GE-ALSTOM TRANSACTION Effective 2nd November 2015, GE acquired Alstom’s energy businesses. The Alstom content available on this site is for information purposes only.
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HVDC Point-to-Point With A Submarine Portion

Transmission of bulk power over long distances

Power is transmitted over long distances by using overhead lines, underground cables or a combination of both. HVDC systems enable fast, accurate power flow and effectively prevent the spread of blackouts. HVDC interconnection between different power systems often eliminates the need to build new plants, saves money and reduces impact on the environment.

Standards and Certifications 

  • The H400 valve based HVDC schemes comply with all appropriate international standards.
  • IEC 60919: Performance of HVDC systems.
  • IEC 60700: Thyristor valves for HVDC power transmission.


  • Reduced right-of-way requirements for an overhead line. Less land is required and visual impact is reduced.
  • Interconnecting different power systems makes their existing generating reserves available to both systems. This results in more efficient use and often eliminates the need to build a new plant.
  • Once interconnected, the two systems’ daily and seasonal cost differences can also be exploited.
  • Uses overhead lines, underground cables, or both.
  • HVDC takes electrical power from an alternating current (AC) system and converts it into high voltage direct current (DC) using a converter station. It then transmits the DC to a remote system where it is converted back again to AC by another HVDC converter station.

Alstom Grid has the skills and experience, the network and local resources, to reliably complete and deliver a turnkey system.

  • Engineering and design: Detailed studies and design of all necessary equipment, systems and civil works.
  • The timely completion of Civil works, which requires efficient site management, is vital to the timely completion of the project.
  • Equipment and systems manufacturing is realized by sub-suppliers or Alstom Grid factories.
  • Installation occurs as soon as equipment arrives on site.
  • Commissioning: After equipment verification, control software is installed and the entire system is tested. before handing over the site to the client for commercial operation.
  • Efficient transmission of electricity over long distances.
  • Fast, accurate, fully-controllable and measurable Power Flow.
  • Independent control of the AC voltage and frequency in the two AC networks.
  • Can be used to assist one (or even both) of the AC networks (e.g. power system damping).
  • No increase in system’s short circuit level.
  • Faults do not transfer across HVDC interconnected systems, thereby preventing spread of blackouts.
  • Eliminates need to build new plants and reduces environmental impact.