2021 International Conference on Decision Aid Sciences and Application (DASA), 2021
Energy shortage is being experienced across the developing countries and energy efficiency in res... more Energy shortage is being experienced across the developing countries and energy efficiency in residential buildings is one of key ways to address this challenge. Energy wastage in residential buildings is rising; hence, energy-efficient technologies, energy-utilisation behaviours, and consumption forecasts can help to solve this shortage. Energy wastage resulting from consumers’ behaviour and usage could be dealt with by linking energy consumption with the cost of energy to enable consumers to be conscious of their usage. Hence, the Energy Culture Framework is used to identify drivers that influence energy wastage. It incorporates the human dimension of energy consumption using covenant university and Ekurede-Urhobo community as case studies. The study on consumer's energy behaviour was carried out by administering two hundred and fifty (250) questionnaires. Two hundred and twenty-one (221) were returned. The SPSS statistical tool was used the carry out the statistical analysis. The research observed that the majority of the surveyed participants lacked energy efficient appliances. However, the majority of the consumers surveyed exhibited some energy efficient practices. The norms of these consumers surveyed influenced the type of material culture and energy practice they adopted. This research has investigated a balanced model that can connect consumers’ behaviour to energy consumption to achieve energy efficiency in residential buildings.
Load flow analysis has become increasingly important as power system expansion now involves unbun... more Load flow analysis has become increasingly important as power system expansion now involves unbundling, liberalization, and restructuring networks, putting power system operators in a competitive electricity market. On the other hand, advancements in technology, computing, and software have led to new techniques for carrying out load flow analysis. In this paper, the load flow problem is approached using two techniques: the traditional load flow analysis using the Newton-Raphson method and a non-conventional method using an artificial neural network. This paper presents a load flow solution using the developed artificial neural network on the IEEE 14-bus system and the Nigerian 330kV 28-bus national grid. The results show that load flow analysis can be carried out using the developed artificial neural network with negligible errors between the actual values of voltage magnitudes and voltage phase angles and the neural network output, thus validating the proposed approach. Using the ...
Power rationing has become the bane of the Nigerian power sector, plunging the nation into prolon... more Power rationing has become the bane of the Nigerian power sector, plunging the nation into prolonged periods of darkness and costing about 2.5 percent of her GDP annually. Although, installed generating capacity is almost 13 GW, the situation worsened by an overdependence on thermal and hydro generation, high losses, and a poor tariff structure. In the face of these challenges, Nigeria seeks to achieve universal access by 2030 with sustainable power having a share of 30 per cent in her energy mix. Despite the existence of frameworks supporting this target, Nigeria’s policies are still weak; indicated by her low Regulatory Indicator for Sustainable Energy (RISE) score of 30. To reach universal access by 2030 and fulfil SDG 7; Nigeria needs the right mix of policies. This study aims to review, draw lessons from the successful and unsuccessful implementation of similar policies in five countries and give recommendations.
International Journal of Electrical and Computer Engineering (IJECE), 2021
Unalleviated voltage instability frequently results in voltage collapse; which is a cause of conc... more Unalleviated voltage instability frequently results in voltage collapse; which is a cause of concern in power system networks across the globe but particularly in developing countries. This study proposed an online voltage collapse prediction model through the application of a machine learning technique and a voltage stability index called the new line stability index (NLSI_1). The approach proposed is based on a multilayer feed-forward neural network whose inputs are the variables of the NLSI_1. The efficacy of the method was validated using the testing on the IEEE 14-bus system and the Nigeria 330-kV, 28-bus National Grid (NNG). The results of the simulations indicate that the proposed approach accurately predicted the voltage stability index with an R-value of 0.9975 with a mean square error (MSE) of 2.182415x10−5 for the IEEE 14-bus system and an R-value of 0.9989 with an MSE of 1.2527x10−7 for the NNG 28 bus system. The results presented in this paper agree with those found in ...
Forecasting of electrical load is very crucial to the effective and efficient operation of any po... more Forecasting of electrical load is very crucial to the effective and efficient operation of any power system. This is achieved by obtaining the most accurate forecast which help in minimizing the risk in decision making and reducesthe costs of operating the power plant. Therefore, the comparative study of time series and artificial neural network methods for short term load forecasting is carried out in this paper using real time load data of Covenant University,withthe moving average, exponential smoothing (time series method) and the Artificial Neural Network (ANN) models. The work was done for the day-to-day operation of the soon-to-becompleted power station of the university. For each of the methods, models were developed for the load forecast. The Artificial Neural Network proved to be the best forecast method when the results are compared in terms of error measurementswith amean absolutedeviation(MAD) having 0.225, mean squared error (MSE) having 0.095 and the mean absolute per...
International Journal of Renewable Energy Research, 2013
A potential solution to adequate and sustainable electricity supply problems in most developing c... more A potential solution to adequate and sustainable electricity supply problems in most developing countries is dependent on proper harnessing of solar (radiant) energy. Owing to the over dependence on fossil-fuel based energy, there is an exponential rise in carbon dioxide (CO2) emissions into the atmosphere, thereby causing severe environmental degradation and ozone layer depletion. This paper seeks to apply the readily available radiant energy source to solar water heating, and establish possible economic benefits to its use in domestic applications for residents of Covenant University campus. The microcontroller-based active solar water heating system (ASWHS) is designed to effectively absorb radiant energy using solar collectors, and store it as hot water in a water tank via a direct current (DC) circulation pump powered by a stand-alone photovoltaic (PV) system. The design also incorporates an auxiliary electric heater which is put to use only when there is insufficient radiant e...
Soil layer resistivity modelling is a vital component of grounding system design. Grounding syste... more Soil layer resistivity modelling is a vital component of grounding system design. Grounding system for facility, equipment, power station and general system protection purposes must be designed to be able to handle the anticipated level of fault current. To achieve this; the earth rods, mats and any other equivalent alternatives deployed must be adequately sized in terms of the physical dimensions and the number of such rods required in order to achieve the desired low, overall grounding system resistance. The resistance to earth of a grounding system is a function of the resistivity of the soil in concern, and to ensure appropriate design, the resistivity profile of the soil must be determined via appropriate soil modelling. This paper presents a Monte Carlo simulation approach to two layer soil modelling using the square error as an optimization function. The result of the simulation shows an improvement in model accuracy, and it also conforms significantly with the results of pub...
The numerous power system blackouts in the past decade and in recent times attest to the fact tha... more The numerous power system blackouts in the past decade and in recent times attest to the fact that more work still needs to be done to tackle the problem of voltage instability and the resultant voltage collapse. This research work proposes a new line stability index that is suitable for the prediction of voltage collapse in Power System Networks (PSNs). This index code-named the New Line Stability Index-1 (NLSI_1) was obtained by deriving from first principles equivalent expressions for the Line Stability Index (Lmn) and the Fast Voltage Stability Index (FVSI) and combining them through a switching logic based on the voltage angle difference since it can signal the imminence of voltage collapse. This new index (NLSI_1) was tested on the IEEE 14-bus system and it gives the same results as the other indices (Lmn and FVSI). For the base case, the IEEE 14-bus test system was found to be stable with all the three indices having approximately equal values (< 1) for all the lines. The ...
2020 International Conference on Decision Aid Sciences and Application (DASA), 2020
Engaging in financial transactions has remained a hassle for the visually impaired due to the lac... more Engaging in financial transactions has remained a hassle for the visually impaired due to the lack of technological products to facilitate their financial independence an... View more
Journal of Engineering Science and Technology Review, 2017
In industries, electric motors contribute a major percentage of electrical loads, and by implicat... more In industries, electric motors contribute a major percentage of electrical loads, and by implication, a major portion of the generated electrical energy is consumed by electric motors, and it is therefore vital to ensure that these motors operate with negligible energy loss. In operational environment, many factors can be responsible for a reduction in motor performance. One of the major factors is a regime of voltage unbalance that affects the motor, the load and supply network. Three phase induction motor studies can be carried out using methods such as real load test, finite element analysis, flux linkage-current relations etc. A new model based on phase frame analysis has been developed for easy computation of sequence components. This paper seeks to explore the performance of a 3-phase induction motor operating under unbalance voltage conditions using the phase frame analysis. The results of this study established that there are negative impacts of supply imbalance on the performance of three phase motor.
Three phase induction motors (TPIM) are extensively used for various applications in the industry... more Three phase induction motors (TPIM) are extensively used for various applications in the industry for driving cranes, hoists, lifts, rolling mills, cooling fans, textile operations, and so forth. TPIM are designed to operate on balanced three phase power supply, but sometimes three phase supply line voltages to which the TPIM is connected may be unbalanced. In this data article, the operational data of a TPIM operating under changing voltage scenarios is profiled to determine the variations in the magnitude of the operational parameters of the motor. The magnitude of each of the line voltages was separately varied from the balanced state (0% unbalance) until 5% voltage unbalance condition was achieved, in line with the recommendations and guidelines of the National Electrical Manufactures Association. The motor parameters; both mechanical and electrical, at various slip values were collected in six sets for the 0%, 1%, 2%, 3%, 4%, and 5% unbalance voltage conditions. Frequency distributions and statistical analysis were carried out to identify the data pattern and data variation trends among the parameters in the dataset.
Slack bus is a bus with generating unit and used to balance the real power (P) and reactive power... more Slack bus is a bus with generating unit and used to balance the real power (P) and reactive power (Q) in the power system while performing load flow studies. This study therefore, investigated the best slack bus suitable to be used in the load flow study of the Nigerian 330-kVtransmission network with nine (9) generating stations. The method involve the load flow analysis of the existing network with Egbin, Shiroro and Kanji generating stations chosen as a slack bus at different instances and simulated using Newton-Rapson method and Gauss Seidel. This study revealed that the use of Egbin power station as a slack bus brought about the lowest power mismatch in the network. The result also indicated violation of voltages in some of the network and high reactive power loss.
Handwritten signature image is normally used as a mark of endorsement of written document. Signat... more Handwritten signature image is normally used as a mark of endorsement of written document. Signatures of the same person vary and they can be forged by imposters. Effective feature extraction algorithm is needed in off-line signature verification. Robust features capable of increases interpersonal variation and decreases intra personal variation are required. This work presents robust signature feature that can be used to build effective off-line signature verification system. Signature processing is performed and the preprocessed signature image is vertically divided into sixteen smaller image blocks through the center of gravity. Three features are extracted from these smaller image blocks. Feature vector is formed and are passed to Support Vector Machine (SVM) for training and classification. The proposed signature feature vector increases the accuracy of tested off-line signature verification system.
The subject of control system design has evolved considerably over the years. Although several de... more The subject of control system design has evolved considerably over the years. Although several design techniques and strategies have been adopted to realize control systems that meet a predetermined set of performance criteria, the fundamental problem remains that of developing controllers to adjust the performance characteristics of a dynamic system in order to obtain a desired output behavior. The dynamic behavior of a magnetic levitation system (MLS) of a ferromagnetic ball is compensated in this paper. Consolidating the exposure of undergraduate students to the rudiments of control system design, the paper employs the classical root locus technique to stabilize the system. A combination of analytical and softwarebased methods is used to design proportional-derivative and phase-lead compensators based on the linearized model of the system. Complete details of the design approach, from modeling and analysis of the plant to computing the values of the controller parameters, are shown. MATLAB scripts for plotting root loci and simulating the system are provided.
Electric load forecasting is principal to the economic and efficient provision of electric power ... more Electric load forecasting is principal to the economic and efficient provision of electric power to meet various load demands for a specified period of time. The focus of this paper is on the medium-term load forecast of Covenant University, a Nigerian tertiary educational institution, using the methods of regression analysis. The hourly load information collected from the University's electric power substation is employed as the sample data for the forecast. Three models based on the linear, compound-growth, and cubic methods of regression analysis are developed, and the load forecast results obtained from these models are compared using the mean absolute percentage error (MAPE) and root mean square error (RMSE) performance metrics. It is observed that, among these three models, the linear model has the best error margin: 0.5792 and 41.34 for MAPE and RMSE, respectively.
The thrust of this article is to develop elaborate educational material on linear quadratic regul... more The thrust of this article is to develop elaborate educational material on linear quadratic regulator (LQR)-based power system control for electrical engineering students, especially senior undergraduate and fresh graduate students. The paper considers a comprehensive description of a power system, which is represented by a network of a single generator connected to an infinite bus, highlighting modeling, analysis, and simulation of the system. Graphical outputs for various combinations of system state and input weighting matrices are presented.
A distribution grid is generally characterized by a high R/X (resistance/reactance) ratio and it ... more A distribution grid is generally characterized by a high R/X (resistance/reactance) ratio and it is radial in nature. By design, a distribution grid system is not an active network, and it is normally designed in such a way that power flows from transmission system via distribution system to consumers. But in a situation when wind turbines are connected to the distribution grid, the power source will change from one source to two sources, in this case, network is said to be active. This may probably have an impact on the distribution grid to whenever the wind turbine is connected. The best way to know the impact of wind turbine on the distribution grid in question is by carrying out load flow analysis on that system with and without the connection of wind turbines. Two major fundamental calculations: the steady-state voltage variation at the PCC (point of common coupling) and the calculation of short-circuit power of the grid system at the POC (point of connection) are necessary before carrying out the load flow study on the distribution grid. This paper, therefore, considers these pre-load flow calculations that are necessary before carrying out load flow study on the test distribution grid. These calculations are carried out on a test distribution system.
ABSTRACT Abstract: -The reliability of a power system network depends greatly on the performance ... more ABSTRACT Abstract: -The reliability of a power system network depends greatly on the performance of the protection system. Improving the reliability of the protection scheme of the transmission lines will enhance the overall reliability of the power system network. The focus of this paper is the improvement of the reliability of a power system transmission line using fault tree analysis (FTA). The paper considers the development of fault tree diagrams for the protection scheme of the 150km-long 132-kV transmission line in Northern Nigeria. The existing protection scheme is analyzed and compared with a proposed scheme equipped with a redundancy arrangement. And the result shows that the new scheme offers significant improvement (about 51%) in the availability of the line.
A chatter-free sliding mode controller (SMC) for synchronous generator excitation is presented in... more A chatter-free sliding mode controller (SMC) for synchronous generator excitation is presented in this paper. A linearized model of a single machine connected to an infinite bus is employed to design a variable-structure controller which not only stabilizes the system, but also ensures that this is maintained in the face of system parameter variations. Validating the robustness feature of an SMC, simulation results that show the dynamic performance of the system under both constant excitation and SMC-controlled excitation are presented. Index Terms-Excitation system control, robustness, sliding model control, synchronous generator model. I. INTRODUCTION lectric power systems have witnessed substantial growthmore transmission networks have been built and greater interconnections among generation areas effected, with new measurement and monitoring devices (occasioned by advancements in technology) being added in various parts of the systems. This growth has resulted in high dimensionality and complexity of the power systems, thereby sparking off intense efforts to make them operate satisfactorily. Key to the operation of an electric power network is stability. And this stability principally is dependent on the ability of synchronous generators in the system to maintain synchronism with one another during both normal operating conditions and abnormal conditions. Principally, synchronism is a function of how the power system reacts to disturbances, i.e., whether it has sufficient restoring forces to balance the disturbing forces [1]. Synchronous generator excitation control design has gone through a range of techniques and strategies, such as linear lead/lag control [2], optimal control [3], [4], feedback linearization control [5], [6], [7], adaptive control [8], [9], [10], robust control [5], fuzzy logic control [11], [12], etc., all of which aimed at damping out oscillations and maintaining both small-signal and large-signal stability of power systems.
Today diesel engine-driven standby generators for backup power supply have been adopted for resid... more Today diesel engine-driven standby generators for backup power supply have been adopted for residential, commercial, and industrial use-especially in some developing countries where power from the utility company is highly erratic. Although many of these generators function well in operation, certain engine conditions, such as low oil pressure, high oil and water temperature, abnormally high speed, etc., could lead to malfunction, failure, or complete breakdown of the engine. Therefore, the focus of this work is to present the implementation of a simple, but effective electronic protection unit (EPU) capable of mitigating the adverse effect which may arise as a result of these conditions. It is composed of two major sub-circuits-the main protective sub-circuit and the timing sub-circuit-realized using a combination of passive and active components. Unlike the common electrical relay-based protection system, this unit has an additional advantage of being able to keep the faultindicating system of the generator working even after engine shutdown, thereby facilitating fault tracking. The unit has been tested on a diesel engine-driven generator and found to function satisfactorily. The test results are shown.
2021 International Conference on Decision Aid Sciences and Application (DASA), 2021
Energy shortage is being experienced across the developing countries and energy efficiency in res... more Energy shortage is being experienced across the developing countries and energy efficiency in residential buildings is one of key ways to address this challenge. Energy wastage in residential buildings is rising; hence, energy-efficient technologies, energy-utilisation behaviours, and consumption forecasts can help to solve this shortage. Energy wastage resulting from consumers’ behaviour and usage could be dealt with by linking energy consumption with the cost of energy to enable consumers to be conscious of their usage. Hence, the Energy Culture Framework is used to identify drivers that influence energy wastage. It incorporates the human dimension of energy consumption using covenant university and Ekurede-Urhobo community as case studies. The study on consumer's energy behaviour was carried out by administering two hundred and fifty (250) questionnaires. Two hundred and twenty-one (221) were returned. The SPSS statistical tool was used the carry out the statistical analysis. The research observed that the majority of the surveyed participants lacked energy efficient appliances. However, the majority of the consumers surveyed exhibited some energy efficient practices. The norms of these consumers surveyed influenced the type of material culture and energy practice they adopted. This research has investigated a balanced model that can connect consumers’ behaviour to energy consumption to achieve energy efficiency in residential buildings.
Load flow analysis has become increasingly important as power system expansion now involves unbun... more Load flow analysis has become increasingly important as power system expansion now involves unbundling, liberalization, and restructuring networks, putting power system operators in a competitive electricity market. On the other hand, advancements in technology, computing, and software have led to new techniques for carrying out load flow analysis. In this paper, the load flow problem is approached using two techniques: the traditional load flow analysis using the Newton-Raphson method and a non-conventional method using an artificial neural network. This paper presents a load flow solution using the developed artificial neural network on the IEEE 14-bus system and the Nigerian 330kV 28-bus national grid. The results show that load flow analysis can be carried out using the developed artificial neural network with negligible errors between the actual values of voltage magnitudes and voltage phase angles and the neural network output, thus validating the proposed approach. Using the ...
Power rationing has become the bane of the Nigerian power sector, plunging the nation into prolon... more Power rationing has become the bane of the Nigerian power sector, plunging the nation into prolonged periods of darkness and costing about 2.5 percent of her GDP annually. Although, installed generating capacity is almost 13 GW, the situation worsened by an overdependence on thermal and hydro generation, high losses, and a poor tariff structure. In the face of these challenges, Nigeria seeks to achieve universal access by 2030 with sustainable power having a share of 30 per cent in her energy mix. Despite the existence of frameworks supporting this target, Nigeria’s policies are still weak; indicated by her low Regulatory Indicator for Sustainable Energy (RISE) score of 30. To reach universal access by 2030 and fulfil SDG 7; Nigeria needs the right mix of policies. This study aims to review, draw lessons from the successful and unsuccessful implementation of similar policies in five countries and give recommendations.
International Journal of Electrical and Computer Engineering (IJECE), 2021
Unalleviated voltage instability frequently results in voltage collapse; which is a cause of conc... more Unalleviated voltage instability frequently results in voltage collapse; which is a cause of concern in power system networks across the globe but particularly in developing countries. This study proposed an online voltage collapse prediction model through the application of a machine learning technique and a voltage stability index called the new line stability index (NLSI_1). The approach proposed is based on a multilayer feed-forward neural network whose inputs are the variables of the NLSI_1. The efficacy of the method was validated using the testing on the IEEE 14-bus system and the Nigeria 330-kV, 28-bus National Grid (NNG). The results of the simulations indicate that the proposed approach accurately predicted the voltage stability index with an R-value of 0.9975 with a mean square error (MSE) of 2.182415x10−5 for the IEEE 14-bus system and an R-value of 0.9989 with an MSE of 1.2527x10−7 for the NNG 28 bus system. The results presented in this paper agree with those found in ...
Forecasting of electrical load is very crucial to the effective and efficient operation of any po... more Forecasting of electrical load is very crucial to the effective and efficient operation of any power system. This is achieved by obtaining the most accurate forecast which help in minimizing the risk in decision making and reducesthe costs of operating the power plant. Therefore, the comparative study of time series and artificial neural network methods for short term load forecasting is carried out in this paper using real time load data of Covenant University,withthe moving average, exponential smoothing (time series method) and the Artificial Neural Network (ANN) models. The work was done for the day-to-day operation of the soon-to-becompleted power station of the university. For each of the methods, models were developed for the load forecast. The Artificial Neural Network proved to be the best forecast method when the results are compared in terms of error measurementswith amean absolutedeviation(MAD) having 0.225, mean squared error (MSE) having 0.095 and the mean absolute per...
International Journal of Renewable Energy Research, 2013
A potential solution to adequate and sustainable electricity supply problems in most developing c... more A potential solution to adequate and sustainable electricity supply problems in most developing countries is dependent on proper harnessing of solar (radiant) energy. Owing to the over dependence on fossil-fuel based energy, there is an exponential rise in carbon dioxide (CO2) emissions into the atmosphere, thereby causing severe environmental degradation and ozone layer depletion. This paper seeks to apply the readily available radiant energy source to solar water heating, and establish possible economic benefits to its use in domestic applications for residents of Covenant University campus. The microcontroller-based active solar water heating system (ASWHS) is designed to effectively absorb radiant energy using solar collectors, and store it as hot water in a water tank via a direct current (DC) circulation pump powered by a stand-alone photovoltaic (PV) system. The design also incorporates an auxiliary electric heater which is put to use only when there is insufficient radiant e...
Soil layer resistivity modelling is a vital component of grounding system design. Grounding syste... more Soil layer resistivity modelling is a vital component of grounding system design. Grounding system for facility, equipment, power station and general system protection purposes must be designed to be able to handle the anticipated level of fault current. To achieve this; the earth rods, mats and any other equivalent alternatives deployed must be adequately sized in terms of the physical dimensions and the number of such rods required in order to achieve the desired low, overall grounding system resistance. The resistance to earth of a grounding system is a function of the resistivity of the soil in concern, and to ensure appropriate design, the resistivity profile of the soil must be determined via appropriate soil modelling. This paper presents a Monte Carlo simulation approach to two layer soil modelling using the square error as an optimization function. The result of the simulation shows an improvement in model accuracy, and it also conforms significantly with the results of pub...
The numerous power system blackouts in the past decade and in recent times attest to the fact tha... more The numerous power system blackouts in the past decade and in recent times attest to the fact that more work still needs to be done to tackle the problem of voltage instability and the resultant voltage collapse. This research work proposes a new line stability index that is suitable for the prediction of voltage collapse in Power System Networks (PSNs). This index code-named the New Line Stability Index-1 (NLSI_1) was obtained by deriving from first principles equivalent expressions for the Line Stability Index (Lmn) and the Fast Voltage Stability Index (FVSI) and combining them through a switching logic based on the voltage angle difference since it can signal the imminence of voltage collapse. This new index (NLSI_1) was tested on the IEEE 14-bus system and it gives the same results as the other indices (Lmn and FVSI). For the base case, the IEEE 14-bus test system was found to be stable with all the three indices having approximately equal values (< 1) for all the lines. The ...
2020 International Conference on Decision Aid Sciences and Application (DASA), 2020
Engaging in financial transactions has remained a hassle for the visually impaired due to the lac... more Engaging in financial transactions has remained a hassle for the visually impaired due to the lack of technological products to facilitate their financial independence an... View more
Journal of Engineering Science and Technology Review, 2017
In industries, electric motors contribute a major percentage of electrical loads, and by implicat... more In industries, electric motors contribute a major percentage of electrical loads, and by implication, a major portion of the generated electrical energy is consumed by electric motors, and it is therefore vital to ensure that these motors operate with negligible energy loss. In operational environment, many factors can be responsible for a reduction in motor performance. One of the major factors is a regime of voltage unbalance that affects the motor, the load and supply network. Three phase induction motor studies can be carried out using methods such as real load test, finite element analysis, flux linkage-current relations etc. A new model based on phase frame analysis has been developed for easy computation of sequence components. This paper seeks to explore the performance of a 3-phase induction motor operating under unbalance voltage conditions using the phase frame analysis. The results of this study established that there are negative impacts of supply imbalance on the performance of three phase motor.
Three phase induction motors (TPIM) are extensively used for various applications in the industry... more Three phase induction motors (TPIM) are extensively used for various applications in the industry for driving cranes, hoists, lifts, rolling mills, cooling fans, textile operations, and so forth. TPIM are designed to operate on balanced three phase power supply, but sometimes three phase supply line voltages to which the TPIM is connected may be unbalanced. In this data article, the operational data of a TPIM operating under changing voltage scenarios is profiled to determine the variations in the magnitude of the operational parameters of the motor. The magnitude of each of the line voltages was separately varied from the balanced state (0% unbalance) until 5% voltage unbalance condition was achieved, in line with the recommendations and guidelines of the National Electrical Manufactures Association. The motor parameters; both mechanical and electrical, at various slip values were collected in six sets for the 0%, 1%, 2%, 3%, 4%, and 5% unbalance voltage conditions. Frequency distributions and statistical analysis were carried out to identify the data pattern and data variation trends among the parameters in the dataset.
Slack bus is a bus with generating unit and used to balance the real power (P) and reactive power... more Slack bus is a bus with generating unit and used to balance the real power (P) and reactive power (Q) in the power system while performing load flow studies. This study therefore, investigated the best slack bus suitable to be used in the load flow study of the Nigerian 330-kVtransmission network with nine (9) generating stations. The method involve the load flow analysis of the existing network with Egbin, Shiroro and Kanji generating stations chosen as a slack bus at different instances and simulated using Newton-Rapson method and Gauss Seidel. This study revealed that the use of Egbin power station as a slack bus brought about the lowest power mismatch in the network. The result also indicated violation of voltages in some of the network and high reactive power loss.
Handwritten signature image is normally used as a mark of endorsement of written document. Signat... more Handwritten signature image is normally used as a mark of endorsement of written document. Signatures of the same person vary and they can be forged by imposters. Effective feature extraction algorithm is needed in off-line signature verification. Robust features capable of increases interpersonal variation and decreases intra personal variation are required. This work presents robust signature feature that can be used to build effective off-line signature verification system. Signature processing is performed and the preprocessed signature image is vertically divided into sixteen smaller image blocks through the center of gravity. Three features are extracted from these smaller image blocks. Feature vector is formed and are passed to Support Vector Machine (SVM) for training and classification. The proposed signature feature vector increases the accuracy of tested off-line signature verification system.
The subject of control system design has evolved considerably over the years. Although several de... more The subject of control system design has evolved considerably over the years. Although several design techniques and strategies have been adopted to realize control systems that meet a predetermined set of performance criteria, the fundamental problem remains that of developing controllers to adjust the performance characteristics of a dynamic system in order to obtain a desired output behavior. The dynamic behavior of a magnetic levitation system (MLS) of a ferromagnetic ball is compensated in this paper. Consolidating the exposure of undergraduate students to the rudiments of control system design, the paper employs the classical root locus technique to stabilize the system. A combination of analytical and softwarebased methods is used to design proportional-derivative and phase-lead compensators based on the linearized model of the system. Complete details of the design approach, from modeling and analysis of the plant to computing the values of the controller parameters, are shown. MATLAB scripts for plotting root loci and simulating the system are provided.
Electric load forecasting is principal to the economic and efficient provision of electric power ... more Electric load forecasting is principal to the economic and efficient provision of electric power to meet various load demands for a specified period of time. The focus of this paper is on the medium-term load forecast of Covenant University, a Nigerian tertiary educational institution, using the methods of regression analysis. The hourly load information collected from the University's electric power substation is employed as the sample data for the forecast. Three models based on the linear, compound-growth, and cubic methods of regression analysis are developed, and the load forecast results obtained from these models are compared using the mean absolute percentage error (MAPE) and root mean square error (RMSE) performance metrics. It is observed that, among these three models, the linear model has the best error margin: 0.5792 and 41.34 for MAPE and RMSE, respectively.
The thrust of this article is to develop elaborate educational material on linear quadratic regul... more The thrust of this article is to develop elaborate educational material on linear quadratic regulator (LQR)-based power system control for electrical engineering students, especially senior undergraduate and fresh graduate students. The paper considers a comprehensive description of a power system, which is represented by a network of a single generator connected to an infinite bus, highlighting modeling, analysis, and simulation of the system. Graphical outputs for various combinations of system state and input weighting matrices are presented.
A distribution grid is generally characterized by a high R/X (resistance/reactance) ratio and it ... more A distribution grid is generally characterized by a high R/X (resistance/reactance) ratio and it is radial in nature. By design, a distribution grid system is not an active network, and it is normally designed in such a way that power flows from transmission system via distribution system to consumers. But in a situation when wind turbines are connected to the distribution grid, the power source will change from one source to two sources, in this case, network is said to be active. This may probably have an impact on the distribution grid to whenever the wind turbine is connected. The best way to know the impact of wind turbine on the distribution grid in question is by carrying out load flow analysis on that system with and without the connection of wind turbines. Two major fundamental calculations: the steady-state voltage variation at the PCC (point of common coupling) and the calculation of short-circuit power of the grid system at the POC (point of connection) are necessary before carrying out the load flow study on the distribution grid. This paper, therefore, considers these pre-load flow calculations that are necessary before carrying out load flow study on the test distribution grid. These calculations are carried out on a test distribution system.
ABSTRACT Abstract: -The reliability of a power system network depends greatly on the performance ... more ABSTRACT Abstract: -The reliability of a power system network depends greatly on the performance of the protection system. Improving the reliability of the protection scheme of the transmission lines will enhance the overall reliability of the power system network. The focus of this paper is the improvement of the reliability of a power system transmission line using fault tree analysis (FTA). The paper considers the development of fault tree diagrams for the protection scheme of the 150km-long 132-kV transmission line in Northern Nigeria. The existing protection scheme is analyzed and compared with a proposed scheme equipped with a redundancy arrangement. And the result shows that the new scheme offers significant improvement (about 51%) in the availability of the line.
A chatter-free sliding mode controller (SMC) for synchronous generator excitation is presented in... more A chatter-free sliding mode controller (SMC) for synchronous generator excitation is presented in this paper. A linearized model of a single machine connected to an infinite bus is employed to design a variable-structure controller which not only stabilizes the system, but also ensures that this is maintained in the face of system parameter variations. Validating the robustness feature of an SMC, simulation results that show the dynamic performance of the system under both constant excitation and SMC-controlled excitation are presented. Index Terms-Excitation system control, robustness, sliding model control, synchronous generator model. I. INTRODUCTION lectric power systems have witnessed substantial growthmore transmission networks have been built and greater interconnections among generation areas effected, with new measurement and monitoring devices (occasioned by advancements in technology) being added in various parts of the systems. This growth has resulted in high dimensionality and complexity of the power systems, thereby sparking off intense efforts to make them operate satisfactorily. Key to the operation of an electric power network is stability. And this stability principally is dependent on the ability of synchronous generators in the system to maintain synchronism with one another during both normal operating conditions and abnormal conditions. Principally, synchronism is a function of how the power system reacts to disturbances, i.e., whether it has sufficient restoring forces to balance the disturbing forces [1]. Synchronous generator excitation control design has gone through a range of techniques and strategies, such as linear lead/lag control [2], optimal control [3], [4], feedback linearization control [5], [6], [7], adaptive control [8], [9], [10], robust control [5], fuzzy logic control [11], [12], etc., all of which aimed at damping out oscillations and maintaining both small-signal and large-signal stability of power systems.
Today diesel engine-driven standby generators for backup power supply have been adopted for resid... more Today diesel engine-driven standby generators for backup power supply have been adopted for residential, commercial, and industrial use-especially in some developing countries where power from the utility company is highly erratic. Although many of these generators function well in operation, certain engine conditions, such as low oil pressure, high oil and water temperature, abnormally high speed, etc., could lead to malfunction, failure, or complete breakdown of the engine. Therefore, the focus of this work is to present the implementation of a simple, but effective electronic protection unit (EPU) capable of mitigating the adverse effect which may arise as a result of these conditions. It is composed of two major sub-circuits-the main protective sub-circuit and the timing sub-circuit-realized using a combination of passive and active components. Unlike the common electrical relay-based protection system, this unit has an additional advantage of being able to keep the faultindicating system of the generator working even after engine shutdown, thereby facilitating fault tracking. The unit has been tested on a diesel engine-driven generator and found to function satisfactorily. The test results are shown.
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Papers by Isaac Samuel