Variable Frequency Transformers for Large Scale Power Systems Interconnection: Theory and Applications

Cover......Page 1
Title Page......Page 5
Copyright......Page 6
Contents......Page 7
About the Authors......Page 13
Preface to the English Version......Page 15
Preface......Page 17
1.1 Overview......Page 21
1.2.1 Objectives of Energy Reform and the Mission of Power Grid Development......Page 22
1.2.2 Development and Upgrading of Power Grids......Page 30
1.3.1 The Necessity and Importance of Large Power Grid Interconnection......Page 34
1.3.1.1 Power Grid Attributes......Page 37
1.3.1.2 Grid Interconnection......Page 38
1.3.1.3 Clean Energy and Grid Interconnection......Page 40
1.3.1.4 Large Power Grid Interconnection is Required to Adapt to the Needs of Development of the Third Generation of Power Grids......Page 47
1.3.1.5 Large Power Grid Interconnection is an Important Trend in World Power Grid Development......Page 48
1.3.2.1 AC Synchronous Interconnection......Page 52
1.3.2.2 DC Asynchronous Interconnection......Page 55
1.3.2.4 VFT Asynchronous Interconnection......Page 57
1.4 Main Content of this Book......Page 58
1.5 Summary......Page 60
References......Page 61
2.2 VFT System Constitution......Page 63
2.2.1 VFT Device......Page 65
2.2.3 Step‐Down Transformer......Page 69
2.3 Basic Functions of VFTs......Page 70
2.3.5 Black‐Start Power......Page 71
2.4.3 Synchronizing Close......Page 72
2.5 VFT Mechanism for Improving System Stability......Page 73
2.6 Existing VFT Applications in Power Systems......Page 76
2.7.1.1 Smart Grid......Page 78
2.7.1.2 UHV Grid......Page 92
2.7.1.3 Clean Energy......Page 97
2.7.1.4 GEI......Page 100
2.7.2 Potential Applications of VFTs in GEI Systems......Page 105
2.7.2.2 Using VFTs to Realize the Marginal Interconnection of Asynchronous Grids......Page 107
2.7.2.3 Using VFTs to Suppress System Low‐Frequency Oscillation......Page 108
2.7.2.4 Using VFTs to Improve Operation Characteristics of an Unstable Power Supply......Page 110
2.7.2.6 Using VFTs to Optimize System Power Flow......Page 111
2.8.5 Development and Manufacturing of VFTs......Page 112
References......Page 113
3.1 Overview......Page 117
3.2.1 Steady‐State Frequency Equation......Page 121
3.2.2 Steady‐State Power Flow Equation......Page 122
3.2.4 Using PSASP to Realize the VFT Power Flow Calculation Model......Page 125
3.3.1 Electromechanical Transient Equation......Page 128
3.3.3 Using PSASP to Realize the Electromechanical Transient Model of VFT......Page 130
3.4.1 Electromagnetic Transient Equation......Page 136
3.4.2 Electromagnetic Transient Model......Page 138
3.5.2 Short‐Circuit Calculation Model......Page 139
3.6.2 VFT Electromechanical Transient Model Verification......Page 140
3.6.3 VFT Electromagnetic Transient Model Verification......Page 143
3.7 Summary......Page 144
References......Page 145
4.1 Overview......Page 147
4.2.3 System‐Level Control......Page 149
4.3 VFT Element‐Level Control and DC Drive System Design......Page 151
4.3.1 Constitution of the VFT DC Motor Drive System......Page 152
4.3.2 Basic Equations of the DC Motor Drive System......Page 154
4.3.3 Trigger Control and Response Characteristics of the Rectifier Circuit......Page 155
4.4.1 Rotor Speed Control......Page 156
4.4.3 Voltage Phase Angle Control......Page 158
4.4.5 Reactive Voltage Control......Page 159
4.5.1 Optimize System Power Flow......Page 160
4.5.2 Regulate System Frequency......Page 161
4.5.3 Suppressing Low‐Frequency Oscillation......Page 162
References......Page 163
5.2 VFT Parameters and Research System Design......Page 165
5.2.1 Basic Parameters of VFTs......Page 166
5.2.3 Typical Four‐Generator System......Page 167
5.2.4 Large‐Scale Complex Power System......Page 169
5.3.1 VFT Power‐On Process......Page 170
5.3.2 VFT Grid Connection Process......Page 171
5.3.3 VFT Power Regulation......Page 174
5.4.1 Optimizing the Power Flow Distribution of Interconnected Systems......Page 176
5.4.3 System Reactive Voltage Control......Page 177
5.5.3 Three‐Phase Short‐Circuit Fault......Page 179
5.6 Using VFTs to Regulate System Frequency......Page 180
5.7 Using VFTs to Supply Power to Weak Power Grids and Passive Systems......Page 182
5.7.2 Supplying Power to Passive Systems......Page 183
5.8 Application of VFTs in a Large Complex Electrical Power System......Page 184
5.8.1 Power Flow Control of VFTs in the Complex Electrical Power System......Page 185
5.8.2 Transient Stability of VFTs in a Complex Power System......Page 186
5.9 Using VFTs to Suppress Low‐Frequency Power Oscillation in the Electrical Power System......Page 188
5.10 Summary......Page 191
References......Page 192
6.2 Impacts of the Variable‐Frequency Oscillations of Power Systems and Corresponding Control Actions......Page 193
6.3 Prony Method‐Based Transfer Function Identification......Page 195
6.4 Low‐Frequency Oscillation Damping Controller Design with VFTs and a Prony Method......Page 198
6.5.2 Transfer Function Identification......Page 199
6.5.4 Application Effect of the Damping Controller......Page 203
6.5.5 Parameter Design and Damping Effect of the Damping Controller After a Structural Change of the Power System......Page 205
6.5.6 Adaptability of Power System Mode Identification with the Prony Method......Page 208
6.6.1 Power System Overview......Page 210
6.6.2 Transfer Function Identification......Page 211
6.6.4 Simulation of Application Effect of the Damping Controller in a Large Power System......Page 212
6.6.5 Parameter Design and Damping Effect of the Damping Controller After a Change of the Power System......Page 213
6.7 Summary......Page 214
References......Page 216
7.2.1 Phase‐Shifting Transformers......Page 217
7.2.2 Structures and Types of Phase‐Shifting Transformers......Page 221
7.2.3 A Comprehensive Comparison of VFTs and Phase‐Shifting Transformers......Page 227
7.3.2 Development and Types of DC Transmission Systems......Page 228
7.3.3 A Comprehensive Comparison of VFTs and DC Transmission Systems......Page 234
7.4 Summary......Page 241
References......Page 243
8.2.1 Structure of a VFT System......Page 245
8.2.3 Simulation Technologies of VFTs......Page 246
8.2.5 System Characteristics of VFTs......Page 247
8.2.7 Technical and Economic Characteristics of VFTs......Page 248
8.3.3 Simulation Tools of VFTs......Page 249
8.3.4 Application of VFTs in Projects......Page 250
A.2 Main Structure and Systematic Control of a VFT......Page 251
A.3 The World's First VFT Station: Langlois Substation......Page 252
A.4 The World's Second VFT Station: Laredo Substation......Page 263
A.5 The World's Third VFT Station: Linden Substation......Page 265
References......Page 266
Index......Page 267
EULA......Page 270