operating conditions.

Selected references:
C.L. Bottasso, F. Campagnolo, A. Croce, L. Maffenini,`Development of a Wind Tunnel Model for Supporting Research on Aero-servo-elasticity and Control of Wind Turbines', 13th International Conference on Wind Engineering, ICWE13, July 10-15, 2011, Amsterdam, The Netherlands. [paper, presentation]

	< First wind tunnel entry (April 2010)
Lateral view of nacelle and hub systems >