Abstract:
Series compensation using capacitor banks is a
common technique used in power transmission systems, to
improve the power transferring capability. However, it may
lead to the generation of some natural frequencies due to
the combination of inductor and capacitor. These frequencies
are called as sub-synchronous frequencies which are below
the power frequency of the power systems. They can give
rise to sub-synchronous resonance (SSR). The SSR can cause
physical damages to the power system equipment unless it
is detected and mitigated prudently. This paper presents a
robust controller which can be used to damp undesirable
sub-synchronous oscillations. The small signal model required
to design the controller is constructed using dynamic phasor
approach. The performance of the controller is demonstrated
using IEEE first benchmark model (FBM) for SSR studies. It’s
shown that the proposed robust controller satisfactorily work
under different operating conditions.
