Tore Langeland, Yongtao Yang and Carl Öhlen Risk based approach for development of offshore HVDC transmission technologies EWEA 2012

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Agenda  Motivation  Technology Qualification Process  Qualification Basis  Technology Assessment  Other relevant initiatives  Further work 2

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Motivation

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Motivation Background  40 GW offshore wind in Northern Europe by 2020  150 GW offshore wind in Europe by 2030  Grid connection of offshore oil & gas installations  The vision of an offshore Super Grid The challenge  To date there exists no operational experience with high capacity offshore HVDC transmission technologies  Installations far from shore and in harsh marine environments will require high focus on Reliability, Availability and Maintainability  Interoperability challenges arise with technology from multiple vendors 4 Picture source: 50Herz

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Motivation Offshore HVDC transmission Level 1 Two converter stations Capacity less than maximal loss of infeed Level 2 Three or more converter stations Capacity less than maximal loss of infeed Level 3 Multiple converter stations Capacity higher than maximal loss of infeed 5

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Lack of relevant standards for offshore transmission 6 Offshore IEC Standards and DNV Standards only up to 1.5 kV DC (35 kV AC) Lack of standards for HVDC gas insulated switchgear (HVDC GIS) No standards for interconnection of Voltage Source Converters (VSC’s) No Standards for HVDC circuit breakers No overall standard addressing performance of offshore grids

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Qualification Process

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Qualification Process DNV’s Definition of Qualification: Qualification is the process of providing the evidence that the technology will function within specific limits with an acceptable level of confidence.

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Qualification Process DNV RP-A203  First edition published in 2001  Qualification of new technologies where failure poses risk to life, property, the environment or high financial risk.  Qualification of technologies that are not new - Proven components assembled in a new way - Not covered by existing requirements and standards - Proven technology in a new environment  Developed for the offshore oil&gas industry to increase stakeholder confidence in applying new technologies.

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Qualification Process Qualification Basis Technology Deployment Modifications Qualification PlanExecution of the PlanPerformance AssessmentTechnology AssessmentThreat Assessment Requirements not met or changing requirements All requirements met

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Why do we need technology qualification? Testing is conducted according to old schemes that do not take into account new failure modes  Equipment placed in a new environment - Harsh climate - Difficult access  New approach to maintenance and repair strategy  Auxiliary systems - Control of indoor environment  Higher voltage, current and power ratings - Converter and cables  New applications - Multi-Terminal DC (MTDC) - Meshed MTDC grid  New design of major components - DC converter station and valves - Cables - DC switchgear  System behaviour - Control, protection and communication 11 Increases the RISK exposure

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Added value of technology qualification for offshore HVDC  Demonstration of technology capabilities  Address stakeholder uncertainties - Maturity and uncertainty of technologies - Feasibility of offshore HVDC transmission  Address the risk exposure - Identification and categorization of technologies w.r.t. industry experience and maturity - Identification and understanding of failure modes and the risk picture - Development of methods and activities to address the risks - Overall reliability and availability of technologies and systems 12

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Qualification Basis

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Qualification Basis Technology specification  System description  Standards and industry practice  Maintenance and Operation strategy  Boundary conditions Requirements specification  Reliability, Availability, Maintainability  Functional requirements 14

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Assessment

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Assessment Technology breakdown  Component  Purpose/description  Grid level  Main challenges Technology categorization 1. No new technical uncertainties 2. New technical uncertainties 3. New technical challenges 4. Demanding new technical challenges 16 Application Area Degree of novelty Proven Limited field history New or unproven Known123 Limited Knowledge234 New344

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Assessment Based on STRI experience from Testing, Simulation & Studies  Accredited high voltage testing for testing of major equipment according to relevant standards and customer requirements, e.g. CIGRE recommendations for MI DC cables and extruded DC cables. IEC and IEC for extruded AC cables.  Simulation of HVDC and HVAC systems using most suitable program; SIMPOW, PSS-E, PSCAD-EMTDC, DigSilent etc.  Feasibility and application studies involving users and manufacturers

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Assessment Level 2-4 categorized offshore HVDC technologies  Fast and selective detection, location and clearing of faults in a DC grid  DC circuit breaker  Control system for MTDC  Polymer cable system (rating)  Dynamic cable system  DC Switchgear (AIS*/GIS*)  DC/DC converter 18

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Assessment Level 2-4 categorized offshore grid technologies  Fast and selective detection, location and clearing of faults in a DC grid  DC circuit breaker  Control system for MTDC  Polymer cable system (rating)  Dynamic cable system  DC Switchgear (AIS*/GIS*)  DC/DC converter 19

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Technology Assessment Level 2-4 categorized offshore grid technologies  Fast and selective detection, location and clearing of faults in a DC grid  DC circuit breaker  Control system for MTDC  Polymer cable system (rating)  Dynamic cable system  DC Switchgear (AIS*/GIS*)  DC/DC converter 20 *AIS: Air Insulated Switchgear, GIS: Gas Insulated Switchgear Test of HVDC VSC for an offshore application at STRI high voltage laboratory (Photo: ABB) Test of UHVDC switchgear at STRI high voltage laboratory (Photo: STRI)

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Other relevant initiatives

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Other relevant initiatives Cigré  SC B4 - HVDC and Power Electronics - B4-52, B4-55, B4-56, B4-57, B4-58, B4-59, B4-60  SC B1 - Insulated Cables - B1.27, B1.32, B1-34, B1-35, B1.38, B1.40, B1.43 EC DG Energy  Working group for offshore/onshore grid development NSCOGI  WG 1 Offshore Transmission Technology ENTSO-E  Regional Group North Sea (RG NS) 22 Picture source: ABB

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Future work

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Joint Industry Project Why:  The need for a faster, more efficient and more reliable deployment of offshore HVDC transmission systems for connection of wind farms, oil and gas platforms, multi terminal interconnectors as well as a future HVDC grid. How:  Integrating ongoing activities and experiences of different technologies in new environments with a proven method for risk management - DNV RP-A203 "Qualification Procedure for new technologies". 24

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Joint Industry Project  Scope of work - Activity 1 – Develop a Technology Qualification procedure for offshore HVDC transmission technologies - Activity 2 – Qualification examples - Activity 3 – Hearing process and publication  Participants - Manufacturers - Developers - Operators  Timeline - Kick off in September Industry wide hearing by Q Final publication in Q

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies DNV and STRI DNV  Independent foundation with the purpose of safeguarding life property and the environment  More than 40 years of experience in managing risk for the offshore oil and gas sector  The world’s second largest consulting company for wind energy projects with 30 years of wind energy experience  Leading certifying agency for offshore wind projects STRI  Independent power system consulting company with an accredited high voltage laboratory.  Several large flexible high voltage test halls to conduct tests on products with system voltages up to 1000 kV.  Test halls for testing of pollution, snow, ice, salt, fog and rain effects as well as chambers for multiple stress, salt fog and extreme temperatures.  Experience in system studies for wind power integration and HVDC applications, including multi terminal VSC technology. 26 Test of HVDC VSC for an offshore application at STRI high voltage laboratory (Photo: ABB)

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies

© Det Norske Veritas AS. All rights reserved. Risk based approach for development of offshore HVDC transmission technologies Safeguarding life, property and the environment 28