Tore Langeland, Yongtao Yang and Carl Öhlen 17.04.2012 Risk based approach for development of offshore HVDC transmission technologies EWEA 2012.

Tore Langeland, Yongtao Yang and Carl Öhlen17.04.2012

Risk based approach for development of offshore HVDC transmission technologies

EWEA 2012

© Det Norske Veritas AS. All rights reserved.


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Agenda

Motivation

Technology Qualification Process

Qualification Basis

Technology Assessment

Other relevant initiatives

Further work



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Motivation



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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

Picture source: 50Herz



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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



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Lack of relevant standards for offshore transmission

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• 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



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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.



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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.



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Qualification Basis

Technology Deployment

Mod

ific

atio

ns

Qualification Plan

Execution of the Plan

Performance Assessment


Threat Assessment

Requirements not met or changing requirements

All requirements met



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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

Increases the RISK exposure



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Qualification Basis



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Qualification Basis

Technology specification

System description

Standards and industry practice

Maintenance and Operation strategy

Boundary conditions

Requirements specification

Reliability, Availability, Maintainability

Functional requirements



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Technology AssessmentTechnology 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

Application Area

Degree of novelty

ProvenLimited field

historyNew or

unproven

Known 1 2 3

Limited Knowledge 2 3 4

New 3 4 4



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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



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Level 2-4 categorized offshore grid technologies


DC circuit breaker





DC/DC converter



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Level 2-4 categorized offshore grid technologies


DC circuit breaker





DC/DC converter

*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)



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Other relevant initiatives



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Other relevant initiativesCigré

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)

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Picture source: ABB



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Future work



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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".



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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 2012- Industry wide hearing by Q1 2014- Final publication in Q2 2014

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Safeguarding life, property and the environment

www.dnv.com

Tore Langeland, Yongtao Yang and Carl Öhlen 17.04.2012 Risk based approach for development of offshore HVDC transmission technologies EWEA 2012.

Documents

offshore transmission

qualification of technologies

offshore iec standards

det norske veritas

gw offshore wind

offshore super grid

performance of offshore

motivation slide