Swedish Symposium provides HVDC insights

A recent CIGRE symposium entitled “Across Borders – HVDC Systems and Markets Integration” held in Lund, Sweden was sponsored by five of CIGRE’s Study Committees and had more than 300 participants from across a cross section of countries. A number of Australian representatives also attended.

The Symposium provided an ideal opportunity to gain an understanding of the current state of HVDC technology, its potential as a system development aid and associated planning and operational issues from across the world.

This was supplemented by tutorials presented by a range of international experts, coincidental meetings of most of the sponsoring Study Committees, a number of Working Group meetings and, most importantly, the opportunity to network with experts from all over the world.

The event was highly successful and provided a number of insights into the use of HVDC technologies and offered a number of take home learning’s relevant to Australia.  (Some slides from the symposium can be found here)

The Technology in Europe

Large scale renewable installations are seen as essential long term generation assets in Europe. They however present a number of challenges that require innovative transmission solutions.

Embedded HVDC offer a number of benefits for meeting this challenge including enhanced management of changing power flows as well as suitability for undersea cables.

Further to this, multi terminal HVDC links are seen as the way of the future especially if DC grids are to be the long-term solution to these challenges.

As a result of this and other known benefits, HVDC is becoming the interconnector of choice to deal with the management of complex cross border power flows.

However, whilst the reliability of the HVDC converter stations is proven and this is being further enhanced in new stations through the extensive use of fibre optics and component standardisation, a number of challenges still exist.

Many legacy assets are historically one off investments and achieving a degree of standardisation will be crucial if they are ultimately to be part of a DC grid.

Considerable work is also still needed on optimising the operation of parallel AC systems with DC links to utilise the technical flexibility of DC and still satisfy the economic requirements of the market.

Another area that is increasing in popularity and of particular interest to Australia is Voltage Source Converters (VSC). The development of a 1000MW VSC scheme between France and Spain has recently commenced.

Australian connections

A number of learning’s were taken back from the symposium for Australian DC activities.

Les Brand, convenor of the working group WG B4.63 "Commissioning VSC HVDC Schemes", comments on his particular area

“Of particular interest is the development of Voltage Source Converter (VSC) technology. Australia held an important role in the development of this technology, with two of the first five commercial high voltage VSC constructed and commissioned here (Directlink and Murraylink).

Since then, and thanks in part to the operational experience in Australia – this technology has now developed to the point of becoming the technology of choice in many HVDC transmission applications.”

The development of VSC technology beyond the ‘small scale, underground cable only’ application is exciting and may open this technology up in Australia for longer distance overhead applications, such as supply from remote renewable generation sources or long distance supply to remote locations.”

CIGRE Australia remains at the forefront of knowledge exchange around these and other technologies and we plan to continue to understand what’s happening in Europe and bring home this know-how to meet our local challenges. Particularly as renewable generation grows in importance.