Milestone-Proposal:Gotland HVDC Link

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Docket #:2015-05

This Proposal has been approved, and is now a Milestone

To the proposer’s knowledge, is this achievement subject to litigation? No

Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

Gotland High Voltage Direct Current Link, 1954

Plaque citation summarizing the achievement and its significance:

The Gotland HVDC Link was the world’s first commercial HVDC transmission link using the first submarine HVDC cable. It connected the Island of Gotland to mainland Sweden. The 96 km-long cable used mass-impregnated technology. The Swedish manufacturer ASEA produced the link for Vattenfall, the state-owned utility. The project used mercury-arc valves for the 20 MW/100 kV HVDC converters, developed by an ASEA-Vattenfall team led by Dr. Uno Lamm.

In what IEEE section(s) does it reside?

IEEE Sweden Section

IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: IEEE Sweden PE/PEL Chapter
Senior Officer Name: Olof Samuelsson

Unit: IEEE Sweden PE/PEL Chapter
Senior Officer Name: Lina Bertling

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: IEEE Sweden PE/PEL Chapter
Senior Officer Name: Olof Samuelsson

Unit: IEEE Sweden PE/PEL Chapter
Senior Officer Name: Lina Bertling

IEEE section(s) monitoring the plaque(s):

IEEE Section: IEEE Sweden Section
IEEE Section Chair name: Mats Edvinsson

Milestone proposer(s):

Proposer name: Olof Samuelsson
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates of the intended milestone plaque site(s):

N 57.587716 E 18.194615

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. The proposed site of the plaque is at the converter station at the Gotland end of the HVDC link. Västerhejde Ygnevägen 53 622 61 Visby, Sweden

Are the original buildings extant?

The HVDC link has been upgraded several times and the plaque will be mounted in connection with the existing converter station.

Details of the plaque mounting:

The plaque will be mounted on a plinth outside the fence of the converter station.

How is the site protected/secured, and in what ways is it accessible to the public?

The plaque will be visible from the public street outside the converter station.

Who is the present owner of the site(s)?

Vattenfall Eldistribution AB, the local distribution network owner.

What is the historical significance of the work (its technological, scientific, or social importance)?

The world’s first commercial High Voltage Direct Current (HVDC) transmission link in operation was the Gotland HVDC Link, commissioned in 1954. The Gotland HVDC was installed between the Swedish mainland and the island Gotland in the Baltic Sea. It was the Swedish State Power Board (Vattenfall, the state owned utility) that decided to connect the island’s transmission system to the main transmission system in Sweden with HVDC, and placed the order to ASEA in 1950. The rating for the Gotland HVDC link was set to 20 MW, 200 A, and 100 kV. The project scope in the contract included both the HVDC converters on the mainland and the island as well as the 96 km submarine HVDC cable. The cable utilized mass‐impregnated (MI) technology, and was the worlds’ first submarine HVDC cable. The Gotland HVDC Link capacity was increased in 1970, when power semiconductor technology was introduced in the form of thyristor valves connected in series with the existing mercury‐arc valves, raising the voltage to 150 kV. 1983 a new thyristor valve was installed as a monopole, extended to a bipole in 1987 giving the Gotland HVDC link a capacity of 260 MW at +/‐ 150 kV.

What obstacles (technical, political, geographic) needed to be overcome?

For the HVDC converters, where the conversion of high‐voltage alternating current to high‐voltage direct current and vice versa takes place, the recently developed mercury‐arc valve technology was chosen. ASEA had worked with the research and development of this technology since 1929 together with Vattenfall, a project lead by Dr. Uno Lamm. In his memory IEEE founded the IEEE PES Uno Lamm High Voltage Direct Current Award to recognize outstanding contributions to HVDC technology.

What features set this work apart from similar achievements?

The Gotland HVDC Link with the mercury‐arc valves and HVDC submarine cable commissioned in 1954 stands for a clear milestone in the development of modern and reliable electrical transmission technology. The project comprised several of “the world’s first”, and was the breakthrough in both cable and converter technologies that paved the ground for a number of well‐known large transmission projects using the mercury‐arc valves. Examples of projects include; between England – France (the English Channel), between Denmark – Sweden (Konti‐Skan), in New Zealand (Cross Sound), in the USA (the Pacific Intertie), in Japan (Sakuma), and in Canada (Nelson River).

Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.

D. Tiku, “dc power transmission – mercury-arc to thyristor HVdc valves”, IEEE Power & Energy Magazine, march/april 2014, pp 76-96: “Subsequently in 1954, the first commercial HVdc submarine Gotland link (20 MW, 100 kV) was commissioned by ASEA” W. Long and S. Nilsson, “HVDC Transmission: Yesterday and Today”, IEEE Power & Energy Magazine, march/april 2007, pp 22-31: “The first commercial order for an HVDC system was given to ASEA by Vattenfall for a 20-MW, 100-kV undersea cable between the Swedish mainland and the island of Gotland in 1950.” “The Gotland HVDC link was commissioned in March of 1954.” O. Peake, “The history of high voltage direct current transmission”, Australian Journal of Multi-disciplinary Engineering, Vol 8, No 1, 2010, pp 47-55: “The Gotland scheme, generally considered to be the first truly commercial scheme in the world, also became the test site for a series of new technology breakthroughs in the development of HVDC. This site is therefore the most significant heritage site in the development of HVDC for several reasons.” F. Nozari and H. S. Patel, “Power Electronics in Electric Utilities: HVDC Power Transmission Systems”, IEEE Proceedings, Vol 76, No 4, April 1988, pp 495-506: “The first commercial dc installation, which remains in operation today, was the Gotland transmission system in Sweden, commissioned in 1954” Bahrman Bjorklund, “The New Black Start – System Restoration with Help from Voltage-Sourced converters”, IEEE Power & Energy Magazine, January/February 2014, pp 44-53: “The very first commercial high-voltage dc (HVdc) transmission system, commissioned in 1954, had blackstart capability. This system links the island of Gotland in the Baltic Sea with the Swedish mainland.”

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to Please see the Milestone Program Guidelines for more information.


Media:Ref2 Long Nilsson 2007 IEEE PE Magazine.pdf




Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to with the subject line "Attention: Milestone Administrator." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s).