Presenting the latest developments in the field, Wind Energy Systems: Control Engineering Design offers a novel take on advanced control engineering design techniques for wind turbine applications. The book introduces concurrent quantitative engineering techniques for the design of highly efficient and reliable controllers, which can be used to solve the most critical problems of multi-megawatt wind energy systems.

This book is based on the authors’ experience during the last two decades designing commercial multi-megawatt wind turbines and control systems for industry leaders, including NASA and the European Space Agency. This work is their response to the urgent need for a truly reliable concurrent engineering methodology for the design of advanced control systems. Outlining a roadmap for such a coordinated architecture, the authors consider the links between all aspects of a multi-megawatt wind energy project, in which the wind turbine and the control system must be cooperatively designed to achieve an optimized, reliable, and successful system.

Look inside for links to a free download of QFTCT—a new interactive CAD tool for QFT controller design with MATLAB® that the authors developed with the European Space Agency.

The textbook’s big-picture insights can help students and practicing engineers control and optimize a wind energy system, in which large, flexible, aerodynamic structures are connected to a demanding variable electrical grid and work automatically under very turbulent and unpredictable environmental conditions. The book covers topics including robust QFT control, aerodynamics, mechanical and electrical dynamic modeling, economics, reliability, and efficiency. It also addresses standards, certification, implementation, grid integration, and power quality, as well as environmental and maintenance issues.

To reinforce understanding, the authors present real examples of experimentation with commercial multi-megawatt direct-drive wind turbines, as well as on-shore, offshore, floating, and airborne wind turbine applications. They also offer a unique in-depth exploration of the quantitative feedback theory (QFT)—a proven, successful robust control technique for real-world applications—as well as advanced switching control techniques that help engineers exceed classical linear limitations.

Introduction

Broad Context and Motivation

Concurrent Engineering: A Road Map for Energy

Quantitative Robust Control

Novel CAD Toolbox for QFT Controller Design

Outline

Part I: Advanced Robust Control Techniques: QFT and Nonlinear Switching

Introduction to QFT

Quantitative Feedback Theory

Why Feedback?

QFT Overview

Insight into the QFT Technique

Benefits of QFT


MISO Analog QFT Control System

Introduction

QFT Method (Single-Loop MISO System)

Design Procedure Outline

Minimum-Phase System Performance Specifications

J LTI Plant Models

Plant Templates of P?(s), P( j_i )

Nominal Plant

U-Contour (Stability Bound)

Tracking Bounds BR(j?) on the NC

Disturbance Bounds BD(j?i)

Composite Boundary Bo(j?i)

Shaping of Lo(j?)

Guidelines for Shaping Lo(j?)

Design of the Prefilter F(s)

Basic Design Procedure for a MISO System

Design Example 1

Design Example 2

Template Generation for Unstable Plants

Discrete Quantitative Feedback Technique

Introduction

Bilinear Transformations

Non-Minimum-Phase Analog Plant

Discrete MISO Model with Plant Uncertainty

QFT w-Domain DIG Design

Simulation

Basic Design Procedure for a MISO S-D Control System

QFT Technique Applied to the PCT System

Applicability of Design Technique to Other Plants

Designing L(w) Directly


Diagonal MIMO QFT

Introduction

Examples and Motivation

MIMO Systems—Characteristics and Overview

MIMO QFT Control—Overview

Nonsequential Diagonal MIMO QFT (Method 1)

Sequential Diagonal MIMO QFT (Method 2)

Basically Noninteracting Loops

MIMO QFT with External (Input) Disturbances

Non-Diagonal MIMO QFT

Introduction

Non-Diagonal MIMO QFT: A Coupling Minimization Technique (Method 3)

Coupling Elements

Optimum Non-Diagonal Compensator

Coupling Effects

Quality Function of the Designed Compensator

Design Methodology

Some Practical Issues

Non-Diagonal MIMO QFT: A Generalized Technique (Method 4)

Reformulation

Translating Matrix Performance Specifications

Comparison of Methods 3 and 4

QFT for Distributed Parameter Systems

Introduction

Background

Generalized DPS Control System Structure

Extension of Quantitative Feedback Theory to DPS

Modeling Approaches for PDE

Examples


Nonlinear Switching Control Techniques

Introduction

System Stability under Switching

Methodology

Examples


Part II: Wind Turbine Control

Introduction to Wind Energy Systems

Introduction

Birth of Modern Wind Turbines

Market Sizes and Investments

Future Challenges and Opportunities


Standards and Certification for Wind Turbines

Introduction

Standards: Definition and Strategic Value

Standards: Structure and Development

Certification of Wind Turbines

General Concepts


Wind Turbine Control Objectives and Strategies

Introduction

Control Objectives

Control Strategies

Control System


Aerodynamics and Mechanical Modeling of Wind Turbines

Introduction

Aerodynamic Models

Mechanical Models


Electrical Modeling of Wind Turbines

Introduction

Electrical Models

Power Electronic Converters

Power Quality Characteristics

Wind Farms Integration in the Power System


Advanced Pitch Control System Design

Introduction

QFT Robust Control Design

Nonlinear Switching Multi-Objective Design

Nonlinear Robust Control Design for Large Parameter Variation


Experimental Results with the Direct-Drive Wind Turbine TWT-1.65

Introduction

Variable-Speed Direct-Drive Torres Wind Turbine Family

Torres Wind Turbine Pitch and Rotor Speed Control Results

Wind Farm Grid Integration: Torres Wind Turbine Results

Voltage Dip Solutions: Torres Wind Turbine Results


Blades Manufacturing: MIMO QFT Control for Industrial Furnaces

Introduction

Composite Materials

Industrial Furnace Description

Furnace Model

Estimation of Furnace Parameters

MIMO QFT Controller Design

Experimental Results


Smart Wind Turbine Blades

Introduction

General Description

Some History


Offshore Wind Energy: Overview

Introduction

History of Offshore Platforms

Offshore Wind Farms

Offshore Floating Wind Turbines


Airborne Wind Energy Systems

Introduction

Overview of Airborne Wind Energy Systems

Eagle System

Appendix A: Templates Generation

Appendix B: Inequality Bound Expressions

Appendix C: Analytical QFT Bounds

Appendix D: Essentials for Loop Shaping

Appendix E: Fragility Analysis with QFT

Appendix F: QFT Control Toolbox: User’s Guide

Appendix G: Controller Design Examples

Appendix H: Conversion of Units

Problems

Answers to Selected Problems

References

Index