Browsing by Author "Olufeagba, Benjamin"

Now showing 1 - 5 of 5
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    A control model of the operating head dynamics of Jebba hydropower system
    (Federal University of Technology, Minna, Niger Sate, Nigeria, 2019) Akanni, Jimoh; Ogunbiyi, Olalekan; Thomas, Cornelius; Omeiza, Issac; Olufeagba, Benjamin
    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 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.
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    Dynamical control model of the cascaded Kainji-Jebba hydropower operating head
    (Published by Faculty of Engineering, Federal University Oye-Ekiti, Ekiti state, Nigeria, 2019) Akanni, Jimoh; Ogunbiyi, Olalekan; Thomas, Cornelius; Omeiza, Issac; Olufeagba, Benjamin
    Operation and design of control system for the cascaded Kainji-Jebba hydropower system poses 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 makes 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 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 measured head, a deviation within ±2% was observed, making it a good prediction of the system response and appropriate for control system design.
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    Investigation of the unified rain attenuation prediction method with data from tropical climates
    (IEEE, 2014) Akanni, Jimoh; Abdulrahman, Yusuf; Olufeagba, Benjamin; Rahman, T. A; Islam, M.D.R; Abdulrahman, T. A; Amuda, S. A. Y
    The semi-empirical method recently proposed by Silva Mello and Pontes (SMP) for the prediction of rain attenuation in slant paths is investigated in this letter. The SMP method uses the simplified model of equivalent rain cell and the concept of an effective rain rate. However, substantial deviations were observed in SMP predictions when compared to the rain cell diameters derived from experimental data. The measured rain rates and attenuations were obtained from three tropical climates (Australia, and USM and IIUM both in Malaysia). The measured rain attenuation complementary cumulative distributions (CCDs) were also compared to SMP and the Rec. ITU-R P. 618-11. The test results show that the ITU-R model performs much better compared to SMP method in the three tropical climates.
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    Nonlinear control model and operational support system for the Kainji Hydroelectric Power System
    (Faculty of Engineering, University of Nigeria, Nsukka, Nigeria, 2019) Akanni, Jimoh; Ogunbiyi, Olalekan; Thomas, Cornelius; Omeiza, Issac; Olufeagba, Benjamin
    Over the past years, hydropower model and control were largely based on classical and linear transfer function, 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.
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    A steepest descent algorithm for the optimal control of a cascaded hydropower system
    (Institute of Advanced Engineering and Science, 2020) Akanni, Jimoh; Ogunbiyi, Olalekan; Thomas, Cornelius; Omeiza, Issac; Olufeagba, Benjamin; Ogundepo, O.Y.
    Optimal power generation along the cascaded Kainji-Jebba hydroelectric power system had been very difficult to achieve. The reservoirs operating heads are being affected by possible variation in impoundments upstream, stochastic factors that are weather-related, availability of the turbo-alternators and power generated at any time. Proposed in this paper, is an algorithm for solving the optimal release of water on the cascaded hydropower system based on steepest descent method. The uniqueness of this work is the conversion of the infinite dimensional control problem to a finite one, the introduction of clever techniques for choosing the steepest descent step size in each iteration and the nonlinear penalty embedded in the procedure. The control algorithm was implemented in an Excel VBA® environment to solve the formulated Lagrange problem within an accuracy of 0.03%. It is recommended for use in system studies and control design for the optimal power generation in the cascaded hydropower system.