The differential protection of power transformers appears to be more difficult than any type of protection for any other part or element in a power system. Such difficulties arise from the existence of the magnetizing inrush phenomenon. Therefore, it is necessary to recognize between inrush current and the current arise from internal faults. In this paper, two approaches based on wavelet packet transform (WPT) and S-transform (ST) are applied to recognize different types of currents following in the transformer. In WPT approach, the selection of optimal mother wavelet and the optimal number of resolution is carried out using minimum description length (MDL) criteria before taking the decision for the extraction features from the WPT tree. In ST approach,
the spectral energy index and the standard deviation (STD) are calculated from the S-matrix obtained by discrete S-transform. The two approaches are tested for generating a trip signal and disconnecting the transformer supply experimentally using 1KVA, 220/110V, 50Hz, ∆ / Y threephase transformer. The experimental results show that the trip signal is initiated faster in WPT approach while the transformer is disconnected from the supply after a delay of 10-15msec in the
two approaches due to computer interface and the relay circuit used.
Abstract
The research aims to identify the extent of the practice of social responsibility in accordance with the social dimension and diagnosis of constraints applied.
Find the problem represented by the Social Responsibility and obstacles facing application in Baghdad Municipality through their workers trends analysis.
The adoption of the statistical method to analyze the data and information gathering, and selected municipalities of Adhamiya and Kadhimiya deliberate manner applied as a state and municipal councils of both cities as representatives of the local community to be the subject of research and comparison between them to see the reality of soci
... Show MoreThe synthesis of new substituted cobalt Phthalocyanine (CoPc) was carried out using starting materials Naphthalene-1,4,5, tetracarbonic acid dianhydride (NDI) employing dry process method. Metal oxides (MO) alloy of (60%Ni3O4 40%-Co3O4 ) have been functionalized with multiwall carbon nanotubes (F-MWCNTs) to produce (F-MWCNTs/MO) nanocomposite (E2) and mixed with CoPc to yield (F-MWCNT/CoPc/MO) (E3). These composites were investigated using different analytical and spectrophotometric methods such as 1H-NMR (0-18 ppm), FTIR spectroscopy in the range of (400-4000cm-1), powder X-rays diffraction (PXRD, 2θ o = 10-80), Raman spectroscopy (0-4000 cm-1), and UV-Visib
... Show MoreSolar energy has significant advantages compared to conventional sources such as coal and natural gas, including no emissions, no need for fuel, and the potential for installation in a wide range of locations with access to sunlight. In this investigation, heterocyclic derivatives were synthesized from several porphyrin derivatives (4,4',4",4"'-(porphyrin-5,10,15,20-tetrayl) tetra benzoic acid) compound (3), obtained by reaction Pyrrole with 4-formyl benzoic acid. Subsequently, porphyrin derivative-component amides 5a, 5b, and 5c were produced by reacting compound (3) with amine derivatives at a 1:4 molar ratio. These derivatives exhibited varying sensitivities for utilization in solar cells, with compound 5a displaying the highest power
... Show MoreIn this work, a joint quadrature for numerical solution of the double integral is presented. This method is based on combining two rules of the same precision level to form a higher level of precision. Numerical results of the present method with a lower level of precision are presented and compared with those performed by the existing high-precision Gauss-Legendre five-point rule in two variables, which has the same functional evaluation. The efficiency of the proposed method is justified with numerical examples. From an application point of view, the determination of the center of gravity is a special consideration for the present scheme. Convergence analysis is demonstrated to validate the current method.
The main theme of this thesis could be divided into three objectives : The first is to define and classify integral equations with one and multiple delay, including Fredholm, Volterra and integro-differential equations (Retarded, Neutral and Mixed types). While the second and popular objective of this work is to study the inverse problems related to delay integral equations by using non-classical variational formulation method. Some examples are given for each of the discussed type of delay integral equations. Also, a study to the direct and inverse problems related to integral equations with multiple delay, also considered as a third objective. Several examples are given for each type of these equations. Finally, the suggested approach
... Show MoreNanoparticles (NPs) have been suggested for subsurface projects, including enhanced oil recovery (EOR), carbon capture and storage (CCS), and hydrogen storage, due to their small size, high surface energy, controlled surface properties, and significant effects on the underground formation properties. Silica is an excellent NP that efficiently modifies the surface properties of subsurface formations for incremental oil recovery and to derisk carbon and hydrogen leaks. However, the retention of injected NPs in a narrow area near the injection inlet can limit a project’s feasibility. In the present study, hydrophobic (hybrid) NPs were produced via silanization of silica NPs, and the mobility behavior of bare (hydrophilic) and hybrid
... Show MoreThe study deals with reactivity insertion linear and non linear and/or Ramp reactivity expressed as a polynomial in time in the presence of two Feedback mechanisms, using the neutronic-thermohydraulic coupling in order to predict the neutron behavior as a function of time in terms of reactor power. Also, a comparative study has been achieved in the case of the presence of the feedback mechanisms. Insertion of Ramp reactivities in terms of polynomial in time to study the behavior of power and reactivity as a function of time in the presence of two feedback mechanisms (fuel and coolant) has been carried out and the results are displayed as plots, and showed this results corresponding with international results. The present study shows t
... Show MoreThe study aims to study the geographical distribution of electricpower plants in Iraq, except the governorates of Kurdistan Region (Dohuk, Erbil, Sulaymaniyah) due to lack of data.
In order to reach the goal of the research was based on some mathematical equations and statistical methods to determine how the geographical distribution of these stations (gas, hydropower, steam, diesel) within the provinces and the concentration of them as well as the possibility of the classification of power plants in Iraq to facilitate understanding of distribution in a scientific manner is characterized by objectively.
The most important results of the research are that there are a number of factors that led to the irregular distribution
... Show MoreAlthough the events of September 2001 marked the United States' employment of solid forces in its direct comprehensive strategy to counter terrorist organizations and any other challenges to US national security, the United States did not lose sight of the importance of the cultural variable. The cultural variable is the United States' most important instrument of soft power in ensuring its dominance of the international system and promoting its global project. France viewed US soft power as a threat to its own civilizational pattern. Therefore, France considers culture to be an inherent component of its national personality and a cornerstone of its international standing as a major force. Additionally, the US-French political and economic
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