Search or add a thesis

Advanced Search (Beta)
Home > Economic Dispatch Usin Ghybrid Approaches

Economic Dispatch Usin Ghybrid Approaches

Thesis Info

Access Option

External Link

Author

Malik, Tahir Nadeem

Program

PhD

Institute

University of Engineering and Technology

City

Taxila

Province

Punjab

Country

Pakistan

Thesis Completing Year

2009

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/626

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676725941818

Similar


Power Economic Dispatch (ED) is necessary and vital step in power system operational planning. It is nonconvex constrained optimization problem defined as the process of calculating the generation of the generating units for the minimum total production cost in such a way that both equality and inequality constraints are satisfied. In system operation studies generators are represented by input-output curves. These characteristics curves are inherently nonlinear and non-smooth due to valve point effect, multiple fuels and operational constraints such as prohibited operating zones. The accurate economic dispatch depends mainly upon the accurate representation of these curves and their handling in the optimization process. Generally, economic dispatch is formulated as convex problem and has been solved using mathematical programming techniques by approximating generator input/output characteristic curves of monotonically increasing nature thus resulting in an inaccurate dispatch. However, the nonconvex ED problem cannot be handled effectively by such approaches. The Genetic algorithm is the potential solution methodology due to its inherent ability to address the convex and nonconvex problems equally. This dissertation presents the application of genetic algorithm (GA) for the solution of economic dispatch problem independently as well as in hybrid form in conjunction with the other techniques. The problem is addressed first by developing a extensible and flexible computational framework called “PED_Frame” as common environment which becomes a platform for the computer implementation of different algorithms under consideration. This framework has been used for implementation of economic dispatch algorithms for (i) GA based models, (ii) Hybrid models. Economic dispatch problem has been formulated in binary coded genetic algorithm environment based on real power search and λ search methodologies. Two biological mechanism “inversion” and “deletion-regeneration” has also been mapped as an operator with crossover probability. Various GA based evolution models have been constructed by adopting different initial population generation schemes, selectionvi methods, and crossover operators. Convex ED studies have been conducted using standard test systems and results have been compared with λ iteration approach. GA based hybrid approach for convex ED dispatch is proposed. This approach initially run GA based ED with λ-search and passes the control to conventional λ iteration technique. This approach gives another systematic method for selection of initial value of λ. The results of the proposed approach on standard test system show that costs of generation by this approach is almost the same as the λ iteration alone, however, it takes less number of iterations. The performance of GA based economic dispatch problem has been evaluated with reference to different evolution models on the basis of empirical data available by actually running the program for the nonconvex ED due to valve point effect. National utility system has been reviewed with reference to its operation problems. Four test systems close to original network have been developed and tested by load flow analysis using Newton’s Raphson algorithm. Finally 12-Machine 32 bus test circuit, 15, 25 and 34 Machines systems for economic dispatch studies have been developed. ED studies have been conducted using test circuit The Genetic algorithm has the inherent ability to bring the solution to the global minimum region of search space in a short time and then takes longer time to converge to the solution. This research work proposed hybrid approaches to fine tune the near optimal results produced by GA. In this context, three hybrid approaches have been used for the solution of nonconvex economic dispatch problem with valve point effect. These include (i) A Synergy of GA and ED using Newton’s Second Order Approach, (ii) Neuro-Genetic Hybrid Approach, and (iii) Hybrid of GA and Sequential Quadratic Programming. These models have been tested on standard test systems and the results obtained from all the three hybrid approaches offer significant improvement in the generation cost showing the promise of the proposed approaches.
Loading...

Similar Thesis

Showing 1 to 20 of 100 entries
TitleAuthorSupervisorDegreeInstitute
PhD
University of Engineering and Technology, Taxila, Pakistan
MS
University of Management and Technology, Lahore, Pakistan
MS
University of Management and Technology, Lahore, Pakistan
PhD
University of Engineering and Technology, Taxila, Pakistan
BS
University of Management and Technology, Lahore, Pakistan
MS
National University of Sciences & Technology, Islamabad, Pakistan
MS
University of Management and Technology, Lahore, Pakistan
PhD
Bahauddin Zakariya University, Multan, Pakistan
RCS
COMSATS University Islamabad, Islamabad, Pakistan
Mphil
Quaid-i-Azam University, Islamabad, Pakistan
MSc
Quaid-i-Azam University, Islamabad, Pakistan
PhD
The Islamia University of Bahawalpur, Bahawalpur, Pakistan
PhD
University of Engineering and Technology, Taxila, Pakistan
Allama Iqbal Open University, Islamabad, Pakistan
Mphil
Allama Iqbal Open University, Islamabad, Pakistan
Mphil
Quaid-i-Azam University, Islamabad, Pakistan
REE
COMSATS University Islamabad, Islamabad, Pakistan
PhD
Pakistan Institute of Engineering and Applied Sciences, Islamabad, Pakistan
Mphil
Quaid-i-Azam University, Islamabad, Pakistan
Mphil
Quaid-i-Azam University, Islamabad, Pakistan
TitleAuthorSupervisorDegreeInstitute
Showing 1 to 20 of 100 entries

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

نیاز فتح پوری

نیاز فتح پوری
نیازصاحب فتح پوری بھی اکاسی(۸۱) برس کی عمر میں کراچی میں انتقال کر گئے۔موصوف کی ساری عمر شعروادب کے چمن زارمیں گلگشت کرتے گزری، اگرچہ انھوں نے مورخ ،عالمِ دین، ماہرِ نفسیات ،ان میں سے ہرایک کاروپ دھارنا چاہا لیکن ان کوکامیابی نہیں ہوئی۔ البتہ وہ عربی اور انگریزی سے آشنا، فارسی میں پختہ استعداد اوراُردو زبان کے صاحبِ طرز انشا پرداز ادیب، نغز گو شاعر اوربلند پایہ نقاد تھے۔ اُن کاتعلق اُردو زبان وادب کی اُس نسل سے تھا جو اب آفتابِ لب بام ہے ۔یہ نسل اب ختم ہورہی ہے، لیکن اس نے اپنے فیضِ قلم وانشا سے ہزاروں چراغ روشن کردیے ہیں جوآج برِصغیر میں اُردو کے سرمایۂ ادبیات میں گراں قدر اضافہ کررہے ہیں۔کتنے نوجوان ہیں جو’’ نگار‘‘ اور ’’شہاب کی سر گزشت‘‘ وغیرہ جیسی موصوف کی کتابیں اورمقالات پڑھ پڑھ کر ادیب ہوگئے۔ اس لحاظ سے کوئی شبہ نہیں وہ اُردو کے معمار تھے اورتاریخِ ادب میں اُن کانام اورکام قدر اور عزت کی نگاہ سے دیکھا جائے گا ۔
[جولائی ۱۹۶۶ء]

 

Memorization Without Comprehension: A Window onto the ‘Extremities’ of the Capability of Human Brain

Muslims across the world memorize the Quran in Arabic for verbatim recall. Memorizers can be native speakers of Arabic, non-native speakers of Arabic, or non-Arabic speakers. The purpose of this study is to investigate expert Quran memorizers on their memorization practices including what they brought to the act of memorization and what, according to them, underlay their success in memorization. Ten memorizers were interviewed about their reflections on their memorization practices. The analysis reveals that while some practices of the Quran memorizers are in line with findings from research literature on memory, there are others which are peculiar to them. The conclusion drawn is that Quran memorizers recite accurately because they do not learn the language. It is further concluded that Quran memorization is a special case, in which a range of extra linguistic factors such as identity, motivation and intention play an important role.

Synthesis and Characterization of Silicon Carbide Layers Grown on Silicon Substrates by Low Pressure Chemical Vapor Deposition Technique

Wide bandgap semiconductor materials have gained considerable attention for fabrication of electronic devices that can operate at high power, high frequency and high temperature for various applications where conventional semiconductor cannot work satisfactorily. These materials have potential applications in optoelectronics, such as light emitting diodes (LEDs), in the blue and ultraviolet (UV) wavelengths regions. It is widely recognized that the performance, yield, reliability and degradation behavior of devices are adversely affected due to presence of defects. In this study synthesis and characterization of most common polytypes 3C, 4H and 6H-SiC are performed. 3C-SiC layers grown on low cost p-type silicon (100 and/or 111) substrates maintained at constant temperature (1050 - 1350 0C) in a low pressure chemical vapor deposition (LPCVD) reactor. Typical Fourier transform infrared (FTIR) spectrum revealed a dominant peak at 800 cm -1 due to Si-C bond excitation. Large area x-ray diffraction spectra showed single crystalline cubic structure of 3C-SiC (111) and 3C-SiC (200) at 2θ angles of 28.280 and 34.080 on Si (111) and Si (100) substrates, respectively. Cross-sectional viewed revealed by scanning electron microscopy (SEM) display up to 104 μm thick SiC layer. Energy dispersive spectroscopy (EDS) of the grown layers demonstrated a stoichiometric growth of SiC. Surface roughness and morphology of the films were studied using atomic force microscopy (AFM). It was observed that resistivity of the as-grown layers increased with increasing substrate temperature due to decrease of isolated intrinsic defects such as silicon and/or carbon vacancies having activation energy 0.59 ± 0.02 eV. The p-type 6H- SiC were grown by fast sublimation method. The epilayer is co-doped with boron– nitrogen with free carrier concentration 3 × 1017 cm-3 (NA–ND). The detail investigations of electrical properties of deep level defects in the grown sample were carried out by deep level transient spectroscopy (DLTS). A hole H1 majority carriers and electron E1 minority carriers trap were observed in the device having activation energies Ev + 0.24 eV and Ec - 0.41 eV, respectively. The capture cross-section (trap concentration) of H1 and E1 deep levels were found to be 5 × 10-19 cm2 and 2 × 1 015 cm-3 (1.6 × 10-16 cm2 and 3 × 1015 cm-3) respectively. Considering the background involvement of aluminum in growth reactor and comparison of the obtained data with the available literature, the H1 defect was identified as aluminum acceptor and a sound justification was given to correlate the E1 defect to a nitrogen donor. The n-type 6H-SiC layers were also grown by sublimation method. To study the deep level defects in n-type 6H-SiC, as-grown, nitrogen doped and nitrogen- boron co-doped samples represented as ELS-1, ELS-11 and ELS-131 having free carrier concentration (ND–NA) 2.0 × 1012, 2× 1016 and 9× 1015 cm-3, respectively, DLTS was performed. The DLTS measurement of ELS-1 and ELS-11 samples revealed three electron trap A, B and C having activation energies EC – 0.39, Ec – 0.67 and Ec – 0.91 eV, respectively. The isochronal annealing study of the samples demonstrated that the observed electron traps were stable up to 750 oC. While DLTS spectra of sample ELS-131 showed only single ‘A’ level. This observation indicated that levels B and C in ELS-131 were compensated by boron and/or nitrogen–boron complex. A comparison with the published data revealed that A, B and C were related to E1/E2, Z1/Z2 and R levels, respectively in n-type 6H-SiC. The 4H-SiC layers were grown on p-type Si (100) substrate by simple evaporation method. The chamber was evacuated using mechanical and diffusion pump with base pressure of 5 × 10-7 torr. A mixture of Si and C60 powder of high purity (99.99%) with weight ratio of 1:1 was used as source material and was evaporated by Mo boat. A high current of 210A was used to increase the temperature of boat in the vicinity of 1100 0C. The temperature of substrate was fixed at 300 0C. The distance between substrate and boat was kept 10 cm and total evaporation time was 3 hours. To study the crystalline quality of as-grown material, x-ray diffraction, FTIR and photoluminescence (PL) were performed. The x- ray spectrum consist of six peaks at 2Θ angles 25.50, 28.5, 30.70, 32.70, 36.10 and 59.00 and four of them were related to 4H-SiC. Typical Fourier transform infrared (FTIR) spectrum revealed a dominant peak at 790 cm-1 due to Si-C bond excitation. The PL spectrum of grown samples showed strong band to band emission at 3.22 eV seemed an evident of 4H-SiC.