2015 SC B1 ANNUAL PROGRESS REPORT (INSULATED CABLES)

2015 SC B1 Progress report April 2016

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2015 SC B1 ANNUAL PROGRESS REPORT

(INSULATED CABLES)

by A. GILLE, Secretary of the Study Committee

April 2016


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TABLE OF CONTENTS

1 Overview .................................................................................................................... 4 2 SC organization ......................................................................................................... 4 3 Publications ............................................................................................................... 5 4 2015 main events ....................................................................................................... 6

5 2016 main events ....................................................................................................... 6 6 2017 main events . ..................................................................................................... 7 7 Administrative report ............................................................................................... 7

7.1 SC Meeting ............................................................................................................... 7 7.2 TC Award .................................................................................................................. 8

7.3 Web site ..................................................................................................................... 8 8 Technical report ............................................................................................................. 8

8.1 Advisory Groups ....................................................................................................... 8 8.1.1 Strategic Advisory Group ............................................................................... 8 8.1.2 Customer Advisory Group .............................................................................. 9 8.1.3 Tutorial and Publication Advisory Group .................................................. 10

8.1.4 Prospective Advisory Group ......................................................................... 13 8.2 Working Groups ..................................................................................................... 14

8.2.1 WG B1.28 On-site Partial Discharge Assessment of HV and EHV cable

systems ..................................................................................................................... 14 8.2.2 WG B1.34 Mechanical forces in large cross section cable systems ........... 14

8.2.3 WG B1.35 Guide for rating calculations of HV cables ............................... 15

8.2.4 WG B1.36 Life cycle assessment and environmental impact of

underground cable systems .................................................................................... 15 8.2.5 WG B1.37 Guide operation of fluid filled cable systems ............................ 17

8.2.6 WG B1.38 After laying tests on AC and DC cable systems with new

techniques ................................................................................................................ 18 8.2.7 WG B1.41 Issues regarding soil thermal characteristics ........................... 19

8.2.8 WG B1.42 Testing of Transition Joints between HVDC Cables with

Lapped and Extruded Insulation up to 500 kV.................................................... 20

8.2.9 WG B1.43 Recommendations for mechanical testing of submarine cables

................................................................................................................................... 21

8.2.10 WG B1.44 Work under Induced Voltages and Induced Currents + Link

Boxes ......................................................................................................................... 22

8.2.11 WG B1.45 Thermal monitoring of cable circuits and grid operators’ use

of dynamic rating systems ...................................................................................... 22 8.2.12 WG B1.46 Conductor Connectors: Mechanical and Electrical Tests ..... 23 8.2.13 WG B1.47 Implementation of Long AC HV & EHV Cable Systems ...... 25

8.2.14 WG B1.48 Trenchless Technologies ........................................................... 26

8.2.15 JWG B1/B3.49 Standard design of a common, dry type plug-in interface

for GIS and power cables up to 145 kV ................................................................ 27

8.2.16 WG B1.50 SVL and bonding systems (design, testing, operation and

monitoring) .............................................................................................................. 28 8.2.17 WG B1.51 Fire issues for cable installed in air ......................................... 29 8.2.18 WG B1.52 Fault location on land and submarine links (AC and DC) .... 30


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8.2.19 WG B1.54 Behavior of cable systems under large disturbances

(earthquake, storm, flood, fire, landslide, climate change) ................................. 31

8.2.20 WG B1.55 Recommendations for additional testing for submarine cables

from 6 kV (Um = 7.2 kV) up to 60 kV (Um = 72.5 kV) ........................................ 32

8.2.21 WG B1.56 Cable rating verification ........................................................... 32

8.2.22 WG B1.57 Update of service experience of HV underground and

submarine cable systems ........................................................................................ 33 8.3 Task Forces ............................................................................................................ 34

8.3.1 TF B1.58 Diagnostic methods used in MV cable network ......................... 34

8.3.2 TF B1.59 Possible systems design issues ...................................................... 34 8.3.3 TF B1.60 Update of the TB 279 “Maintenance” ......................................... 34

8.3.4 JTF SC B1/ICC Interactions between CIGRE SC B1 and IEEE/PES

Insulated Conductors Committee .......................................................................... 34

8.4 Relations with other CIGRE Study Committees ................................................... 35 8.5 B1 Asia-Oceania Regional Council of Cigre (AORC) ......................................... 36

8.6 IEC .......................................................................................................................... 36


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1 Overview

The main highlights of 2015 are:

SC B1 launched 4 Working Groups and 3 Task Forces. 5 Working Groups and 1 Task Force were disbanded.

Around 330 different experts are working in SC B1 leading to more than 460 contributions in the various working bodies including SC membership.

Excellent progress was made on tutorials and many of them were delivered.

The Chairman decided to devote each SAG Member to a specific SC or organization to have the best possible relations with the other SCs. Each SAG Member will have to liaise and to disseminate the information and collect the needs of the other SC or organization.

Six B1 Working Groups (WG) published important technical brochures "Feasibility of a common, dry type interface for GIS and Power cables of 52 kV and above " (TB 605), “Upgrading and uprating of existing cable systems” (TB 606), “Off shore generation cable connections” (TB 610), “Testing of transition joints between HVDC cables with lapped and extruded insulation up to 500 kV” (TB 622), “Recommendations for mechanical testing of submarine cables” (TB 623) and “Guide for rating calculations of HV cables” (TB640).

The cooperation with IEC TC 20 and IEEE/ICC continues to be very good.

The B1 AORC organization meets regularly with an increasing success This event is now more than a simple panel meeting and is not far from being a WG meeting, and this organization is strongly supported by the regional SC B1 representatives.

2 SC organization

The activities of CIGRE Study Committee B1 concern all types of AC and DC insulated cable systems for land and submarine power connections and are focused mainly on high voltage and extra high voltage applications. Whenever appropriate, however, lower voltage applications are also considered.

Within this field, the scope of work of the Study Committee covers theory, design, applications, manufacture, installation, testing, operation, maintenance and diagnostic techniques of insulated cables.

The main goals of the SC B1 are the following:

to contribute effectively to the progress in insulated cable systems technology,

to facilitate the integration of insulated cable systems in electric power networks and in the environment, covering the complete life cycle of cables,

to maintain its leading position in the field of power cables by providing and actively presenting unbiased and neutral information on all essential cable aspects,

to be recognised by the Electric Power Industry (EPI) as a leading and reliable partner with competence in all engineering issues related to insulated cable systems, i.e. technical, economical, ecological and social,

to monitor and assess current trends in cable technology,

to promote advancements in cable technology.

to detect at the earliest stage the signals from the EPI regarding topics that could affect the work of SC B1.


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4 Strategic Directions were defined in April 2010 by the Technical Committee for the period 2010-2020 (Electra 249)

Technical Direction 1: The electrical power system of the future,

Technical Direction 2: Making best use of the existing power system,

Technical Direction 3: Focus on environment and sustainability,

Technical Direction 4: Communication on power system issues for decision-makers.

The SC B1 is on very good track as it already covers correctly some of them through its past and present WGs. Improvements have been made in TD 3 and TD4 with the launch of the latest WGs/TFs (WG B1.51 and WG B1.54) and a significant number of tutorial sessions.

The basic operating structures of the SC are its Working Groups. Their effective performances are based on a clear definition of their Terms of Reference (ToR) and on work plans with specific time limits (typically three years).

In order to achieve this, it is the normal practice of SC B1 to set up a Task Force (TF) to define the Terms of Reference of a new WG prior to its establishment. The duration of this type of TF must not exceed one year.

By the end of 2015, the SC is composed of 24 Regular Members, 14 Observer Members, a Secretary and a Chairman (40), 15 coming from Manufacturers, 19 from Utilities, 2 from Consultants, 2 from Institutes and 2 from Universities.

The SC B1 has its web site at the following address: http://b1.cigre.org.

3 Publications

Published in 2015 and early 2016.

WG number

Name of the Publication Publication date (on eCigre)

Electra issue Technical Brochure number

JWG B1/B3.33

Feasibility of a common, dry type interface for GIS and Power cables of 52 kV and above

January 2015

Electra 279 (April 2015)

TB 605

WG B1.11

Upgrading and uprating of existing cable systems

January 2015

Electra 279 (April 2015)

TB 606

WG B1.40

Off shore generation cable connections

February 2015

Electra 280 (June 2015)

TB 610

WG B1.42

Testing of transition joints between HVDC cables with lapped and extruded insulation up to 500 kV

June 2015 Electra 281 (August 2015)

TB 622

WG B1.43

Recommendations for mechanical testing of submarine cables

June 2015 Electra 281 (August 2015)

TB 623

WG B1.35

Guide for rating calculations of HV cables

December 2015

Electra 284 (February 2016)

TB 640

http://b1.cigre.org/


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To come

WG number

Name of the Publication Publication date (on eCigre)

Electra issue Technical Brochure number

WG B1.37

Guide for the operation of fluid filled cable systems

Expected: April 2016

WG B1.28

On-site Partial Discharge Assessment of HV and EHV cable systems

Expected: June 2016

WG B1.34

Mechanical Forces in Large Cross Section Cable Systems

Expected: June 2016

WB B1.36

Life Cycle Assessment and Environmental Impact of Underground Cable Systems

Expected: November 2016

4 2015 main events

The 71th meeting of SC B1 was held in Kristiansand (Norway) on September 1-2, 2015.

A technical visit of and a Tutorial Session were organized in conjunction with the event.

The meeting was well attended by regular members. It is noteworthy that this year, all the SC members and conveners were present or replaced with the exception of one SC member. During the meeting several Working Groups and Preparatory Task Forces were launched:

SC B1 also offered tutorials during the year: - Mumbai (India), - Lund (Sweden), - Versailles (Jicable - France), - Rio (Brazil).

5 2016 main events

In 2016, SC B1 will hold its Group Discussion Meeting during the CIGRE Session.

The program of the week is the following :

Monday 22nd of August in the afternoon : SC B1 meeting

Tuesday 23th of August : SC B1 meeting

Thursday 25th of August : SC B1 session

Friday 26th of August in the morning : SC B1 Poster session The Special Report has been prepared by Walter Zenger from United States. It will be soon posted on CIGRE Website (June 2016). To allow fruitful spontaneous discussion during the Meeting, a maximum of 45 prepared contributions will be accepted. A template for presentations will be posted on the website. As usual, no commercialism will be accepted.


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The Preferential Subjects that will be discussed are :

PS 1 : Feedback from newly installed or upgraded underground and submarine AC and DC cable systems

Design, installation techniques, improved safety and operation

Advances in testing and relevant experience

Environmental issues and mitigation

Lessons learnt from permitting, consent and implementation PS 2: Best use of existing T&D cable systems

Condition assessment and Diagnostic testing of cable systems

Trends in monitoring cables and accessories

Upgrading methodologies and related experiences

Trends in maintenance strategies, remaining life and asset management

PS 3: Insulated cables in the Network of the Future.

New functionalities expected from cable systems

Advances in modelling

Innovative Cables, accessories and Systems

Environmental challenges for future cable systems

Higher voltage levels for AC and DC Cables

Longer lengths for AC and DC

6 2017 main events .

The 2017 SC B1 meeting will be hosted by India. The meeting will take place in New Delhi on October 10 and 11 with 2 other days for workshop and technical visit.

7 Administrative report

7.1 SC Meeting

Five WGs and one preparatory TF finished their work. The WGs kept an editorial team to finalize the documents to be published as Technical Brochure and Executive summary in Electra. The TFs were disbanded during the SC meeting and the WGs will be disbanded as well after their report is officially sent to the Central Office and their tutorial is sent to the TAG.

WG B1.28 “On-site Partial Discharge Assessment of HV and EHV cable systems”

WG B1.35 “Guide for rating calculations of HV cables”

WG B1.34 “Mechanical forces in large cross section cable systems”

WG B1.42 “Testing of transition joints between HVDC cables with lapped and extruded insulation up to 500 kV”

WG B1.43 “Recommendations for mechanical testing of submarine cables”

and

TF B1.54 "Behavior of cable systems under large disturbances (earthquake, storm, flood, fire, landslide, climate change)"


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SC B1 launched four new Working Groups and three preparatory Task Forces :

WG B1.54 "Behavior of cable systems under large disturbances (earthquake, storm, flood, fire, landslide, climate change)" (convener : Harry Orton from Canada).

WG B1.55 "Recommendations for additional testing for submarine cables from 6 kV (Um = 7.2 kV) up to 60 kV (Um = 72.5 kV) (convener : Marc Jeroense from Sweden)

WG B1.56 “Cable ratings verification” (convener : Frank de Wild from Netherlands)

WG B1.57 " Update of service experience of HV underground and submarine cable systems " (convener : Soren Mikkelsen from Denmark)

and

TF B1.58 " Diagnostic methods used in MV cable network” which term of office is 2016 (convener : Sławomir Noske from Poland)

TF B1.59 “Possible systems design issues” which term of office is 2016 (convener : Kieron Leeburn from South Africa)

TF B1.60 “Update of the TB 279 Maintenance” which term of office is 2016 (convener : Wim Boone from Netherlands)

By the end of 2015, SC B1 currently has four Advisory Groups, nineteen WGs, one JWG and three TFs and participates in several WGs or JWGs led by other SCs and in one JTF with another organization.

7.2 TC Award

From 2014 the Technical Committee Award is granted every two years, to one person from each Study Committee. In 2014 Johan Karlstrand from Sweden was honored with the CIGRE Technical Committee Award for his contribution to the work of the Study Committee.

7.3 Web site

The new SC B1 web site is on line since June 15, 2005 (now http://b1.cigre.org). It offers an open space to the public and private pages to SC Members. Each Working body has private pages where documents can be exchanged among members. The increasing number of visits, over 1000 per month, confirms that Internet is a very important tool for internal and external communication. In order to obtain a better efficiency, a new Cigre web site will be launched in 2016 and extended step by step. A new webmaster has been appointed in 2016: Gabriel de Robien from France.

8 Technical report

8.1 Advisory Groups

Four Advisory Groups have been launched in 2011 by the incoming SC Chairman. Following the Cigre rules, these advisory Groups will be disbanded at the next change of SC Chairman in 2016.

8.1.1 Strategic Advisory Group

Convener: Pierre Argaut (France)

A permanent Strategic Advisory Group (SAG) was set up in 2011 which terms of reference are to assist the Chairman in the definition of the strategic directions that should be followed by SC B1.


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The SAG is composed of a limited number of members: the Chairman, who will convene, the SC Secretary, and a few other SC Members or experts, all chosen by the Chairman. The Conveners of the other SC B1 Advisory Groups are permanent members of the SAG. The SAG will consider, if needed, the setup of other specialized Advisory Groups. The SAG will initiate, whenever appropriate, the setup of new TFs or WGs. The SAG will meet at least once a year, but will communicate as required. All the items discussed during the 2015 SAG meeting were covered in the 2015 SC B1 meeting agenda.

8.1.2 Customer Advisory Group

Convener: Eugene Bergin (Ireland)

A permanent Customer Advisory Group was installed in 2011 in SC B1 with the Scope to implement CIGRE TC’s suggestion that “Study Committees have to ensure that the needs of their Target Groups are fulfilled.” The B1-CAG is the Reference Body within SC B1 to co-ordinate all activities in this field. It works in close contact with the SC Chairman and the Strategic Advisory Group B1 (SAG) and involves all SC B1 members as contacts and interfaces to their national or local customers.

The Terms of Reference (ToR) of the B1-CAG are as follows:

1. Identification of Target Group

systematically identify SC B1’s Target Groups in different countries

listing of respective organizations, persons, social groups, etc.

analyzing of organizational levels and hierarchies

identifying of most important and influential addressees

2. Communication means with TGs

develop systematic and effective concepts for active contacts and communication

consider how to implement sustainable communication links to organizations and persons

consider how to disseminate most effectively B1’s activities and outcomes to TGs

propose appropriate presentations (Paris Session, Tutorials, Symposia, etc.) in accordance with the TAG

3. Collection and mapping of TG’s needs

identify problems and map systematically needs of TGs

propose review/revision of current SC B1 activities with regard to needs of TGs

4. Collection and evaluation of feed-back from TGs

collect and map the degree of TG’s satisfaction

evaluate the findings and derive, if necessary, measures for improvements and new actions

identify opportunities to increase TG’s satisfaction

coordinate activities at national level where appropriate


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The mission of this Advisory Group is a difficult one as there is not a CAG in each SC and each of them does not have the same target groups. Nevertheless, it is important to collect their needs and to feed them back with our reports. The principle for their representation is to have one representative per continent or sub-continent. It is of evidence that a SC could not communicate directly to all the target groups and should preferentially do it through the National SC members. Based on the questionnaire of the 2014 session, inputs have been given to SAG and Conveners of various WGs. They were generally very positive about the work already done and the future work items (23 replies and 63 suggestions for work). The questionnaire circulated during the 2014 Session and the replies to this questionnaire are available on the website: http://b1.cigre.org/Events/Session. CAG has now completed the collation of SC B1 information published since 1968 up to March 2015 (Technical Brochures, Electra articles, Tutorials and Session Papers). Jicable papers coming from Cigre WGs and approved by SC B1 are also included. The majority of these documents are already available on e-Cigre. The Secretary has put this file on the website: collation of SC B1 documents (http://b1.cigre.org/Publications) and Jicable papers (http://b1.cigre.org/Publications/SC-Library).

Two newsletters are also available on the SC B1 website : http://b1.cigre.org/What-is-SC-B1.

The CAG also :

Prepares the 2016 Session Questionnaire and collates SC Members’ Annual Reports Discusses the above with SAG regarding future plans and inputs to existing WGs Feeds inputs to WGs Ensures CAG is representative of continents and customers Participates and advises SC about TG’s concerns.

Individual SC Members shall be responsible for identifying and communicating with the individual Target Groups in their country.

8.1.3 Tutorial and Publication Advisory Group

Convener: Wim Boone (Netherlands)

A permanent Tutorial and Publication Advisory Group was installed in 2011 in SC B1 with the Scope to implement CIGRE TC’s suggestion that “Study Committees have to deal with education, continuous training, tutorials and publications”. The B1-TAG is the working body within SC B1 to co-ordinate all activities in this field. It works in close contact with the EPEE, the SC Chairman, the Strategic Advisory Group B1-SAG and the Customer Advisory Group B1-CAG. It involves all SC B1 Members and Conveners as contacts.

The Terms of Reference (ToR) of the B1-TAG are as follows:

1. Identification of the potential groups interested in education, continuous training, tutorials or technical presentations

identify SC B1’s Tutorial Target Groups in different countries,

listing of respective organizations: students, young or older engineers, universities, etc…,

identification of the respective expected topics to be taught and training levels,

identification of other learned societies, IEE, IEEE, …

http://b1.cigre.org/Events/Session

http://b1.cigre.org/Publications

http://b1.cigre.org/Publications/SC-Library

http://b1.cigre.org/What-is-SC-B1


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2. Identification of the means to disseminate the SC B1 knowledge

prepare the structure of appropriate presentations (Paris Session, Tutorials, Symposia, events organized by other learned societies, etc.) in accordance with the CAG

3. Checking of final reports before submission to SC Chairman for approval

reading of documents,

opinion to the Convener,

proposal of editorial comments, rewording of sentences

4. Collection of SC presentations with the following goals:

establish an education and training procedure

prepare a standard presentation (template),

issue the official Tutorial starting from a deliverable produced by each WG :or more generally each SC working body which will prepare a full presentation (up to 30 slides),

prepare a synthetic presentation (up to 4 slides) to introduce each tutorial

5. Coordination of activities with other SCs

6. Participation in the validation of the documents before publication

To compensate the lack of expertise, one solution is to propose technical education and training through tutorials that could be addressed from basic to advanced experts, from students and teachers to managers and public. The TAG offers a common tutorial structure that could be easily managed according to the “depth” needed by the public. Each WG has in its terms of reference the production of a tutorial as deliverable. For the past WGs, some SC B1 experts are preparing the relevant tutorials when necessary, and update past tutorials similarly.

By the end of 2015, the list of validated tutorials is:

Thermal Environment of Underground Links Thermal Monitoring of Underground Cables Dynamic Rating of Underground Cables Environmental Impact Assessment Technical and Environmental Issues regarding the integration of a new cable system in the

Network Special Bonding of High Voltage Power Cables Large Cross-sections design Composite Screens design Maintenance for HV Cables and Accessories Accessories for HV / EHV Extruded Cables Earth Potential Rises Lightning Impulse Transients on Long Cables Statistics of AC underground cables in power networks Up-Dating of Service Experience of HV Underground and Submarine Cable Systems Remaining Life Management and Replacement Program for HV Cables Test procedures for HV transition joints Third Party Damage Advanced Design of Metal laminated Coverings


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Construction, laying and installation techniques for cable systems Cable Accessory Workmanship Recommendations for testing of long AC submarine cables for extruded insulation for

system voltage above 30 (36) to 500 (550) kV Recommendations for testing DC extruded cable systems for power transmission at a rated

voltage up to 500 kV Mitigation Techniques of Power Frequency Magnetic Fields Originated from Electric Power

Systems Cable systems electrical characteristics Recommendations for Testing of Superconducting Cables Impact of EMF on Current ratings and Cable systems Guidelines for maintaining the integrity of XLPE cable accessories Off shore generating cable connections Testing of transition joints between HVDC cables with lapped and with extruded insulation

up to 500kV Guide for rating calculations of HV cables Recommendations for mechanical testing of submarine cables Feasibility study of a common dry type interface for GIS power cable of 52 kV and above

There is no direct access to tutorials on the website for the moment. The TAG convener may distribute tutorials only if:

The copyright is clearly mentioned, There is no commercialism around, There is no major change from anybody from the Group to the Tutorial except the first page

(Date, location of use), TAG is informed about the use of the tutorial: Date, location, audience.

Tutorials to come:

Upgrading and uprating of existing cable systems Mechanical forces in large cross section cable systems

The next targets are:

Cables for the future Submarine cables. This tutorial will not deal with critical points which could be part of

manufacturers Know How History of cable industry

The total number of events since 2006 up to December 2015 has been 39. 11 tutorials (5 events) have been presented in 2015:

February - Mumbai (India) – Two tutorials May - Lund (Sweden) – One tutorial, June - Versailles (Jicable - France) – 4 tutorials September – Kristiansand (Norway) – Two tutorials September - Rio (Brazil) – Two tutorials


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8.1.4 Prospective Advisory Group

Convener: Marco Marelli (Italy)

A permanent Prospective Advisory Group was installed in 2011 in SC B1 with the Scope to pay attention at the earliest stage to any change related to the Power Networks of the Future, which may have consequences in the domain of Power Cables. In particular,

New enabling technologies to explore New strategic orientations New needs for standardization

will be considered. PAG will have a long term view, as compared to CAG which is working on short term needs from Target Groups. This will be done by:

Detecting in TOR of WB of other SCs of CIGRE any future involvement of SC B1 Detecting in Publications, Call for papers, Proceedings of workshops and Colloquia

organized in the EPI any items that could affect the steering of SC B1 Informing CAG in order to obtain more formal information to confirm the collected

information Preparing SC B1 to face new challenges (resources recruiting, planning, installation of

preliminary TF, preparation of special reports in CIGRE Sessions, …). Based on the work done at the early stages by PAG, it was considered necessary to redefine the main missions of PAG as follows:

To analyze the work done outside the enlarged CIGRE community, and relevant to cable systems. This external view would include institutions, interest groups, existing standardization bodies without established relations with CIGRE, new standardization bodies (or “new for cable industry”)

Through above analysis, to detect the activities that could affect the steering of SC B1

To inform CAG in order to obtain more formal information to confirm the collected information

To prepare SC B1 to face new challenges (resources recruiting, planning, installation of preliminary TF; preparation of special reports in CIGRE Sessions…).

Within this frame, five sub-Groups have been established:

sG1: Wind Energy

sG2: Solar Energy

sG3: Interconnectors

sG4: Wave and Tidal Energy

sG5: New ideas for Power Transmission Sub-Groups will analyze the available information, will select the information that are relevant to the cable industry and will report them in a “deliverable” that primarily consists in a report to be prepared annually and sent to SAG. There is a need that all SC B1 Members and all B1 experts contribute in the collection of information.


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8.2 Working Groups

8.2.1 WG B1.28 On-site Partial Discharge Assessment of HV and EHV cable systems

Convener: Mark Fenger (Canada)

WG B1.28 was set up in 2008 and was due to present its final report in 2011. Following a change of Convener, two additional years were agreed

The last comments from the SC has been received. The final document is under review by the Strategic Advisory Group and will be sent very soon to the Central Office. The final report will be delivered in 2016.

Terms of Reference:

The work should be limited to HV and EHV extruded AC cables, but addressing both commissioning and diagnostic testing,

The WG shall:

collect experience with PD testing, with respect to methods/equipment and results

evaluate the added value of the PD testing at site for commissioning and diagnostic testing

evaluate the applied technology, taking into account what previous CIGRE and ICC WG’s have done so far

recommend the protocol, to validate the on-site measurement results (calibration, sensitivity assessment)

recommend guidelines for PD test procedures at site (voltage level, measuring time, measuring conditions

identify widely acceptable requirements for commissioning and diagnostic testing. .

8.2.2 WG B1.34 Mechanical forces in large cross section cable systems

Convener: Johannes Kaumanns (Germany)

WG B1.34 was set up in 2010 and was due to present its final report in 2013. The final report has been circulated within SC B1 and numerous comments have been received.

The report of WG B1.34 is not an update of the TB 194.

The TB 194 will be updated after final reports from WG B1.34, WG B1.35, WG B1.41 and WG B1.48 and taking into consideration the recommendations of TF B1.53. To avoid any conflict between TB 194 which will remain the reference TB and the coming TB from WG B1.34, an editorial team has been set up to identify in the report of WG B1.34 everything related to the TB 194 and reword it or remove it in a separate chapter under the title “Recommendations for update of TB 194”. Under these conditions, the TB will be published. The final report is expected for Summer 2016. A report has been presented by the WG in Jicable 2015.


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Reminder of the Terms of Reference:

The WG should identify the forces that interact with the cable system, the internal design of the cable or the accessories being out of the scope. The interaction with all types of joints should be addressed, including transition joints.

The work will be limited to polymeric cables, but should study all types of sheaths and the different installation arrangement such as rigid, flexible, transition from ducts to rigid installations, installation in tunnels, …

The WG should address:

recommendations to IEC SC 17C for requirements to be covered by the standard,

short circuit forces,

those derived from temperature

cables in vertical laying

8.2.3 WG B1.35 Guide for rating calculations of HV cables

Convener: Frank De Wild (Netherlands)

WG B1.35 was set up in 2010 and was due to present its final report in 2013.

The final report has been published in February 2016.


To collect experiences and information from different countries

To assess and interpret the results from the inquiries and to make conclusions and recommendations on how to make a cable rating study

To set up a general framework to guide the user to calculate the current rating of a cable circuit in any situation

To report potential difficulties and problems with the methods, as well as to report recent developments in the methods.

Scope:

All AC and DC cables with emphasis on HV and EHV cables, when possible extended to MV as well. The WG has also taken into account the crossings between cables and other heat sources and the temporary ratings.

8.2.4 WG B1.36 Life cycle assessment and environmental impact of underground cable systems

Convener: Aude Laurens (France)


Different High Voltage Cable types as well as their associated civil works and installation techniques do not impact the environment in the same way. In order to minimize such impact, it is important to develop the necessary tools that would enable the engineers and the decision makers


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to compare the Global Environmental Impact (GEI) of different underground cable systems over their whole life cycle (including end of life and disposal). A few methods have been devised by electric utilities, particularly in Scandinavian countries and Japan, to assess the environmental impact of Underground High Voltage Systems over their life cycle.

The content of the TB is made up 4 sections.

1 – Generalities on Life Cycle Assessment

Principles, historical approach, standards and guidelines Interests, tools and limits

2 – State of the Art : LCA of electricity power systems

3 – Methodology to perform LCA in the case of underground cables

Scope definition, data collection, interpretation Conclusion and recommendations

4 – Case Study : Life Cycle Assessment of an undergound line (90 kV)

General presentation of the study Results, sensitivity analysis Conclusions and prospects

The various phases considered in the case study are: extraction of raw materials as metal (aluminium or copper) or fossil fuels and refining, manufacturing of secondary materials as plastic granulates or wire rod and of cables and accessories, transportation from the cable factory to the line site, construction and line installation, use phase and end-of-life of the line.

Regarding the contribution to Greenhouse Effect for every phase of the life cycle, the use phase represents about 50% of the impact and the share of the manufacturing phase reaches 34% (essentially because of aluminium extraction).

The main conclusions of the case study are:

Electricity losses and manufacturing are identified as responsible for the most important share of the impacts in most of LCA related to underground lines that have been carried on.

The sensitivity analysis emphasized the fact that, in terms of impacts, meaningful differences exist depending on the country where the underground line is operated. Hence, recommendations which aim at limiting environmental impacts will not necessarily be the same. Besides, because of energy transition in Europe, sensitivity mixes are quickly evolving, and this may have a significant impact on the results of LCA.

The limits of the study are:

Data collection: this is the most significant limit of this study. The main reason why some impacts have been excluded is that data which quantify them was too hard to collect.

Avoided impacts and long-term evolutions.

No avoided impact has been taken into account in the end-of-life phase. Moreover, the consequences of energy transition cannot be neglected when considering a life cycle which lasts 40 years.


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The recommendations of the report are:

Electricity losses are identified as responsible for the most important share of the impacts in most of LCA related to underground lines that have been carried on.

LCA also stress that manufacturing phase may be improved from an environmental point of view. Studies could be carried out to improve the performances of recycled materials.

Concerning the end of life phase, XLPE is used as an insulator in most installed cables mainly because of its strong resistance to high temperatures than can be reached in conductors. But one of its leading drawbacks is that it cannot be reshaped like the other thermoplastics.

LCA has an outstanding potential to accurately identify parameters whose environmental impact is prevalent, for every considered step of the lifespan of underground cables.

Finally, a specific attention should be paid to the hypothesis (lifespan of cable, electricity mix, end of life...) as it can change considerably the results of the study. Regardless of the hypothesis made, it should always be specified in the report.

The convener pointed out that environmental concerns are relatively new. Therefore ecoconception approach is often experimental and not yet operational. The WG encountered difficulty in the availability of certain data (civil work, end-of-life…) and in the elaboration of a credible scenario as underground cable is a product that has a very long lifespan (more than 40 years). The SC Chairman emphasized that the content of the TB is checked with the SC C3. Some statements have to be carefully expressed in the appropriate Cigre wording.

The final document is presently being reviewed by the Strategic Advisory Group and is expected to be published at the end of 2016.


To analyze methodology and existing tools and to ascertain their range of application for HV underground cable systems

To develop methodologies as appropriate for life cycle assessment of underground HV cable systems

To provide a picture of the interaction of an underground HV cable system with the environment

To provide the engineers and the decision makers with information which identifies opportunities for reducing the Global Environmental Impact of underground HV systems.

The WG will not cover environmental or biological effects of EMF associated with underground HV cable systems.

Scope of work:

The work shall focus on HV, AC and DC underground land cable systems utilizing lapped and extruded dielectric insulation.

8.2.5 WG B1.37 Guide operation of fluid filled cable systems

Convener: Colin Peacock (Australia)

WG B1.37 was set up in 2010 and is due to present its final report in 2014.


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The paper cables are very reliable and should continue their service as long as possible. The present risk is to see the cable suppliers leaving the field, without anybody able to repair the existing cable circuits.

The final report has been made available on eCigre in April 2016.

Scope of work:

The scope will exclude pipe type cables. It will cover AC and DC land and submarine cables which have in principle the same problems. The voltage range is from EHV to distribution levels.


To establish the appropriate terminology

To collect information and experience on the operation of fluid filled cable systems, using a questionnaire developed by the WG. The WG should consider refurbishment strategies for the continued operation of self-contained fluid filled cable systems.

To collate, summarize and review the information

To produce a working group report as a brochure recommending guidelines on the best practices for the continued operation of self-contained fluid filled cable systems. The WG will address the technical aspects on the continued operation of these cables such as: recommended maintenance, testing (routine and after repair), refurbishment and modifications for improved performance, operational availability and constraints, fault repairs, oil system capacity reviews, fluid monitoring and analysis, leak location techniques and a cable and accessories suppliers list.

Some items have been added such as: extension of service life, extension strategies including use of transition joints, cable cooling systems.

8.2.6 WG B1.38 After laying tests on AC and DC cable systems with new techniques

Convener: Mark Fenger (Canada)


Extruded (XLPE) insulation is rapidly becoming the insulation of choice in both new and replacement transmission class cable circuits. While the cable and accessories are tested in the factory, the workmanship to install the accessories can only be tested after the installation has been completed and before the cable system is put into service. As DC testing, commonly used for FF cables, is not applicable for XLPE cables for AC transmission systems, attention has to be focussed on AC testing methods. The testing of DC cable systems will also be addressed. In the past test equipment capable of testing long lengths of cables were not available so that a soak test at operating voltage for 24 hours was carried out by connecting the cable to the power system. In the last ten years different power sources have been developed that have the power rating to test long cable lengths. These include AC resonant power supplies, damped AC (DAC) and, more recently, very low frequency (VLF). In addition, there have been significant improvements in diagnostic tools such as off-line PD and dissipation factor measurement to assess the condition of a cable system. However, as there are presently only withstand test levels given in IEC 60840 and 62067 for AC resonant test voltages, there is a need to establish test voltage levels for other voltage sources and also establish suitable diagnostic tests.


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The main tasks of the WG have been divided into three separate TFs : “Industry Survey” : to develop and distribute a survey to utilities and industry for existing

practices, experiences and, most importantly, outcomes with field-testing of HV & EHV cable systems. The survey is finished and has been distributed to membership countries.

“Equipment Survey” : to develop and distribute a survey for exiting and upcoming equipment for field-testing of cables. The survey is complete and is currently being distributed to equipment manufactures amongst the membership countries. The work of this TF is now completed.

“Existing Standards & Knowledge” : to identify knowledge gabs with respect to various test methodologies and their impact on cable insulation systems. This is achieved by conducting a literature survey of research already performed with respect to electrical testing with DC, VLF, near power frequency AC test sets as well as with damped AC test sets. This includes evaluating insulation breakdown, PD behavior, electrical tree initiation and growth under various electrical field conditions. A rather large database of peer-reviewed papers, master and Ph.D. thesis covering this topic has been generated. The database consists of more than 110 different papers (after filtering out multiple publications on the same topic). The published work is currently in the process of being evaluated.

The full report shall be made available for final review at the B1 annual meeting in 2016. Reminder of the Terms of Reference: The WG will:

Examine the present status, including limitations, of available voltage sources capable of testing HV and EHV AC and DC transmission cable systems.

Investigate the practical implications, risks and test burden related to the different test methods.

Examine the technical considerations involved to establish test parameters for AC and DC cable systems such as voltage levels, test durations (number of shots for damped AC) and frequency ranges for the different voltage sources

Recommend what work needs to be done to establish these parameters if the technical background is not available

If the technical data are available, test parameters will be discussed and recommended for use

Address the merits of different diagnostic tests.

8.2.7 WG B1.41 Issues regarding soil thermal characteristics

Convener: Walter Zenger (United States)


Existing and up-rated cable systems are loaded increasingly higher. This can be driven particularly by real time rating systems and by re-conductored systems with new high stress dielectrics permitting larger conductor sizes within the same duct or pipe. In all cases the higher loads result in higher operating temperatures for the backfill even if the rated operating temperatures remain the same. The higher loads will increase the cable / duct to soil interface temperatures that will impact the external thermal environment of the backfill and native soil. Depending on the aged backfill and soil condition, this can severely limit the potential capability of the technological advances.


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Many of the existing circuits have been in service for 40 or more years when engineered backfills were in their infancy. Limited knowledge is available of past backfill design and how it will change over time. Recent work showed that properties have changed, such as degree of compaction and stratification of backfill components. Reason for the changed physical backfill conditions could be road vibration, ground water movement or settling. Of particular interest is how high load conditions, change in physical properties and environmental changes will impact aged backfill and soil conditions. Collaboration with IEEE / ICC would be possible to develop a better critical temperature gradient test. The WG has decided to limit the scope for submarine cable installations to beach crossings and cable landings as well general terms as environment of individual submarine cable routes is very site specific and fully evaluated with individual surveys. Very little data or reports are available on specific subject of aging/change over time of soils and backfill. Terminology, characterization parameters, anticipated nature of changes, review of methods to measure thermal, mechanical and chemical soil/backfill properties and stability is largely completed. The main work is with determination of long-term degradation, consequences of performance changes and mitigation of long-term aging. Due to high workload in their regular jobs, some of the members have been slow to produce the scheduled tasks. This results in the request for a one year extension of the WG which has been accepted. The final report for publication is expected for end of 2016.


To review the literature (experience, history) on the subject

To establish the appropriate terminology and characterization parameters.

To review methods to measure the thermal, mechanical and chemical soil / backfill properties and stability.

To review methods to measure the aging and long-term stability of soil and backfill properties over system life

To review technical methods how to mitigate deterioration of soil and backfill conditions including moisture depletion by vegetation or other utilities

To evaluate the consequences, if no action is taken, such as loss of ampacity, including cost and overheating of the cable system.

To integrate the information in a practical users guide.

To apply to extruded, paper, and paper-laminate cable systems

To apply to HV AC and DC land cable systems including direct buried, direct buried ducts or pipe, duct bank / manhole systems, and Horizontal Directional Drill (HDD) installations

To apply to HV AC and DC submarine cable systems including ploughing, jetting, trenching and HDD installations

To apply to MV AC cable systems of high importance

8.2.8 WG B1.42 Testing of Transition Joints between HVDC Cables with Lapped and Extruded Insulation up to 500 kV

Convener: Gunnar Evenset (Norway)

WG B1.42 was set up in 2012 and was due to present its final report in 2014. The report is at its final stage after review by SAG and will be available on ecigre in April 2015.


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Although the extruded HVDC cable technology is developing very fast, lapped HVDC cables will still be on the market for many years. There are projects that consider mass-impregnated cables for the submarine part of the route and extruded cables for the land part of the route. There is a need to define test specifications for how to qualify transition joints between these two technologies.

The final report has been published in August 2015 and a report was presented in Jicable 2015.


Review relevant test recommendations for testing of HVDC cables

Review relevant test recommendations for testing of transition joints for AC cables

Prepare a Technical Brochure on testing of transition joints between lapped and

extruded HVDC cable.

8.2.9 WG B1.43 Recommendations for mechanical testing of submarine cables

Convener: Marc Jeroense (Sweden)

WG B1.43 was set up in 2011 and was due to present its final report in 2014. The report is now being circulated among SCB1 to receive comments from SCB1 members.

Update of mechanical tests for submarine cables is needed since submarine cable installations are growing for higher powers and new applications (wind farm connections, dynamic power cables and deeper sea installations etc.).

The existing recommendation from 1997 (Electra 171) needs to be updated in the light of the experience gained during the last 15 years.

The final report has been published in August 2015.


Cover both impregnated paper cables and extruded cables (AC and DC) including a review of cable installation methods and cable protection for submarine cables

Examination of relevant IEC standards, CIGRE recommendations and standards from the offshore industry (e.g. umbilical testing)

Assess the risk for mechanical damage during installation and cable protection

Assess the risk for mechanical damage after installation (anchoring, drag-net fishing, pile driving)

Calculation of tensile tests to be updated and a more detailed background to be described to the selected factors (security factors and torsion as well as dynamic forces)

Propose test methods to cover: Dynamic cable system installations Very deep sea installations (including extruded cables) Impact tests

Consider the heat cycling influence on the metallic sheath and evaluate possible test methods

Update/introduce mechanical tests for rigid joint

Consider tests with for free-spans, strumming

Consider tests for the cable interaction with e.g. J-tubes, bend restrictors etc.


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The WG should not consider umbilicals in general but follow the development of umbilical power cables.

8.2.10 WG B1.44 Work under Induced Voltages and Induced Currents + Link Boxes

Convener: Caroline Bradley (United Kingdom)


During several phases of a cable system life (installation/maintenance/testing/upgrading/removal), it can be necessary to work under induced voltages or induced currents:

During the pulling or the laying of a cable in the vicinity of an energized system: underground cable or overhead line

During the jointing operations in the installation process

When checking maintaining link boxes

During the repair of the cable after fault

When removing the cable for disposal at the end of its life.

As hazardous conditions could occur, it is important to provide Target Groups (utilities, manufacturers,…) with guidelines for safe work on cable systems.

The progress is good. A draft of the TB has been produced with most chapters containing content and where information is still required, each section has been allocated to a group member(s) to work on, and progress is being made. As previously agreed analysis of EMFs will not form part of this group’s work. An extension to 2016 have been requested and accepted last year. Unfortunately due to a change in job and personal circumstances, the convener can no longer continue and some additional delays are maybe expected even if the new convener appointed for the WG is Stella Gudmundsdottir, previously secretary of the WG.

Reminder of the Terms of Reference :

The WG should address :

Extruded or lapped cable systems

HV but also MV and even LV AC when they are part of the connection scheme,

Permanent or fault conditions (Cable system stresses under grid fault)

Methods to calculate induced voltages and/or currents in various possible configurations

(including EMF or Magnetic effect from cables installed in the vicinity)

Protecting equipment (gloves, earthing systems....)

Jointing, Terminating and work on Link Boxes.

8.2.11 WG B1.45 Thermal monitoring of cable circuits and grid operators’ use of dynamic rating systems

Convener: Blandine Hennuy (Belgium



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Nowadays, due to a more variable situation and increasing loads in the power grids, a dynamic rating system and other measurement values aid the asset manager in making optimal decisions in planning investments in the High Voltage grid. Based on measurement a grid operator can on the one hand decide if a hotspot in network should be taken away to increase the capacity or if the hotspot should be managed with the dynamic rating system and on the other hand will know the load and overload possibilities in real time and for the coming hours. The progress is good. Two questionnaires have been issued: one for the users and one for the manufacturers. The WG has received only a few filled questionnaires. This is too little to make a correct analysis. Saudi Arabia and the Gulf countries could also contribute via the different manufacturers. A comparison with the TB 247 led to the conclusion that it is obvious that almost all the topics covered in TB 247 will be part of the new TB. Only the discrete temperature measurements will not be covered. Therefore, it has been accepted to replace the TB 247 and add an annex with the chapter on discrete measurements taken from TB 247. The final report is expected for December 2016.


To review the literature (experience, history) on the subject

To establish the appropriate terminology and characterization parameters

To collect the present experience with thermal measurements on cable systems by means of a questionnaire

To define the needs of the grid operator

To determine which data should be collected in order to assess the transmission capacity of the link

To collect information about the technology

To examine the points of attention during installation

To describe the necessary maintenance operations and the time intervals between those operations

The WG will take into account system complexity, effectiveness, ease of operation, maintenance, history, experience of workers, practicality of retrofitting (if required) to existing circuits and cost.

The following assets will be managed: EHV, HV and MV cable systems, Underground and submarine cable systems and HVDC cable systems

The following points are considered as out of the scope: Integration with a temperature monitoring system of overhead lines, Systems that do not involve temperature measurements, Type, sample and routine tests of the systems and thermal model of the cable system

8.2.12 WG B1.46 Conductor Connectors: Mechanical and Electrical Tests

Convener: Milan Uzelac (United States)


Current IEC 61238-1 standard applies to connectors for medium voltage cables. There is no IEC standard for connectors for HV cables. The procedures from IEC 61238-1 along with manufacturer and user specifications have been used to type test HV cable connectors. The thermal, mechanical and resistance stability tests specified in current standard are applicable to HV but some requirements are specific to high voltage applications. These include dimensional and functional requirements of connectors within HV cable accessories, typically larger cable sizes, versatility of


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the conductor constructions as well as different circuit load patterns, short circuit levels and mechanical stresses due to tensile and thrust loads. The IEC WG16 of the TC20 commenced work on revision of current IEC61238-1 standard. During this work, some members of WG16, expressed interest that the scope of this standard is extended to high voltage cable application. The TF in charge of the revision believes this work needs to be done by a dedicated group of high voltage experts. At the Study Committee B1 meeting held in Paris on August 28 and 29 2012 it was agreed that a task force be established to consider if further guidance was needed on the testing of connectors for HV cable accessories. It was also decided during the meeting that the topics should be expended to cover mechanical loads (not only thermal), to include all connectors (mechanical and other types) and to include termination and joints connectors. The progress is good. The major activities were focused on:

Collecting and understanding requirements on connector test procedure from IEC and some national Standards.

Getting as much information as possible on field experience with connectors for HV cable systems. Two methods have been used:

o A survey (total installed circuit lengths, cable conductor sizes, conductor materials, ampacities, S.C. currents, types of connectors used and failures related to connectors). The WG has received 28 survey returns from 11 countries so far, which is not satisfactory (especially coming from Europe). In order to get more returns each WG member is contacting the SC B1 member from their country requesting status on survey. The data is being analyzed. Very few failures due to connectors in HV and EHV underground network were found.

o Live presentations by utility members.

Collecting information on the results of the tests that have been performed in different labs with MV and HV cable connectors or that have been shared by manufacturers or users.

Understanding the science behind behavior of connectors exposed to high thermal and mechanical stresses.

The WG is starting analysis phase (thermo-mechanical, behavior of connectors within HV accessories at high, intermittent loads and SC conditions). The final report is expected for December 2016.


To review

o The range and types of connectors currently available.

o Existing international standards and the extent to which they cover the testing of

connectors.

o Any work been done by CIGRE, CIRED, JICABLE…

o Extent of service experience so far for different connector types.

o Customer needs.

To analyse

o Operation on high loaded systems where conductors are approaching or temporarily exceeding maximum conductor operating temperature.

o Thermo-mechanical performance of connectors under cycling loads. o Performance of connectors in short circuit conditions, taking into account thermal

and dynamic forces and actual network ratings. o Performance of connectors installed in cable joints and terminations


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To propose thermal and mechanical test regimes for connectors for HV and EHV cables

with special attention be given to connectors for large size cables.

o Type, routine and sample tests including mechanical, cycling and resistance

stability tests.

o Consider practicality of the short circuit test for large-size conductors and test

loop arrangement.

o WG should be free to consider mechanical tests (e.g. tensile, thrust forces…) in

order to evaluate mechanical strength of connection and physical properties of

connector itself.

o WG should be free to consider separate or integral test sequences combining

mechanical, cycling, short-circuit and resistance stability (assessment) acting on

the same samples.

o Extent of connector type test experience so far (for different connector types).

o Evaluate necessity of performing type tests on connectors that already

successfully passed qualification tests per IEC 60840.

o WG should consider range of type test approval

The WG should consider the tests that reflect mutual impact between connectors, cable

conductors and accessories.

The conductor connectors for HV and EHV applications are to be considered. The WG

will make recommendation to include or not connectors for MV applications.

8.2.13 WG B1.47 Implementation of Long AC HV & EHV Cable Systems

Convener: Ken Barber (Australia)


The power transmission network has been developed during the last decades based on the use of overhead lines. EHV underground cables systems have been available since a long time, but their development has been limited by large capacitance and dielectric losses as well as relatively low current rating compared to OHL. However with the use of new materials and processing technology the situation has changed significantly, so that the constraints on maximum length and power transfer have been largely overcome. The difficulties in installing new overhead lines are making it essential to consider the use of longer underground cables links, as demonstrated by the increasing number of long underground projects. There are still however technical challenges to consider whilst planning new cable installations. The most sensitive topics are those concerning reliability, impact on the transmission grid and installation. The WG proposes the following definition of long length of HVAC cables for this topic:

“A long length of insulated cable is one where the load due to the capacitive current (at power frequencies cables behave as capacitors therefore they generate reactive power) needs to be taken into account in the system design. Typically this would be 40 km for voltages less than 220 kV and 20 km for 220 kV or greater”.

The progress is good. The WG has identified more than 80 projects which meet the WG criteria for a long AC link. The different chapters of the report have been defined :

Current State of Development Reasons for growth, Cable design trends and cable types, New Installation trends, Associated equipment and Reliability of supply.


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Challenges for Implementation Effect on the grid, Protection systems, Voltage effect, Harmonics, Mitigation of EMF and Life time expectancy.

System Design AC-DC comparison, Compensation, Sheath Voltages, Thermo-Mechanical, EMF, Maintaining Circuit Ratings, Limiting induced voltages and future systems

Installation Selection of cable, routes & planning, Installation methods, Transport and Testing

Monitoring Temperature, Condition e.g. P.D. and condition of SVL’s, damage in service, etc.

Maintenance Route information, Land, Submarine, Fault location, Rapid repair options

Practical Experience of Long AC links – Review world experience Examples from the 18 Working group member countries & worldwide experience.

The final report is expected for June 2016.


The aim of the new WG is to create a Technical Brochure which covers the practical issues relating

to system design, installation and monitoring of long HVAC cables. A particular focus will be made on:

Current state development (SCFF cable vs. XLPE cable, Surge arrestors, Reactive

compensation) Challenges for implementation (Matching power rating by hybrid circuits, controlling EMF)

System design (Amount of reactive compensation, Losses, Sheath bonding for long

length)

Installation (Construction, Horizontal directional Drilling, Right of Way) Monitoring (Temperature monitoring, control of route condition)

Maintenance (Fault location, access to route information)

Practical experience (Table of significant projects).

8.2.14 WG B1.48 Trenchless Technologies

Convener: Eugene Bergin (Ireland)


In October 2001 Technical Brochure 194 was published, describing “Construction, laying and installation techniques for extruded and self-contained fluid filled cable systems”. The Technical Brochure included a brief description of innovative techniques including horizontal drilling, pipe jacking and micro-tunneling. TB 194 describes the techniques, their limitations and the changes in cable design necessary to make use of each technique (for example, the changes needed in order to match the ampacity of a shallow, direct buried installation). Although much of the information on trenchless cable installation in TB 194 is still valid, it is relatively brief and few practical examples are given. There is increasing pressure to underground transmission circuits and it is becoming more common for a length of underground cable to be introduced into an overhead line circuit. There is also increasing pressure to reduce the cost of undergrounding and reduce the disruption (e.g. to traffic flow) caused when underground circuits are installed.


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A number of significant technical changes to underground cable circuits have been seen since TB 194 was written; for example, extruded cable has almost completely superseded fluid filled cable for new installations, delivery lengths for land cable have increased and there is a trend towards larger conductor sizes. There has been a large increase in the use of cable in sensitive habitats (e.g. shore landings for AC cable from offshore wind farms and DC cable interconnectors). In some cases the landing sites of submarine cables have been contaminated by prior use. Trenchless technologies do not disturb such sensitive areas and have been used in these applications. In addition to changes in cable technology and attitudes to undergrounding, there have been technical advances in the methods used for trenchless installation since TB 194 was written. The progress is good and four TFs have been established : ploughing, HDD, pipe jacking and microtunnel.


To review the range of trenchless technologies currently available for cable installation ( HDD, pipe jacking and micro tunnels, …)

To review the technical constraints (thermal, mechanical, civil, geotechnical and environmental) relating to the trenchless installation of HV cable systems.

To provide examples of where trenchless techniques have been used in the installation of HV cable systems, highlighting the benefits and adverse experiences in each case.

Full cable tunnels should be excluded because they have their specific issues like fire, smoke, access, sharing with other services, etc. to be addressed and this topic has already been dealt in the TB 403 “Cable Systems in Multi-purpose or Shared Structures” by WG B1.08.

8.2.15 JWG B1/B3.49 Standard design of a common, dry type plug-in interface for GIS and power cables up to 145 kV

Convener: Pierre Mirebeau (France) Based on the recommendations of the JWG B1/B3.33, JWG B1/B3.49 was set up in 2013 and is due to present its final report in 2016. Taking into account the market trend in some countries towards a commoditization of the High Voltage cables lower or equal to 145kV, the working group B1-B3.33 had concluded that there is room in these voltage levels for a standard design in parallel with the present designs. The convener reported that the last nominations from SC B3 were received in May 2015. The first meeting has therefore been planned in October 2015.


The goal of the JWG is to recommend a functional design of an insulator with a common interface.

Current is ≤ 1000A, short circuit ≤ 40 kA 1 sec. Cross sections are ≤ 1000mm² Cu or 1600mm² Al

Technology has to be defined (inner or outer cone), with a detailed evaluation of technical advantages/disadvantages of the two technologies.

The number of sizes has to be defined; the short circuit current can be altered for the smallest sizes. Dimensions of insulator components have to be defined (current connection, electric design and properties, mechanical design and properties). The type and dimension of the main current connection have to be defined.


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Consideration to be given to the consequence of a termination failure, the upgrading of the cable link for higher current loads and installation constraints, with a special focus on the basement dimensions.

The design has to meet the requirements of IEC 62271-209 and IEC 60840 and there is a need to define the initial and cross qualification processes.

The stress cone design and material, the lubricant and the design of the compression device should be left to the discretion of the accessory manufacturer within the limits of the standardized insulator properties.

8.2.16 WG B1.50 SVL and bonding systems (design, testing, operation and monitoring)

Convener: Tiebin Zhao (United States) The basic information needed to design a bonding system is included in several documents such as Electra 128-1990, TB 283-2005, and TB 347-2008. Some of these documents need to be updated. In addition it is noted that cable bonding components and related national regulations have changed in recent years. The WG plans to address related issues with sheath voltage limiters (SVLs) and bonding systems. The progress is good. The final report is expected for 2017.


Basic information o Provide an overview of the functions of the bonding systems. o Review existing documents and other engineering information related to bonding

systems. o Review service experience depending on bonding schematics, standing voltage

and withstand levels.

Bonding system design o Consider different bonding designs: single point, multiple point (solid), cross-

bonding, and point out different challenges regarding screen protection of cable systems, including joints, terminations and link boxes.

o Provide basic knowledge (voltages, current rating, and energy absorption) for selection and implementation of bonding leads, link boxes and SVLs depending on cable system parameters and bonding designs.

o Provide recommendations for screen insulation coordination. o Provide guidance on cable system models for overvoltage calculation using

computer software. May work with liaison members nominated by SC C4 if such interests arise from C4 side on modeling aspects of this task.

Testing of bonding system o Provide guidance on testing of bonding system components. o Provide guidance on testing of bonding systems after installation.

Maintenance o Provide recommendations on maintenance of bonding systems including SVLs. o Provide testing criteria while considering interference with implemented

monitoring systems. o Consider monitoring of bonding systems


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8.2.17 WG B1.51 Fire issues for cable installed in air

Convener: Paolo Maioli (Italy) A significant concern is the fire safety of insulated cables installed in air, since it is often not practical for fire protection services to give a rapid response in case of fire. This subject has been raised in the Technical Brochure 403 “Cables Systems in multipurpose or shared structures”. Whilst it is possible to bury some of the more hazardous cables in the floor of the tunnel, provide protection barriers or install fire protection systems such as water sprays or other devices, these systems are all expensive. It was therefore important to establish if more suitable cable designs could provide an adequate level of fire protection without the need for separate protection systems. Quite often tunnels are “ventilated” with certain airflow, having an incremental effect on some of the typical fire behavior of cables, including fire propagation, development of smoke and to a lesser extend development of corrosive fumes Standardizing work was done by IEC, but in terms of fire behavior these standards, at present, are mainly applicable to low voltage cables. More recent developments of new designs and requirements of power cable systems in terms of flame retardant properties are not yet considered; for this reason it is difficult to apply the above mentioned standards to transmission and distribution. The progress is good. The major activities focused on:

Collecting and start understanding all existing international and national standard requirements on Fire issues.

Getting as much information as possible regarding cable construction, material requirements, fire test requirements and flame propagation, smoke requirements, toxicity.

What experience do you have regarding relevant installation with cables in air (particularly in tunnels), description of major installations, accidents and recovery and local regulation for fire.

Comparing all existing international and national standard requirements on Fire issues.

What experience do you have regarding detection measures (temperature, smoke, fire, …), procedure in case of fire, measures to protect already existing installation and statistics of relevant installations, and accidents.

Test methods under fire conditions The final report is expected for 2017


To review: o All existing international and national standard, any work done by CIGRE, CIRED,

IEC, IEEE. o Extent of service experience, customer needs; so far for different connector types. o Papers presented at Conferences (e.g. Jicable). o Customer needs.

To analyze: o Type of Installation: single purpose (tunnel, substations) or multi-purpose (bridges,

shared tunnels and other shared civil works) o Ancillary components like fire monitoring, sprinkler protection, barriers, and other

control measures could be the object of a list of general rules/suggestions and civil works (improvements, arrangements) as well.

o In addition, the effect of certain mitigation measures on the performances of cable (i.e.: current rating) should be considered.

o As a final contribution, the WG could provide for a ranking of cables types/design in relation to fire risk.


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To propose: o Suitable cable designs o Additional methods o Development Tests, Type Tests including Fire Tests. o To consider the whole range of cables from MV to EHV, mainly with extruded

insulation, excluding joints; o To prepare only general rules for joints installation.

8.2.18 WG B1.52 Fault location on land and submarine links (AC and DC)

Convener: Robert Donaghy (Ireland)

The increasing number of land and submarine cable assets globally has created a focus on cable fault location capabilities. All faults in cable systems are different and cable fault location depends to a great extent on applying the appropriate technique or combination of techniques. The methods for locating power cable faults require competent engineers and service providers. Guidance is therefore required for engineers on the correct application of the various techniques available. The progress is good. The following task forces were set up :

TF1: Technical Brochure Structure

TF2: Cable failure types & fault location techniques

TF3: Design factors affecting fault location capability – Land Cables

TF4: Design factors affecting fault location capability – Submarine Cables

TF5: Emergency Planning & Marine Logistics for Fault Location

TF6: Case Studies

TF7: Innovation and Future Developments. The final report is expected in 2017.


To cover fault location on the following installed cable types: MV/HV/EHV; AC/DC; land and submarine cable systems; single core, 3-core and pipe type cables.

To focus on main insulation & sheath faults

To provide overview of existing fault location techniques and underlying principles

For land and submarine cable systems, to provide guidance and strategies for effective fault location for a variety of installation types including but not limited to:

o Direct buried cable systems o Ducted land cable systems o Cables between GIS bays o Cables installed in horizontal directional drills and tunnels o Cables at large burial depths o Cable systems with different bonding types o Very long cables o …

To examine the different methods of pre-location and pinpointing from an accuracy and suitability viewpoint

To prepare a flowchart to assist in selecting appropriate methods according to fault type and cable type

To examine design factors (cable design and installation method) affecting fault location capability

To examine safety considerations

To examine marine vessel and support requirements for finding submarine cable faults


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To collect case studies of fault location experiences

To examine training requirements for fault location personnel

To examine assess applicability of on-line methods to support fault location

To review new and innovative fault location techniques & future developments

The WG should not cover: o Leak location in fluid filled cables o Gas leak location on gas compression cables o Diagnostic testing o Defects in cathodic protection systems

8.2.19 WG B1.54 Behavior of cable systems under large disturbances (earthquake, storm, flood, fire, landslide, climate change)

Convener: Harry Orton (Canada)

This topic is extremely important since in the recent past several large disturbances occurred in various countries. Everybody remembers for example the earthquakes in Nepal this year and Christchurch, New Zealand in 2010. More than 500 cable faults requiring repair were counted in Christchurch. In the closing session of the Auckland Symposium, in September 2013, the General Report outlined the need of further work in this area regarding cable design and/or installation design for seismic areas. The Scope of Work will document the resultant damage, required repairs, recommend improved accessory and cable designs and suggest alternate installation methods for LV, MV, HV and EHV cable systems due to the occurrence of major disturbances. Major disturbances include the following events:

Floods, fire and global warming,

Major earthquakes, liquefaction and resultant landslide or tsunami,

Hurricanes, cyclones, tornadoes, typhoons,

Ice storms, windstorms and mud and/or landslides.

Terms of Reference:

Assess extent of damage to the cable system categorized by event and voltage class,

Document the repairs carried out,

List spares required for deployment,

Recommend measures to mitigate damage severity,

Recommend cable and accessory design changes,

Recommend installation improvements, for example, alternative cable duct designs, to use or not to use direct buried cables and to include cable snaking or not,

Suggest test protocols specific for each major disturbance, for example seismic situations, reference industry and academic investigations,

Whenever possible visit utilities and sites to gain first-hand knowledge of events,

Evaluate existing international and domestic standards for their relevance to cable

systems due to large disturbances, for example IEEE Standard 693-2005 on Recommended Practices for Seismic Design of Substations

Make contact with storm centers around the world to assess availability and advantages of early warning systems.


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8.2.20 WG B1.55 Recommendations for additional testing for submarine cables from 6 kV (Um = 7.2 kV) up to 60 kV (Um = 72.5 kV)

Convener: Marc Jeroense (Sweden)

As a result of the growing demand for the connection of the offshore facilities there is a need to develop an international standard on medium voltage submarine cable systems. To this end an IEC TF within TC20/WG16 has been created and is already working. The IEC TF will consulate existing documents like IEC60520, IEC60840, CIGRE TB490 and CIGRE TB623 in order to write the new standard. The role of this CIGRE WG is to support with recommendations for testing medium voltage submarine cable systems that are not covered by the named documents. The topic, for instance, that is known not to be covered by these documents is the aspect of new cable constructions up to 60 kV being of the wet type. In addition there might be other topics that are not or wrongly covered.

Terms of Reference:

A survey of existing standards and recommendations. The survey must also contain those dealing with wet constructions.

The recommendations shall apply to armored single-core and three-core cables in combination with their accessories, termination and joints, for usual conditions of installation and operation.

The recommendations shall cover both static and dynamic applications. The latter wrt to the growing interest of floating wind-parks.

The scope is limited to “extruded” meaning extruded of either filled (e.g. with mineral or carbon) or unfilled crosslinked (e.g. crosslinked polyethylene, ethylene propylene rubber, etc.) insulations.

The scope is limited to AC cables.

This recommendation is applicable to submarine cables installed in relatively shallow water having depths of the order of some tens up to few hundreds, i.e. 200 of meters.

The recommendation shall at least cover: Long Term ‘wet’ test, Type tests, Routine tests, Sample tests and After installation tests.

The recommendation shall focus on topics NOT covered by IEC60520, IEC60840, CIGRE TB490 and CIGRE TB623 and focus on tests in these documents that otherwise are not or wrongly applicable to medium voltage submarine cable systems.

8.2.21 WG B1.56 Cable rating verification

Convener: Frank de Wild (Netherlands)

WG B1.35 drafted a guide for rating calculations of insulated cables. One of the issues considered in that guide was the use of calculation tools. It was recommended by the WG that the user should verify the calculations of the tool before using it. Despite some tools being used frequently, and by multiple companies, it is generally unclear exactly how a calculation is performed by the calculation tool. Given the many different installation situations and cable designs which exist, and for which a strict IEC based calculation is not even possible (refer to the many examples in the technical brochure of WG B1.35), the user should verify how the situation is treated by the calculation tool. The assumptions made and the formulae used must be applicable, but these are not gathered in any standard. For dynamic or transient ratings, verification becomes even more important as the dynamic behavior significantly complicates the models and their output. As it is rather difficult to verify calculations of calculation tools, especially when these tools provide transient or dynamic ratings, or real life situations which are not precisely covered by IEC, it is currently proposed to help the cable community by setting up a uniform calculation


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verification protocol, which can be used to ensure a correctly working software within a certain (limited) domain.

Terms of Reference:

To define and detail a uniform calculation verification protocol giving the possibility to the user to ensure a correctly working software within a certain (limited) domain. Steps to be taken are:

Define the scope of the verification protocol (domain of applicability) in detail

Define a limited series of: o duty aspects (steady state current, dynamic current, harmonics,..) o cable systems (MV, HV, submarine cable, DC cable,….) o installation types (direct, pipe, tunnel, air,…)

Make calculations for defined situations

Report calculation results in full detail

Establish verification protocol (how to verify a software with these calculations, and how to interpret differences)

Update B1.35 report and the tutorial.

It is noted that in this work, no verification of tools itself will take place.

8.2.22 WG B1.57 Update of service experience of HV underground and submarine cable systems

Convener: Soren Mikkelsen (Denmark)

In recent years, significant quantities of land and submarine cables and accessories have been installed and the associated technology and laying techniques have matured and evolved. With the increasing demands on electrical power transmission and distribution systems, including the need to connect new (renewable) sources of generation, significant quantities of land and submarine cable are currently being installed. In 2009, CIGRE WG B1.10 published a Technical Brochure (TB 379) which collated survey data relating to the installed quantities of underground and submarine cable systems rated at 60 kV and above together with the service experience/performance of existing underground and submarine cable systems. The survey covered a 5 year period ending December 2005 for land cables and a 15 year period ending December 2005 for submarine cables. Our stakeholders have expressed the need to have these data updated. The WG Convener should consider setting up separate Task Forces to consider independently the statistics for land, submarine cable and DC systems. This would enable results for each type of cable to be reported as soon as data are available rather than wait for all work to be completed.

Terms of Reference:

To update the service experience to the end of 2015, using a format comparable to earlier publications (where possible). Published information is to include:

Land and submarine cables and accessories

Type of current (AC, DC)

Technology (the main designs of cables in use)

Mode of installation (Land Cables: direct burial, tunnels, troughs, duct banks and Submarine Cables: protected or unprotected)

Internal and external faults

Number of faults per year.

The voltage range will be limited to systems operating at 60 kV and above.


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8.3 Task Forces

The TFs are launched by the Study Committee to define the terms of reference of a new WG prior to its establishment. The duration of this type of TF must not exceed one year. Task Forces do not publish any report in Electra.

8.3.1 TF B1.58 Diagnostic methods used in MV cable network

Convener: Sławomir Noske (Poland)

Indeed DSO Companies are looking for possibility to analyse condition of MV cables. They use diagnostics systems (PD and Tan delta). Poland has good experience in this area. It will be good to connect knowledge from different DSOs. The Polish SC B1 panel believes that it will be very helpful and useful to launch a WG/TF. The scope would cover the following topics:

Diagnostic methods used in MV cable network

Cable diagnostics requirements in electrical tests after installation and after repair

Diagnostics in assessing technical condition of the cable line.

Management of data received from diagnostic

The TF is due to discuss and conclude in 2016 on whether or not to install a full WG to address this topic.

8.3.2 TF B1.59 Possible systems design issues

Convener: Kieron Leeburn (South Africa)

During the last SAG meeting in Arnhem early 2015, it has been suggested to set up a TF to look at this topic which was in a response to the 2014 CAG questionnaire issued in Paris: multi cables per phase for high loads (load sharing, cross bonding and grounding, maintenance tests, repairs, …).


8.3.3 TF B1.60 Update of the TB 279 “Maintenance”

Convener: Wim Boonen (Netherlands)


8.3.4 JTF SC B1/ICC Interactions between CIGRE SC B1 and IEEE/PES Insulated Conductors Committee

Convener: Walter Zenger (United States)

The CIGRE/ICC JTF was launched in 2000 and the evaluation made in 2010 concluded that the cooperation should continue. A new evaluation will be done in 2016.

The JTF CIGRE/ICC is now composed of 7 B1 Members.


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SC B1 regularly presents the update of CIGRE work, some tutorials and exchanges views with WGs dealing with common issues. The future activities are the:

Intensification in exchange of technical information

Increase of coordination between SC B1 and ICC WG and DG

Presentation of new Cigre Tutorials as part of the ICC Educational Program

Continue cooperation/coordination between similar WG in SC B1 and ICC

Exchange of information on how to motivate utility participation in technical organizations.

8.4 Relations with other CIGRE Study Committees

Cables are more and more involved in the networks and there is a need to communicate with other SCs. It has been decided to devote each SAG Member to a specific SC or organization to have the best possible relations with the other SCs. Each SAG Member will have to liaise and to disseminate the information and collect the needs of the other SC or organization. In some cases, it could be an exchange of mails and/or an annual report, in others, it could go up to an attendance in the meeting of the other party. The current liaises are:

SC B2: Steve Swingler

SC B3: Eugene Bergin

SC B4: Christian Jensen

SC C3: Eugene Bergin

SC C4: Johan Karlstrand

SC C6: Marco Marelli

SC D1: Wim Boone

AORC: Ken Barber

ICC: Walter Zenger

IEC: Pierre Mirebeau

Jicable: Alain Gille

The need to have more common formal exchanges between SCs to better understand each other has been identified. It could be done through Symposium, Colloquium, tutorials, panels, …

SC B1 is involved in several WGs where B1 experts are among the WG members to provide their expertise in the cable systems. These WGs are:

WG B4.55 “HVDC connection of offshore wind power plants”

JWG C3/B2/B1/13 “Environmental issues of HV transmission lines for rural and urban areas”

WG C4.207 "EMC of communication circuits, low voltage systems and metallic structures in the vicinity of power systems”

WG D1.23 "Diagnostics and accelerated life endurance testing of polymeric materials for HVDC application"

JWG D1/B1.49 “Harmonized test for the measurement of residual inflammable gases in insulating materials by gas chromatography”

WG D1.54 “Basic principles and practical methods to measure the AC and DC resistance of conductors of power cables and overhead lines”

WG D1.63 “Partial Discharge detection under DC voltage stress”.


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8.5 B1 Asia-Oceania Regional Council of Cigre (AORC)

The aim of the AORC is to promote Cigre in the Asia-Oceania region and foster technical cooperation among (member) countries in this region. This Yearly Meeting is now more than a panel and is not far from working as a WG, and this organization is strongly supported by the regional SC B1 representatives. The 11th AORC meeting has been held in Sabah (Malaysia) on August 19, 2015. 4 sessions were scheduled on the agenda of the Technical meeting. During the first session, the SC B1 member for Japan made a presentation on the Paris sessions in 2014 and the work done by SC B1 since the last meeting in Japan. For the second session, presentations from the attending countries (Australia, China, Japan, Singapore, Malaysia, Indonesia, Thailand, …). Five presentations were made on the third session “New designs of cables and accessories, installation and assembly methods for cable systems and others”. The last session was on “Deterioration, diagnostic and maintenance methods for cable systems”.. There was also a workshop on the subject of the ASEAN Grid. Whilst it was accepted that the technology existed to provide such a grid which would benefit the region it was noted that there were many political challenges to achieve this objective. During the discussion it was noted that there was a problem in Malaysia with a lack of experience in fault location and repair of cable systems so that they had a clear preference for overhead line transmission & distribution systems despite the trend to undergrounding which was occurring elsewhere. This was a very clear message for SC B1 to address a possible topic for a new Cigre WG. The 12th meeting would be held in Bangkok in October 2016. As the SC B1 meeting in October 2017 would be held in New Delhi, AORC has received an invitation from the Indian National Committee of Cigre to hold the AORC B1 meeting at the same time.

8.6 IEC

In 2014, IEC TC20 has had its bi-annual meeting in Paris. Pierre Mirebeau (FR), the liaison officer with IEC, attended the meeting. The 4 four WGs, the Project Team and the Maintenance Team of IEC TC 20 are the following :

WG 16 : High voltage cables (1 kV and above), their accessories and cable systems

WG 17 : Low voltage cables below 1 kV

WG 18 : Burning characteristics of electric cables

WG 19 : Current rating and short-circuit limits of cables

PT 62895 : High Voltage Direct Current (HVDC) power cables with extruded 0insulation and their accessories for rated voltages up to 320 kV for land applications – Test methods and requirements

MT 20 : Environmental statement specific to TC20 Many CIGRE B1 experts are also nominated for IEC TC 20 activities. They are aware of CIGRE TF and WGs and they can disseminate the knowledge of Cigre.


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WG16 HVDC The PT 62895 standardization project is based on Cigre TB 496 (Recommendations for Testing DC Extruded Cable Systems for Power Transmission at a Rated Voltage up to 500 kV). It has concluded the CD stage; some 180 comments have been received and discussed in detail. The PT 62895 Chairman is an active B1 representative in WG B4/C1.65, in addition to Christian Jensen (DK), who is corresponding member, to ease future work being made in IEC TC 20. Submarine cables At the Paris meeting TC20 endorsed the start of the standardization project IEC 63023 “ Submarine power cables with extruded insulation and their accessories for rated voltages from 6 kV (Um = 7.2 kV) up to 60 kV (Um = 72.5 kV) - Test methods and requirements“. There is again a strong relation to Cigre SC B1, the IEC work will be based on the recommendations given in Electra 171 (1997) and the recently published TB 623 "Recommendations for mechanical testing of submarine cables" prepared by WG B1.43. HV connectors TC20 is waiting for the conclusions of the WG B1.46 to complete the standard with connector for high voltage cables systems. The MV part of the standard "IEC 61238 Compression and mechanical connectors for power cables for rated voltages up to 30 kV (Um = 36kV)" has concluded the CD stage; the TF is working down the long list of comments received. Laminated coverings The new release of the Technical Report TR 61901 "Tests recommended on cables with a longitudinally applied metal foil for rated voltages above 30 kV (um = 36 kV)", took advantage of TB 446. Publication of the new edition of TR 61901 is pending. Test standard for HTS cables At the Paris meeting TC20 endorsed the start of the standardization project “Recommendations for testing of superconducting cables”. The work on this project will be done in a Project Team and will include members from IEC/TC90 as well. This standard will be based on TB 538 "Recommendations for testing of superconducting cables" (WG B1.31). WG 19 TC20 endorsed the proposal to develop TR 62602 (data for US cable sizes) to an International Standard. Publication of a TB prepared by WG B1.35 (Guide for rating calculations) is expected.

Documents

2015 SC B1 ANNUAL PROGRESS REPORT (INSULATED CABLES)