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

..................................................................................................................................................... iii ACKNOWLEDGMENTS......................................................................................................................... iv List of Figures ............................................................................................................................................ vi List of Tables.............................................................................................................................................. vi 1.0 Introduction ...........................................................................................................................................1 2.0 Concept Description ..............................................................................................................................1 2.1 Design Philosophy and Approach.......................................................................................................1 2.2 Rationale for Major Design Features ..................................................................................................1 2.3 Operational Strategies .........................................................................................................................2 2.4 Critical Innovations.............................................................................................................................3 2.5 Advantages and Disadvantages...........................................................................................................3 3.0 Methodology...........................................................................................................................................3 3.1 Design Constraints and Alternatives ...................................................................................................3 3.2 Software Tool Development ...............................................................................................................4 3.2.1 Control System Model: SymDyn.................................................................................................4 3.2.2 Aero-Structural Model: ADAMS ................................................................................................7 3.2.3 WindPACT Design and Analysis Tools ....................................................................................13 3.3 Analysis Methodology ......................................................................................................................14 3.3.1 Baseline Turbine........................................................................................................................14 3.3.2 Preliminary Design ....................................................................................................................15 3.3.3 Final Design...............................................................................................................................16 3.4 Assumptions and Limitations............................................................................................................16 4.0 Results...................................................................................................................................................17 4.1 Preliminary Design: System Performance and Influential Design Parameters .................................17 4.2 Final Design: System Performance and Influential Design Parameters............................................20 4.2.1 Structural Design Results...........................................................................................................21 4.2.2 Performance Results ..................................................................................................................25 4.3 Figure-of-Merit Impacts....................................................................................................................25 4.3.1 Reliability, Maintainability, System Lifetime ...........................................................................25 4.3.2 Cost of Energy Impact ...............................................................................................................26 5.0 Market Integration..............................................................................................................................27 5.1 Enabling Technology ........................................................................................................................27 5.1.1 Controller Hardware ..................................................................................................................28 5.1.2 Angle of Attack Sensors ............................................................................................................28 5.1.3 Pitch Drives ...............................................................................................................................34 5.1.4 Backup Power for Controller and Pitch System ........................................................................34 5.2 Performance, Costs, and Figures of Merit.........................................................................................35 5.3 Other Market Considerations ............................................................................................................37 5.4 Turbine Development Plan ...............................................................................................................37 5.4.1 Detailed Engineering Design .....................................................................................................37 5.4.2 Proof-of-Concept Testing ..........................................................................................................37 5.4.3 Prototype and Demonstration ....................................................................................................38 5.4.4 Market Introduction ...................................................................................................................38 6.0 Conclusions ..........................................................................................................................................38 References ..................................................................................................................................................40 Appendices .................................................................................................................................................41