Preface |
|
xiii | |
Acknowledgements |
|
xv | |
About the Companion Website |
|
xvii | |
Nomenclature |
|
xix | |
Introduction |
|
1 | (6) |
1 Introduction to Modular Multilevel Converters |
|
7 | (53) |
|
|
7 | (2) |
|
1.2 The Two-Level Voltage Source Converter |
|
|
9 | (6) |
|
1.2.1 Topology and Basic Function |
|
|
9 | (3) |
|
1.2.2 Steady-State Operation |
|
|
12 | (3) |
|
1.3 Benefits of Multilevel Converters |
|
|
15 | (2) |
|
1.4 Early Multilevel Converters |
|
|
17 | (6) |
|
1.4.1 Diode Clamped Converters |
|
|
17 | (3) |
|
1.4.2 Flying Capacitor Converters |
|
|
20 | (3) |
|
1.5 Cascaded Multilevel Converters |
|
|
23 | (34) |
|
1.5.1 Submodules and Submodule Strings |
|
|
23 | (5) |
|
1.5.2 Modular Multilevel Converter with Half-Bridge Submodules |
|
|
28 | (15) |
|
1.5.3 Other Cascaded Converter Topologies |
|
|
43 | (14) |
|
|
57 | (1) |
|
|
58 | (2) |
2 Main-Circuit Design |
|
60 | (73) |
|
|
60 | (1) |
|
2.2 Properties and Design Choices of Power Semiconductor Devices for High-Power Applications |
|
|
61 | (31) |
|
2.2.1 Historical Overview of the Development Toward Modern Power Semiconductors |
|
|
61 | (3) |
|
2.2.2 Basic Conduction Properties of Power Semiconductor Devices |
|
|
64 | (1) |
|
2.2.3 P—N Junctions for Blocking |
|
|
65 | (2) |
|
2.2.4 Conduction Properties and the Need for Carrier Injection |
|
|
67 | (5) |
|
2.2.5 Switching Properties |
|
|
72 | (1) |
|
|
73 | (7) |
|
2.2.7 Reliability of Power Semiconductor Devices |
|
|
80 | (4) |
|
2.2.8 Silicon Carbide Power Devices |
|
|
84 | (8) |
|
2.3 Medium-Voltage Capacitors for Submodules |
|
|
92 | (4) |
|
2.3.1 Design and Fabrication |
|
|
93 | (2) |
|
2.3.2 Self-Healing and Reliability |
|
|
95 | (1) |
|
|
96 | (2) |
|
2.5 Submodule Configurations |
|
|
98 | (14) |
|
2.5.1 Existing Half-Bridge Submodule Realizations |
|
|
99 | (5) |
|
2.5.2 Clamped Single-Submodule |
|
|
104 | (1) |
|
2.5.3 Clamped Double-Submodule |
|
|
105 | (1) |
|
2.5.4 Unipolar-Voltage Full-Bridge Submodule |
|
|
106 | (1) |
|
2.5.5 Five-Level Cross-Connected Submodule |
|
|
107 | (1) |
|
2.5.6 Three-Level Cross-Connected Submodule |
|
|
107 | (1) |
|
|
108 | (1) |
|
2.5.8 Semi-Full-Bridge Submodule |
|
|
109 | (1) |
|
2.5.9 Soft-Switching Submodules |
|
|
110 | (2) |
|
2.6 Choice of Main-Circuit Parameters |
|
|
112 | (6) |
|
|
112 | (2) |
|
2.6.2 Choice of Power Semiconductor Devices |
|
|
114 | (1) |
|
2.6.3 Choice of the Number of Submodules |
|
|
115 | (2) |
|
2.6.4 Choice of Submodule Capacitance |
|
|
117 | (1) |
|
2.6.5 Choice of Arm Inductance |
|
|
117 | (1) |
|
2.7 Handling of Redundant and Faulty Submodules |
|
|
118 | (3) |
|
|
118 | (1) |
|
|
119 | (1) |
|
2.7.3 Comparison of Method 1 and Method 2 |
|
|
120 | (1) |
|
2.7.4 Handling of Redundancy Using IGBT Stacks |
|
|
121 | (1) |
|
2.8 Auxiliary Power Supplies for Submodules |
|
|
121 | (5) |
|
2.8.1 Using the Submodule Capacitor as Power Source |
|
|
121 | (2) |
|
2.8.2 Power Supplies with High-Voltage Inputs |
|
|
123 | (2) |
|
2.8.3 The Tapped-Inductor Buck Converter |
|
|
125 | (1) |
|
|
126 | (1) |
|
|
126 | (1) |
|
|
127 | (6) |
3 Dynamics and Control |
|
133 | (81) |
|
|
133 | (1) |
|
|
134 | (3) |
|
|
135 | (1) |
|
|
135 | (1) |
|
|
136 | (1) |
|
|
136 | (1) |
|
|
136 | (1) |
|
3.3 Converter Operating Principle and Averaged Dynamic Model |
|
|
137 | (11) |
|
3.3.1 Dynamic Relations for the Currents |
|
|
137 | (1) |
|
3.3.2 Selection of the Mean Sum Capacitor Voltages |
|
|
137 | (1) |
|
3.3.3 Averaging Principle |
|
|
138 | (2) |
|
3.3.4 Ideal Selection of the Insertion Indices |
|
|
140 | (1) |
|
3.3.5 Sum-Capacitor-Voltage Ripples |
|
|
141 | (3) |
|
3.3.6 Maximum Output Voltage |
|
|
144 | (2) |
|
|
146 | (2) |
|
|
148 | (1) |
|
3.4 Per-Phase Output-Current Control |
|
|
148 | (13) |
|
3.4.1 Tracking of a Sinusoidal Reference Using a PI Controller |
|
|
149 | (1) |
|
3.4.2 Resonant Filters and Generalized Integrators |
|
|
150 | (2) |
|
3.4.3 Tracking of a Sinusoidal Reference Using a PR Controller |
|
|
152 | (1) |
|
3.4.4 Parameter Selection for a PR Current Controller |
|
|
153 | (4) |
|
3.4.5 Output-Current Controller Design |
|
|
157 | (4) |
|
3.5 Arm-Balancing (Internal) Control |
|
|
161 | (14) |
|
3.5.1 Circulating-Current Control |
|
|
163 | (1) |
|
3.5.2 Direct Voltage Control |
|
|
163 | (3) |
|
3.5.3 Closed-Loop Voltage Control |
|
|
166 | (2) |
|
3.5.4 Open-Loop Voltage Control |
|
|
168 | (4) |
|
3.5.5 Hybrid Voltage Control |
|
|
172 | (3) |
|
|
175 | (9) |
|
3.6.1 Balanced Three-Phase Systems |
|
|
175 | (1) |
|
3.6.2 Imbalanced Three-Phase Systems |
|
|
175 | (1) |
|
3.6.3 Instantaneous Active Power |
|
|
176 | (1) |
|
3.6.4 Wye (Y) and Delta (Δ) Connections |
|
|
177 | (1) |
|
|
177 | (1) |
|
|
178 | (4) |
|
3.6.7 Instantaneous Power |
|
|
182 | (2) |
|
3.6.8 Selection of the Space-Vector Scaling Constant |
|
|
184 | (1) |
|
3.7 Vector Output-Current Control |
|
|
184 | (8) |
|
|
186 | (2) |
|
3.7.2 Reference-Vector Saturation |
|
|
188 | (1) |
|
|
188 | (2) |
|
3.7.4 Zero-Sequence Injection |
|
|
190 | (2) |
|
|
192 | (15) |
|
|
193 | (4) |
|
3.8.2 Open-Loop Active- and Reactive-Power Control |
|
|
197 | (1) |
|
3.8.3 DC-Bus-Voltage Control |
|
|
198 | (2) |
|
3.8.4 Power-Synchronization Control |
|
|
200 | (7) |
|
3.9 Control Architectures |
|
|
207 | (5) |
|
3.9.1 Communication Network |
|
|
209 | (2) |
|
3.9.2 Fault-Tolerant Communication Networks |
|
|
211 | (1) |
|
|
212 | (1) |
|
|
212 | (2) |
4 Control under Unbalanced Grid Conditions |
|
214 | (18) |
|
|
214 | (1) |
|
|
214 | (1) |
|
4.3 Shortcomings of Conventional Vector Control |
|
|
215 | (4) |
|
4.3.1 PLL with Notch Filter |
|
|
216 | (3) |
|
4.4 Positive/Negative-Sequence Extraction |
|
|
219 | (4) |
|
|
219 | (2) |
|
|
221 | (2) |
|
4.5 Injection Reference Strategy |
|
|
223 | (3) |
|
4.5.1 PSI with PSI-LVRT Compliance |
|
|
225 | (1) |
|
4.5.2 MSI-LVRT Mixed Positive- and Negative-Sequence Injection with both PSI-LVRT and NSI-LVRT Compliance |
|
|
226 | (1) |
|
4.6 Component-Based Vector Output-Current Control |
|
|
226 | (2) |
|
4.6.1 DDSRF-PNSE-Based Control |
|
|
226 | (1) |
|
4.6.2 DSOGI-PNSE-Based Control |
|
|
227 | (1) |
|
|
228 | (3) |
|
|
231 | (1) |
5 Modulation and Submodule Energy Balancing |
|
232 | (40) |
|
|
232 | (1) |
|
5.2 Fundamentals of Pulse-Width Modulation |
|
|
233 | (3) |
|
|
233 | (1) |
|
5.2.2 Performance of Modulation Methods |
|
|
234 | (1) |
|
5.2.3 Reference Third-Harmonic Injection in Three-Phase Systems |
|
|
235 | (1) |
|
5.3 Carrier-Based Modulation Methods |
|
|
236 | (7) |
|
5.3.1 Two-Level Carrier-Based Modulation |
|
|
236 | (1) |
|
5.3.2 Analysis by Fourier Series Expansion |
|
|
237 | (5) |
|
|
242 | (1) |
|
5.4 Multilevel Carrier-Based Modulation |
|
|
243 | (9) |
|
5.4.1 Phase-Shifted Carriers |
|
|
243 | (7) |
|
5.4.2 Level-Shifted Carriers |
|
|
250 | (2) |
|
5.5 Nearest-Level Control |
|
|
252 | (4) |
|
5.6 Submodule Energy Balancing Methods |
|
|
256 | (14) |
|
|
256 | (3) |
|
|
259 | (4) |
|
5.6.3 Tolerance Band Methods |
|
|
263 | (6) |
|
5.6.4 Individual Submodule-Capacitor-Voltage Control |
|
|
269 | (1) |
|
|
270 | (1) |
|
|
271 | (1) |
6 Modeling and Simulation |
|
272 | (11) |
|
|
272 | (2) |
|
6.2 Leg-Level Averaged (LLA) Model |
|
|
274 | (1) |
|
6.3 Arm-Level Averaged (ALA) Model |
|
|
275 | (3) |
|
6.3.1 Arm-Level Averaged Model with Blocking Capability (ALA-BLK) |
|
|
276 | (2) |
|
6.4 Submodule-Level Averaged (SLA) Model |
|
|
278 | (2) |
|
6.4.1 Vectorized Simulation Models |
|
|
279 | (1) |
|
6.5 Submodule-Level Switched (SLS) Model |
|
|
280 | (1) |
|
6.5.1 Multiple Phase-Shifted Carrier (PSC) Simulation |
|
|
281 | (1) |
|
|
281 | (1) |
|
|
282 | (1) |
7 Design and Optimization of MMC-HVDC Schemes for Offshore Wind-Power Plant Application |
|
283 | (22) |
|
|
283 | (1) |
|
7.2 The Influence of Regulatory Frameworks on the Development Strategies for Offshore HVDC Schemes |
|
|
284 | (2) |
|
7.2.1 UK's Regulatory Framework for Offshore Transmission Assets |
|
|
285 | (1) |
|
7.2.2 Germany's Regulatory Framework for Offshore Transmission Assets |
|
|
286 | (1) |
|
7.3 Impact of Regulatory Frameworks on the Functional Requirements and Design of Offshore HVDC Terminals |
|
|
286 | (1) |
|
7.4 Components of an Offshore MMC-HVDC Converter |
|
|
287 | (7) |
|
7.4.1 Offshore HVDC Converter Transformer |
|
|
289 | (1) |
|
7.4.2 Phase Reactors and DC Pole Reactors |
|
|
290 | (2) |
|
7.4.3 Converter Valve Hall |
|
|
292 | (1) |
|
7.4.4 Control and Protection Systems |
|
|
293 | (1) |
|
7.4.5 AC and DC Switchyards |
|
|
293 | (1) |
|
|
293 | (1) |
|
7.5 Offshore Platform Concepts |
|
|
294 | (1) |
|
7.5.1 Accommodation Offshore |
|
|
295 | (1) |
|
7.6 Onshore HVDC Converter |
|
|
295 | (3) |
|
7.6.1 Onshore DC Choppers/Dynamic Brakers |
|
|
296 | (1) |
|
7.6.2 Inrush Current Limiter Resistors |
|
|
297 | (1) |
|
7.7 Recommended System Studies for the Development and Integration of an Offshore HVDC Link to a WPP |
|
|
298 | (5) |
|
7.7.1 Conceptual and Feasibility Studies with Steady-State Load Flow |
|
|
299 | (2) |
|
7.7.2 Short-Circuit Analysis |
|
|
301 | (1) |
|
7.7.3 Dynamic System Performance Analysis |
|
|
301 | (1) |
|
7.7.4 Transient Stability Analysis |
|
|
301 | (1) |
|
|
302 | (1) |
|
|
302 | (1) |
|
|
303 | (1) |
|
|
303 | (2) |
8 MMC-HVDC Standards and Commissioning Procedures |
|
305 | (13) |
|
|
305 | (1) |
|
8.2 CIGRE and IEC Activities for the Standardization of MMC-HVDC Technology |
|
|
306 | (3) |
|
8.2.1 Hierarchy of Available and Applicable Codes, Standards and Best Practice Recommendations for MMC-HVDC Projects |
|
|
309 | (1) |
|
8.3 MMC-HVDC Commissioning and Factory and Site Acceptance Tests |
|
|
309 | (8) |
|
|
311 | (1) |
|
8.3.2 Offsite Commissioning Tests or Factory Acceptance Tests |
|
|
312 | (1) |
|
8.3.3 Onsite Testing and Site Acceptance Tests |
|
|
313 | (1) |
|
8.3.4 Onsite Energizing Tests |
|
|
314 | (3) |
|
|
317 | (1) |
|
|
317 | (1) |
9 Control and Protection of MMC-HVDC under AC and DC Network Fault Contingencies |
|
318 | (18) |
|
|
318 | (1) |
|
9.2 Two-Level VSC-HVDC Fault Characteristics under Unbalanced AC Network Contingency |
|
|
319 | (3) |
|
9.2.1 Two-Level VSC-HVDC Fault Characteristics under DC Fault Contingency |
|
|
321 | (1) |
|
9.3 MMC-HVDC Fault Characteristics under Unbalanced AC Network Contingency |
|
|
322 | (3) |
|
9.3.1 Internal AC Bus Fault Conditions at the Secondary Side of the Converter Transformer |
|
|
323 | (2) |
|
9.4 DC Pole-to-Ground Short-Circuit Fault Characteristics of the Half-Bridge MMC-HVDC |
|
|
325 | (2) |
|
9.4.1 DC Pole-to-Pole Short-Circuit Fault Characteristics of the Half-Bridge MMC-HVDC |
|
|
325 | (2) |
|
9.5 MMC-HVDC Component Failures |
|
|
327 | (2) |
|
9.5.1 Submodule Semiconductor Failures |
|
|
327 | (1) |
|
9.5.2 Submodule Capacitor Failure |
|
|
328 | (1) |
|
9.5.3 Phase Reactor Failure |
|
|
329 | (1) |
|
9.5.4 Converter Transformer Failure |
|
|
329 | (1) |
|
9.6 MMC-HVDC Protection Systems |
|
|
329 | (4) |
|
9.6.1 AC-Side Protections |
|
|
331 | (1) |
|
9.6.2 DC-Side Protections |
|
|
331 | (1) |
|
9.6.3 DC-Bus Undervoltage, Overvoltage Protection |
|
|
331 | (1) |
|
9.6.4 DC-Bus Voltage Unbalance Protection |
|
|
332 | (1) |
|
9.6.5 DC-Bus Overcurrent Protection |
|
|
332 | (1) |
|
9.6.6 DC Bus Differential Protection |
|
|
332 | (1) |
|
9.6.7 Valve and Submodule Protection |
|
|
332 | (1) |
|
9.6.8 Transformer Protection |
|
|
333 | (1) |
|
9.6.9 Primary Converter AC Breaker Failure Protection |
|
|
333 | (1) |
|
|
333 | (1) |
|
|
334 | (2) |
10 MMC-HVDC Transmission Technology and MTDC Networks |
|
336 | (37) |
|
|
336 | (1) |
|
10.2 LCC-HVDC Transmission Technology |
|
|
336 | (2) |
|
10.3 Two-Level VSC-HVDC Transmission Technology |
|
|
338 | (1) |
|
10.3.1 Comparison of VSC-HVDC vs. LCC-HVDC Technology |
|
|
338 | (1) |
|
10.4 Modular Multilevel HVDC Transmission Technology |
|
|
339 | (4) |
|
10.4.1 Monopolar Asymmetric MMC-HVDC Scheme Configuration |
|
|
340 | (1) |
|
10.4.2 Symmetrical Monopole MMC-HVDC Scheme Configuration |
|
|
340 | (1) |
|
10.4.3 Bipolar HVDC Scheme Configuration |
|
|
341 | (1) |
|
10.4.4 Homopolar HVDC Scheme Configuration |
|
|
342 | (1) |
|
10.4.5 Back-to-Back HVDC Scheme Configuration |
|
|
342 | (1) |
|
10.5 The European HVDC Projects and MTDC Network Perspectives |
|
|
343 | (2) |
|
10.5.1 The North Sea Countries Offshore Grid Initiative (NSCOGI) |
|
|
343 | (1) |
|
10.5.2 Large Integration of Offshore Wind Farms and Creation of the Offshore DC Grid |
|
|
344 | (1) |
|
10.6 Multi-Terminal HVDC Configurations |
|
|
345 | (3) |
|
10.6.1 Series-Connected MTDC Network |
|
|
346 | (1) |
|
10.6.2 Parallel-Connected MTDC Network |
|
|
346 | (1) |
|
10.6.3 Meshed MTDC Networks |
|
|
347 | (1) |
|
10.7 DC Load Flow Control in MTDC Networks |
|
|
348 | (1) |
|
10.8 DC Grid Control Strategies |
|
|
349 | (6) |
|
10.8.1 Dynamic Voltage Control and Power Balancing in MTDC Networks |
|
|
350 | (1) |
|
10.8.2 Power and Voltage Droop Control Strategy |
|
|
351 | (1) |
|
10.8.3 Voltage Margin Control Method |
|
|
352 | (1) |
|
10.8.4 Dead-Band Droop Control |
|
|
352 | (2) |
|
10.8.5 Centralized and Distributed Voltage Control Strategies |
|
|
354 | (1) |
|
10.9 DC Fault Detection and Protection in MTDC Networks |
|
|
355 | (2) |
|
10.10 Fault-Detection Methods in MTDC |
|
|
357 | (5) |
|
10.10.1 Overcurrent and Voltage Detection Methods |
|
|
357 | (2) |
|
10.10.2 Distance Relay Protection |
|
|
359 | (1) |
|
10.10.3 Differential Line Protection |
|
|
359 | (1) |
|
10.10.4 Voltage Derivative Detection |
|
|
359 | (1) |
|
10.10.5 Traveling Wave Based Detection |
|
|
360 | (1) |
|
10.10.6 Frequency Domain Based Detection |
|
|
361 | (1) |
|
10.10.7 Wavelet Based Fault Detection |
|
|
361 | (1) |
|
10.11 DC Circuit Breaker Technologies |
|
|
362 | (5) |
|
10.11.1 DC Circuit Breaker with MOVs in Series with the DC Line |
|
|
364 | (2) |
|
10.11.2 DC Breakers with MOVs in Parallel with the DC Line |
|
|
366 | (1) |
|
10.12 Fault-Current Limiters |
|
|
367 | (2) |
|
10.12.1 Fault Current Limiting Reactors |
|
|
367 | (1) |
|
10.12.2 Solid-State Fault-Current Limiters |
|
|
368 | (1) |
|
10.12.3 Superconducting Fault-Current Limiters |
|
|
369 | (1) |
|
10.13 The Influence of Grounding Strategy on Fault Currents |
|
|
369 | (1) |
|
10.14 DC Supergrids of the Future |
|
|
370 | (1) |
|
|
371 | (1) |
|
|
371 | (2) |
Index |
|
373 | |