Modeling and Analysis with Induction Generators, 3rd Edition

v

Contents

Foreword ................................................................................................................ xiii

Preface......................................................................................................................xv

Acknowledgments ................................................................................................... xix

Authors .................................................................................................................... xxi

Chapter 1 Principles of Alternative Sources of Energy and Electric Generation ... 1

1.1 Scope of This Chapter ............................................................... 1

1.2 Legal Denitions .......................................................................2

1.3 Principles of Electrical Conversion ...........................................3

1.4 Basic Denitions of Electrical Power ........................................ 5

1.5 Characteristics of Primary Sources ...........................................7

1.6 Characteristics of Remote Industrial, Commercial,

andResidential Sites and Rural Energy ....................................8

1.7 Selection of the Electric Generator ......................................... 10

1.8 Interfacing Primary Source, Generator, and Load .................. 11

1.9 Example of a Simple Integrated Generating and Energy-

Storing System ......................................................................... 13

1.10 Solved Problems ...................................................................... 15

1.11 Suggested Problems ................................................................. 16

References .......................................................................................... 16

Chapter 2 Steady-State Model of Induction Generators ..................................... 17

2.1 Scope of This Chapter ............................................................. 17

2.1.1 Interconnection and Disconnection of the

Electric Distribution Network .................................... 17

2.1.2 Robustness of Induction Generators ........................... 18

2.2 Classical Steady-State Representation of the

Asynchronous Machine ........................................................... 19

2.3 Generated Power ......................................................................22

2.4 Induced Torque ........................................................................24

2.5 Representation of Induction Generator Losses ........................27

2.6 Measurement of Induction Generator Parameters ...................28

2.6.1 Blocked Rotor Test (s = 1) ..........................................30

2.6.2 No-Load Test (s = 0) ................................................... 31

2.7 Features of Induction Machines Working as Generators

Interconnected to the Distribution Network ............................32

2.8 High-Efciency Induction Generator ...................................... 34

2.9 Doubly Fed Induction Generator ............................................. 35

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2.10 Solved Problems ......................................................................36

2.11 Suggested Problems .................................................................37

References .......................................................................................... 37

Chapter 3 Transient Model of Induction Generators ..........................................39

3.1 Scope of This Chapter ............................................................. 39

3.2 Induction Machine in Transient State ...................................... 39

3.3 State Space–Based Induction Generator Modeling .................40

3.3.1 No-Load Induction Generator .................................... 40

3.3.2 State Equations of SEIG with Resistive Load, R .......42

3.3.3 State Equations of SEIG with RLC Load ................... 43

3.4 Partition of SEIG State Matrix with RLC Load ...................... 45

3.5 Generalization of the Association of Self-Excited

Generators ..............................................................................51

3.6 Relationship between Torque and Shaft Oscillation ...............53

3.6.1 Oscillation Equation ...................................................54

3.7 Transient Simulation of Induction Generators ........................56

3.7.1 Example of Transient Model of an Induction

Generator ....................................................................58

3.7.2 Effect of RLC Load Connection.................................58

3.7.3 Loss of Excitation .......................................................58

3.7.4 Parallel Connection of Induction Generators .............59

3.8 Concepts Covered in This Chapter to Help Practical Design ..... 60

3.9 Solved Problems ...................................................................... 61

3.10 Suggested Problems ................................................................. 62

References .......................................................................................... 63

Chapter 4 Self-Excited Induction Generators .....................................................65

4.1 Scope of This Chapter ............................................................. 65

4.2 Performance of Self-Excited Induction Generators.................65

4.3 Magnetizing Curves and Self-Excitation ................................68

4.4 Mathematical Description of theSelf-Excitation Process .......70

4.5 Series Capacitors and Composed Excitation of Induction

Generators ...............................................................................77

4.6 Three-Phase Generators Operating in Single-Phase Mode .....77

4.7 Solved Problems ...................................................................... 83

4.8 Suggested Problems .................................................................85

References ..........................................................................................85

Chapter 5 General Characteristics of Induction Generators ...............................87

5.1 Scope of This Chapter ............................................................. 87

5.2 Torque–Speed Characteristics of Induction Generators ..........87

5.3 Power versus Current Characteristics ......................................89

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5.4 Rotor Power Factor as a Function of Rotation .........................91

5.5 Nonlinear Relationship between Air-Gap Voltage V

g

and

Magnetizing Current I

m

...........................................................92

5.5.1 Minimization of Laboratory Tests .............................95

5.6 Example for Determining Magnetizing Curve and

Magnetizing Reactance ...........................................................99

5.7 Voltage Regulation ................................................................ 101

5.8 Characteristics of Rotation .................................................... 101

5.9 Comparison of Induction Generators with Other Generators .....105

5.10 Solved Problem ...................................................................... 108

5.11 Suggested Problems ............................................................... 113

References ........................................................................................ 114

Chapter 6 Construction Features of Induction Generators ............................... 115

6.1 Scope of This Chapter ........................................................... 115

6.2 Electromechanical Considerations ........................................ 116

6.3 Optimization of the Manufacturing Process ......................... 120

6.4 Types of Design ..................................................................... 122

6.5 Sizing the Machine ................................................................ 125

6.6 Efciency Issues .................................................................... 127

6.7 Comparison of Induction Generators, PM, and Ferrite

Machines ................................................................................130

6.8 Solved Problems .................................................................... 133

6.9 Suggested Problems ............................................................... 133

References ........................................................................................ 133

Bibliography ..................................................................................... 134

Chapter 7 Power Electronics for Interfacing Induction Generators .................. 135

7.1 Scope of This Chapter ........................................................... 135

7.2 Power Semiconductor Devices .............................................. 135

7.3 Power Electronics and Converter Circuits ............................. 137

7.3.1 Regulators ................................................................. 137

7.3.2 Inverters .................................................................... 139

7.3.3 Protection and Monitoring Units .............................. 139

7.4 DC to DC Conversion ............................................................ 141

7.5 AC to DC Conversion ............................................................ 145

7.5.1 Single-Phase Full-Wave Rectiers,Uncontrolled

and Controlled Types ............................................... 145

7.5.1.1 Center-Tapped Single-Phase Rectier ...... 146

7.5.1.2 Diode-Bridge Single-Phase Rectier ........ 146

7.5.1.3 Full-Controlled Bridge ............................. 147

7.5.1.4 Half-Wave Three-Phase Bridge ................ 152

7.5.1.5 Three-Phase Full-Wave Bridge

Rectier (Graetz Bridge) ........................... 153