°ÄÃÅÁùºÏ²Ê¸ßÊÖ

Subscribe options

Select your newsletters:

Please enter your email address:

@

Your email address will only be used for the purpose of sending you the °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization publication(s) that you have requested. °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization will not transfer your email address or other personal data to any other party or use it for commercial purposes.

If you change your mind, you can easily unsubscribe by clicking the unsubscribe option at the bottom of an email you've received from °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization.

For more information, see our Privacy policy.

News & Media

Latest °ÄÃÅÁùºÏ²Ê¸ßÊÖ Newsline

  • Fusion supply chain | A glimpse into the future for commercial fusion reactors

    Most of the USD 7 billion in investment in private fusion initiatives has gone to companies that are building devices from the ground up. But recently, another [...]

    Read more

  • Outreach | °ÄÃÅÁùºÏ²Ê¸ßÊÖ @ October science festivals

    Every October, before schools pause for two weeks of holiday, towns and cities in France open their municipal spaces to scientific experts of all stripes who ar [...]

    Read more

  • Image of the week | °ÄÃÅÁùºÏ²Ê¸ßÊÖ Director-General visits Russia

    The °ÄÃÅÁùºÏ²Ê¸ßÊÖ Director-General was in Russia last week, meeting with stakeholders and holding technical meetings with colleagues in Moscow and Saint Petersburg. As [...]

    Read more

  • Image of the Week | Sector 5 is on its way

    The first vacuum vessel sector produced in Europe travelled last week between Monfalcone, Italy, and the French port of Fos-sur-Mer. The 440-tonne component had [...]

    Read more

  • Anniversary | °ÄÃÅÁùºÏ²Ê¸ßÊÖ Document Management system turns 20

    Whatever its nature, every large project generates huge numbers of documents. And when project collaborators operate from different countries, as was the case f [...]

    Read more

Of Interest

See archived entries

Electrical networks

Don't mess with AC current

Operating the °ÄÃÅÁùºÏ²Ê¸ßÊÖ magnetic system requires the same kind of current that batteries deliver to flashlights, laptop computers and smartphones. This current, which flows in one direction only, is called "direct current" (DC), as opposed to the "alternating current" (AC) that powers most appliances and industrial machines. The behaviour of the AC current can be represented by a sine wave, also called a sinusoid, and it is very important that this wave remain regular. The problem is: the conversion process from AC to DC "pollutes" the AC current and disturbs its distribution. It is therefore imperative that operators, for the sake of their own equipment and for preserving the quality of distribution throughout the grid, implement corrective actions to protect the regularity of the AC current's sine wave.
 
What can be contained in a medium-size building in a steelworks or another heavy industrial facility requires a one-hectare yard at °ÄÃÅÁùºÏ²Ê¸ßÊÖ. Adjacent to the Reactive Power Control Building, the reactive power compensators area accommodates reactors, capacitors, resistors and sensors that aim to smooth the flow of AC current both inside the °ÄÃÅÁùºÏ²Ê¸ßÊÖ installation and in the immediate vicinity. (Click to view larger version...)
What can be contained in a medium-size building in a steelworks or another heavy industrial facility requires a one-hectare yard at °ÄÃÅÁùºÏ²Ê¸ßÊÖ. Adjacent to the Reactive Power Control Building, the reactive power compensators area accommodates reactors, capacitors, resistors and sensors that aim to smooth the flow of AC current both inside the °ÄÃÅÁùºÏ²Ê¸ßÊÖ installation and in the immediate vicinity.
In most heavy industry zones, such as steelworks or shipyards, the equipment for "reducing the harmonic distortion" in the AC current fits into a medium-size building. In °ÄÃÅÁùºÏ²Ê¸ßÊÖ, which requires up to 500 MW of DC power, it occupies not only a building—the Reactive Power Control Building—but also the adjacent one-hectare "reactive power compensators area."
 
What happens within this dense arrangement of thyristor-controlled valves*, reactors, capacitors, resistors and sensors is a complex process aimed at smoothing the flow of AC current both inside the °ÄÃÅÁùºÏ²Ê¸ßÊÖ installation and in the immediate vicinity—namely the neighboring CEA-Cadarache research centre and the villages closest to the °ÄÃÅÁùºÏ²Ê¸ßÊÖ site.
 
The process is about compensating the "reactive power" that is generated in the AC current by the presence of "charges," such as the AC/DC converters in the °ÄÃÅÁùºÏ²Ê¸ßÊÖ Magnet Power Conversion Buildings.
 
Contrary to "active power," which lights lamps and operates machines, this ghost-like current does not perform any useful work—it simply moves back and forth within the AC flow.
 
Any AC/DC conversion installation tends to intensify the reactive power in the AC network and to create harmonic distortions in the sine wave. Because the equipment inside the °ÄÃÅÁùºÏ²Ê¸ßÊÖ Magnet Power Conversion Buildings is exceptionally powerful, the distortions, if not compensated, would deeply affect the local distribution of AC current.
 
It could also be quite costly in terms of electricity bills: transporting the useless reactive power has a cost, which the utility provider would end up billing the customer for. In this perspective, the construction of an efficient reactive power compensation system is a sound investment.
 
The °ÄÃÅÁùºÏ²Ê¸ßÊÖ reactive power compensation and harmonic filtering system is among the largest in the world. In the Reactive Power Control Building, which hosts nine 3-metre-tall thyristors, equipment installation is now 80 percent complete; in the reactive power compensators area, it has passed the 75 percent mark.
 
Provided by China and manufactured by Rongxin Power Electronic Co. Ltd (RXPE), the equipment is being installed by the Italian Consortium Fincantieri SI and its partner SAET.
 
*Thyristors are powerful electronic switch controllers.


return to the latest published articles