Damping of inter-area electromechanical oscillations is one of the major challenges to the electric power system operators. This paper presents Gravitational Search Algorithm (GSA) for tuning Static Synchronous Series Compensator (SSSC) based damping controller to improve power system oscillation stability. In the proposed algorithm, the searcher agents are a collection of masses which interact...

Both fixed-speed squirrel-cage induction generators and variable-speed doubly-fed induction generators are used in wind turbine generation technology. Modeling and simulation of induction machines using vector computing technique in Matlab/Simulink provides an efficient approach for further research on wind generation system integration and control. In this paper, the vector computing technique...

Wind turbine generators can be operated in various types of system configurations. Once the configurations change, oscillation mode shapes change accordingly. The modelling full is necessary for studying this issue, yet it quite hard. In paper, a simple approach developed to study wind power systems without necessity adopting complex full-system models. key that q-d axis model electric transfor...

Experimental control over inter-atomic interactions by adjusting external parameters is discussed. Qualitatively different time evolution of the order parameter are predicted theoretically in ultracold atomic fermions with time-dependent pairing interaction. Following an abrupt change of the pairing strength, the order parameter undergoes undamped oscillation, damping oscillation and exponentia...

Power system oscillation damping remains as one of the major concerns for secure and reliable operation of large power systems, and is of great current interest to both industry and academia. The principal reason for this is that the inception of poorly-damped low-frequency inter-area oscillations (LFIOs) when power systems are operating under stringent conditions may lead to systemwide breakup...

Oscillations in electrical activity are a characteristic feature of many brain networks and display a wide variety of temporal patterns. A network may express a single oscillation frequency, alternate between two or more distinct frequencies, or continually express multiple frequencies. In addition, oscillation amplitude may fluctuate over time. The origin of this complex repertoire of activity...

Considerable attention has recently been devoted to the linear trend of drought at the decadal to inter-decadal time scale; however, the nonlinear variation of drought at multi-decadal scales and its relation to atmospheric circulation need to be further studied. The linear and nonlinear variations of the Palmer drought severity index (PDSI) in Shandong from 1900 to 2012 and its relations to th...

A two-step attribution and causality diagnostic is designed by employing singular spectrum analysis to unfold the attributed climate time series into a trajectory matrix then subjected an empirical orthogonal function identify evolving driving forces, which can finally be related major modes through their independent frequencies wavelet analysis. Application results from arid drought-prone sout...

the main objective of this study was to reveal the impact of nine climate indices on temperature changes and climate oscillations in golestan province along the southern coast of the caspian sea. climate indices data from across the atlantic-eurasian sector were collected from the ncep/ncar, the climate prediction centre (cpc) and the climatic research unit (cru) over a period of 40 years (1971...

0022-1694/$ see front matter 2009 Elsevier B.V. A doi:10.1016/j.jhydrol.2009.06.024 * Corresponding author. Tel.: +1 414 229 6756; fax E-mail address: [email protected] (H.R. Bravo). Ice duration has shortened and the ice-off date has become earlier for Lake Mendota from 1905 to 2000 as air temperatures have warmed and snowfall has increased. In addition, the ice record has cyclic components at i...