CONVERTERS IN POWER VOLTAGE-SOURCED SYSTEMS. Modeling, Control, and Applications IEEE UNIVERSITATSBIBLIOTHEK HANNOVER. Amirnaser Yazdani.

Transcription

1 VOLTAGE-SOURCED CONVERTERS IN POWER SYSTEMS Modeling, Control, and Applications Amirnaser Yazdani University of Western Ontario Reza Iravani University of Toronto r TECHNISCHE INFORMATIONSBIBLIOTHEK UNIVERSITATSBIBLIOTHEK HANNOVER J IEEE PRESS IEEE A JOHN WILEY & SONS, INC., PUBLICATION

2 PREFACE ACKNOWLEDGMENTS ACRONYMS 1 Electronic Power Conversion 1.1 Introduction Power-Electronic Converters and Converter Systems Applications of Electronic Converters in Power Systems 1.4 Power-Electronic Switches Switch Classification Switch Characteristics Classification of Converters Classification Based on Commutation Process Classification Based on Terminal Voltage and Current Waveforms Voltage-Sourced Converter (VSC) Basic Configurations Multimodule VSC Systems Multilevel VSC Systems Scope of the Book 20 PARTI FUNDAMENTALS 2 DC/AC Half-Bridge Converter 2.1 Introduction Converter Structure Principles of Operation Pulse-Width Modulation (PWM) Converter Waveforms Converter Switched Model Converter Averaged Model Nonideal Half-Bridge Converter 38

3 viii CONTENTS Analysis of Nonideal Half-Bridge Converter: Positive AC-Side Current Analysis of Nonideal Converter: Negative AC-Side Current Averaged Model of Nonideal Half-Bridge Converter 45 3 Control of Half-Bridge Converter Introduction AC-Side Control Model of Half-Bridge 3.3 Control of Half-Bridge Converter 50 Converter Feed-Forward Compensation Impact on Start-Up Transient Impact on Dynamic Coupling Between Converter System and AC System Impact on Disturbance Rejection Capability Sinusoidal Command Following 59 4 Space Phasors and Two-Dimensional Frames Introduction Space-Phasor Representation Three-Phase Function 70 of a Balanced Definition of Space Phasor Changing the Amplitude and Phase Angle of a Three-phase Signal Generating a Controllable-Amplitude/Controllable-Frequency Three-Phase Signal Space-Phasor Representation of Harmonics Space-Phasor Representation of Three-Phase Systems Decoupled Symmetrical Three-Phase Systems Coupled Symmetrical Three-Phase Systems Asymmetrical Three-Phase Systems Power in Three-Wire Three-Phase Systems a/3-frame Representation and Control of Three-Phase Signals and Systems a/8-frame Representation of a Space Phasor Realization of Signal Generators/Conditioners in a/3-frame Formulation of Power in a^-frame Control in a/3-frame Representation of Systems in a/s-frame d<j-frame Representation and Control of Three-Phase Systems G?#-Frame Representation of a Space Phasor Formulation of Power in dq-frame Control in dq-ftame Representation of Systems in dg-frame 107

4 ix 5 Two-Level, Three-Phase Voltage-Sourced Converter Introduction Two-Level Voltage-Sourced Converter Circuit Structure Principles of Operation Power Loss of Nonideal Two-Level VSC Models and Control of Two-Level VSC Averaged Model of Two-Level VSC Model of Two-Level VSC in a^-frame Model and Control of Two-Level VSC in d^-frame Classification of VSC Systems Three-Level, Three-Phase, Neutral-Point Clamped, Voltage-Sourced Converter Introduction Three-Level Half-Bridge NPC Generating Positive AC-Side Voltages Generating Negative AC-Side Voltages PWM Scheme For Three-Level Half-Bridge NPC Switched Model of Three-Level Half-Bridge NPC Switched AC-Side Terminal Voltage Switched DC-Side Terminal Currents Averaged Model of Three-Level Half-Bridge NPC Averaged AC-Side Terminal Voltage Averaged DC-Side Terminal Currents Three-Level NPC Circuit Structure Principles of Operation Midpoint Current Three-Level NPC with Impressed DC-Side Voltages Three-Level NPC with Capacitive DC-Side Voltage Divider Partial DC-Side Voltage Drift Phenomenon DC-Side Voltage Equalization Derivation of DC-Side Currents Unified Models of Three-Level NPC and Two-Level VSC Impact of DC Capacitors Voltage Ripple on AC-Side Harmonics Grid-Imposed Frequency VSC System: Control in a/j-frame Introduction Structure of Grid-Imposed Frequency VSC System 160

5 7.3 Real-/Reactive-Power Controller Current-Mode Versus Voltage-Mode Control Dynamic Model of Real-/Reactive-Power Controller Current-Mode Control of Real-/Reactive-Power Controller Selection of DC-Bus Voltage Level Trade-Offs and Practical Considerations PWM with Third-Harmonic Injection Real-/Reactive-Power Controller Based on Three-Level NPC Midpoint Current of Three-level NPC Based on Third-Harmonic Injected PWM Controlled DC-Voltage Power Port Model of Controlled DC-Voltage Power Port DC-Bus Voltage Control in Controlled DC-Voltage Power Port Simplified and Accurate Models Grid-Imposed Frequency VSC System: Control in dq-frame 8.1 Introduction Structure of Grid-Imposed Frequency VSC System Real-/Reactive-Power Controller Current-Mode Versus Voltage-Mode Control Representation of Space Phasors in dg-frame Dynamic Model of Real-/Reactive-Power Controller Phase-Locked Loop (PLL) Compensator Design for PLL Current-Mode Control of Real-/Reactive-Power Controller VSC Current Control Selection of DC-Bus Voltage Level AC-Side Equivalent Circuit PWM with Third-Harmonic Injection Real-/Reactive-Power Controller Based on Three-Level NPC 8.6 Controlled DC-Voltage Power Port Model of Controlled DC-Voltage Power Port Control of Controlled DC-Voltage Power Port Simplified and Accurate Models Controlled-Frequency VSC System 9.1 Introduction Structure of Controlled-Frequency VSC System Model of Controlled-Frequency VSC System Voltage Control Autonomous Operation 262

6 xi 10 Variable-Frequency VSC System Introduction Structure of Variable-Frequency VSC System Control of Variable-Frequency VSC System Asynchronous Machine Doubly-Fed Asynchronous Machine Permanent-Magnet Synchronous Machine 307 PART II APPLICATIONS Static Compensator (STATCOM) Introduction Controlled DC-Voltage Power Port STATCOM Structure Dynamic Model for PCC Voltage Control Large-Signal Model of PCC Voltage Dynamics Small-Signal Model of PCC Voltage Dynamics Steady-State Operating Point Approximate Model of PCC Voltage Dynamics STATCOM Control Compensator Design for PCC Voltage Controller Model Evaluation Back-to-Back HVDC Conversion System Introduction HVDC System Structure HVDC System Model Grid and Interface Transformer Models Back-to-Back Converter System Model HVDC System Control Phase-Locked Loop (PLL) ^-Frame Current-Control Scheme PWM Gating Signal Generator Partial DC-Side Voltage Equalization Power Flow Control DC-Bus Voltage Regulation HVDC System Performance Under an Asymmetrical Fault PCC Voltage Under an Asymmetrical Fault Performance ofpll Under an Asymmetrical Fault Performance of rf^-frame Current-Control Scheme Under an Asymmetrical Fault 358

7 Xii CONTENTS Dynamics of DC-Bus Voltage Asymmetrical Fault 360 Under an Generation of Low-Order Harmonics Under an Asymmetrical Fault Steady-State Power-Flow Under an Asymmetrical Fault DC-Bus Voltage Control Under an Asymmetrical Fault Variable-Speed Wind-Power System Introduction Constant-Speed and Variable-Speed Wind-Power Systems Constant-Speed Wind-Power Systems Variable-Speed Wind-Power Systems Wind Turbine Characteristics Maximum Power Extraction from A Variable-Speed Wind-Power System Variable-Speed Wind-Power System Based on Doubly-Fed Asynchronous Machine Structure of the Doubly-Fed Asynchronous Machine-Based Wind-Power System Machine Torque Control by Variable-Frequency VSC System DC-Bus Voltage Regulation by Controlled DC-Voltage Power Port Compensator Design for Controlled DC-Voltage Power Port 401 APPENDIX A: Space-Phasor Representation of Symmetrical Three-Phase Electric Machines 413 A.l Introduction 413 A.2 Structure of Symmetrical Three-Phase Machine 413 A.3 Machine Electrical Model 414 A.3.1 Terminal Voltage/Current Equations 415 A.3.2 StatorFlux Space Phasor 415 A.3.3 Rotor Flux Space Phasor 417 A.3.4 Machine Electrical Torque 418 A.4 Machine Equivalent Circuit 418 A.4.1 Machine Dynamic Equivalent Circuit 418 A.4.2 Machine Steady-State Equivalent Circuit 420

8 xiii A.5 Permanent-Magnet Synchronous Machine (PMSM) 421 A.5.1 PMSM Electrical Model 421 A.5.2 PMSM Steady-State Equivalent Circuit 424 APPENDIX B: Per-Unit Values for VSC Systems 426 B. l Introduction 426 B. 1.1 Base Values for AC-Side Quantities 426 B.1.2 Base Values for DC-Side Quantities 426 REFERENCES 431 INDEX 439