John tarilanyo afa (9 Ergebnisse)

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - Technical Report from the year 2011 in the subject Engineering - Power Engineering, grade: A, ( Atlantic International University ) (Niger Delta University), course: PRE 677, language: English, abstract: Rural electrification is a global challenge especially in the developing countries. The problem of rural electrification is acute in Nigeria because the country has not been able to provide adequate supply to the connected consumers. The case of Bayelsa State is peculiar because the geographical position of the state offer various problems to rural electrification. The state is bounded by rivers, estuaries, creeks and stagnant swamps that pose problems to rural electrification in terms of settlements, accessible roads, good available means of transport etc.The climatic conditions and flooding are factors militating against the rapid growth of this area. Lack of industrial customers, low load forecast and very long distances from the grid with huge cost of installation, maintenance and operations are key factors.Bayelsa State is dissected centrally by longitude 6° East and latitude 4.5° North. Bayelsa State with a population of 1,121,693 spread over a land area of 12,000 sq kilometer most of which is water or wet lands. Its definitive boarder is the 185 kilometer of coast line through which its many rivers issue into the Atlantic Ocean. There are few big cities due to the flooding and erosion and some are almost cut off from the capital due to the area of settlement.Bayelsa State is located in the heart of the Niger Delta and is one of the central areas that produce the resources (Oil and Gas) which account for about 97 percent of the National total earning (Sambo 2008). The operational base of the oil companies are not located within the source of the revenue, thereby making the place poor, rejected with no impact of such huge revenue taken out of this areas. These areas of Bayelsa State was regarded as rural areas before the creation of the state, therefore it has little or no development. The Oil Companies contributed to the level of poverty because the administrative headquarter of these companies are out of state and are far from the source of the oil deposit. The outcome of this was denial of the people from all social amenities, unemployment, rejection, poverty and devastation of the ecological sources due to spillages and gas flaring.Due to the outcry, the government is trying to put certain things in place for the development of the Niger Delta, therefore it is necessary to study the problems facing the environment so that policies, designs and construction will be based on facts concerning the development of the area.…

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - Technical Report from the year 2011 in the subject Engineering - Power Engineering, grade: A, ( Atlantic International University ) (Niger Delta University), course: LPH 657, language: English, abstract: Lightning is a major source of danger to H.V transmission lines resulting in serious overvoltage which may cause flashover, puncture and sometimes loss of transmission line up to few hours or complete destruction of lines.The study is focused on Bayelsa State whose coastal areas occupy about eighty percent of the state. Due to its geographical location (Mangrove swamp forest) especially the coastal areas, these are areas of high thunderstorm and lightning days per year. This will pose significant influence on transmission line performance.From the present load with the proposed projects when completed may demand bulk power supply. The need of using high voltage transmission lines is there. Presently, it is expected that 132kv line may run from Yenagoa to Brass through Ogbia. It is therefore necessary to study the line performance in these areas of high Isokeraunic level. Lightning faults may be single or multi-phase and their elimination causes reclosing cycles, voltage dips and outages. Therefore the outage rate of a line and the quality of the delivered voltage depends on the lightning performance of the line. No transmission line design can be considered lightning proof, nor designers aimed at this goal. An acceptable design is to allow a certain number of outage per 100km of line or other line durations (Razevig 2003, Uglesic 2009). The probability of an outage depends on many factors which are statistical in nature that a worst case design is neither practical nor economical.…

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - Technical Report from the year 2011 in the subject Geography / Earth Science - Physical Geography, Geomorphology, Environmental Studies, grade: A, ( Atlantic International University ) (Niger Delta University), course: SCE 672, language: English, abstract: The purpose of earthing electrical equipment or an installation is to ensure safety. No matter the sensitivity of a protective device, without proper earthing good performance of the device cannot be ensured. One of the major problems of having a continued low earthing resistance is corrosion. Corrosion is not limited to earth electrode only but all electrical equipments, buried metals, undergrounds telecommunication system, etc.The life expectancy of a material or equipment depends on the severity of corrosion in the area (Gonos and Stathopuslos, 2006, Liu et al, 2004). The processes of corrosion are not simple and their effects are not easily predicted. Therefore if the corrosion processes are not controlled it will result to frequent and costly replacement of materials and equipments. Due to the geographic location, the closeness to the ocean, and the soil conditions, the soil of Niger Delta are corrosive. This is particular true with the coastal soil. For this reasons, it was necessary to carry out a study of various soil structure and their corrosivity. Such records when properly presented will serve as a guide in the selection of earthing materials as well as help in the control of corrosion on buried materials. …

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - Technical Report from the year 2011 in the subject Engineering - Power Engineering, grade: A, ( Atlantic International University ) (Niger Delta University), course: STV 678, language: English, abstract: The strategic position of Port Harcourt in the Niger Delta region has made the city one of the fastest growing cities in Nigeria. The Niger Delta which is rich in oil and gas provide Nigeria with Ninety-five percent foreign earnings. The oil companies operating in the state has attracted several small, medium and large scale industries. The telecommunication industry which is the fastest growing company in Nigeria has provided job opportunities through several mini companies. Whether small, medium or large companies require the use of electricity and electrical equipments and therefore require proper and safe earthing (grounding). The electrical, electronics and the telecommunication industries require various grounding methods, therefore it is necessary to study the seasonal variation and temperature effect on the grounding systems.All calculations related to the design of grounding system and the determination of transfer, step and touch potential require information about the soil resistivity at site. Resistivity of soil depends on the physical composition of the soil, moisture content, dissolved salts, season variation, current magnitude and soil temperature. Different soil compositions have different average resistivity but moisture has great influence on the resistivity value of soil. For example, the resistivity of clay varies from 4ohm-m to 150 ohm-m depending on the water content. The study therefore will enable earth system designers, installation engineers to have available records of the earth parameters in this growing city that will enable designers and installer to install safe and reliable system.…

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - Technical Report from the year 2011 in the subject Engineering - Power Engineering, grade: A, ( Atlantic International University ) (Niger Delta University), course: FEM 633, language: English, abstract: A machine is a device that does useful work in a predictable way according to physical Laws. A machine could be referred to a motor or a generator and in most cases is reversible, therefore electro mechanical energy conversion devices are necessary. Motor and generator which are in the category of continuous energy conversion equipment in an electro mechanical energy conversion uses magnetic medium. With magnetic field more than a million joules can be stored in a cubic meter of air but with an electrostatic medium breakdown of the air limit the storage to few joules. The motoring and generating action is basically a reversible process that is, the same machine can be used as a generator or a motor and shown in fig. 1Fig. 1: Reversible Process of Energy conversion.Electro-mechanical energy conversion device is a link between an electrical and mechanical system and electromagnetic system needs the presence of natural phenomena which inter-relate electric and magnetic fields on one hand and mechanical force and motion on the other hand.…

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - Technical Report from the year 2011 in the subject Engineering - Power Engineering, grade: A, ( Atlantic International University ) (Niger Delta University), course: SFP 673, language: English, abstract: The purpose of this work is to establish the type of faults that may result when substations are sited in the region of the Niger Delta due to the prevailing climatic conditions. This will aimed at ensuring as far as possible a small probability of damage to substation insulations.For most transmission lines, relatively large numbers of yearly flashovers are permitted but such number of insulation damages is absolutely not allowed for substations. Flashover of insulation at substation means a short circuit on the busbar which even with the modern means of relay protection can cause most sever system damages. Substations unlike lines have very low probability of damage therefore a quantitative idea of the probability, the so called index of lightning resistance of a substation is used. It is equal to the calculated number of years during which a voltage dangerous for the substation installation does not occur. For modern high voltage substations, the index of lightning resistance is calculated as hundred or even as thousand years which is a proof of attempts made by designers to ensure the largest degree of lightning resistance of substation (Rao,2008,U.S Dept of Agri.2001,Martinez and Castro 2003).Substations must be protected from the direct lightning strokes and voltage waves travelling from the line as well as switching surges. In transmission lines the induced strokes (indirect strokes) due to lightning are important for 11kv lines only. For high voltage transmission lines (up to 220kv) the surges due direct lightning strokes determine the line insulations design. For extra high voltage (400kv and above) the severity of swiching surges is much more than that due to lightning (Gupta, 2008). Whether external or internal over voltage, for reliable operations of substation proper protection is necessary. There are factors that may not produce over voltage but are capable of affecting the operation of the equipments as well as lowering the flashover, these are humidity, rain temperature, pressure and to some extent contamination on the surface of insulator and equipments (outdoor).For proper consideration of these factors with the external and internal over voltages, a proper selection of protective devices may be made for the safe operation of substation.…

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - Technical Report from the year 2011 in the subject Environmental Sciences, grade: A, ( Atlantic International University ) (Niger Delta University), course: CEC 633, language: English, abstract: The Niger Delta is located at the Atlantic Coast of the Southern part of Nigeria. It is the outlet of River Niger and Benue to the Ocean through rivers, creeks and estuaries. It is the second largest delta in the world with coastline spanning about 450 kilometers terminating at the Imo river entrance (Uyique, Etiosa 2007). It is described as the largest wetland in Africa and among the three largest in the world. The region spans over 20,000 square kilometers hoisting about 25% of the Nigeria population. About 2370 square kilometers of the Niger Delta consist of Rivers, creeks and estuaries while stagnant swamp covers about 8,600 square kilometers and has the largest mangrove swamp in Africa. The mangrove swamp extends about 1900 square kilometers. The region falls within the tropical rain forest zone (Joe-Alagoa, E., 2002).…

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - Technical Report from the year 2011 in the subject Engineering - Power Engineering, grade: A, ( Atlantic International University ) (Niger Delta University), course: SAC 672, language: English, abstract: Knowledge of electric fields is necessary in numerous high voltage applications. Electrode geometries that are encountered in practice or under laboratory experimental condition are very many but the rod-plane arrangement with rod tip of various shapes (cone, needle, sphere, co-axial cylinder etc) are more common (Onal, 2004). These gaps are subjected to several types of voltage shape so that breakdown and withstand voltage have to be ascertained.Several models for explaining the observed characteristics of the fifty percent breakdown of long gaps have been put forward by many researchers. Some theories or models used experimental data to obtain numerical estimates for some factors. Even with the varying assumptions the results were similar because they were based on the same avalanche and streamer theories.Based on the critical flashover (CFO) voltage of long gap put forward by Paris (Begamudre, 2008) there was need to relate this study to small gaps. This was particularly necessary since calculation of small gap field distribution is easier because the controlling factors could be checked.The most important factors by which engineers describe the breakdown voltage of various gaps are the critical flashover and the withstand voltages. The critical flashover (CFO) voltage is the voltage that yields flashover of 50 percent of the number of shots given probability of voltage flashover (V50%).The withstand voltage which is critical to the designer could be determined in various statistical form.Due to large number of variables involved in insulation design especially the use of long gaps tends towards a statistical procedure because each of these variables has its own characteristics probability of occurrence either alone or in conjunction with other variables.Also the probability of most events occurring simultaneously is also remote. Therefore a flashover once in many operations is allowed. The most usual case is to allow one flashover in 100 switching operations. This could form the basis for design of airgap insulation.Some designers use 0.2% probability of flashover (1 in 500 operations). In insulation design and operation, the withstand voltage is of outmost importance. Thus, the low probability region of flashover, 0.1% or 0.2% must be obtained from flashover probabilities of higher values .It is necessary to note that the flashover probability of a given gap distance with voltage follow a nearly Gaussian or normal distribution.…

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - Technical Report from the year 2011 in the subject Engineering - Power Engineering, grade: A, ( Atlantic International University ) (Niger Delta University), course: ESE 637, language: English, abstract: Electricity plays a very important role in the socio economic and technological development of every nation. The electricity demand in Nigeria far outstrips the supply and the supply also is epileptic in nature. The country is faced with acute electricity problems which are hindering its development, notwithstanding the availability of vast natural resources in the country.The history of electricity in Nigeria dates back to 1896 where electricity was first produced in Lagos, fifteen years after its introduction in England. Despite the fact that its existence in the country is over a century, its development has been at a slow rate. In 1950, a central body was established by legislative council, which transferred electricity supply and development to the care of the central body known as the Electricity Corporation of Nigeria (ECN). Other bodies like the Native Authorities and Nigeria Electricity Supply Company (NESCO) have licenses to produces electricity in some locations in Nigeria.There was another body known as Niger Dams Authority (NDA) established by an act of parliament. The Authority was responsible for the construction and maintenance of dams and other works on the River Niger and also generating electricity by means of water power, improving, production and promoting fish brims and irrigation. The energy produced by NDA was sold to the Electricity Corporation of Nigeria for distribution and sales at utility voltages.In 1972 the National Electric Power Authority of Nigeria (NEPA) was established with the amalgamation of Electricity Corporation of Nigeria (ECN) and the Niger Dam Authority (NDA). NEPA was empowered to maintain an efficient coordinated and economically viable electricity supply in Nigeria (Sambo, 2008, Onwioduokit and Omoigui, 2000, ECN, 2004). In about 2005, the Power Holding of Nigeria gradually took over the functions of NEPA with little or no improvement to the power sector.…