SVC Static Var Compensator

High- voltage static var compensator (SVC) is a shunt device of the flexible AC
transmission system (FACTS) family using power electrics to control power flow
and improve transient stability on power grid. Increase the ability of
transmission and strengthen the damping of low frequency oscillation and
suppress sub synchronous oscillation. in addition, SVC suppress the busbar
voltage change that when cause by impact load, is better to transient voltage
recover, improve the system voltage stability, when this device is applied to
distribution network, such as electric railway, metallurgy and other industry,
the users can control reactive power effectively, improve power factor, reduce
voltage influence and harmonic interference that cause by nonlinear load,
balance three phase load, improve power quality, efficiency and product
quality, reduce the energy consumption.
Static VAR Compensators (SVCs) can be customized to the specific needs of each
customer. SVCs consist of multiple fixed or switched branches, at least one of
which includes thyristors, and the combination of branches can vary greatly
depending on the requirements. SVCs typically include a combination of at least
two of the following given items (e.g. TCR/FC or TCR/TSC/FC):
Thyristor Controlled Reactors (TCR)
Thyristor Switched Capacitors (TSC)
Harmonic Filters (FC)
The most common topologies for static VAR compensators are: TCR/FC or
TCR/TSC/FC. The main advantage of using a topology with TSC branches is reduced
losses (by reducing filter size). Hitachi Energy's SVC control system can be
used to control new or existing external shunt banks.

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