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- ItemGenetic Algorithm Based Routing Algorithm for Packet Switching Network(International Journal Of Electrical, Electronics and Computer Systems (IJEECS), 2014) Ogunbiyi, O., & Ahmed, W. A.The distributed nature of routers in a packet switching network (PSN) and the need for them to send packet to one another following an optimal path make routing algorithm a necessity. In this paper, genetic algorithm (GA) is proposed to solve routing problem in a PSN. Computer simulation showed that GA approach obtain a result similar to Dijkstra’s algorithm (used in routing information protocol (RIP)) but with some improvement. The GA technique finds the optimal path between any source and destination nodes in a network. The network may be simple or complex, such that a feasible path or optimal path seems intractable. The developed technique was able to determine an entire route right from the source node, quick adaptation to changes in the network. It can also handle a numerous number of different constraints in the network. The binary coding used will also make it easier to implement in hardware.
- ItemAutomatic Generation of Root Locus Plots for Linear Time Invariant Systems(Nigerian Journal of Technology (NIJOTECH), 2017) Durutoye, N., & Ogunbiyi, O.Design and analysis of control systems often become difficult due to the complexity of the system model and the design techniques involved. This paper presents the development of a Tools Box in Microsoft Excel for control engineers that uses root locus as a time domain technique for system design and analysis. The Tool Box can also serve as a computer-aided graphical analytical tool for trainers. The work was done in two phases: the first phase is the development of programmable algorithms for root locus using the angle condition and bisection method while the second phase is the implementation of the developed algorithms. The implementation was done using Microsoft Excel (R) Visual Basic Application (VBA). Results of simulations for different systems show the potential of the Tool Box as an alternative for other software package and the ease of using it on the readily available Microsoft Excel environment.
- ItemA Study of Energy Conversion at the Jebba Hydroelectric Power Station(IEEE 3rd International Conference on Electro-Technology for National Development (NIGERCON), 2017) Thomas C. T., Akorede M. F., Ogunbiyi O., Olufeagba B. J., & Samuel S. J.Hydroelectric power significantly contributes to the national power grid of Nigeria. This paper examined the extent of utilization of the energy supplied into each of the turboalternators at the Jebba Hydroelectric Power Station (JHEPS), Nigeria and suggests a corrective culture to be employed for improved efficiency. The basic principle of a hydropower scheme and its conversion considerations were highlighted. The daily discharge, Q, in cumecs and the power generated, P, in MW at JHEPS over a decade period (2005 – 2014) were analyzed using codes and scripts of Microsoft EXCEL-VBA. Jebba hydroelectric power station is one of the three major hydropower stations in Nigeria and the potential is just beginning to be exploited. The stochastic distribution pattern of the station is also presented for further analysis of failure and repair of the station. The conversion behavior of each unit was found to be linear and all have a value greater than 0.5 on a scale of 0.00 to 1.00. Turbo-alternator (TA) unit 1 was found to have the highest conversion characteristic of 0.9951, while unit 4 was the least at 0.6884. However unit 6 was exempted in this analysis as it was not in use during this period. The paper also gave an insight into the effective operating head of each TA, the paper also suggests the corrective measure to employ for each turbine.
- ItemAssessment of Failure and Repair Behaviours of the Jebba Hydroelectric Power Station(ELEKTRIKA- Journal of Electrical Engineering, 2018) Thomas, C. T., Ogunbiyi, O., Akorede, M. F., & Olufeagba, J. B.Nigeria power generation is circa 4000 MW as at October 2016, this is far less than the national required value. Jebba Hydroelectric Power Station (JHEPS) is one of the three major hydropower stations in the country which its maximum average generation value is still less than the rated value of 578.4 MW. This paper presented some basic concepts of analysis of failure and repair. An algorithm was set up to extract the contiguous set of up-times and down-times to determine time-tofail (TTF) and time-to-repair (TTR) events, these events were analyzed for stochastic study. It was observed that the longest up time was 262 days and seen in turbo-alternator unit five, while the shortest was zero day and seen in the entire units except that of unit two. The longest downtime was 133 days and seen in the turbo-alternator of unit one, the least time-to-repair is a day and common to all the units. The frequency distributions for both TTF and TTR showed that 79% of TTF events and 57% of TTR events are distributed in the first 2 classes
- ItemEvaluation of Failure and Repair of the Jebba and the Shiroro Hydroelectric Power Stations(Journal of Failure Analysis and Prevention, 2019) Thomas C. T. , Ogunbiyi . O., Akorede M. F., Yahaya . B., Alabi . K. O., Olufeagba B. J.Nigeria power generation hovers around 7000 MW as at January 2019; this is far less than the national required electricity per capita value. Jebba Hydroelectric Power Station (JHEPS) and Shiroro Hydroelectric Power Station (SHEPS) are two of the three major hydropower stations in the country in which their maximum average generation values are still less than the rated values of 578.4 MW and 600 MW, respectively. This paper presented some basic concepts of analysis of failure and repair. An algorithm was set up to extract the contiguous set of uptimes and downtimes to determine timebetween-failures (TBF) and time-between-repairs (TBR) events; these events were analyzed for the stochastic study. It was observed that the longest uptime was 262 days and seen in turbo-alternator unit five, while the shortest was zero day and seen in the entire units except that of unit two. For JHEPS, the longest downtime was 133 days and seen in the turbo-alternator of unit one, and the least time-between-repairs is a day and common to all the units. The frequency distributions for both TBF and TBR showed that 79% of TBF events and 57% of TBR events are distributed in the first two classes. For SHEPS, unit 3 was found to have the longest TBF with a value of 46 days, while the least was found in unit 1 with a value of 17 days
- ItemOptimal Control of Jebba Hydropower Operating Head by a Dynamic Programming(Computer Engineering and Applications, 2019) Ogunbiyi, O., Thomas, C. T., Omeiza, I. O. A., & Akanni, J.Nigeria with a generating potential of roughly 12,522 MW only supplies less than 20% of the national demand. This necessitates an optimal use of the Jebba Hydroelectric Power Plant whose optimal generation depends on the operating head. This paper presents the solution to an optimal control problem involving the operating head of the plant. An optimal control problem consisting of a model of the system dynamics, performance index and system constraints was solved using a dynamic programming approach. The control procedure was built on the integration of the nonlinear dynamical model by an Adams-Moulton technique with AdamsBashfort as predator and Runge-Kutta as a starter. The numerical solution, coupled with dynamic programming was employed in developing an optimal control procedure for the regulation of the operating head. The result presented shows the potential of the control procedure in determining the amount of inflow required to restore the operating head to a nominal level whenever there is a disturbance.
- ItemA Direct Optimal Control of the Jebba Hydropower Station(2nd International Conference of the IEEE Nigeria Computer Chapter, NigeriaComputConf, 2019) Ogunbiyi, O., Thomas, C. T., Olufeagba, B. J., Madugu, I. S., Adebiyi, B. H., & Adesina, L. M.The optimal power generation from the Jebba hydroelectric power station is subject to the reservoir operating head, weather-related factors, units’ availability and system dynamics. In this paper, a computer control system is designed to ensure safe operation and maximize power generation. The controller is an optimal controller, which determines the amount of inflow required to regulate the reservoir operating head. The control law is an optimal control procedure developed around the steepest descent and conjugate gradient algorithm. The algorithms determine the control signal and state trajectories for the minimization of a performance index defined for the regulation of the reservoir operating head. The results show that the two techniques are feasible in estimating an optimal inflow needed to move the reservoir operating head from any level to the nominal head. The two techniques were compared under different operating conditions of the hydropower system, the conjugate gradient algorithm performs better in terms of computational time. The control algorithm is recommended for use in the realization of a computer control system for the station.
- ItemA Nonlinear Control Model and Operational Support System for the Kainji Hydroelectric Power System.(Nigerian Journal of Technology (NIJOTECH), 2019) Ogunbiyi, O., Thomas, C. T., Omeiza, I. O. A., Akanni, J., & Olufeagba, B. J.Over the past years, the hydropower model and control were largely based on classical and linear transfer functions, this was motivated by the available control system design techniques that were available and the desire to simplify the design procedure. Such a model is inadequate for dynamic study and design of hydropower station in the presence of uncertainties in the water head, discharge rate, elastic water effect, traveling wave effect, large variation power output and frequency. This research, therefore, focuses on developing a nonlinear model for the Kainji hydroelectric power station. The model relies on the energy conversion principles, inflows, discharge, evaporation rate and number of units on busbar. The parameters of the model were also estimated, and the model validated with an error within +1.4% to -3.6%. The model is expected to be used to determine the optimal control policies for the operation of the station and the release of water to the downstream.
- ItemA Nonlinear Control Model and Operational Support System for the Kainji Hydroelectric Power System(2019) Ogunbiyi, O., Thomas, C. T., Omeiza, I. O. A., Akanni, J., & Olufeagba, B. J.Over the past years, the hydropower model and control were largely based on classical and linear transfer functions, this was motivated by the available control system design techniques that were available and the desire to simplify the design procedure. Such a model is inadequate for dynamic study and design of hydropower stations in the presence of uncertainties in the water head, discharge rate, elastic water effect, travelling wave effect, large variation power output and frequency. This research, therefore, focuses on developing a nonlinear model for the Kainji hydroelectric power station. The model relies on the energy conversion principles, inflows, discharge, evaporation rate and number of units on the busbar. The parameters of the model were also estimated, and the model was validated with an error within +1.4% to -3.6%. The model is expected to be used to determine the optimal control policies for the operation of the station and the release of water to downstream.
- ItemSpatial Modelling and Analysis of an Electrical Distribution System(Space Science and Technology for Sustainable Development AZOJETE, 2019) Ogunbiyi, O., Olayinka, A. A., & Ahmed, M. O.The distribution of electrical energy to end-users in Nigerian communities is faced with diverse spatial problems leading to low voltage, overload on equipment, difficulties in fault tracing and delay in fault clearing. The traditional management system is not only manual but also has flaws such as difficulties in searching and updating previous records as well as no real-time information on their distribution assets. In this study, a geospatial technique was employed for the effective management of the electricity distribution system in Malete, Kwara State, Nigeria. Spatial information of distribution assets was collected from the field and used in the structural modelling of the distribution network in the ArcMap software. Analysis of the model and the available information showed that 80 % of the transformers were not properly located at the centroid of the load. The span of the network fairly conformed to standard as only 45.73 % were within 45-50 m. The result also showed that 40 % of the transformers were overloaded with an unbalanced load, hence the need for restructuring of the network
- ItemA Control Model of the Operating Head Dynamics of Jebba Hydropower System.(Nigerian Journal of Technological Research (NJTR), 2019) Ogunbiyi O., Thomas C., Omeiza I. O. A. , Akanni J., Olufeagba B. J.Electricity availability in Nigeria has been very poor over the years, underscoring the need for a better approach for managing generating resources. This paper presents the development of a dynamical model of the operating head of Jebba hydroelectric power plants for system studies and control system design. The mathematical model of the plant was developed from flow continuity conditions, some model parameters were obtained from the source while others were estimated from observations and analysis of the measured data. The developed dynamical equation was validated by comparing the response produced with values obtained by measurement. Upon integrating the model equation in the Microsoft EXCEL VBA® environment, a deviation of 2% from measured values was observed. Operators can therefore use the model as a decision support system, while control engineers can find the model directly applicable for optimal and robust control system design for the station.
- ItemFailure Behaviour of the Shiroro Hydroelectric Power Station Turbo-Alternators: A Performance Evaluation.(ABUAD Journal of Engineering Research and Development (AJERD), 2019) Ogunbiyi, O., Thomas, C. T., Aluko, O., & Olufeagba, B. J.A reliable electrical power supply is non-negotiable for national growth and development, as electricity is needed in virtually every sector of production and commercial activities. The Shiroro hydroelectric power station (SHEPS) commissioned in 1990 comprises four units of turbo-alternators made of Francis turbine rated at 150 MW each. In this paper, an EXCEL-VBA script was used to extract a contiguous set of up and down times which were used to compute ‘time-between-failures’ (TBF). The failure events and failure rate of each unit were estimated using the power generation data of the station from the year 2008 to 2015. A structured database was organized for accurate analysis. Unit 3 was found to have the longest TBF with a value of 46 days, while the least was found in unit 1 with a value of 17 days. The Reliability value of each unit was also computed and unit 3 was found to be the only unit having a value up to 70%. SHEPS was found to still be in its productive age and possesses a tendency of still generating close to the rated value if properly refurbished.
- ItemOptimal Control of the Cascaded Kainji-Jebba Hydroelectric Power Station Based on Conjugate Gradient(ELEKTRIKA- Journal of Electrical Engineering, 2019) Ogunbiyi, O., Thomas, C. T., Omeiza, I. O. A., Akanni, J., & Olufeagba, B. J.Electricity supply in Nigeria has been far below the estimated demand and the installed capacity of the plants. Hence, there has been continuous research on improving the performance of the existing plants, but the government mainly focuses on increasing the installed capacity. This paper presents the determination of the optimal release of water to maximize the energy generation potential of the cascaded Kainji-Jebba hydroelectric power station in Nigeria. The problem was formulated as an optimal control problem with an objective of minimizing the deviation of the head of the Jebba reservoir within a set limit. A conjugate gradient algorithm was then used as a direct solution to the optimal control problem. The computed control law and the resulting state trajectories of 2% error affirms the solution to be genuine and reliable. The algorithm is recommended for use in the design of a real time optimal controller for the system and a decision guide for the operators.
- ItemDynamical Control Model for the Cascaded Kainji -Jebba Hydropower Operating Head.(FUOYE Journal of Engineering and Technology, 2019) Ogunbiyi, O., Thomas, C. T., Omeiza, I. A. O., Akanni, J., & Olufeagba, B. J.Operation and design of control systems for the cascaded Kainji-Jebba hydropower system pose a great challenge to researchers and engineers. The difficulties arose from the fact that the system is affected by several nonlinear interacting factors such as variations in inflows, stochastic factors that are weather-related, availability of the turbo-alternators, and numerous other constraints that are influenced by the system dynamics. All these make the mathematical representation of the system difficult. This paper presents the development of a dynamical model for the operation and optimal control of the operating heads of the cascaded system. The mathematical models were developed from the energy conversion equation and Bernoulli’s equation. The model was calibrated and tuned using measured data. Upon validation by comparing the response of the model with the measured head, a deviation within was observed, making it a good prediction of the system response and appropriate for control system design.
- ItemA chi-square-SVM based pedagogical rule extraction method for microarray data analysis(Institute of Advanced Engineering and Science (IAES), 2020) Salawu, Mukhtar Damola; Arowolo, Micheal Olaolu; Abdulsalam, Sulaiman Olaniyi; Isiaka, Rafiu Mope; Jimada-Ojuolape, Bilkisu; Olumide, Mudashiru Lateef; Gbolagade, Kazeem A.Support Vector Machine (SVM) is currently an efficient classification technique due to its ability to capture nonlinearities in diagnostic systems, but it does not reveal the knowledge learnt during training. It is important to understand of how a decision is reached in the machine learning technology, such as bioinformatics. On the other hand, a decision tree has good comprehensibility; the process of converting such incomprehensible models into an understandable model is often regarded as rule extraction. In this paper we proposed an approach for extracting rules from SVM for microarray dataset by combining the merits of both the SVM and decision tree. The proposed approach consists of three steps; the SVM-CHI-SQUARE is employed to reduce the feature set. Dataset with reduced features is used to obtain SVM model and synthetic data is generated. Classification and Regression Tree (CART) is used to generate Rules as the Last phase. We use breast masses dataset from UCI repository where comprehensibility is a key requirement. From the result of the experiment as the reduced feature dataset is used, the proposed approach extracts smaller length rules, thereby improving the comprehensibility of the system. We obtained accuracy of 93.53%, sensitivity of 89.58%, specificity of 96.70%, and training time of 3.195 seconds. A comparative analysis is carried out done with other algorithms.
- ItemImpact of the Integration of Information and Communication Technology on Power System Reliability: A Review(IEEE Access, 2020) Jimada-Ojuolape, Bilkisu; Teh, JiashenThere has been a progressive development in the synthesis of Information and Communication Technologies (ICTs) in power networks recently. ICT systems have become a vital part of every aspect of our daily lives and its integration into the electric power system has become paramount. ICTs support efficient incorporation of activities of all stakeholders of the power system to certify a more cost-effective and sustainable power system. The power system will exhibit intelligent monitoring and control, bidirectional communication between stakeholders and power system elements, security and safety of supply and self-healing qualities. However, asides from the vast benefits ICTs, their implementation within the power network come with some drawbacks which include element failures, failures due to interdependencies as well as vulnerabilities to cyber-attacks. These drawbacks can impact the reliability of the power network negatively. The objective of this paper is to investigate the impact of ICTs integration on the reliability of power networks in terms of empirical validation of standard reliability indices. This study groups the findings into four perspectives, including the effects of cyber power interdependencies, ICT infrastructure failures, cyber-attacks and environmental conditions. As expected, results show that failures and maloperations in the ICT network have adverse effects on system reliability and careful considerations need to be made to dampen these shortcomings.
- ItemSurveys on the reliability impacts of power system cyber–physical layers(Sustainable Cities and Society, 2020) Jimada-Ojuolape, Bilkisu; Teh, JiashenInformation and communication technology (ICT) is a vital addition to modern society living and is a crucial feature of the smart grid. It boosts the power system with the advantage of using intelligent infrastructure to aid monitoring, protection, bidirectional communication, supply safety, security and self-healing characteristics. ICT infrastructures are integrated into the power network by using technologies, such as active distribution net- works, smart cities and societies, dynamic line ratings, special protection schemes and demand-side management programmes. Deployment of these technologies has beneficial impacts on the reliability of power systems. However, these infrastructures are naturally prone to failures and cybersecurity issues because of Internet of things standards, which can further jeopardise system reliability. Various studies have examined the effect of these technologies on the reliability of power systems whilst ignoring that the associated ICTs could be un- available. Thus, this work comprehensively reviews studies that go beyond component-based reliability as- sessment and accounts for the impact of ICT integrations on system-wide reliability whilst explicitly considering the effects of malfunctions of the cyber system. Moreover, the paper presents quantitative and qualitative in- formation about the impact of ICT deployed with various smart grid technologies and applications on the re- liability of modern power systems.
- ItemCustomer Churn Prediction in Banking Industry Using K-Means and Support Vector Machine Algorithms(International Journal of Multidisciplinary Sciences and Advanced Technology, 2020) Abdulsalam, Sulaiman Olaniyi; Arowolo, Micheal Olaolu; Jimada-Ojuolape, Bilkisu; Saheed, Yakub KayodeThis study proposes a customer churn mining structure based on data mining methods in a banking sector. This study predicts the behavior of customers by using clustering technique to analyze customer’s competence and continuity with the sector using k-means clustering algorithm. The data is clustered into 3 labels, on the basis of the transaction in and outflow. The clustering results were classified using Support Vector Machine (SVM), an Accuracy of 97% was achieved. This study enables the banking administrators to mine the conduct of their customers and may prompt proper strategies as per engaging quality and improve proper conducts of administrator capacities in customer relationship.
- ItemA Progressive Domain Expansion Method for Solving Optimal Control Problem.(TELKOMNIKA (Telecommunication, Computing, Electronics and Control), 2020) Ogunbiyi, O., Ogundepo, O. Y., & Sani, M. I.Electricity generation at the hydropower stations in Nigeria has been below the expected value. While the hydro stations have a capacity to generate up to 2,380 MW, the daily average energy generated in 2017 was estimated at around 846 MW. A factor responsible for this is the lack of a proper control system to manage the transfer of resources between the cascaded Kainji-Jebba Hydropower stations operating in tandem. This paper addressed the optimal regulation of the operating head of the Jebba hydropower reservoir in the presence of system constraints, flow requirements and environmental factors that are weather-related. The resulting two-point boundary value problem was solved using the progressive expansion of domain technique as against the shooting or multiple shooting techniques. The results provide the optimal inflow required to keep the operating head of the Jebba reservoir at a nominal level, hence ensuring that the maximum number of turbo-alternator units are operated.
- ItemReliability Indices of Electric Power Distribution System in Ilorin, Nigeria(Nigerian Research Journal of Engineering and Environmental Sciences, 2020) Ogunbiyi, O., Akomolafe, T., & Adesina, L. M.The failure probability and epileptic power supply is a pointer to the reality that there is a need for reliability studies and fault evaluation of the electric power system in Nigeria. The recent blackout faced in the country has paralyzed many activities and has destroyed many industrial processes. Therefore, it is worth considering reliability assessments as it provide an opportunity to incorporate the cost or losses incurred by the utility customer as a result of a power failure and this must be considered in planning and operating practices. The reliability assessment and estimation of indices were carried out on selected 11 kV injection substation feeders in Ilorin, Nigeria. Using the analytical method and network reduction technique, the substation reliability was analyzed based on recorded outage data. Results show the low level of reliability of power supply to customers on the feeder, the failure rate is quite on the high side and a low system average interruption frequency index was recorded on most feeders. The overall system availability shows that the system needs improvement and quick response to network failure.
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