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Implication of Using Auxiliary Service Voltage Transformer Sub-Stations for Rural Electrification
Michael Juma Saulo,
Charles Trevor Gaunt
Issue:
Volume 4, Issue 2-1, March 2015
Pages:
1-11
Received:
10 November 2014
Accepted:
13 November 2014
Published:
19 November 2014
DOI:
10.11648/j.ijepe.s.2015040201.11
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Abstract: Providing an affordable and reliable electricity supply to rural communities is seen by countries round the world as one of the major keys to development. A good quality and stable electricity supply can provide a wide variety of benefits including lighting (allowing evening activities), clean cooking and heating, access to television/radio, telephone (including mobile), improved health (due to example refrigeration), and many small industrial uses. Often this can be provided by extending the main electricity network to the community. However, for remote rural areas the costs involved can be very high. Therefore, Un-conventional Rural Electrification (URE) technologies are thus very relevant, particularly for countries in sub-Saharan Africa (SSA), as they have potential to make connection to the electricity network affordable. While such systems are already in use, their penetration level is very low. Hence, if the penetration level of such system in power network increases, what is the effect on power and voltage quality, stability and capacity constraints of the overall system? What are the limiting factors, and how can this limit be determined for any particular rural electrification project. These are some of the major questions that this paper address progressively. The paper investigated the maximum penetration level of sub-station based Auxiliary Service Voltage Transformer (ASVT) technologies in transmission power networks with regard to voltage quality, stability, and capacity constraints. This was done by comparing the simulation results of ASVT(s) penetration on a transmission power network with the constructed Surge Impedance Loading (SIL) curves. The curves were derived from the ABCD parameters of the transmission line under investigation. Results showed that ASVT sub-station technologies can be applicable to any HV transmission line whose voltage level is within the 6% tolerance when the load power factor is varied between 0.2 and unity power factor. Moreover, the Loadability tests carried out showed that ASVT system could be operated within allowable voltage profile, if 1MW at 0.3 to 0.5 power factor lagging load was connected.
Abstract: Providing an affordable and reliable electricity supply to rural communities is seen by countries round the world as one of the major keys to development. A good quality and stable electricity supply can provide a wide variety of benefits including lighting (allowing evening activities), clean cooking and heating, access to television/radio, teleph...
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The Impact of Capacitor Coupled Sub-Station in Rural Electrification of Sub-Saharan Africa
Michael Juma Saulo,
Charles Trevor Gaunt
Issue:
Volume 4, Issue 2-1, March 2015
Pages:
12-29
Received:
10 November 2014
Accepted:
13 November 2014
Published:
27 December 2014
DOI:
10.11648/j.ijepe.s.2015040201.12
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Abstract: The overall electricity access rate is still very low in most sub-Saharan African (SSA) countries. The rate is even lower in rural areas where most of the population in these countries lives. One of the main obstacles to rural electrification (RE) is the high cost of laying the distribution infrastructure owing to the dispersed nature of loads and low demand. Thus, electrifying the rural areas needs to be considered holistically and not just on the financial viability. To reduce cost, it is important that un-conventional rural electrification (URE) technologies, which are cheaper than the conventional ones be explored. This paper investigates the adoptability and maximum penetration level of sub-station based URE i.e. Capacitor Coupled Sub-station (CCS) technologies in power transmission networks with regard to voltage quality, stability, and capacity constraints without steady and transient state voltage violation. Quantitative data collected from practical power transmission lines in Kenya were used for empirical and analytical approaches developed in this research. The paper developed a method of determining maximum allowable penetration level of CCS without steady state voltage violation derived from a modified distributed generation analogy. The method was based on determination of voltage sensitivities from linearized power system model. Consequently, this method was used to validate repetitive power flow simulations carried out in the case studies.
Abstract: The overall electricity access rate is still very low in most sub-Saharan African (SSA) countries. The rate is even lower in rural areas where most of the population in these countries lives. One of the main obstacles to rural electrification (RE) is the high cost of laying the distribution infrastructure owing to the dispersed nature of loads and ...
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Thermal Analysis of a CSP-Biogas Hybrid Power Plant
S. Kariuki,
V. Siyoi,
L. Mogaka,
M. J. Saulo,
J. Maroko
Issue:
Volume 4, Issue 2-1, March 2015
Pages:
29-41
Received:
14 November 2014
Accepted:
19 November 2014
Published:
27 December 2014
DOI:
10.11648/j.ijepe.s.2015040201.13
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Abstract: As the energy costs continue to rise steadily, researchers are looking for alternative sources of energy to meet the rising demand for sustainable energy. Finding an inexpensive and reliable energy generation technology is a big challenge both in developed and developing countries. Innovation and invention of new technologies, mass production and economies of scale will together enable a reduction in the cost of solar electricity to levels comparable with other electricity generating sources. Solar energy producers can increase their energy production by creating solar thermal hybrids by using concentrating solar thermal hybrids together with other energy sources like coal, biomass, oil, gas, geothermal and others. The performance of concentrating solar thermal power is limited by the availability of the sun and the design. The first solution is the hybridization of the solar power plants with fossil backup systems. For this case the fossil is used as a fuel to help meet the desired energy output of the system. Hybrid concepts are most suitable for utility application since they offer high power availability during peak and base loads operation. The hybrid model is assumed to be operated exclusively on renewable energy and net production of carbon dioxide.
Abstract: As the energy costs continue to rise steadily, researchers are looking for alternative sources of energy to meet the rising demand for sustainable energy. Finding an inexpensive and reliable energy generation technology is a big challenge both in developed and developing countries. Innovation and invention of new technologies, mass production and e...
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Electricity Generation from Municipal Solid Waste (MSW)
S. Kariuki,
V. Siyoi,
L. Mogaka,
M. J. Saulo,
J. Maroko
Issue:
Volume 4, Issue 2-1, March 2015
Pages:
42-51
Received:
14 November 2014
Accepted:
19 November 2014
Published:
27 December 2014
DOI:
10.11648/j.ijepe.s.2015040201.14
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Abstract: With the world’s energy demand increasing by the day, carbon dioxide emission rate also increases due to the dependency on fossil fuels for energy production. Several attempts have been made to reduce the dependence fossil fuels but to date coal is still a major energy resource used worldwide. The main focus of this paper is to investigate aspects with regard to the generation of energy by the use of biogas in terms of the economic, technological and environmental factors associated with the generation process.
Abstract: With the world’s energy demand increasing by the day, carbon dioxide emission rate also increases due to the dependency on fossil fuels for energy production. Several attempts have been made to reduce the dependence fossil fuels but to date coal is still a major energy resource used worldwide. The main focus of this paper is to investigate aspects ...
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The Impacts of Distributed Generation Using High Speed Wind Turbines on Power System Transient Stability
Annastacia Maina,
Michael J. Saulo
Issue:
Volume 4, Issue 2-1, March 2015
Pages:
52-62
Received:
14 November 2014
Accepted:
19 November 2014
Published:
27 December 2014
DOI:
10.11648/j.ijepe.s.2015040201.15
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Abstract: Wind power generation source differs in several respects from conventional sources of energy like hydro and thermal. Furthermore, wind generators are usually based on different generator technologies other than the conventional synchronous generators. The stochastic nature of wind, makes it very difficult to control the generator power output. Most wind turbines are based on induction generators which consume reactive power just like induction motors during system contingency, which in turn deteriorates the local grid stability. This paper proposes to study and analyze the impact of distributed generation using high speed wind turbines on power systems transient stability. This is achieved using a simplified model of the IEEE 30 bus system which replicates the Kenyan grid system. The base line case simulations were carried out using Dig SILENT Power factory version 14.0 software and results recorded. Thereafter, a Double Fed Induction Generator (DFIG) model was integrated to the system and various faults introduced in the system. The results showed that, the addition of the DFIGs to a power system network, does not negatively affect the stability of the system. It was evident that even with increased penetration of wind power up to 10.2%, the system showed a high degree of transient stability. Consequently, from the simulation results, as the system approaches stability, the swings are more or less of equal magnitude. As the penetration level of DFIGs increased from 0% to 10.2%, the critical clearing time also increased. This clearly shows that the transient stability of the power system is improved by DFIG penetration in the power network.
Abstract: Wind power generation source differs in several respects from conventional sources of energy like hydro and thermal. Furthermore, wind generators are usually based on different generator technologies other than the conventional synchronous generators. The stochastic nature of wind, makes it very difficult to control the generator power output. Most...
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Power Swing Prediction for Out-of-Step Mitigation
V. Siyoi,
S. Kariuki,
M. J. Saulo
Issue:
Volume 4, Issue 2-1, March 2015
Pages:
63-72
Received:
17 November 2014
Accepted:
20 November 2014
Published:
27 December 2014
DOI:
10.11648/j.ijepe.s.2015040201.16
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Abstract: This paper explored the possibility of accurately predicting the classification of developing power swings. The notion of machine learning was employed, and tested the application of Decision Tree (DT) algorithms to wide area power system protection schemes. The novelty of the designed Wide Area Protection (WAP) scheme was portrayed by the WAP’s ability to adaptively and accurately predict the classification of developing successive power swings. DTs being a Data Mining (DM) technique, a transient stability analysis was performed on an IEEE 39 bus test system in Dig SILENT®. The learning sample from the Phasor Measurement Unit (PMU) data was organized and stored in a data base in Microsoft Excel® 2010. The CART analysis and DT model design was done using Salford Predictive Modeller-CART® v6, trial licence. The results of this investigation were quite accurate and gave DT algorithms ‘thumbs-up’ in terms of classification prediction.
Abstract: This paper explored the possibility of accurately predicting the classification of developing power swings. The notion of machine learning was employed, and tested the application of Decision Tree (DT) algorithms to wide area power system protection schemes. The novelty of the designed Wide Area Protection (WAP) scheme was portrayed by the WAP’s ab...
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Solar-Wind Hybrid Energy System for New Engineering Complex- Technical University of Mombasa
Austin Wasonga,
Michael Saulo,
Victor Odhiambo
Issue:
Volume 4, Issue 2-1, March 2015
Pages:
73-80
Received:
17 November 2014
Accepted:
20 November 2014
Published:
27 December 2014
DOI:
10.11648/j.ijepe.s.2015040201.17
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Abstract: A hybrid energy system combines multiple types of energy generation in order to meet the demand of the users effectively and efficiently. The Solar-Wind hybrid system consists of electrical energy generated from wind and solar PV systems, it is a valuable method in the transition away from fossil fuel based economies. It capitalizes on existing wind regimes and solar energy available in a particular area or region. It is in public domain that environmental degradation has greatly increased due to the adaptation of fossil fuel driven generators to produce electricity. Power system interruptions and black-outs have posed major threats to most sub-Saharan African Countries. This has negatively affected the operations of industries and universities. Resulting in major losses that cumulatively impact negatively on their economy. The objective of this paper was to analyze and design a solar-wind hybrid system for powering the New Engineering Complex at the Technical University of Mombasa (NEC-TUM). The methodology involved was first to determine the electrical loading of the building in terms of lighting and power loads. The next step was to analyze the wind speed pattern and solar intensity on the roof of the building using RET Screen software. The results obtained and specifications of the components used in the model were fed into HOMER software for simulation purposes. It was found that the optimum mix of wind and photovoltaic power with an electromechanical storage system, with or without fossil fuel generator back up, depends upon the individual sub-systems economics. Furthermore, the hybrid system was able to produce 63.36kWh/day against the 50kWh/day required by the NEC-TUM for lighting and power loads.
Abstract: A hybrid energy system combines multiple types of energy generation in order to meet the demand of the users effectively and efficiently. The Solar-Wind hybrid system consists of electrical energy generated from wind and solar PV systems, it is a valuable method in the transition away from fossil fuel based economies. It capitalizes on existing win...
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Strategic PMU Placement for Stability Enhancement
V. Siyoi,
S. Kariuki,
M. J. Saulo
Issue:
Volume 4, Issue 2-1, March 2015
Pages:
81-94
Received:
17 November 2014
Accepted:
20 November 2014
Published:
27 December 2014
DOI:
10.11648/j.ijepe.s.2015040201.18
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Abstract: This paper explored a novel method for strategic monitoring of a power system to schematically monitor power system variables that are sensitive to transients. The characteristics of a fully developed transient or power swing increase frequency slip rates, generator pole slips, rotor out-of-step etc. whose effects lead to loss of synchronism of coherent generators in a power system. When these occur, the resulting remedy could be load shedding schemes, generator tripping or controlled islanding. Failure to achieve any of these might lead to geographically extensive blackouts and/or the damage of auxiliary power system equipment.This paper looked at the Wide Area Monitoring (WAM) principle, consisting of collection and pre-processing of field data, using Phasor Measurement Units (PMUs). A data mining exercise was performed purposing to identify strategic positions for PMU placement using the Classification and Regression Trees (CART) algorithm. The logic of CART was therefore also discussed.The proposition of strategic PMU placement as implied by the Decision Tree (DT) model acknowledges that a few PMUs in the power system network are capable of achievingWide Area Protection(WAP)functions.
Abstract: This paper explored a novel method for strategic monitoring of a power system to schematically monitor power system variables that are sensitive to transients. The characteristics of a fully developed transient or power swing increase frequency slip rates, generator pole slips, rotor out-of-step etc. whose effects lead to loss of synchronism of coh...
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Integrated Electricity Tarrif Model for Kenya
Muli Mumo,
Michael Saulo,
Samuel Kibaara
Issue:
Volume 4, Issue 2-1, March 2015
Pages:
95-98
Received:
20 November 2014
Accepted:
24 November 2014
Published:
27 December 2014
DOI:
10.11648/j.ijepe.s.2015040201.19
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Abstract: Tariffs and tariff structures has been changing over a period of time all over the world. This has acted as a key factor which limits development in third world country. This project therefore seeks to detemine the best tarrif model that can be used in kenya to improve on the electricy consumption, the research explores all the factors which affect the costing of electrical energy. The tariff model is developed considering fuel prices, the economic factors such as inflation and the puchasing power of the consmers ,and the other factors asssociated with sytem costs ie capital cost and running costs above all these it seeks to elliminate the electricty energy poverty by encouraging many consumers to connect to the grid. In additon, some recent developments and significant trends in distribution and pricing of the electrical enegy such as pre-paid metering . It is expected that this will help Kenya to develop better tariff structures and more reasonable charging rates. The research uses the data provided by the KPLC to analyse the consumer puchasing trends and and uses the current tarrif sytem as a reference to see how best the power company can supply the energy to the country at a cost which is balanced and which encourages industrial development. The resaerch develops a tarrif model which is gradual in nature and one which excludes the fixed changes but the consumers are charged on a gradual basis where the price will increase with the increase of the Kwh consumed.
Abstract: Tariffs and tariff structures has been changing over a period of time all over the world. This has acted as a key factor which limits development in third world country. This project therefore seeks to detemine the best tarrif model that can be used in kenya to improve on the electricy consumption, the research explores all the factors which affect...
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