European Seminar on materials for HVDC cables and accessories:
Performance, Modelling, Testing, Qualification
V1 - Installation site of the link INELFE: France / Spain
A technical visit of the installation site of the link INELFE "France-Spain" (electrical interconnection through the Catalan Pyrenees) will be organized for participants. This link, under construction, 64.5 km long, connects the substations of Santa Llogaia (near Figueras, Spain) and Baixas (near Perpignan, France). The link is underground: the section that crosses the Pyrenees by the Albères, 8.5 km long, is laid in a tunnel while the rest of the link is undergrounded by means of trenches.
The DC link of 2 x 1000 MW is achieved with ± 320 kV polymer insulated cables, the converter stations are installed at Santa Llogaia and Baixas. This link, which should be in service in 2015, aims to ensure greater safety of the electrical system and the quality of the electricity supply in both countries as well as the exchanges of the renewable energies on the European grid.
The technical visit will show the works in progress, specifically the cable laying and the converter station.
The number of places is limited to 50 participants but two dates are proposed.
Monday, November 18th 2013 - 14:00 – 18:00 ; Registrations are still open for this date
Wednesday, November 20th 2013 - 14:00 – 18:00 ; registrations are now closed for this date
V2 - PROMES Laboratory
A visit of PROMES (PROcesses, Materials and Solar Energy), a research laboratory is proposed. PROMES belonging to the French National Centre for Scientific Research (CNRS), is a laboratory that closely operates in partnership with the University of Perpignan via Domitia (UPVD). PROMES depends on the "INSIS" Institute of CNRS (Institute for Engineering and Systems Sciences). The laboratory aims at developing scientific knowledge and technology in the field of solar energy conversion and use, particularly dealing with concentrated solar energy. Researches at PROMES include all the scales of systems, from nanomaterials to energy networks. They address two main fields: "Materials and extreme conditions" and "Transformation, storage and transport of energy".
The visit will focus primarily on the themes: plasma deposition, thin layers and energy conversion system for photovoltaic.
This visit will be held on Wednesday, November 20th 2013 - 14:00 – 18:00. The number of places is limited to 50 participants and are still available.
Tutorials (two parallel tutorials are organized as a prelude to the seminar)
Monday, November 18 th 2013 - 15:00 – 18:30 (break from 16:00 to 16:30)
T1: Performance of the materials used in the development of HVDC cables
by Petru Notingher, IES Montpellier, France and Gilbert TEYSSEDRE, Laplace Toulouse, France
Demands and challenges for materials to be used in HVDC cable development are mainly focused on synthetic insulation. Polyethylene materials have been successful in replacing other cable technologies for HVAC undersea or underground cables, and the trend is actually to adapt materials compounding and extrusion processes for HVAC cables to the case of HVDC.
In this tutorial, the constrains driven by the DC cable conditions and construction on the materials constituting cables, being insulation as well as field grading materials, will be given, with consideration of cable junctions and the differences with AC stress. Despite a generally higher dielectric strength under AC than DC stress, issues related to resistive field grading and to space charge phenomena under DC stress mark the real challenges for the reliability of HVDC links.
These features will be an opportunity to revisit dielectric physics in general, physics of organic dielectrics in particular, polyethylene in specific, with focus on the nature of charge carriers involved in transport processes (conductivity), and the nature of sites providing charge stabilization and trapping in materials (long lasting space charge effects). The approaches for understanding and evaluation of materials behavior ranging from molecular scale approaches to experimental characterization in flat specimen and to cable scale testing will be reviewed.
T2: Qualification procedures of HVDC cables
by Marc JEROENSE, ABB AB High Voltage Cables, Sweden
Simplified one can state two major types of HVDC cables exist: MI and extruded cables.
Also converter stations come in two flavors, Line Commutated Converter stations (LCC) and Voltage Source Converter stations (VSC). Both station types, LCC and VSC have their own characteristics relevant for the cable system connected to them.
Qualification of cable systems covers the whole range of development tests, pre-qualification tests (also called long-term tests), type tests, sample tests, routine tests, factory acceptance tests and after-laying tests.
Three major CIGRE recommendations exist relevant for our topic. Electra 171 Recommendations for mechanical tests on sub-marine cables, Electra 189 Recommendations for tests of power transmission DC cables for a rated voltage up to 800 kV, for MI cables and TB496 Recommendations for testing DC extruded cable systems for power transmission at a rated voltage up to 500 kV.
The tutorial will cover the principles of the fundamental sets of tests, when to use them and when not to use them (that is, the list starting with development tests and ending with after-laying tests).
Furthermore the tutorial will cover step by step the three major recommendations and their contents. It will be high-lighted how these tests relate to the usage of the cable systems from an installation perspective (Electra 171) as well as from the use of LCC or VSC stations (Electra 189 and TB 496).