Press Presse Press Presse
Energy Sector
Power Transmission Division
Erlangen, Germany, May 8, 2008
Enhanced voltage quality in grids: Innovative reactive power compensation system
for wind farms, power grids and industry
Siemens Energy is expanding its product spectrum of Flexible AC Transmission Systems
(FACTS) with its new reactive power compensation system SVC Plus (Static Var
Compensator). This system operates on the basis of innovative Voltage-Sourced Converter
technology (VSC), with continuously variable control through high-power transistors
(IGBT). The result is enhanced voltage quality and stability in the power system which
allows grid access of fluctuating energy sources, such as offshore wind farms. Siemens is
supplying the SVC-Plus system in space-saving, standardized and modular units. These
pre-tested units of ±25, ±35 or ±50 MVAr can be operated individually or in parallel.
The core of SVC Plus, an advanced Statcom (static synchronous compensator), is made up of a
modular multilevel converter technology. In contrast to other self-commutated converter topologies,
the voltage waveshape generated by SVC Plus is nearly sinusoidal, thanks to the multilevel
technology used. This renders the low-frequency harmonic filters, used in solutions up to now,
superfluous and it substantially reduces the space requirements for the overall unit. The SVC Plus
converter consists of a number of capacitive voltage sources connected in series, thus giving the
unit its name – multilevel voltage-sourced converter. These series-connected voltage sources act
as a voltage divider, which builds up the sinus-wave voltage to the grid. Each of these voltage
sources consists of a capacitor and a transfer switch with standard industrial IGBT components.
The electronic control system switches the power transistors such that the capacitor can be
bypassed or activated as needed, allowing the SVC voltage that is tapped at the center of the
voltage divider to be set to nearly any required level.
Using this multilevel technology, the SVC Plus system is not only excellently predestined for grid
access of energy sources with fluctuating in-feed, such as offshore wind farms, but also fits
extremely well in transmission systems for dynamic voltage support during and after system faults.
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Siemens AG
Corporate Communications and Government Affairs
Wittelsbacherplatz 2, 80333 Munich
Germany
Reference number: EPT200905.046x
Media Relations: Dietrich Biester
Telephone: +49 9131 7-33559
E-mail: dietrich.biester@siemens.com
Siemens AG
Energy Sector - Power Transmission Division
Freyeslebenstr. 1, 91058 Erlangen, Germany
A further field of application for this system is in industrial systems for reactive power and flicker
compensation in the power range of up to approximately ±100 MVAr.
The first SVC Plus system will be put into operation this summer as the core component for grid
access of the Thanet offshore wind farm that is being constructed around eleven kilometers off the
coast of Kent in the North Sea. Siemens is currently fitting the substation, which constitutes the
grid in-feed point on the coast, with an SVC Plus unit. This system will ensure that the power
quality requirements (grid code) stipulated by the British power grid operator are fulfilled. Energyefficient grid access solutions for offshore wind farms are part of the Siemens environmental
portfolio, which earned the company revenues of nearly EUR 19 billion in fiscal 2008, roughly a
quarter of Siemens total revenues.
The Siemens Energy Sector is the world’s leading supplier of a complete spectrum of products, services and solutions
for the generation, transmission and distribution of power and for the extraction, conversion and transport of oil and gas.
In fiscal 2008 (ended September 30), the Energy Sector had revenues of approximately EUR22.6 billion and received
new orders totaling approximately EUR33.4 billion and posted a profit of EUR1.4 billion. On September 30, 2008, the
Energy Sector had a work force of approximately 83,500. Further information is available at: www.siemens.com/energy.
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Siemens Energy expanding its product spectrum of Flexible AC Transmission Systems (FACTS)
with the new, innovative reactive power compensation system SVC Plus. The system is supplied
by Siemens in space-saving, modular ±25, ±35 or ±50 MVAr units, similar to a package unit whose
pre-tested units can be operated individually or in parallel.
2/2
Siemens AG
Corporate Communications and Government Affairs
Wittelsbacherplatz 2, 80333 Munich
Germany
Reference number: EPT200905.046x
Media Relations: Dietrich Biester
Telephone: +49 9131 7-33559
E-mail: dietrich.biester@siemens.com
Siemens AG
Energy Sector - Power Transmission Division
Freyeslebenstr. 1, 91058 Erlangen, Germany