Showing 3 results for Facts Devices
H. Shateri, S. Jamali,
Volume 2, Issue 3 (7-2006)
Abstract
This paper presents the effects of instrument transformers connection points on
the measured impedance by distance relays in the presence of Flexible Alternating Current
Transmission System (FACTS) devices with series connected branch. Distance relay
tripping characteristic itself depends on the power system structural conditions, pre-fault
operational conditions, and especially the ground fault resistance. The structural and
controlling parameters of FACTS devices as well as the connection points of instrument
transformers affect the ideal tripping characteristic of distance relay. This paper presents a
general set of equations to evaluate the measured impedance at the relaying point for a
general model of FACTS devices to consider different affecting parameters.
R. Ghazi, N. Pariz, R. Zeinali,
Volume 9, Issue 2 (6-2013)
Abstract
In this paper, the effect of Static VAr Compensator (SVC) parameters on the nonlinear interaction of steam power plant turbine-generator set is studied using the Modal Series (MS) method. A second order representation of a power system equipped with SVC is developed and then by MS method the nonlinear interaction of torsional modes is assessed under various conditions and the most influencing factors are determined. The results show that the stress conditions and some SVC control parameters will adversely affect the dynamic performance of a power system by increasing the nonlinear interaction of torsional modes. In this situation, the MS method can precisely provide a reliable prediction of the torsional oscillations amplitudes and the frequency content of the output system response. As the angle and speed of turbine-generator segments are used as input signals in several controllers, the frequency content of these signals are quite important in designing such controllers. This analysis is performed on a 4-areas WSCC system, which is equipped with a SVC. The obtained results can provide some important guidelines for coordinate operation and design of FACTS controllers to reduce the risk of shaft failure arising from torsional interaction in long term.
A. R. Moradi, Y. Alinejad-Beromi, K. Kiani,
Volume 13, Issue 1 (3-2017)
Abstract
Congestion and overloading for lines are the main problems in the exploitation of power grids. The consequences of these problems in deregulated systems can be mentioned as sudden jumps in prices in some parts of the power system, lead to an increase in market power and reduction of competition in it. FACTS devices are efficient, powerful and economical tools in controlling power flows through transmission lines that play a fundamental role in congestion management. However, after removing congestion, power systems due to targeting security restrictions may be managed with a lower voltage or transient stability rather than before removing. Thus, power system stability should be considered within the construction of congestion management. In this paper, a multi-objective structure is presented for congestion management that simultaneously optimizes goals such as total operating cost, voltage and transient security. In order to achieve the desired goals, locating and sizing of series FACTS devices are done with using components of nodal prices and the newly developed grey wolf optimizer (GWO) algorithm, respectively. In order to evaluate reliability of mentioned approaches, a simulation is done on the 39-bus New England network.
