Papers by Author: E.U. Ubeku

Abstract: Earthing systems made basically from earth electrodes need to be effectively designed to meet the increasing demand on safety. The aim of this paper is to use computer simulation to analyze the transient response of a horizontally buried earth electrode and how this response is influenced by factors like the energization type, the soil parameters, the depth of burial and the earth electrode geometry. The model used is the transmission line theory with a general application of the telegraphy equations which are solved numerically using the finite difference time domain scheme while the per unit length parameters were computed from a well known integral expression using the moment’s method. The results of the parametric analysis are validated by comparison with those found in literature.

Abstract: In this paper a motorized solar energy collector system-a driver system that positioned the solar cell panel differently during day-time was design and implemented. The aim is to optimize the amount of solar energy that can be trapped from the sun using a solar cell panel. This is achieved by using a stepper motor, controlled by Atmel AT89C52 microcontroller, to align the panel such that all incident rays strike normal to the panel’s surface thereby maximizing the amount of solar energy that can be trapped from the sun. The alignment is time dependant. This model was implemented and tested and the results proved to be successful in maximizing the energy received from the sun than if the solar panel was fixed at a particular position.

Abstract: This paper presents the use of a user-interactive MATLAB programme for the design and the parameter estimation of a three-phase induction motor (TPIM) using a per phase equivalent circuit model. Optimum design parameters such as the bore diameter, the rotor diameter, the slot dimensions, the air-gap length and the performance curves are obtained by iterative procedure of a design algorithm. The performance curves of the TPIM i.e., torque and efficiency are drawn from the model’s per phase parameters and then analyzed for different number of poles, number of slots ,varying air-gap, rated slip etc and their effect on the performance of the TPIM are analyzed and the results discussed. The results obtained were validated with similar studies carried out using finite element software FEMM. The comparison shows that the TPIM model is satisfactory.

Abstract: Application of Pareto Analysis technique in major feeder pillar faults identification is presented in this paper. Power outage data due to feeder pillar faults were collected between January, 2005 and September, 2007 from Power Holding Company of Nigeria (PHCN), Ugbowo district office, Edo State, Nigeria for four feeder pillars. The data were processed and Pareto Analysis technique was applied to the field data. The results obtained shows that eliminating wrong fusing and overloading in Edaiken 2 and Holex feeder pillars will reduce faults by 77.42 and 79.53% respectively while eliminating wrong fusing, overloading and line-to-line faults in Uwasota 2 and Holy Rosary feeder pillars will reduce faults by 87.9 and 88.35% respectively.