The paper describes a new method to generate the reactance reference for a TCSC, which has been installed in order to provide damping in a power system. The knowledge of the expected oscillation frequency in the power system is used to create a coordinate system, which rotates with that frequency. In this coordinate system a phasor representing the power swing is being extracted from the input ...

The oscillation spectrum of a one-dimensional vertical dust string formed inside a glass box on top of the lower electrode in a gaseous electronics conference (GEC) reference cell was studied. A mechanism for creating a single vertical dust string is described. It is shown that the oscillation amplitudes, resonance frequencies, damping coefficients, and oscillation phases of the dust particles ...

The simultaneous effect of amplification due to cooling and damping due to resonant absorption on the kink oscillations of coronal loops is studied. The governing equation describing the kink oscillations is derived in the thin tube thin boundary layer approximation. The cooling time is assumed to be much larger than the oscillation period, and the Wentzel-Kramers-Brillouin (WKB) method is used...

Context. Standing transverse oscillations of coronal loops are observed to operate in two regimes: rapidly decaying, large amplitude oscillations and undamped small amplitude oscillations. In the latter regime the damping should be compensated by energy supply, which allows the loop to perform almost monochromatic oscillations with almost constant amplitude and phase. Different loops oscillate ...

We study acoustic oscillations (eigenfrequencies, velocity distributions, damping times) of normal crusts of strange stars. These oscillations are very specific because of huge density jump at the interface between the normal crust and the strange matter core. The oscillation problem is shown to be self-similar. For a low (but non-zero) multipolarity l the fundamental mode (without radial nodes...

Timely remote activation of frequency response, provided by converter-based generation, can improve the damping very low-frequency (VLF) oscillations. The research presented is based on both power system models and actual data from phasor measurement units (PMU) Irish system. performance active control (APC) investigated, variations in wind speed, droop, time lag resource capacity demonstrate t...

Reactive power modulation of wind power plants is an effective way to damp inter-area oscillation in wind power penetrated power systems. For doubly fed induction generator (DFIG) based wind farms, there are two different ways to achieve reactive power modulation: one is via reactive power feedback control, and the other method is via voltage feedback control. While both of the control schemes ...

In the quest of improving frequency response capability wind turbines, control solutions trying to emulate synchronous machines have been proposed. While their performance in terms support is relatively good, they may trigger torsional oscillations, cause fatigue and damage drivetrain, reduce its lifetime. this paper, oscillations caused by a virtual machine (VSM)-based controller are illustrat...

The grid strapdown inertial navigation system (SINS) used in polar navigation also includes three kinds of periodic oscillation errors as common SINS are based on a geographic coordinate system. Aiming ships which have the external information to conduct a system reset regularly, suppressing the Schuler periodic oscillation is an effective way to enhance navigation accuracy. The Kalman filter b...