HVDC cable systems (cables, joints and terminations)

About This Committee

The scope of the HVDC cable systems committee is developing IEEE Standards for testing HVDC extruded cable systems (cables, joints and terminations). The focus of the committee is on the following subtopics:

  • Lightning and switching impulse tests based on a proper selection of the level and the polarity of impulse voltage.
  • Load cycle tests based on a proper selection of the level and duration of test voltages (check of CIGRE brochures).
  • Cable characterization in prequalification and type tests, including protocols for space charge measurements, crosslinking by-products evaluation, and other effective parameters for diagnosis.
  • Polarity reversal test.
  • Weathering tests on composite terminations.

Additional Information About  The HVDC Cable Systems Technical Committee

Traditionally, high voltage DC (HVDC) cable systems have been the best solution for long-distance submarine transmission links. However, the improved performance of AC/DC converters and the environmental concerns of overhead lines have now made HVDC cable transmission more and more attractive worldwide. All of this has led to a quasi-exponential growth of installed HVDC cable lines worldwide, particularly in the last two decades. In this scenario, the relatively new HVDC extruded cable systems, have become more and more competitive compared with the traditional mass-impregnated nondraining HVDC extruded cable systems, as HVDC extruded cable systems are much more environmentally friendly, their maximum conductor temperature in normal operation is higher, and splicing is much easier. Due to extensive research and development, much of which reported in the IEEE Dielectric and Electrical Insulation Society (DEIS) publications, the voltage and power ratings of installed HVDC extruded cable systems have increased, with DC extruded cable systems already in service at voltage and power levels up to 400 kV and 1 GW, respectively (see the “Nemo Link between UK and Belgium), and DC extruded cable systems being qualified at voltage ratings above 600 kV. Furthermore, the impressive German Corridors (A-Nord, Sued and Sued-Ost links, with an overall connection length exceeding 2000 km) are under construction between the huge Renewable Energy Sources (RES) in Northern Germany and demanding load centers in Central and Southern Germany, featuring underground extruded HVDC cables at a voltage rating of 525 kV, with a transmission capacity up to 2 GW.

Today, extruded insulation for DC cables does not imply necessarily XLPE, as a new PP-based thermoplastic extruded insulation has been developed, which appears to be capable of withstanding a higher temperature and a higher stress. As this new insulation is not cross-linked, manufacturing time is reduced, and the insulation is fully recyclable and therefore more environmentally friendly.

It is in this context that in 2012 the then DEIS president, Simon Rowland, asked Giovanni Mazzanti to form the Technical Committee (TC) titled “HVDC cable systems (cables, joints, and termination). The first meeting of the TC was in Bologna, Italy, in July 2013, at the 2013 IEEE ICSD. Since then, the TC has been very active.

The first goal of the TC was to convert a protocol originally proposed in for measuring space charge in HVDC cables during qualification tests into an IEEE Recommended Practice. After a position paper was prepared on the method, the TC developed IEEE Standard 1732-2017.

After completing this first task, the TC activity moved on to accessories, in particular on Partial Discharge based test methods for joints. In this respect, the TC has developed IEEE Std. 2862-2020, issued in March 2021.

Land (left, photo courtesy of Prysmian) and submarine (right, photo courtesy of Sumitomo Electric) HVDC extruded cables.


High-performance thermoplastic elastomer (HPTE)-insulated HVDC land cable (courtesy Prysmian Cables & Systems)


Installed length of HVDC cable lines worldwide since 1950s

Current and Future Activities

  • Focus is currently on new techniques to characterize HVDC cable systems. For this reason the TC has established in 2021 a new Study Group for the feasibility study of space charge measurements on HVDC cable joints (Chair: Antonios Tzimas, Secretary: Bassel Diban), which ended its work with the publication of the following position paper in the Electrical Insulation Magazine:

Tzimas, B. Diban, L. Boyer, G. Chen, J. Castellon, N. Chitiris, J. Fothergill, N. Hozumi, Y. Kim, J.-H. Lee, F. Mauseth, G. Mazzanti, P. Morshuis, I. Troia, Y. Tanaka, K. Wu, “Feasibility of Space Charge Measurements on HVDC Cable Joints”, prepared by the Study Group—IEEE DEIS Technical Committee “HVDC Cable and Systems”, IEEE Electrical Insulation Magazine, vol. 38, no. 5, pp. 18-27, Sep./Oct. 2022

  • Moreover, two new study groups have been established in July 2023, namely:
  1. a Study Group for a possible new IEEE std. on space charge measurements on thin flat specimens under temperature gradient;
  2. a Study Group for a possible new IEEE std. on space charge measurements in the qualification of factory joints.
  • The TC is also currently in liaison with IEC to let IEC adopt IEEE Std. 1732-2017 and IEEE Std. 2862-2020 intact as IEC/IEEE Dual Logo International Standards, by exploiting the IEEE-IEC Dual Logo Agreement.
  • The TC will also follow closely the forthcoming revision of IEC Standard 62895 “High Voltage Direct Current (HVDC) power cables with extruded insulation and their accessories for rated voltages up to 320 kV for land applications—test methods and requirements”, as extruded cable systems have overcome the 320-kV barrier.

Achievements

  • Writing of the Position Paper– G. Mazzanti, G. Chen, J. Fothergill, N. Hozumi, J. Li, M. Marzinotto, F. Mauseth, P. Morshuis, A. Tzimas, C. Reed, K. Wu, “A protocol for space charge measurements in full-size HVDC extruded cables”, IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 22, N. 1, pp. 21-34, Feb.2015 – where a procedure for the measurement of space charge in prequalification and type tests for full-size HVDC extruded cable systems is proposed for the first time worldwide.
  • From the above Position Paper, writing, balloting, approval by IEEE SA,final editing and publication of Standard IEEE 1732-2017 entitled “IEEE Recommended practice for space charge measurements in High Voltage Direct Current extruded cables for rated voltages up to 550 kV” (June 2017). This is the first Standard document worldwide recommending a good practice for the measurement of space charge in qualification tests (prequalification and type tests) for full-size HVDC extruded cable systems.
  • Management of the Workshop on HVDC Extruded Cable Systems, held at IEEE CEIDP 2016– Toronto, Ontario (Canada), on October 16th 2016. The workshop, chaired by Giovanni Mazzanti as being the chairman of the TC, was attended by 27 people. Apart from Thomas Andritsch (University of Southampton, UK), all other presenters are members of the TC/WG, i.e.: 1) Frank Mauseth (1 presentation), 2) Clive Reed (1 presentation), 3) Yasuhiro Tanaka (1 presentation), 4) Jerome Castellon (1 presentation), 5) Kai Wu (1 presentation), 6) Giovanni Mazzanti (4 presentations).
  • Publication of a Special Issue of the IEEE Electrical Insulation Magazine(vol. 33, no. 4, Jul./Aug. 2017) devoted to the Workshop on HVDC Extruded Cable Systems (IEEE CEIDP 2016). The presentations at the above-mentioned Workshop have been complied into 7 articles, plus and Editorial written by Giovanni Mazzanti, Guest Editor of the Special Issue as being the chairman of the TC.
  • Writing of two position papers for the June 2019 issue of the IEEE Transactions on Dielectrics and Electrical Insulation, entitled:

I) G. Mazzanti, J. Castellon, G. Chen, J.C. Fothergill, M. Fu, N. Hozumi, J. H. Lee, J. Li, M. Marzinotto, F. Mauseth, P. Morshuis, C. Reed, I. Troia, A. Tzimas, K. Wu, “The insulation of HVDC extruded cable system joints. Part 1: review of materials, design and testing procedures”, IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 27, N. 3, pp. 964-972, June 2019

II) G. Mazzanti,  J. Castellon, G. Chen, J.C. Fothergill, M. Fu, N. Hozumi, J. H. Lee, J.  Li, M. Marzinotto, F. Mauseth, P. Morshuis, C. Reed, I. Troia, A.  Tzimas, K. Wu, “The insulation of HVDC extruded cable system joints. Part 2: Proposal of a new AC voltage PD measurement protocol for quality control during routine tests”, IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 27, N. 3, pp. 973-980, June 2019

  • From the above Position Papers, writing, balloting, approval by IEEE SA,final editing and publication of Standard IEEE 2862-2020 entitled “Recommended Practice for Partial Discharge Measurements under AC Voltage with VHF/UHF Sensors during Routine Tests on Factory and Pre-moulded Joints of HVDC Extruded Cable Systems up to 800 kV”, Found on the web here (March 2021). This is the first Standard document worldwide recommending a good practice for the measurement of partial discharges with VHF/UHF sensors in tests for HVDC extruded cable system joints.
  • Writing of the Position Paper  in the Electrical Insulation Magazine:

Tzimas, B. Diban, L. Boyer, G. Chen, J. Castellon, N. Chitiris, J. Fothergill, N. Hozumi, Y. Kim, J.-H. Lee, F. Mauseth, G. Mazzanti, P. Morshuis, I. Troia, Y. Tanaka, K. Wu, “Feasibility of Space Charge Measurements on HVDC Cable Joints”, prepared by the Study Group—IEEE DEIS Technical Committee “HVDC Cable and Systems”, IEEE Electrical Insulation Magazine, vol. 38, no. 5, pp. 18-27, Sep./Oct. 2022

Committee Members & Affiliation

No. Member Name Member Affiliation
1 Giovanni Mazzanti Chairman, University of Bologna, Italy
2 Jérôme Castellon University of Montpellier, France
3 George Chen University of Southampton, UK
4 Bassel Diban Secretary, University of Bologna, Italy
5 John Fothergill Professor Emeritus, City University London, UK, & Southampton Dielectric Consultants
6 Mingli Fu China Southern Power grid, China
7 Naohiro Hozumi Toyohashi University of Technology, Toyohashi, Japan
8 June-Ho Lee Hoseo University, Korea
9 Jian Li Chongquing University, China
10 Massimo Marzinotto Terna, Italian TSO, Italy
11 Frank Mauseth NTNU-Trondheim University, Norway
12 Peter Morshuis Xi’an Jaotong University, Xi’an, China, and Solid Dielectric Solutions
13 Clive Reed free consultant, USA
14 Yasuhiro Tanaka Tokyo City University, Japan
15 Ivan Troia Vice Chairman, Scapa Italia, Italy
16 Antonios Tzimas Advanced Energy, UK
17 Kai Wu Xi’an Jiaotong University, China
18 Natanaele Chitiris Hellenic Cables, Soussaki – Korinthos, Greece
19 Ludovic Boyer Supergrid Institute, Lyon, France
20 Yoonhyoung Kim LS Cable & System., Ltd, Korea
21 Zepeng Lv Xi’an Jaotong University, China

For more information about this technical committee, please contact

Prof. Dr. Giovanni Mazzanti: [email protected]