Low Wind Speed Turbine Project Conceptual Design Study: Advanced Independent Pitch Control; July 30, 2002--July 31, 2004 (Revised)

Abstract

Advanced Energy Systems (AES) Inc. conducted a conceptual study of independent pitch control using inflow angle sensors. The control strategy combined input from turbine states (rotor speed, rotor azimuth, each blade pitch) with inflow angle measurements (each blade angle of attack at station 11 of 15) to derive blade pitch demand signals. The controller reduced loads sufficiently to allow a 10% rotor extension and to reduce cost of energy 6.3%. iv ACKNOWLEDGMENTS This study was performed by a team of wind energy consultants, including Tim Olsen of Advanced Energy Systems (project manager), Eric Lang of E3-Design (principal investigator), Craig Hansen of Windward Engineering, Marvin Cheney of PS Enterprises, John VandenBosche and Terrance Meyer of Chinook Wind, and Gene Quandt. Technical and management support were provided by a National Renewable Energy Laboratory (NREL) technical review team, led by Alan Wright and Dave Simms (technical monitors), with Neil Wikstrom serving as contract administrator. David Malcolm and Dayton Griffin of Global Energy Concepts also provided substantial support in establishing and understanding the WindPACT baseline turbine and its associated design and analysis tools. Funding was made possible through the NREL Low Wind Speed Turbine Project, subcontract number RAM-2-31235 (84%), and cost-sharing by the project team members (16%). v

The Path From Functional to Detailed Design of a Coning Rotor Wind Turbine Concept

“…Conventional PTF machine developments towards individual pitch control [47,48] are aimed at load mitigation; with reduced operational loading, longer blades are possible [49]. The goal is the same as the coning rotor, to maximize energy capture from a larger rotor area.…”

Individual Pitch Control for Wind Turbine Load Reduction Including Wake Modeling

“…Various IPC schemes have been developed to deal with the asymmetric loads of turbine structures. Different sensing schemes have been investigated, such as strain gage at blade root [8], local blade inflow [9][10] and LIDAR [11]. In particular, Hand et al [11] designed an IPC through directly measuring the upwind incoming flow field by use of LIDAR system, which appears promising for improving the system performance for feed-forward and model-based feedback control strategies.…”

“…Then the wake profile at the downstream turbine is given by (10) where V wcenter = V (x 2 , 0, H) is the wind speed at the wake center, following the notations in As shown in Figure 3, the wind profile in the incoming wind region is calculated with Eq. (8) and that in the wake region with Eq.…”

choix des capteurs et l'estimation des états pour la commande individuelle du calage des pales /

“…Néanmoins, à cause des coûts et des problèmes de fiabilité, ni les capteurs d'angle d'attaque [35] , ni ceux du LiDAR L'important est donc qu'on se sert toujours de la même norme matricielle quand on compare les jUo entre les paires (A,C).…”