- TB 675 2017 B4-61 General guidelines for HVDC electrode design
- TB 671 2016 B4-62 Connection of wind farms to weak AC networks
- TB 663 Guidelines for the procurement and testing of STATCOMS
- TB 657 2016 Guidelines for the preparation of "connection agreements" or "Grid Codes" for multi-terminal schemes and DC Grids
- TB 649 2016 GUIDELINES FOR LIFE EXTENSION OF EXISTING HVDC SYSTEMS
- TB 619 2015 HVDC CONNECTION OF OFFSHORE WIND POWER PLANTS
- TB 617 2015 HVDC LCC Converter Transformers - CONVERTER TRANSFORMER FAILURE SURVEY RESULTS FROM 2003 TO 2012
- TB 609 2015 Study of Converter Transients Imposed on the HVDC Converter Transformers
- TB 604 2014 Guide for the Development of Models for HVDC Converters in a HVDC Grid
- TB 590 2014 B4-04 Protocol for reporting the operational performance of HVDC Transmission Systems
- TB 563 2013 B4-38 Modelling and Simulation Studies to be performed during the lifecycle of HVDC Systems
- TB 554 2013 B4-49 Performance Evaluation and Applications Review of Existing Thyristor Control Series Capacitor Devices – TCSC
- TB 553 2013 B4-47 Special Aspects of AC Filter Design for HVDC Systems
- TB 536 2013 C4/B4/C1.604 Influence of Embedded HVDC Transmission on System Security and AC Network Performance
- TB 533 2013 B4-52 HVDC Grid Feasibility Study
- TB 508 2012 B4-44 HVDC Environmental Planning Guidelines
- TB 492 2012 B4-46 Voltage Source Converter (VSC) HVDC for Power Transmission - Economic Aspects and Comparison with other AC and DC Technologies
- TB 447 2011 B4-48 Components Testing of VSC System for HVDC Applications
- TB 417 2010 B4-45 Technological Assessment of 800kV HVDC Applications
- TB 407 2010 JWG A2/B4.28 HVDC Converter Transformers - Guidelines for conducting design reviews for HVDC converter transformers
- TB 406 2010 JWG A2/B4.28 HVDC Converter Transformers - Design review, test procedures, ageing evaluation and reliability in service
- TB 388 2009 JWG B2/B4/C1.17 IMPACTS OF HVDC LINES ON THE ECONOMICS OF HVDC PROJECTS
- TB 371 2009 WG B4.40 Static Synchronous Series Compensator (SSSC)
- TB 370 2009WG B4.39 Integration of large Scale Wind Generation using HVDC and Power Electronics
- TB 364 2008 WG B4.41 Systems with multiple DC Infeed
- TB 352 2008 WG B4.34 Capacitor Commutated Converted (CCC) HVDC Interconnections: Digital modeling and Benchmark Circuit
- TB 337 2007 JWG B4/A3/B3.43 Increased System Efficiency by Use of New Generations of Power Semiconductors
- TB 280 2005 SC B4 WG B4.33 HVDC and FACTS for distribution systems
- TB 269 2005 SC B4 WG B4.37 VSC Transmission
- TB 242 2004 SC B4 WG B4.35 Thyristor controlled voltage regulators: Parts 1 and 2
- TB 240 2004 SC B4/A2 JTF B4.04/A2.01 Analysis of HVDC thyristor converter transformer performance
- TB 237 2003 SC B4 WG B4.19 Static synchronous compensator (STATCOM) for arc furnace and flicker compensation
- TB 223 2003 SC B4 WG B4.28 Active filters in HVDC applications
- TB 222 2003 SC B4 WG B4.05 On voltage and power stability in AC/DC systems
- TB 215 2002 SC 14 WG 14.32 HVDC converter stations for voltages above +/- 600 kV
- TB 205 2002 SC 14 WG 14.31 Custom power - State of the art.
- TB 202 2002 SC 14 WG 14.26 HVDC stations audible noise
- TB 186 2001 SC 14 WG 14.20 Economic assessment of HVDC links
- TB 183 2001 SC 14/37/38/39 JWG 14/37/38/39.24 FACTS technology for open access
- TB 160 2000 SC 14 WG 14.27 Unified power flow controller (UPFC)
- TB 149 1999 SC 14 WG 14.29 Coordination of controls of multiple FACTS/HVDC links in the same system.
- TB 144 1999 SC 14 WG 14.19 Static synchronous compensator (STATCOM)
- TB 143 1999 SC 14 WG 14.25 Cross-modulation of harmonics in HVDC schemes
- TB 139 1999 SC 14 WG 14.30 Guide to the specification and design evaluation of AC filters for HVDC systems.
- TB 136 1999 SC 14 TF 14.01.04 Fire aspects of HVDC thyristor valves and valve halls.
- TB 130 1998 SC 14 WG 14.23 Operational guidelines and monitoring of HVDC systems
- TB 127 1998 SC 14 WG 14.11 Guide for upgrading transmission systems with HVDC transmission
- TB 123 1997 SC 14 WG 14.18 Thyristor controlled series compensation
- TB 119 1997 SC 14 WG 14.05 Interaction between HVDC convertors and nearby synchronous machines.
- TB 116 1997 SC 11/14 JWG 11/14.09 Guide for preliminary design and specification of hydro stations with HVDC unit connected generators.
- TB 115 1997 SC 14 WG 14.07 Guide for planning DC links terminating at AC system locations having low short-circuit capacities. Part II : Planning guidelines.
- TB 114 1997 SC 13/14 WG 13/14.08 Circuit-breakers for meshed multiterminal HVDC system.
- TB 113 1997 SC 14 WG 14.01.03 Test circuits for HVDC thyristor valves.
- TB 112 1997 SC 14 WG 14.17 Semiconductor power devices for use in HVDC and FACTS controllers.
- TB 103 1996 SC 14 WG 14.05 Commutation failures. Causes and consequences.
- TB 097 1995 SC 14 WG 14.12 System tests for HVDC installations.
- TB 093 1995 SC 14 WG 14.01.02 Guidelines for testing of thyristor valves for static var compensators.
- TB 092 1995 SC 14 WG 14.03.02 DC side harmonics and filtering in HVDC transmission systems
- TB 086 1994 SC 33 /21/14 JWG 33/21/14.16 Overvoltages on HVDC cables.
- TB 082 1994 SC 38 WG 38.01.05 Use of DC converters for VAR control.
- TB 078 1994 SC 14 WG 14.01.02 Voltage and current stresses on thyristor valves for static var compensators.
- TB 077 1993 SC 38 WG 38.05.04 Analysis and optimisation of SVC use in transmission systems.
- TB 068 1992 SC 14 WG 14.07 Guide for planning DC links terminating at AC locations having low short-circuit capacities. Part 1. AC/DC interaction phenomena.
- TB 065 1992 SC 14 WG 14.03 AC harmonic filters and reactive compensation for HVDC with particular reference to noncharacteristic harmonics.
- TB 051 1996 SC 38 WG 38.01.06 Load flow control in high voltage systems using FACTS controllers.
- TB 034 1989 SC 33/14 JWG 33/14.05 Guidelines for the applications of metal oxide arresters without gaps for HVDC converter stations.
- TB 025 1986 SC 38 TF 38.01.02 Static var compensators.
- TB 003 1987 SC 14 WG 14.04 Compendium of HVDC schemes throughout the world.
- TB 000 1994 SC 14 WG 14.02 A summary of the report on survey of controls and control performance in HVDC schemes.
- Session papers
- Other Documents
- SC Library
- Documents related to the development of HVDC Grids
TB 619 2015 HVDC CONNECTION OF OFFSHORE WIND POWER PLANTS
The first wave of HVDC connected offshore wind power plants (WPPs) has been commissioned and many more are planned in the North Sea, along with other sites around the world. VSC-based HVDC has become the preferred solution for large offshore WPPs, with cable distances typically above 100 km (including both offshore cable and on shore cable to the converter terminal) to the AC grid connection point. This is largely due to several technology advantages offered by VSCs, when compared to other HVAC or HVDC options, resulting in a more economically attractive transmission solution. In addition, a number of HVDC submarine cable connections for power exchange between countries are being planned and the possibility of connecting WPPs to these interconnections, and to future HVDC grids, are being seriously considered. The issues associated with expanding a WPP and HVDC connections with equipment from multiple vendors are subjects which need to be developed further, but are outside the scope of this brochure. Compliance with Grid Codes (GCs), which define the performance during normal and abnormal operating conditions, is another subject area in need of further development. Existing GCs are however written for AC connected WPPs, and for an offshore WPP these conditions typically apply only at the AC grid connection point. This raises the possibility of optimizing the overall WPP and the HVDC converter, with potential economic and maintenance benefits. However, if the HVDC connection and the WPP are provided by different vendors, such optimization cannot be done properly unless concerns about IP rights and operation benefits are clearly laid out and understood by all stakeholders involved. Guidelines and recommendation for point to point and multi terminal HVDC connection of offshore WPPs are therefore highly needed and of mutual interest for the HVDC and WTG industries in order to be able to provide the best possible solutions for all stakeholders.
TABLE OF CONTENTS
GLOSSARY OF ABBREVIATIONS AND SPECIAL TERMS
1.2 Technical Brochure (TB) Scope
2 VSC-HVDC CONFIGURATIONS
2.3 General VSC-HVDC Design Considerations
2.4 VSC HVDC Configurations
2.4.1 Point-to-Point Connection
2.4.2 Multi-Infeed Connection
2.4.3 Emerging Configurations - Multi-Terminal VSC-HVDC
2.4.4 Future Configurations - VSC-HVDC Grid
2.5 Basic Offshore WPP Configuration
2.6 Basic Configuration of Point-to-Point VSC HVDC for Offshore WPP
2.7 Balance of the Plant
3 HVDC CONNECTED OFFSHORE WPPS: WTG SELECTION AND CONCEPTUAL DESIGN LAYOUTS
3.2 Unique Aspects of WTGs for Offshore Applications
3.2.1 Factors affecting availability of Offshore WTGs
3.2.2 Offshore WTG Design Targets
3.3 WTG Technologies
3.3.1 Type 3: Doubly-fed Induction Generator
3.3.2 Type 4 Full Scale Converter Connections
3.3.3 Foundations of Offshore WTG’s
3.3.4 Future Trends in Offshore WTG Technology
3.4 Connection Between VSC HVDC Converter Station and WPP Collector Substations
3.5 WPP Collector Station Transformers
3.6 Design of the WPP Internal Cable Collector Network
3.6.1 Cable Technology
3.6.2 Substation Placement
3.6.3 Cable Routing and Cable Sizing
3.6.4 Emergency Stand-by Power
3.7 Design of the WPP HVDC Export Cable Connection
4 FUNCTIONAL REQUIREMENTS FOR HVDC AND OFFSHORE WIND POWER PLANT
4.2 System Under Analysis
4.3 Control and Protection Functions Required
4.3.1 Functions required
4.3.2 Considered Situations
4.4 Control and Protection Integration
4.4.1 Control Integration
4.4.2 Protections Integration
4.5 Other issues
4.5.1 Resonance and Harmonics
4.5.2 Start Up-Shut Down Sequence
4.5.3 Controller Instability and Miscoordination
5 INTERCONNECTION REQUIREMENTS
5.1 Interface Connection Points
5.2 Plant Capacity
5.3 Offshore Transmission Ownership
5.3.1 Great Britain
5.4 Voltage and Reactive Power
5.5 Active Power and Frequency Control
5.6 Protection and Fault Ride Through
5.7 Power Quality
5.8 Signal/Communication/Control Points
5.9 Model and Data Provision
5.10 Commissioning, Compliance Testing and Operational Sequence
5.11 Grid Codes Examples
5.11.1 Germany – TenneT TSO GmbH 
5.11.2 Great Britain - National Grid Electricity Transmission plc. (National Grid) 
5.11.3 European Network Transmission System Operator for Electricity: ENTSO-e, Network Code
5.11.4 Offshore Requirements Summary and Recommendation
6 STUDY REQUIREMENTS, DATA, MODELING, AND RECOMMENDED SIMULATIONS
6.2 Steady State Calculations
6.2.1 Steady State Power Flow
6.2.2 Short Circuit Calculation
6.3 Quasi Steady-state Load Flow Models (Long Term Stability)
6.4 Short-term Stability (Dynamic RMS and/or EMT Modelling)
6.4.1 Simulation during voltage dip after fault inception
6.4.2 Simulation of power recovery and system stability after the disturbance
6.4.3 Simulation of stability during changes in normal operation
6.5 Time and Frequency Domain Modelling Above Fundamental Frequencies
6.5.1 Insulation Coordination Study
6.5.2 High Frequency Time Domain Modelling
6.5.3 Frequency Domain Modelling
6.6 Harmonic Analysis, Flicker and Sub-synchronous Interactions
6.7 Study to be made at each stage of the project
6.7.1 Developing Stage (Feasibility Study)
6.7.2 Concept Design Stage
6.7.3 Design Stage (Basic and Detailed)
6.7.4 Documentation Stage
7 OVERVIEW OF PLANNED/DECIDED OR BUILT HVDC CONNECTED WPP PROJECTS
7.1 Offshore Applications
8 GUIDELINES, RECOMMENDATIONS, AND CONCLUSIONS
8.2 Design Guidelines and Tradeoffs
8.2.1 Reliability and Availability
8.2.2 Overload Capability
8.2.3 Control of Real Power
8.2.4 Grid Codes
8.2.6 Conventional vs. Specialized WTG Designs
8.2.7 Off-Shore Grid Protection
8.2.8 Auxiliary Power and Start-Up
8.2.9 Control Interaction
8.2.10 Study Requirements, Data, Modelling, and Simulation Studies
8.2.11 Need for Standards
8.2.12 Recommendations for High Level Control Strategy