Static reactive power compensator
A static var compensator (engl .: static VAR compensator , SVC ) is a complex that for the compensation of reactive power in electric power transmission networks can be used. The term static expresses that the compensation takes place without the use of rotating machines such as three-phase synchronous machines in phase shifter operation.
In contrast to rotating phase shifters with synchronous generators , an SVC consists of a combination of capacitors and coils , which are arranged parallel to the load to be compensated or to the network section to be compensated for cross compensation. The current flow in the individual components is controlled by thyristors and thus the degree of reactive power compensation . Compared to rotating machines, this has the advantage that the system does not wear out, and a static compensator enables a much faster and more dynamic response to load fluctuations.
So that the operating voltages in the area of the compensation circuit are not too high and therefore uneconomical, the SVC are typically connected to the transmission network via their own power transformers or via tertiary windings and are usually operated in the voltage range of a few 10 kV.
In fact, an SVC is primarily not used for reactive power compensation, but for various other tasks:
- Voltage stabilization through the regulated provision of capacitive and inductive reactive power
- Damping of subsynchronous oscillations in the network that could lead to network failures
- Compensation for flicker
The task of pure reactive power compensation is usually carried out using switched coils and capacitors, which can be installed in the power grid independently of the reactive power compensation system.
The Unified-Power-Flow-Controller (UPFC) and Static Synchronous Compensator (STATCOM) are an extension which, in addition to static reactive power compensation or reactive power generation in transverse and longitudinal compensation, can also specifically control active power flows in lines of electrical energy networks . The STATCOM and the general UPFC can completely replace the systems for static reactive power compensation.
Realized systems in high voltage networks
In German-speaking countries:
In Canada:
literature
- Adolf J. Schwab: electrical energy systems . 2nd updated edition. Springer, Berlin et al. 2009, ISBN 978-3-540-92226-1 .