Voltage-Sourced Converters in Power Systems Modeling, Control, and Applications

by Yazdani, Amirnaser; Iravani, Reza

• ISBN13: 9780470521564
• ISBN10: 0470521562
• eBook ISBN(s): 9780470551561
• Edition: 1st
• Format: Hardcover
• Copyright: 2010-02-15
• Publisher: Wiley-IEEE Press

Summary

This book provides a comprehensive modeling approach, detailed control design methodologies and procedures, and wide coverage of the applications of voltage-sourced power electronic converters in electric power systems. Typical applications include wind power conversion and integration in the utility power system; solar-PV power conversion and integration in electric power systems; and, various types of distributed energy resource integration in electric distribution systems.

Author Biography

Amirnaser Yazdani, PhD, is assistant professor in the Department of Electrical and Computer Engineering at the University of Western Ontario. Formerly, he was with Digital Predictive Systems (DPS) Inc., Mississauga, Ontario, active in the design and production of power converters for wind energy systems. Dr. Yazdani has more than ten years of industry experience in the design, modeling, and analysis of switching power converters and railway signaling systems. He is a Senior Member of IEE and a professional engineer in the province of Ontario, Canada. Reza Iravani, PhD, is professor in the Department of Electrical and Computer Engineering at the University of Toronto. Dr Iravani is a Fellow of the IEEE and a professional engineer in the province of Ontario, Canada.

Table of Contents

Preface	p. xv
Acknowledgments	p. xvii
Acronyms	p. xix
Electronic Power Conversion	p. 1
Introduction	p. 1
Power-Electronic Converters and Converter Systems	p. 1
Applications of Electronic Converters in Power Systems	p. 3
Power-Electronic Switches	p. 4
Switch Classification	p. 5
Switch Characteristics	p. 8
Classification of Converters	p. 8
Classification Based on Commutation Process	p. 8
Classification Based on Terminal Voltage and Current Waveforms	p. 9
Voltage-Sourced Converter (VSC)	p. 10
Basic Configurations	p. 10
Multimodule VSC Systems	p. 11
Multilevel VSC Systems	p. 14
Scope of the Book	p. 20
Fundamentals	p. 21
DC/AC Half-Bridge Converter	p. 23
Introduction	p. 23
Converter Structure	p. 23
Principles of Operation	p. 25
Pulse-Width Modulation (PWM)	p. 25
Converter Waveforms	p. 26
Converter Switched Model	p. 27
Converter Averaged Model	p. 32
Nonideal Half-Bridge Converter	p. 38
Analysis of Nonideal Half-Bridge Converter: Positive AC-Side Current	p. 38
Analysis of Nonideal Converter: Negative AC-Side Current	p. 43
Averaged Model of Nonideal Half-Bridge Converter	p. 45
Control of Half-Bridge Converter	p. 48
Introduction	p. 48
AC-Side Control Model of Half-Bridge Converter	p. 48
Control of Half-Bridge Converter	p. 50
Feed-Forward Compensation	p. 53
Impact on Start-Up Transient	p. 53
Impact on Dynamic Coupling Between Converter System and AC System	p. 54
Impact on Disturbance Rejection Capability	p. 57
Sinusoidal Command Following	p. 59
Space Phasors and Two-Dimensional Frames	p. 69
Introduction	p. 69
Space-Phasor Representation of a Balanced Three-Phase Function	p. 70
Definition of Space Phasor	p. 70
Changing the Amplitude and Phase Angle of a Three-phase Signal	p. 73
Generating a Controllable-Amplitude/Controllable-Frequency Three-Phase Signal	p. 78
Space-Phasor Representation of Harmonics	p. 81
Space-Phasor Representation of Three-Phase Systems	p. 82
Decoupled Symmetrical Three-Phase Systems	p. 83
Coupled Symmetrical Three-Phase Systems	p. 87
Asymmetrical Three-Phase Systems	p. 88
Power in Three-Wire Three-Phase Systems	p. 88
¿ß-Frame Representation and Control of Three-Phase Signals and Systems	p. 91
¿ß-Frame Representation of a Space Phasor	p. 91
Realization of Signal Generators/Conditioners in ¿ß-Frame	p. 94
Formulation of Power in or ¿ß-Frame	p. 95
Control in ¿ß-Frame	p. 96
Representation of Systems in ¿ß-Frame	p. 98
dq-Frame Representation and Control of Three-Phase Systems	p. 101
dq-Frame Representation of a Space Phasor	p. 101
Formulation of Power in dq-Frame	p. 105
Control in dq-Frame	p. 105
Representation of Systems in dq-Frame	p. 107
Two-Level, Three-Phase Voltage-Sourced Converter	p. 115
Introduction	p. 115
Two-Level Voltage-Sourced Converter	p. 115
Circuit Structure	p. 115
Principles of Operation	p. 116
Power Loss of Nonideal Two-Level VSC	p. 118
Models and Control of Two-Level VSC	p. 119
Averaged Model of Two-Level VSC	p. 119
Model of Two-Level VSC in ¿ß-Frame	p. 121
Model and Control of Two-Level VSC in dq-Frame	p. 124
Classification of VSC Systems	p. 125
Three-Level, Three-Phase, Neutral-Point Clamped, Voltage-Sourced Converter	p. 127
Introduction	p. 127
Three-Level Half-Bridge NPC	p. 128
Generating Positive AC-Side Voltages	p. 128
Generating Negative AC-Side Voltages	p. 129
PWM Scheme For Three-Level Half-Bridge NPC	p. 130
Switched Model of Three-Level Half-Bridge NPC	p. 133
Switched AC-Side Terminal Voltage	p. 133
Switched DC-Side Terminal Currents	p. 133
Averaged Model of Three-Level Half-Bridge NPC	p. 135
Averaged AC-Side Terminal Voltage	p. 135
Averaged DC-Side Terminal Currents	p. 135
Three-Level NPC	p. 136
Circuit Structure	p. 136
Principles of Operation	p. 136
Midpoint Current	p. 138
Three-Level NPC with Impressed DC-Side Voltages	p. 143
Three-Level NPC with Capacitive DC-Side Voltage Divider	p. 144
Partial DC-Side Voltage Drift Phenomenon	p. 145
DC-Side Voltage Equalization	p. 146
Derivation of DC-Side Currents	p. 152
Unified Models of Three-Level NPC and Two-Level VSC	p. 153
Impact of DC Capacitors Voltage Ripple on AC-Side Harmonics	p. 155
Grid-Imposed Frequency VSC System: Control in ¿ß-Frame	p. 160
Introduction	p. 160
Structure of Grid-Imposed Frequency VSC System	p. 160
Real/Reaetive-Power Controller	p. 161
Current-Mode Versus Voltage-Mode Control	p. 162
Dynamic Model of Real-/Reactive-Power Controller	p. 163
Current-Mode Control of Real-/Reactive-Power Controller	p. 165
Selection of DC-Bus Voltage Level	p. 168
Trade-Offs and Practical Considerations	p. 173
PWM with Third-Harmonic Injection	p. 174
Real-/Reactive-Power Controller Based on Three-Level NPC	p. 181
Midpoint Current of Three-level NPC Based on Third-Harmonic Injected PWM	p. 188
Controlled DC-Voltage Power Port	p. 189
Model of Controlled DC-Voltage Power Port	p. 191
DC-Bus Voltage Control in Controlled DC-Voltage Power Port	p. 195
Simplified and Accurate Models	p. 200
Grid-Imposed Frequency VSC System: Control in dq-Frame	p. 204
Introduction	p. 204
Structure of Grid-Imposed Frequency VSC System	p. 205
Real-/Reactive-Power Controller	p. 206
Current-Mode Versus Voltage-Mode Control	p. 206
Representation of Space Phasors in dq-Frame	p. 208
Dynamic Model of Real/Reactive Power Controller	p. 208
Phase-Locked Loop (PLL)	p. 211
Compensator Design for PLL	p. 213
Current-Mode Control of Real-/Reactive-Power Controller	p. 217
VSC Current Control	p. 219
Selection of DC-Bus Voltage Level	p. 224
AC-Side Equivalent Circuit	p. 226
PWM with Third-Harmonic Injection	p. 231
Real-/Reactive-Power Controller Based on Three-Level NPC	p. 232
Controlled DC-Voltage Power Port	p. 234
Model of Controlled DC-Voltage Power Port	p. 235
Control of Controlled DC-Voltage Power Port	p. 237
Simplified and Accurate Models	p. 242
Controlled-Frequency VSC System	p. 245
Introduction	p. 245
Structure of Controlled-Frequency VSC System	p. 246
Model of Controlled-Frequency VSC System	p. 247
Voltage Control	p. 253
Autonomous Operation	p. 262
Variable-Frequency VSC System	p. 270
Introduction	p. 270
Structure of Variable-Frequency VSC System	p. 270
Control of Variable-Frequency VSC System	p. 273
Asynchronous Machine	p. 274
Doubly-Fed Asynchronous Machine	p. 288
Permanent-Magnet Synchronous Machine	p. 307
Applications	p. 311
Static Compensator (STATCOM)	p. 313
Introduction	p. 313
Controlled DC-Voltage Power Port	p. 313
STATCOM Structure	p. 314
Dynamic Model for PCC Voltage Control	p. 315
Large-Signal Model of PCC Voltage Dynamics	p. 315
Small-Signal Model of PCC Voltage Dynamics	p. 318
Steady-State Operating Point	p. 320
Approximate Model of PCC Voltage Dynamics	p. 321
STATCOM Control	p. 322
Compensator Design for PCC Voltage Controller	p. 324
Model Evaluation	p. 324
Back-to-Rack HVDC Conversion System	p. 334
Introduction	p. 334
HVDC System Structure	p. 334
HVDC System Model	p. 336
Grid and Interface Transformer Models	p. 336
Back-to-Back Converter System Model	p. 338
HVDC System Control	p. 342
Phase-Locked Loop (PLL)	p. 342
dq-Frame Current-Control Scheme	p. 345
PWM Gating Signal Generator	p. 348
Partial DC-Side Voltage Equalization	p. 349
Power Flow Control	p. 350
DC-Bus Voltage Regulation	p. 331
HVDC System Performance Under an Asymmetrical Fault	p. 353
PCC Voltage Under an Asymmetrical Fault	p. 354
Performance of PLL Under an Asymmetrical Fault	p. 357
Performance of dq-Frame Current-Control Scheme Under an Asymmetrical Fault	p. 358
Dynamics of DC-Bus Voltage Under an Asymmetrical Fault	p. 360
Generation of Low-Order Harmonics Under Asymmetrical Fault	p. 365
Steady-State Power-Flow Under an Asymmetrical Fault	p. 369
DC-Bus Voltage Control Under an Asymmetrical Fault	p. 371
Variable-Speed Wind-Power System	p. 385
Introduction	p. 385
Constant-Speed and Variable-Speed Wind-Power Systems	p. 385
Constant-Speed Wind-Power Systems	p. 385
Variable-Speed Wind-Power Systems	p. 386
Wind Turbine Characteristics	p. 388
Maximum Power Extraction from A Variable-Speed Wind-Power System	p. 390
Variable-Speed Wind-Power System Based on Doubly-Fed Asynchronous Machine	p. 393
Structure of the Doubly-Fed Asynchronous Machine-Based Wind-Power System	p. 393
Machine Torque Control by Variable-Frequency VSC System	p. 395
DC-Bus Voltage Regulation by Controlled DC-Voltage Power Port	p. 397
Compensator Design for Controlled DC-Voltage Power Port	p. 401
Space-Phasor Representation of Symmetrical Three-Phase Electric Machines	p. 413
Introduction	p. 413
Structure of Symmetrical Three-Phase Machine	p. 413
Machine Electrical Model	p. 414
Terminal Voltage/Current Equations	p. 415
Stator Flux Space Phasor	p. 415
Rotor Flux Space Phasor	p. 417
Machine Electrical Torque	p. 418
Machine Equivalent Circuit	p. 418
Machine Dynamic Equivalent Circuit	p. 418
Machine Steady-State Equivalent Circuit	p. 420
Permanent-Magnet Synchronous Machine (PMSM)	p. 421
PMSM Electrical Model	p. 421
PMSM Steady-State Equivalent Circuit	p. 424
Per-Unit Values for VSC Systems	p. 426
Introduction	p. 426
Base Values for AC-Side Quantities	p. 426
Base Values for DC-Side Quantities	p. 426
References	p. 431
Index	p. 439
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