PROMOTioN: Progress on Meshed HVDC Offshore Transmission Networks

PROMOTioN seeks to develop meshed HVDC offshore grids on the basis of cost-effective and reliable technological innovation in combination with a sound political, financial and legal regulatory framework.

The project ‘PROgress on Meshed HVDC Offshore Transmission Networks’ (PROMOTioN) applied in 2015 for funding under the EU Horizon 2020 (H2020) programme call ‘Competitive Low-Carbon Energy’ 5 (LCE 5). Within the framework of modernisation of the European electricity grid, this call focused on advancing innovation and technologies relevant to the deployment of meshed offshore HVDC grids. Its specific objective is to pursue an agreement between network operators and major equipment suppliers regarding a technical architecture and a set of multi-vendor interoperable technologies in order to accelerate HVDC grid development.PROMOTioN
PROMOTioN actively addresses the objectives that LCE 5 encompasses. Specifically, these are to:

  • Identify requirements for energy infrastructure priority corridors
    The requirements embrace a broad range of issues, such as the design, development and deployment of the energy infrastructure from a technical, financial, regulatory, management and policy perspective.
  • Facilitate agreement among operators and manufacturers
    Manufacturers and operators need to agree on architectures, control structures and interfaces in order to ensure interoperability and multi-vendor compatibility of equipment.
  • Demonstrate cost-effective HVDC network technologies
    Full-scale and industrially relevant demonstrations will be carried out of novel & innovative components required to enable the realisation of a meshed HVDC transmission network:
    • HVDC circuit breakers
    • HVDC gas insulated switchgear
    • HVDC network protection systems
    • HVDC network control strategies
    • Harmonic performance of wind turbine generators
  • Prepare the first phase for deployment of innovative components…
    … of interoperable meshed offshore HVDC network technologies, services and tools architectures.
  • Propose market rules and revenue streams…
    … to help establish a suitable package of financial resources
  • Propose regulations for permitting and environmental compatibility
    PROMOTioN aims to set up a regulatory framework for operation and management of meshed offshore grids governing legal, technical, and market-related aspects.

Context

A meshed European offshore transmission grid connecting offshore wind farms to shore could provide significant financial, technical and environmental benefits to the European electricity market. Launched in January 2016, PROMOTioN aims to explore and identify these potential benefits. 

PROMOTioNThe main objective of PROMOTioN is the further development and demonstration of three key technologies: multi-vendor HVDC (high-voltage direct current) network protection systems, HVDC network control systems, long duration testing of HVDC GIS (gas insulated switchgear) and full power testing of HVDC circuit breakers. Complementary to this end, a regulatory and financial framework will be developed for the coordinated planning, construction and operation of integrated offshore infrastructures, including an offshore grid deployment plan (roadmap) for the future offshore grid system in Europe.

Currently, the high cost of converter technology, and a lack of experience with protection systems and fault clearance components, hamper the deployment of meshed HVDC offshore grids. In addition, deployment is hindered by limitations inherent to existing European regulations regarding the development of cross-border offshore infrastructures, national legal and regulatory barriers, and financing issues. 

Timetable and Workpackages

PROMOTioN ran over a period of four years. The project is organised in a total of 16 work packages (WP‘s), which are closely interlinked. Laying the foundation by identifying the requirements for meshed offshore grids, WP 1 commenced with the kick-off of the project. WP 2-7 build upon the findings of WP 1 with the implementation of requirements for the project and examination of specific technology issues in detail. These range from grid topology to grid protection systems (WP 2-6) as well as regulatory aspects and financing (WP 7). On the basis of WP 2-6, WP 9-10, 15-16 implement demonstrator and pilot facilities after completion of WP 2-6, in turn leading to WP 11 which addresses harmonization towards standardization. The results from WP 7 and 11 will jointly determine the development of a final deployment plan for the future meshed HVDC offshore grid. The project is flanked by WP 13 and 14, which have the task of dissemination (13) and overall project management (14).

PROMOTioNWorkpackage 8, which was aimed at realising a full-scale demonstrator of a diode rectifier unit (DRU) based wind farm export solution at the Klim wind farm in Denmark, was prematurely terminated for technical reasons. Siemens is continuing to develop the concept towards technical maturity. PROMOTioN continues to consider the DRU as a potential cost-saving technology for future wind farm export solutions. The grid integration and control of the concept is continued to be studied in workpackage 2 and 3, and a small-scale demonstrator is included in the MMC test bench in workpackage 16.

PROMOTioN timetable
Figure 1: Workpackage Overview

An offshore grid in the North Sea could become a flagship project for regional cooperation.

  • Marie Donnelly
  • DG Energy
  • European Commission
WP 1 provides the foundation of the PROMOTioN Project, setting the requirements for offshore meshed grids. WP 1 aims to align the partners of the consortium, and ensure that within the PROMOTioN project the same topologies, assumptions and requirements are being applied. The various tasks of WP 1 will deliver a set of deliverables. The first deliverable (D1.1), a qualitative set of requirements for Meshed Offshore Grids, has already been handed over to the commission. Additionally WP1 will perform a literature study (D1.3) to harvest the knowledge that has been gathered by other studies, and is collecting lessons learned from real life projects (D1.2). Jointly, these projects should ensure optimal absorption of prior Meshed Offshore Grid knowledge into the consortium. With this data, WP1 will deliver preliminary grid topologies, supported by simplified Cost Benefit Analyses (D1.4). These basic topologies are not intended as final grid structures, but as common test-topologies, which can be used for modelling purposes throughout the project. WP1 will also include a visualisation and demonstration of the proposed basic topologies (D1.6). Additionally, WP1 will deliver a starting list of quantified requirements. These requirements are also not set in stone, but are, similar to the topologies, used as common starting ground (D1.5). WP1 will stay active to revise the quantification list throughout the first two years of the project (D1.7).
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PROMOTioN deliverable 1.1

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1.1 Detailed description of the requirements that can be expected per work package

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PROMOTioN deliverable 1.2

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1.2 Report documenting results of the questionnaire on best practices

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PROMOTioN deliverable 1.3

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1.3 Synthesis of available studies on offshore meshed HVDC grids

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PROMOTioN deliverable 1.4

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1.4 Report with reference scenario and related offshore meshed HVDC grid topology

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PROMOTioN deliverable 1.6

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1.5 Quantification of requirements

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PROMOTioN deliverable 1.6

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1.6 Draft roadmap and reference offshore grid expansion plan

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The overall objective is to perform a trade-off analysis and compare different topologies using complex simulation analysis. Interoperability, specifically of diode rectifiers and converters, is investigated by running steady-state, dynamic and transient simulations, thus demonstrating the functionality of these topologies. The results on interoperability as well as control of converters and diode rectifiers, both during normal operation and fault scenarios, are reported and guide the construction and operation of a demonstrator in WP 8 and the definition of requirements for a full scale commercial application in WP 12. In addition, the measured effect of different offshore topologies on the onshore AC grid (e.g. frequency stability) contribute to WPs 8 & 12 in the same manner. Furthermore, WP 2 serves as direct input for WP 11 in order to preserve a close link to current harmonization activities and strongly interacts with WP 3 via joint studies.
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PROMOTioN deliverable 2.4

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2.4 Requirement recommendations to adapt and extend existing grid codes

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The main objective of WP 3 is to identify and specify appropriate analyses and to demonstrate interoperability of wind turbine and wind power plant controls with two different types of HVDC systems for connecting the wind power plants to the DC network: diode rectifier unitss (DRU) and VSC converters. The in-depth study included in this WP, will however be based on models for wind turbine and wind power plant controllers, which are intended to be manufactured independently as ‘black box model’ by participating wind turbine manufacturers, with the focus mainly on the novel DR-HVDC link. Additionally WP 3 will study harmonic interactions between wind turbine inverters and the grid that they are connected to, with the aim of providing guidelines for validating manufacturer black-box harmonic models. At the same time, WP3 will provide input to WP11 in the form of recommendations for good best-practice on how generic open models could be structured. Furthermore, WP 3 gives direct input to WP 8 and extensively interacts with WP 2, as various studies are conducted cooperatively.
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PROMOTioN deliverable 3.1

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3.1 Detailed functional requirements to WPPs

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PROMOTioN deliverable 3.2

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3.2 Specifications control strategies and simulation test cases

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PROMOTioN deliverable 3.4

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3.4 Results on control strategies of WPPs connected to DR-HVDC

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PROMOTioN deliverable 3.5

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3.5 Performance of ancillary services provision from WFs connected to DR-HVDC

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PROMOTioN deliverable 3.6

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3.6 Report with the compliance test procedures for DR and VSC connected WPPs

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PROMOTioN deliverable 3.7

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3.7 Compliance evaluation results using simulations

Part I: WPP/WTG control for Self-Start and Black Start

Part II: WPP/WTG control for DRU Operation

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PROMOTioN deliverable 3.8

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3.8 List of requirement recommendations to adapt and extend existing grid codes

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This WP aims to further develop the most appropriate DC grid protection methodologies for various system topologies. Making use of the reference grids and parameters from WP 1 and WP 2, functional requirements and appropriate tests for the selected topologies are developed. Currently, a wide range of protection methods are proposed, which will be screened and compared using these test methodologies. Of these, the most promising are selected for development towards practical implementation, which includes specification of the protection equipment and the required measurement equipment, post-fault recovery, backup, interoperability, etc.. To implement the different methods in the demonstrator (WP 9), an Intelligent Electronic Device (IED) or protection relay is designed. This device will be able to accommodate the different protection methods and can be connected to the MTTE facilities. The work package will also prepare input for WP 11 in the form of a summary of the performance parameters of the selected DC grid protection systems. Interoperability and failure modes of selected protection methods will be determined, and the factors affecting the cost-benefit analysis will be summarized.
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PROMOTioN deliverable 4.2

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4.2 Broad comparison of fault clearing strategies for DC grids

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PROMOTioN deliverable 4.5

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4.5 Requirements for DC switchgear

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PROMOTioN deliverable 4.7

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4.7 Preparation of cost-benefit analysis from a protection point of view

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HVDC circuit breakers are required to rapidly isolate faults in a meshed grids and guarantee uninterrupted operation of the rest of the HVDC grid. Several types of HVDC circuit breakers have been developed by manufacturers, but none installed to date. The relative lack of experience with this novel technology is also obvious regarding the aspect of testing, as no standardized test methods, requirements and circuits exist. This work package aims to develop a complete test environment in which the ratings and functionality of different types of HVDC circuit breakers can be independently and adequately verified. In order to do so, worst case situations of faults in an internationally recognized benchmark meshed HVDC grid model are identified by means of grid simulations, to understand the various factors that contribute to or determine the fault current. Next, dynamic black-box models of HVDC circuit breakers of different technologies as applied by the project partners are produced, including their relevant functions. Consequently, these models are embedded in the benchmark HVDC grid model in order to quantify the electrical stresses (current, voltage, energy) to which high-voltage DC circuit breakers are subjected in case of fault. Based on the quantified stresses, and based on test methodologies for AC circuit breakers and VSC valves, test requirements and procedures for HVDC circuit breakers are proposed. Then, by simulation, test-circuits based on existing high-power generator sources as present at DNV GL are designed, that can reproduce stresses equivalent to those previously quantified in-service stresses. Since these test-circuits are by nature supplied by AC sources, the test-circuits must fulfil requirements that stress all circuit breakers parts adequately during the total fault current interruption process. The interaction of HVDC circuit breakers with the test-circuit will be quantified for each technology of HVDC circuit breaker.
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PROMOTioN deliverable 5.1

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5.1 HVDC Network Fault Analysis

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PROMOTioN deliverable 5.3

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5.3 Fault Stress Analysis of HVDC Circuit Breakers

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PROMOTioN deliverable 5.5

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5.5 Document on test procedures

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PROMOTioN deliverable 5.6

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5.6 Software and analysis report on candidate test-circuits and their effectiveness

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This WP studies in depth the commercial DC CB topologies. It will complement DC CB demonstration activities in WP5 and WP10, since it develops software models that can be used for fast and flexible studies of DC CBs. Small-scale hardware models will also be developed to facilitate characterisation of some aspects that can notcannot be analysed well with simulation models. The WP will further provide real-time DC CB models for DC grid demonstration in WP9. In the last stages, the researchers will work on the roadmap for increasing voltage levels and enhancing DC CB technology.
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PROMOTioN deliverable 6.1

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6.1 Develop system level model for hybrid DC CB

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PROMOTioN deliverable 6.2

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6.2 Develop system level model for mechanical DC CB

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PROMOTioN deliverable 6.5

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6.5 Low Voltage Hardware Demonstrators of DC CBs

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PROMOTioN deliverable 6.6

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6.6 Demonstrate DC CB failure modes on kw-size hardware models

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PROMOTioN deliverable 6.8

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6.8 Develop roadmap for VARC DC CB scaling to EHV DC voltage

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The current EU framework does not provide specific rules for an interconnected and integrated offshore electricity grid. So far, the focus of the EU framework has been on the regulation of point-to-point interconnectors. Also, clarity on the appropriate financial regulatory model of such an interconnected grid is still lacking, while a meshed North Sea grid comes at high cost and risks. Hence, the main objective is to develop the appropriate European regulatory target framework for the development of integrated offshore electricity transmission infrastructures. This requires a solid framework with different legal, economic and financial properties. Different recent studies identify the main political, legal and regulatory barriers and investigated the needs for a particular EU regulatory framework to support the deployment of offshore grids in a 2020 policy perspective. WP7 will build on those studies and on the work that is ongoing for the implementation of the first energy infrastructure package (TEN-E Regulation), which includes the development of a Cost Benefit Analysis method; regulatory procedures on Cross-Border Cost Allocation, TSO incentives, and EU funding under the Connecting Europe Facility. This also includes the Energy Union initiatives, such as interconnection targets and the European Fund for Strategic Investments.
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PROMOTioN deliverable 7.1

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7.1 Deliverable 1 Intermediate report for stakeholder review:
Legal framework and legal barriers to an offshore HVDC electricity grid in the North Sea

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PROMOTioN deliverable 7.2

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7.2 Designing the Target Legal Framework for a Meshed Offshore Grid

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PROMOTioN deliverable 7.3

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7.3 Intermediate Deliverable_Economic framework for offshore grid planning

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PROMOTioN deliverable 7.4

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7.4 Economic framework for a meshed offshore grid

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PROMOTioN deliverable 7.5

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7.5 Intermediate report_Financing framework for meshed offshore grid investments

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PROMOTioN deliverable 7.6

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7.6 Financing framework for meshed offshore grid investments

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PROMOTioN deliverable 7.9

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7.9 Regulatory and Financing principles for Meshed HVDC Offshore Grid

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PROMOTioN deliverable 7.10

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7.10 Final Stakeholder Report

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PROMOTioN deliverable 7.11

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7.11 Cost-benefit analysis methodology for offshore grids

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TERMINATED - The work package aims was intended to develop and build a Windfarm Demonstrator plant to demonstrate the diode rectifier technology used for connecting offshore windfarms to the onshore grid and future DC grids. It shall should proof the functionality and feasibility of the new technology. This applies for each individual piece of equipment from the turbine up to the new developed Diode Rectifier Unit (DRU) which converts the offshore AC power into DC power for transmission to shore. A new wind turbine controller maintains voltage and frequency in the offshore grid, as there is no VSC control existing any more. The only active partners offshore will be the turbines. System parameters and/or equipment are adjusted or simulated as required, presuming that the wind farm is located far offshore. It also includes the development and possible manufacturing of a hybrid submarine cable prototype combining AC and DC cores in one jacket.
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TERMINATED

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The objective of this WP is to demonstrate operation of the DC grid protection systems developed in the project using hardware in the loop real-time methods. This WP will integrate results from DC CB modelling (WP 6 and WP 10) and DC protection development (WP 4) including hardware prototype of relay at The National HVDC Centre facility (Scotland) and demonstrating DC Grid protection system interoperability.
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PROMOTioN deliverable 9.1

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9.1 Real-time models for benchmark DC grid systems

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PROMOTioN deliverable 9.2

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9.2 DC grid protection testing procedures and guidelines

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PROMOTioN deliverable 9.3

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9.3 Selective protection system demonstration

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PROMOTioN deliverable 9.5

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9.5 Hardware-in-the-loop test environment and guidelines for demonstrating non-selective protection systems for meshed HVDC grids

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PROMOTioN deliverable 9.6

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9.6 Demonstration of Non-selective strategies for Meshed HVDC networks

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The objectives of the WP include demonstrating the correct functioning of full-power AC-based test circuits to generate adequate stresses for all available DC test objects, including prototypes and scale models. Additionally, the project aims to perform tests on these test objects, evaluate the interaction between the HVDC circuit breaker (and other critical components) and its electrical environment. This evaluation covers aspects such as steady state DC current, rate-of-rise of fault current, current interruption, fault current commutation, counter voltage generation, and energy absorption. It also seeks to acquire detailed information on various microscopic physical processes during the fault clearing process to support studies in WP6. Further goals include performing current-zero analysis on arc-based HVDC circuit breaker demonstrators, analyzing and quantifying failure modes of selected sub-components with support from WP6, demonstrating full-power testing on HVDC circuit breakers of participants, and initiating standardization activities.
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PROMOTioN deliverable 10.1

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10.1 Test Report Describing the Functioning of Test Circuits

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10.2 Report Describing the Interaction of Test Objects with the Test Environment

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PROMOTioN deliverable 10.3

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10.3 Acquissition of input data for characterization of stress withstand of breaker subcomponents

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PROMOTioN deliverable 10.4

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10.4 Document on Test Result Analysis

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PROMOTioN deliverable 10.5

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10.5 Document on failure mode analysis of HVDC circuit breakers

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PROMOTioN deliverable 10.7

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10.7 Full Test Setup and Documentation

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PROMOTioN_Deliverable 10.8

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10.8 Initiation of Standardization activities for HVDC circuit breaker design, testing and application

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PROMOTioN_Deliverable 10.9

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10.9 Reporting on HVDC circuit breaker testing

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The overall objective of WP11 is to support and establish harmonization of the industry’s best practices, standards, and requirements for HVDC systems and HVDC-connected offshore wind power plants. WP11 strives to ensure that the experience gathered from research, engineering efforts in WP 2-6, and demonstrations in WP 8-10 is utilized in ongoing and future standardization efforts. The project seeks to harmonize work across existing and future working groups in organizations such as IEC, CENELEC, CIGRE, as well as in national and European grid codes, noting the overlapping topics covered by several groups and the necessity for alignment. WP11 involves the main HVDC system manufacturers to ensure that various manufacturer concepts are considered within the relevant working groups. More specifically, WP11 aims to provide a consistent and harmonized set of functional specifications for HVDC systems, wind power plants, and other AC systems connected to the HVDC systems. It also aims to recommend test procedures for converters, protection systems/components, wind turbines, and wind power plants, as well as functional specifications for models of HVDC systems and wind power plants connected to these systems. Lastly, WP11 seeks to recommend best practices for compliance validation of wind power plants connected to HVDC systems.
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PROMOTioN deliverable 11.1

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11.1 Harmonization Catalogue

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11.2 Report on harmonisation of HVDC systems

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PROMOTioN deliverable 11.3

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11.3 Harmonization of wind power plants connected to HVDC systems

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PROMOTioN deliverable 11.4

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11.4 Report with justified recommendations to grid codes

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PROMOTioN deliverable 11.6

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11.5 Best practice and recommendations for compliance evaluation

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The key objective is to produce a Deployment Plan for future European offshore grid development. This plan will comprehensively outline all necessary technical, regulatory, economic, financial, legal, governmental, and market actions. The plan aims to evaluate the results of all work packages to identify critical technical, regulatory, economic, financial, legal, governmental, and market barriers. Additionally, it involves collecting relevant data and analyzing underlying grid development scenarios to identify an 'optimal scenario' for the development of a future European offshore grid and its integration with the onshore grid. The project also focuses on analyzing the economic and financial viability of the results and recommendations from the different work packages and developing a business case. Finally, it aims to integrate the current PROMOTioN project and past project results into a final deployment plan for future European offshore grid development.
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PROMOTioN deliverable 12.1

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12.1 Preliminary analysis of key technical, financial, economic, legal, regulatory and market barriers and related portfolio of solutions

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PROMOTioN deliverable 12.2

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12.2 Optimal Scenario for the Development of a Future European Offshore Grid

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PROMOTioN deliverable 12.3

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12.3 Draft Deployment Plan

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PROMOTioN deliverable 12.4

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12.4 Final Deployment Plan

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PROMOTioN deliverable 12.5

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12.5 Deployment Plan for Future European offshore Grid Development: Short-Term Project – Bornholm Island CleanStream Energy Hub

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The project aims to disseminate findings to all target groups, stakeholders, and the wider public through the project website, reports, workshops, stakeholder consultations, media activities, and social media channels. It seeks to raise awareness about the potential and cost benefits of meshed HVAC/DC offshore grids and communicate innovative technology demonstrator solutions to key decision makers. The project also aims to inform policymakers about recommendations for a coherent EU and national regulatory framework for meshed and cross-border offshore grid solutions. Discussions will include an action plan for the HVDC grid implementation, featuring the EU PCI project ISLES as a test case, with a letter of encouragement ensuring access to ISLES project data. Additionally, the project will facilitate and organize a dialogue between policy and industry stakeholders to accelerate DC offshore grid development through the Reference Group, which consists of key industry stakeholders and national/European policymakers and regulators.
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PROMOTioN deliverable 13.1

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13.1 Development of project identity

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13.2 Newsletter – bi-annual

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13.4 Mailing list - regularly updated

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13.5 Executive summary of project interim and final report

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13.7 Stakeholder Interaction

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The main objective of this work package is to meet the overall project goals within the allocated time and budget. Key accompanying objectives include coordinating the project activities and decisions at various milestones, setting up an effective management framework for the consortium, reporting to the EU, and ensuring proper cooperation and synergy between the different work packages.
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PROMOTioN deliverable 14.4

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14.4 Exploitation Plan

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14.5 Exploitation of results

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The HVDC gas insulated systems (GIS) technology spans several switchgear components, for example: Bus-ducts and high voltage DC conductors, disconnect- and earthing switches, bushings, and cable terminations, current - and voltage transformer and surge arresters. HVDC gas-insulated systems have a much smaller clearance distance than air-insulated systems and can be built with a much higher degree of compactness and significantly lower sensitivity to ambient factors. The most obvious cost-saving potential can be found on offshore converter platforms which are currently implemented as air-insulated systems. By using HVDC-GIS, the volumetric space of the switchgear installation itself can be drastically reduced e.g. by 70%- 90% which may result in a size reduction of circa 10% of the total converter platform. HVAC GIS technology was introduced to the market in 1966 and is well established today. The potential of gas-insulated systems for High Power DC (HiPoD) applications was recognized and studied in the 1960s already. However, the commercial application of HVDC GIS was limited to one application with limited components in Japan. Since commissioning, the operating voltage is only 50% of the rated values. The gas-insulated components are over dimensioned and therefore too large to be an alternative solution for offshore applications. The further use of gas-insulated systems was hampered by a tendency for the insulating materials to fail during polarity reversal tests. This was generally attributed to the presence of space charges trapped within the insulation. Today, the increasing demand for HVDC connections for both submarine and land applications was the reason to develop new HVDC gas-insulated systems. The dimensioning of a HVDC GIS requires the knowledge of electric field distributions, which is completely different compared to the known AC world. First of all the DC conduction mechanisms are strongly sensitive to many parameters like temperature. Secondly, the solid-gas interface can be charged up. Not only DC, but also transient fields must be predicted: i.e. after polarity reversal or impulses superimposed on DC fields. New field simulation tools ware developed for the optimization of the GIS geometry and insulators, and for the verification of design changes. Using of multi-physics simulation tools the analysis of temperature and electrical field distribution is now possible with high accuracy, taking the following parameters into consideration: temperature and electrical field dependent characteristics of the used insulating materials, accumulation of space- and surface charges and the superposition of DC and impulse voltages.
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PROMOTioN deliverable 15.1

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15.1 Recommendations for specifying DC GIS systems

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15.2 Document on test requirements, prodedures and methods

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15.3 Report on DC GIS diagnostic and monitoring tools and methods

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15.6 White- and position papers on pre-standardization of DC GIS testing

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In Work Packages 2, 3, and 4, the project focuses on the concepts of controllability and interoperability of different converter types in offshore HVDC grids. The analysis includes various grid topologies such as meshed, radial, and combinations, alongside converter types like MMC-HB, MMC-FB, DRU, and HVDC system topologies like symmetrical monopolar and bipolar, primarily conducted through simulations. Work Package 16 aims to complement these simulation studies by demonstrating the interoperability of different converter technologies across various grid topologies and showcasing different control objectives for a meshed DC offshore grid. It also seeks to enhance confidence in the simulated analysis of Task 2.3 through verification with a hardware setup and analyze harmonic resonance phenomena caused by interactions between wind turbine generators (WTG) and VSC converters.
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PROMOTioN deliverable 16.1

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16.1 Definition and Specification of Test Cases

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16.3 Overview of the conducted tests, the results and the associated analyses with respect to the research questions and analyses within WP3

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16.4 Test Case Analysis

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16.5 Implementation of an analytical method for analysis of harmonic resonance phenomena

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There is great potential in the Northern Seas to deliver significant quantities of clean energy.

  • Marie Donnelly
  • DG Energy
  • European Commission