Doubly Fed Induction Machine

GONZALO ABAD, PhD, is an Associate Professor in the Electronics Department at the Mondragon University, where he teaches modeling, control, and power electronics.

This book will be focused on the modeling and control of the DFIM based wind turbines. In the first part of the book, the mathematical description of different basic dynamic models of the DFIM will be carried out. It will be accompanied by a detailed steady-state analysis of the machine. After that, a more sophisticated model of the machine that considers grid disturbances, such as voltage dips and unbalances will be also studied. The second part of the book surveys the most relevant control strategies used for the DFIM when it operates at the wind energy generation application. The control techniques studied, range from standard solutions used by wind turbine manufacturers, to the last developments oriented to improve the behavior of high power wind turbines, as well as control and hardware based solutions to address different faulty scenarios of the grid. In addition, the standalone DFIM generation system will be also analyzed.

Preface xiii1 Introduction to A Wind Energy Generation System 11.1 Introduction 11.2 Basic Concepts of a Fixed Speed Wind Turbine (FSWT) 21.3 Variable Speed Wind Turbines (VSWTs) 101.4 Wind Energy Generation System Based on DFIM VSWT 251.5 Grid Code Requirements 391.6 Voltage Dips and LVRT 461.7 VSWT Based on DFIM Manufacturers 571.8 Introduction to the Next Chapters 83Bibliography 852 Back-to-Back Power Electronic Converter 872.1 Introduction 872.2 Back-to-Back Converter based on Two-Level VSC Topology 882.3 Multilevel VSC Topologies 1142.4 Control of Grid Side System 1332.5 Summary 152References 1533 Steady State of the Doubly Fed Induction Machine 1553.1 Introduction 1553.2 Equivalent Electric Circuit at Steady State 1563.3 Operation Modes Attending to Speed and Power Flows 1653.4 Per Unit Transformation 1733.5 Steady State Curves: Performance Evaluation 1843.6 Design Requirements for the DFIM in Wind Energy Generation Applications 2023.7 Summary 207References 2084 Dynamic Modeling of the Doubly Fed Induction Machine 2094.1 Introduction 2094.2 Dynamic Modeling of the DFIM 2104.3 Summary 238References 2385 Testing the DFIM 2415.1 Introduction 2415.2 Off-Line Estimation of DFIM Model Parameters 2425.3 Summary 262References 2626 Analysis of the DFIM Under Voltage Dips 2656.1 Introduction 2656.2 Electromagnetic Force Induced in the Rotor 2666.3 Normal Operation 2676.4 Three-Phase Voltage Dips 2686.5 Asymmetrical Voltage Dips 2786.6 Influence of the Rotor Currents 2906.7 DFIM Equivalent Model During Voltage Dips 2976.8 Summary 300References 3017 Vector Control Strategies for Grid-Connected DFIM Wind Turbines 3037.1 Introduction 3037.2 Vector Control 3047.3 Small Signal Stability of the Vector Control 3147.4 Vector Control Behavior Under Unbalanced Conditions 3277.5 Vector Control Behavior Under Voltage Dips 3317.6 Control Solutions for Grid Disturbances 3407.7 Summary 358References 3608 Direct Control of the Doubly Fed Induction Machine 3638.1 Introduction 3638.2 Direct Torque Control (DTC) of the Doubly Fed Induction Machine 3648.3 Direct Power Control (DPC) of the Doubly Fed Induction Machine 3878.4 Predictive Direct Torque Control (P-DTC) of the Doubly Fed Induction Machine at Constant Switching Frequency 399Switching Frequency 4118.5 Predictive Direct Power Control (P-DPC) of the Doubly Fed Induction Machine at Constant Switching Frequency 4168.6 Multilevel Converter Based Predictive Direct Power and Direct Torque Control of the Doubly Fed Induction Machine at Constant Switching Frequency 4258.7 Control Solutions for Grid Voltage Disturbances, Based on Direct Control Techniques 4518.8 Summary 473References 4749 Hardware Solutions for LVRT 4799.1 Introduction 4799.2 Grid Codes Related to LVRT 4799.3 Crowbar 4819.4 Braking Chopper 4929.5 Other Protection Techniques 4959.6 Summary 497References 49810 Complementary Control Issues: Estimator Structures and Start-Up of Grid-Connected DFIM 50110.1 Introduction 50110.2 Estimator and Observer Structures 50210.3 Start-up of the Doubly Fed Induction Machine Based Wind Turbine 51210.4 Summary 534References 53511 Stand-Alone DFIM Based Generation Systems 53711.1 Introduction 53711.2 Mathematical Description of the Stand-Alone DFIM System 54411.3 Stator Voltage Control 55811.4 Synchronization Before Grid Connection By Superior PLL 57311.5 Summary 576References 57712 New Trends on Wind Energy Generation 57912.1 Introduction 57912.2 Future Challenges for Wind Energy Generation: What must be Innovated 58012.3 Technological Trends: How They Can be Achieved 58412.4 Summary 599References 600Appendix 603A.1 Space Vector Representation 603A.2 Dynamic Modeling of the DFIM Considering the Iron Losses 610References 618Index 619The IEEE Press Series on Power Engineering