Use of FACTS devices in Mitigating Sub Synchronous Resonance

This study evaluates the use of Flexible Alternating Current Transmission System (FACTS) devices in mitigating Subsynchronous Resonance (SSR). SSR is defined as a condition wherein an electrical network exchanges energy with a turbine generator at one or more of the natural frequencies of the combined systems below its synchronous frequency. The presence of SSR in a system can lead to catastrophic outcomes, and the application of FACTS devices has been found to be one of the most effective approaches to reduce SSR. The study investigates the core concepts associated with FACTS devices and SSR. The concepts underlying SSR interactions, including self-excitation and transient torques, are examined in this study. The study also focuses on the use of FACTS devices in mitigating or eliminating SSR from the system or network of interest. The results of simulations conducted by using eigenvalue analysis and the IEEE second benchmark model are also presented and discussed

Article Electricity Consumption and GHG Emissions in GCC Countries

energie

Electricity Consumption and GHG Emissions in GCC Countries

CO2, N2O, and CH4 are the three most widespread Greenhouse Gases (GHGs). Electricity consumption and the related CO2-equivalent gas emissions resulting from oil and gas combustion for the six countries that comprise the Cooperation Council for the Arab States of the Gulf [Kingdom of Saudi Arabia (KSA), Kuwait, Bahrain, Oman, United Arab Emirates (UAE) and Qatar; also referred to as the Gulf Cooperation Council, GCC)] have been compared. The analysis of the relevant data shows that GCC countries contribute significantly to the global CO2 emissions, and that the majority of their emissions are concentrated in the energy extraction and conversion sectors, mainly from oil drilling and electricity production. Some analysis is offered as to the reasons behind the excessive increase in the electrical demand that is obviously linked to a non-rational pattern of electricity consumption

Influence of System Parameters on Fuse Protection Use in Regenerative DC Drives

Current limiting fuses are widely used to protect the thyristors in DC drive systems. One very important problem is the choice of the correct voltage rating for fuses protecting regenerative DC drives, where many types of fault may occur, which makes fuse protection difficult. In the event of a commutation failure while regenerating, the fuses need to interrupt the loop supplied by the AC and DC voltages acting in series, which is the most difficult case for protection by fuses. In this paper a detailed study of the complete interruption process has been investigated by modeling of arcing process of the fuse protection against the regenerative circuit internal commutation fault. The effect of varying the motor time constant, supply impedance, number of fuses used to clear the fault and DC machine rating on the total transient response is studied. The model of a 200 A fuse is employed in this study. Fuses in series with both the semiconductor devices (F1) and fuses in AC lines (F2) are considered. Comparison was made between arc energy produced for fuses protecting the regenerative circuit if failure occurs, with the arc energy produced in a standard AC test in order to investigate the required voltage rating for the fuse