What is SC B4 ?

B4 deals with High Voltage Direct Current (HVDC) Transmission and Power Electronics for use in Transmission and Distribution Networks. In a HVDC Transmission system converter stations are used to convert AC into DC and vice versa at the connection points in the ac network(s). An HVDC system provides an asynchronous link between the ac network terminals. As there is no reactive power flow on the dc link between the converter stations, it is possible to have very long cable and overhead lines between the stations, without the need for intermediate stations. Today there are two main technologies, thyristor based, Line Commutated Converter HVDC (LCC HVDC), and IGBT based Voltage Sourced Converter HVDC (VSC HVDC). You can find more information about HVDC transmission by clicking the What is LCC HVDC or What is VSC HVDC links below.

What is LCC HVDC?

What is LCC HVDC? (pdf, 196kB)

What is VSC HVDC?

What is VSC HVDC? (pdf, 20kB)



You will be able to find information about existing HVDC schemes by using the HVDC Compendium, which can be found by going to the Publications Page, and then Clicking the link to Other Publications or on the Compendium link below.


What is FACTS?

Power Electronic Devices used in Transmission and Distribution networks include controlled shunt and series reactive power, such as SVCs, STATCOMs, TCSC, as well as devices capable of transferring active power between its terminals and provide shunt and series reactive power control, as well as devices with energy storage capability. Other types of devices may be developed as it becomes necessary to have more control over ac networks because of the need for increased power flows on the existing power lines in the ac networks. These devices are often referred to as Flexible AC Transmission or FACTS devices. You can find more information about Power Electronics in AC Transmission networks by clicking the What is Facts link below.

What is FACTS? (pdf, 116kB)


“If anyone spots a mistake or incorrect information in any of the above documents, please contact the webmaster”

The MISSION of B4 is: To facilitate and promote the progress of engineering and the international exchange of information and knowledge in the field of HVDC and power electronics. To add value to this information and knowledge by means of synthesizing state-of-the-art practices and developing recommendations.

The Scope of B4’s activities can be found by clicking the Scope link in the left margin. An overview of the current activities of SC B4 can be found by clicking the Activities link in the left margin. The link provides a brief description of the subject areas of each of the different working bodies.

B4 invites all Cigre and non-Cigre engineers to participate in its activities. If you would be interested in participating, please contact the Regular Member for your country. The Membership link in the margin provides the name of all current Regular Members of B4. Because of Cigre confidentiality rules, the list does not include the Regular Member’s contact details. If you do not have it, please contact the Secretary or the Chairman, explaining why you would like to make contact. The Regular Member will then contact you.

The Structure page, which can be accessed from the link on the left, gives a graphical view of the organisation of B4, and shows the name of the convenor responsible for each of these activities. Again, if you are interested in any of the activities, you may contact the convenor, or the Chairman or Secretary of B4. However, please notice that membership of a Working Group brings with it the expectation that you provide input and other Work, that will benefit the Working Group.Documents which are necessary for the SC Members and Convenors in carrying out their work can be found by following the link Official SC Documents.

The list of recent and all Technical Brochures produced by B4 can be found under the PUBLICATIONS, with a link to the eCigre site.