440 research outputs found
Implementation of Fast technique for Unit Commitment Based on Unit Clustering
A new approach to the problem of large scale unit commitment is presented in this paper. The units are classified into various clusters based on their similar characteristics in order to reduce the computational time and also to satisfy the minimum up/down constraints easily. Unit commitment problem is an important optimizing task in daily operational planning of power systems which can be mathematically formulated as a large scale nonlinear mixed-integer minimization problem. A new methodology employing the concept of cluster algorithm called as additive and divisive hierarchical clustering has been employed along with particle swarm optimization in order to carry out the technique of unit commitment. Proposed methodology involves two individual algorithms. While the load is increasing, additive cluster algorithm has been employed while divisive cluster algorithm is used when the load is decreasing. The proposed technique is tested on a 10 unit system and the simulation results show the performance of the proposed technique. Keywords: Unit commitment, additive clustering, divisive clustering, Lambda iteration method
Comparison of Performance of SSSC and TCPS in Automatic Generation Control of Hydrothermal System Under Deregulated Scenario
This paper presents the modelling and simulation of Static Synchronous Series Compensator (SSSC) in a two area system for Automatic Generation Control (AGC) under deregulated environment. The modelling of Thyristor Controlled phase Shifter (TCPS) is also carried out and comparison is made between SSSC and TCPS. A two area hydrothermal system under deregulated environment has been considered for this purpose. The devices are modeled and attempt has been made to incorporate these devices in the two area system thus improving the dynamic response of the system. The effect of these parameters on the system is demonstrated with the help of computer simulations. A systematic method has also been demonstrated for the modeling of this component in the system. Computer simulations reveal that due to the presence of SSSC along with TCPS, the dynamic performance of the system in terms of settling time, overshoot is greatly improved than that of without SSSC.DOI:http://dx.doi.org/10.11591/ijece.v1i1.2
Techno-economic Study by Teaching Learning-based Optimization Algorithm for Optimal Placement of DG Units in Distribution Systems
A significant improvement in system performance can be achieved by placing Distributed Generator (DG) units of the optimal size in optimum network of radial distribution locations. In order to maximize the economic and technological benefits, it is necessary to reduce yearly economic losses. These losses include expenditures associated with installation and operation of the buses as well as power loss and voltage difference between buses. In view of these multi-objective frameworks, the current problem is assessed and the best compromise solution also referred as the Pareto-optimal solution is provided. In the framework of the multi-objective optimization problem, specific equality as well as inequality constraints is investigated. It is shown in this study that a Multi-Objective Teaching-Learning Based Optimization (MOTLBO) algorithm has been proposed to solve the multi-objective problem. For the purpose of evaluating its performance, the proposed method is being deployed on IEEE-33 and IEEE-69 System of radial bus distribution. A comparison with other recent multi-objective algorithms such as OCDE, KHA and LSFSA is also included in this study. It has been revealed that the algorithm proposed can offer superior outcomes concerning power loss, annual economic loss mitigation and voltage profile enhancement
Seaweed resources of the Tuticorin-Tiruchendur coast, Tamil Nadu, India
The southern coast of Tamil Nadu (Mandapam to Kanyakumari) supports luxuriant growth
of economic seaweeds. The entire indigenous phycocoUoid industry of the country gets the raw
material from this region and during the last two decades, due to indiscriminate harvesting, there
has been over-exploitation of the resource. The present paper deals with survey conducted in the
first sector from Tuticorin to Tiruchendur during December 1986—March 1987. In this study 58
species of marine algae were recorded of which 7 belong to Chlorophyta, 12 to Phaeophyta and 39
to Rhodophyta besides 3 species of seagrasses namely Cymodocea seiriilata, Halophila ovalis and //.
ovata within 650 sq. km area surveyed. The total standing crop of the seaweeds was estimated at 9,100
tonnes (wt.). The estimates for the dominant species are Dictyota maxima 530 t, Sargassum tenerrium
640 t, D. bartayresiana 8601, Selieria rebusta 2,0901 and Hypnea valemiae 2,4301. The seaweed potential
for commercial exploitation has been briefly discussed
Seaweed resources off Tamil Nadu coast: Sector II. Alanthali - Manapad and Vembar – Nallathanni Thivu
The seaweeds are used for the production of polysaccharides such as agar, algin, carragennan and they are harvested from intertidal regions along the southeast shores of India. The resource potential from intertidal regions was estimated (Anon 1978
Distribution of sea weeds off Kattapadu - Tiruchendur coast, Tamil nadu
The present paper deals with the distribution of seaweeds and seagrasses during the
deep sea survey conducted in the first sector from Kattapadu to Tiruchendur in Tamil Nadu
coast between December 1986 and March 1987 covering an area of 650 sq.km. In thiS survey.
58 species of marine algae \\ere recorded. of which 7 belong to Chlorophyta. 12 to Phaeophyta
and 39 to Rhodophyta. Three species of seagrasses vi z. Cymodocea serrl/lata. Halophila
ovails and H. ovala were also recorded at the depths ranging from 5.5 to 21.5 III Halim eda
macroloba, D,ClyOIO barlayresiana, D. Maxima, Gracliaria corl/cala var. corlicala, G. edulis,
Sarcodia indica, Sarconema filiform e, Soliena rob"sla, flypnea esperi and H. "alenliae were
found to be dominant and widely distributed. Hydrological data were also collected from
area surveyed. The atmospheric and bottom water temperature varied from 25.0 to 36.8'C
and 26.0 to 31.8'C respectively. The pH ranged from 8.3 to 8.6 and the salinity from 26.39
to 33.430/00 . The dissolved oxygen ranged from 3A2 to 6.47 mill. The phosphate content
varied from 0.05 to 0. 15 I'g atm/ l, silicate from 4.00 to 12.00 I'g atmll, nitrate from 0.25
to 1.00 I'g at mil and nitrite from 1.05 to 3.99 I'g atml l
Seaweed resources off Tamil Nadu coast: Sector III. Valinokkam - Kilakkarai
Survey of seaweed resources in deep water was carried out in the area between Valinokkam and Kilakkarai during January 1989 and March,l990 respectively. In the survey from Valinokkam to Kilakkarai 33 species of marine algae were recorded of which 8 species belong to Chlorophyta, 8 to Phaeophyta and 17 to Rhodophyta. Only one species of seagrass Halophila ovalis was recorded. Among the 200 sq Icm area surveyed, vegetation occurred only in 27.5 sq.km with a total standing crop of 2962.5 tonnes (wet wt)
Seaweed resources off Tamil nadu coast, Sector - IV Kilakkarai - Rameswaram island (Dhanushkodi
Survey of the deep water area from Kilakkarai (Appa Tivu to Rameswaram Island
(Dhanushkodi) was undertaken from December 1990 to January 1991 in the IV Sector survey
of Deep water Seaweed Resources off Tamil Nadu coast, which formed the last phase of the
survey from Rameswaram to Kanyakumari carried out during 1986-91. An area of 417 .5 sq.km.
was surveyed yielding a total biomass of 18,162.5 tons (wet) seaweeds. Out of 167 stations
surveyed in 13 transects, vegetation occurred only in 12 stations. Of the 29 species of marine
algae recorded 8 belonged to Chlorophyta, 8 to Phaeophyta, 12 to Rhodophyta, and I to
Cyanophyta, One species of seagrass Cymodocea serrulata was also recorded. Twenty species
were found in estimable quantities, of which the following 8 species were abundant: Halimeda
macr%ba, Spatog/ossum asperum, Zonaria crenata, Sargassum ilicijolium, Amphiroa
jragilissima, Hypnea muscijormis, Botryocladia /eplOpoda and Lyngbya majuscula with a biomass
of 1325, 9775, 650, 1550, 1925,300,862.5 and 1012.5 tons (wet) respectively. The species of
Hypnea and Sargassum could be exploited for the manufacture of phytochemicals
Hexavalent Chromium Cr(VI) Up-Regulates COX-2 Expression through an NFκB/c-Jun/AP-1–Dependent Pathway
Background: Hexavalent chromium [Cr(VI)] is recognized as a human carcinogen via inhalation. However, the molecular mechanisms by which Cr(VI) causes cancers are not well understood
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