Titus AJEWOLE - Academia.edu (original) (raw)
Papers by Titus AJEWOLE
Uniosun Journal of Engineering and Environmental Services, Mar 20, 2024
Tanzania Journal of Engineering and Technology/Tanzania Journal of Engeering and Technology, Nov 7, 2023
Journal of digital food, energy & water systems, Dec 30, 2023
Heliyon, Mar 1, 2022
As a way of wastes-to-voltage conversion, experimental benchtest trial of electricity generation ... more As a way of wastes-to-voltage conversion, experimental benchtest trial of electricity generation from a blend of cocoa and kolanut harvest by-products is presented in this study. Bioethanol obtained from the blend, through a process of alcoholic fermentation, was mixed with gasoline at specific proportion and employed to fire a spark ignition engine that served as a prime-mover in driving a four-pole three-phase salient-pole synchronous machine. Performance of the driving machine, as the fuel-mix proportion and its speed of rotation varied, was studied. Likewise, the electric power output characteristic of the driven machine, when operated at its rated synchronous speed, was examined. It was found that the driving machine performed better on mixed fuel than pure gasoline. There were gradual increases in the torque and the power developed by the machine as the proportion of ethanol in the fuel-mix and the rotational speed increased. While the highest values of torque and power developed on using pure gasoline were 12.4 Nm and 2574 W respectively at 1900 rpm, 13.1 Nm torque and 2953 W power were obtained from the machine when ignited with 10%-bioethanol fuel-mix at the same speed. Also, with 90 Vdc excitation voltage and rotation at 1500 rpm synchronous speed, the driven machine continuously generated electricity at 207.6 Vrms (line-to-line), 1.169 A, 0.698 power factor, 48.17 Hz, 0.294 kW output. This study demonstrated the possibility of continuous generation of electric power from cocoa and kolanut wastes. Result obtained from the laboratory-based trial indicates that at such agricultural regions that are advantaged in the production of the two crops, harvest residues of the crops can be explored as a steady source of biofuel for off-grid microgrid electrification.
International Journal of Emerging Electric Power Systems, Mar 14, 2017
Tanzania Journal of Engeering and Technology, Jun 30, 2022
Zenodo (CERN European Organization for Nuclear Research), Jun 30, 2022
Energy Sources, Part A: Recovery, Utilization, And Environmental Effects, Oct 3, 2019
Jindal journal of business research, Oct 4, 2021
This work studies the satisfaction experienced by electricity customers in Osun, Lagos, and Ogun ... more This work studies the satisfaction experienced by electricity customers in Osun, Lagos, and Ogun States during the recent lockdown occasioned by the COVID-19 pandemic. The measures of the satisfaction are based on the hours of electricity supply during the period, easiness experienced for payment of prepaid bill and swiftness in faults correction of the distribution companies involved. A questionnaire was developed using Google Forms. The form was shared through various online platforms. A total of 274 electricity consumers responded to the questionnaire, but after sorting, 259 consumers across the three states were analyzed. From the responses, majority of respondents claim there was increased hours of supply during the period when compared to before the period. For prepaid customers who had reasons to pay electricity bill, majority claim it was easy paying while most of those who claimed it was not easy was because of their payment method choices, which is using designated points. Majority of those who have reasons for faults to be corrected by the distribution companies claim that there was not promptness in fault correction.
Scientific African, Sep 1, 2020
Abstract In addition to its use as the workhorse in the industry, induction machines are fast gai... more Abstract In addition to its use as the workhorse in the industry, induction machines are fast gaining popularity in renewable energy applications, hence; the need for continual study on the performances of the machines. In this work, a phase frame analysis of a distribution system that feeds single-phase loads and a three-phase induction motor was implemented with the aim of investigating the effects on the distribution system, of an open-circuit fault that occurs in any of the phases of the stator winding of the motor. The IEEE 4-node test feeder was employed for the study and the phase impedance matrices for all the system components of the feeder determined. A programme based on MATLAB code was employed for the analysis that was done for both the healthy and the unhealthy operating conditions of the machine. Based on a specified voltage tolerance value of 0.00001 V, the simulation converged after five iterations giving relatable and reasonable result. The result showed that an open-circuit fault in any of the three phases of the induction machine resulted in high voltage imbalance that get worsened with increase in single-phase loads connected to the system. It is recommended that the machine be disconnected from the distribution network once such a fault is detected.
Tanzania Journal of Engeering and Technology, Dec 31, 2022
UNIOSUN Journal of Engineering and Environmental Sciences, Sep 1, 2019
UNIOSUN Journal of Engineering and Environmental Sciences, Mar 31, 2021
An ever-increasing size of the power system transmission networks has made the system to be prone... more An ever-increasing size of the power system transmission networks has made the system to be prone to various disturbances which could result to system instability. Therefore, increasing the critical clearing time (CCT) of faults before necessary actions are taken is of paramount importance to power system operators in order to maintain and enhance the dynamic security of the system. This paper takes an advantage of STATCOM device to increase the CCT of a multi-machine power system. The differential and algebraic equation model (DAE) of the system is used. The generator transient model (2-axis model) is also utilized with excitation and governor dynamic models. IEEE 14-bus test system is used in the analysis done in the MATLAB environment. The disturbance introduced is the loss of transmission line. The CCT of the system is determined without STATCOM in place and after which STATCOM is connected across the terminal buses of the critical line and the simulation carried out again. The critical clearing time was found to increase with STATCOM across either of the terminal buses of the critical transmission line.
Journal of Ecological Engineering, Sep 1, 2022
Turkish Journal of Electrical Power and Energy Systems, May 9, 2022
Social Science Research Network, 2021
Turkish Journal of Electrical Power and Energy Systems, Oct 27, 2021
Uniosun Journal of Engineering and Environmental Services, Mar 20, 2024
Tanzania Journal of Engineering and Technology/Tanzania Journal of Engeering and Technology, Nov 7, 2023
Journal of digital food, energy & water systems, Dec 30, 2023
Heliyon, Mar 1, 2022
As a way of wastes-to-voltage conversion, experimental benchtest trial of electricity generation ... more As a way of wastes-to-voltage conversion, experimental benchtest trial of electricity generation from a blend of cocoa and kolanut harvest by-products is presented in this study. Bioethanol obtained from the blend, through a process of alcoholic fermentation, was mixed with gasoline at specific proportion and employed to fire a spark ignition engine that served as a prime-mover in driving a four-pole three-phase salient-pole synchronous machine. Performance of the driving machine, as the fuel-mix proportion and its speed of rotation varied, was studied. Likewise, the electric power output characteristic of the driven machine, when operated at its rated synchronous speed, was examined. It was found that the driving machine performed better on mixed fuel than pure gasoline. There were gradual increases in the torque and the power developed by the machine as the proportion of ethanol in the fuel-mix and the rotational speed increased. While the highest values of torque and power developed on using pure gasoline were 12.4 Nm and 2574 W respectively at 1900 rpm, 13.1 Nm torque and 2953 W power were obtained from the machine when ignited with 10%-bioethanol fuel-mix at the same speed. Also, with 90 Vdc excitation voltage and rotation at 1500 rpm synchronous speed, the driven machine continuously generated electricity at 207.6 Vrms (line-to-line), 1.169 A, 0.698 power factor, 48.17 Hz, 0.294 kW output. This study demonstrated the possibility of continuous generation of electric power from cocoa and kolanut wastes. Result obtained from the laboratory-based trial indicates that at such agricultural regions that are advantaged in the production of the two crops, harvest residues of the crops can be explored as a steady source of biofuel for off-grid microgrid electrification.
International Journal of Emerging Electric Power Systems, Mar 14, 2017
Tanzania Journal of Engeering and Technology, Jun 30, 2022
Zenodo (CERN European Organization for Nuclear Research), Jun 30, 2022
Energy Sources, Part A: Recovery, Utilization, And Environmental Effects, Oct 3, 2019
Jindal journal of business research, Oct 4, 2021
This work studies the satisfaction experienced by electricity customers in Osun, Lagos, and Ogun ... more This work studies the satisfaction experienced by electricity customers in Osun, Lagos, and Ogun States during the recent lockdown occasioned by the COVID-19 pandemic. The measures of the satisfaction are based on the hours of electricity supply during the period, easiness experienced for payment of prepaid bill and swiftness in faults correction of the distribution companies involved. A questionnaire was developed using Google Forms. The form was shared through various online platforms. A total of 274 electricity consumers responded to the questionnaire, but after sorting, 259 consumers across the three states were analyzed. From the responses, majority of respondents claim there was increased hours of supply during the period when compared to before the period. For prepaid customers who had reasons to pay electricity bill, majority claim it was easy paying while most of those who claimed it was not easy was because of their payment method choices, which is using designated points. Majority of those who have reasons for faults to be corrected by the distribution companies claim that there was not promptness in fault correction.
Scientific African, Sep 1, 2020
Abstract In addition to its use as the workhorse in the industry, induction machines are fast gai... more Abstract In addition to its use as the workhorse in the industry, induction machines are fast gaining popularity in renewable energy applications, hence; the need for continual study on the performances of the machines. In this work, a phase frame analysis of a distribution system that feeds single-phase loads and a three-phase induction motor was implemented with the aim of investigating the effects on the distribution system, of an open-circuit fault that occurs in any of the phases of the stator winding of the motor. The IEEE 4-node test feeder was employed for the study and the phase impedance matrices for all the system components of the feeder determined. A programme based on MATLAB code was employed for the analysis that was done for both the healthy and the unhealthy operating conditions of the machine. Based on a specified voltage tolerance value of 0.00001 V, the simulation converged after five iterations giving relatable and reasonable result. The result showed that an open-circuit fault in any of the three phases of the induction machine resulted in high voltage imbalance that get worsened with increase in single-phase loads connected to the system. It is recommended that the machine be disconnected from the distribution network once such a fault is detected.
Tanzania Journal of Engeering and Technology, Dec 31, 2022
UNIOSUN Journal of Engineering and Environmental Sciences, Sep 1, 2019
UNIOSUN Journal of Engineering and Environmental Sciences, Mar 31, 2021
An ever-increasing size of the power system transmission networks has made the system to be prone... more An ever-increasing size of the power system transmission networks has made the system to be prone to various disturbances which could result to system instability. Therefore, increasing the critical clearing time (CCT) of faults before necessary actions are taken is of paramount importance to power system operators in order to maintain and enhance the dynamic security of the system. This paper takes an advantage of STATCOM device to increase the CCT of a multi-machine power system. The differential and algebraic equation model (DAE) of the system is used. The generator transient model (2-axis model) is also utilized with excitation and governor dynamic models. IEEE 14-bus test system is used in the analysis done in the MATLAB environment. The disturbance introduced is the loss of transmission line. The CCT of the system is determined without STATCOM in place and after which STATCOM is connected across the terminal buses of the critical line and the simulation carried out again. The critical clearing time was found to increase with STATCOM across either of the terminal buses of the critical transmission line.
Journal of Ecological Engineering, Sep 1, 2022
Turkish Journal of Electrical Power and Energy Systems, May 9, 2022
Social Science Research Network, 2021
Turkish Journal of Electrical Power and Energy Systems, Oct 27, 2021