Electrical & Electronics Engineering
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Electrical & Electronics Engineering
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Item Harmonic Reduction Using Fractional Pitch Winding(3rd Biennial Engineering Conference, Federal University of Technology, Minna. Nigeria, 2013-05-16) Enesi Asizehi Yahaya; Mark Nwohu; Henry Ohize; O. Imoru; Usman N. GaladimaThe power source and the nonlinear loads on transmission line are major sources of harmonics and if these harmonics are not controlled, they could lead to heat loss, break down of machines and reducing the efficiency of any machine connected to the supply. The non-sinusoidal currents from the power source increase harmonic contents in the air gap of electrical machines with pole pitch winding which will lead to excessive losses, vibration and noise. This paper presents the use of fractional pitch winding technique for the stator of three phase motor for the purpose of suppressing harmonics. This is investigated between two windings of pole pitch and short-pitch and the results simulated using Emetor Electric Motor software.Item Electromagnetic field analysis of a single-phase induction motor based on finite element method(3rd International Engineering Conference (IEC 2019) Federal University of Technology, Minna, Nigeria, 2019-05-06) Omokhafe J. Tola; Edwin A. Umoh; Enesi A. Yahaya; Chika Idoko; Ayo ImoruElectric motors are critical components of Electric drives systems, and their performance efficiency has consequences for the fidelity of electric drives and control. This paper presents an analysis of the electromagnetic field of a single-phase induction motor based on two-dimensional finite element method. The developed model of the machine was used to study its performance characteristics at different speed conditions, a view to affirm the accuracy of the specifications of the motor. The motor losses were analyzed and the transient results revealed the losses and a start-up time of 0.07 second with low pulsation at steady state. This implies the specifications are accurate. Therefore, the developed model has possibilities of applications in power system generating systems and industrial plants.Item Permanent Split Capacitor (PSC) alternating current induction motor(Leonardo Electronic Journal of Practices and Technologies, 2015-06-26) Yahaya Asizehi ENESI; Tola J. OMOKHAFE; James G. AMBAFI; Eugene O. AGBACHISingle phase induction motors are found in various applications in which having correct value of the capacitor connected to the auxiliary winding enables the motor to function efficiently. This research aim is to investigate and obtain the value of the capacitor of a given input parameters of a specified permanent split capacitor (PSC) induction motor using MATLAB, which will in turn provide easy computation of the output parameters for the motor optimum efficiency. Electrical and mechanical characteristics of the PSC induction motor where obtained and analysed of which the study shows that the motor was reliable due to the absence of centrifugal switch. With the aid of MATLAB program the results were easily obtained, PSC induction motor capacitor value at optimum efficiency was also easily determined. The motor proved to have low starting torque, low starting current, higher efficiency, high pull out torque and high power factor. The characteristics of PSC induction motor analysed was limited to where higher starting torque is required only.Item Split-phase motor running as capacitor starts motor and as capacitor run motor(Leonardo Electronic Journal of Practices and Technologies, 2016-06-28) Yahaya Asizehi ENESI; Jacob TSADO; Mark NWOHU; Usman Abraham USMAN; Odu Ayo IMORUIn this paper, the input parameters of a single phase split-phase induction motor is taken to investigate and to study the output performance characteristics of capacitor start and capacitor run induction motor. The value of these input parameters are used in the design characteristics of capacitor run and capacitor start motor with each motor connected to rated or standard capacitor in series with auxiliary winding or starting winding respectively for the normal operational condition. The magnitude of capacitor that will develop maximum torque in capacitor start motor and capacitor run motor are investigated and determined by simulation. Each of these capacitors is connected to the auxiliary winding of split-phase motor thereby transforming it into capacitor start or capacitor run motor. The starting current and starting torque of the split-phase motor (SPM), capacitor run motor (CRM) and capacitor star motor (CSM) are compared for their suitability in their operational performance and applicationsItem MANAGEMENT OF ELECTRIC POWER IN NIGERIA(International Conference on Information Systems and Management Science, 2018) Ajiboye, Johnson Adegbenga; Mary Adebola Ajiboye; Misra SanjayItem Performance Analysis of Statistical Time Division Multiplexing Systems(Leonardo Electronic Journal of Practices and Technologies, 2010-01) Ajiboye, Johnson Adegbenga; Yinusa Ademola AdediranMultiplexing is a way of accommodating many input sources of a low capacity over a high capacity outgoing channel. Statistical Time Division Multiplexing (STDM) is a technique that allows the number of users to be multiplexed over the channel more than the channel can afford. The STDM normally exploits unused time slots by the non-active users and allocates those slots for the active users. Therefore STDM is appropriate for bursty sources. In this way STDM normally utilizes channel bandwidth better than traditional Time Division Multiplexing (TDM). In this work, the statistical multiplexer is viewed as M/M/1queuing system and the performance is measured by comparing analytical results to simulation results using Matlab. The index used to determine the performance of the statistical multiplexer is the number of packets both in the system and the queue. Comparison of analytical results was also done between M/M/1 and M/M/2 and also between M/M/1 and M/D/1 queue systems. At high utilizations, M/M/2 performs better than M/M/1. M/D/1 also outperforms M/M1.Item The Challenges Posed by Information Technology to Secretaries: A Study with Reference to Federal Polytechnic, Bida, Niger State, Nigeria(The IUP Journal of Information Technology, 2012-12-01) Ajiboye, Johnson Adegbenga; Mary Adebola Ajiboye; Juliet OmozokpiaThis study was conducted to identify the challenges of information technologies on secretaries in the Federal Polytechnic Bida, Niger State, Nigeria. The study was embarked upon to emphasize the importance or significance of secretaries as they face the challenges of the information technology in an ICT era. The research was carried out using 50 secretaries. The instrument used in the collection of data was a questionnaire and the data collected was analyzed using the SPSS software. From the analysis of data collected, it was found and concluded that among other things most secretaries lack necessary skills required for ICT in the modern office and most of them with just typing and shorthand skills are on the verge of losing their jobs. Although, it was discovered and concluded that secretaries will not be replaced by computers and that the ones with ICT skills are in high demand and with ample career opportunities in the modern office. It was then recommended that organizations should train and retrain their secretaries to be ICT-compliant and that the curriculum of secretarial study programs should be reviewed and widened to include ICT courses so as to give potential secretaries an ICT background.Item Queue Behavior of Statistical Multiplexers(The IUP Journal of Information Technology, 2013-03-01) Ajiboye, Johnson Adegbenga; Yinusa Ademola Adediran; Mary Adebola AjiboyeIn a statistical multiplexer, packets are assumed to be arriving at the multiplexer with the inter arrival times being Independent and Identically Distributed (IID). The service time is also IID. The inter arrival times are generated from the corresponding probability distribution. When a packet arrives to an empty or idle system, the packet is immediately served; otherwise, it is queued. In this paper, the queue behaviors in the multiplexer's buffer were examined. The results show that the average number of packets in the multiplexer queue increases in an exponential form with increase in utilization; and at high utilization, there is a dramatic increase in the number of packets in the multiplexer queue which may lead to packet loss when there is no sufficient buffering. Comparison of the simulation and analytical results for the mean number of packets in an M/M/I Multiplexer Queue reveals that results are within ±23% for offered load of up to 90%.Item Dynamic Spectrum Access (DSA) in Wireless Cognitive Radio Networks (WCRN)(2013-02-01) Ajiboye, Johnson Adegbenga; Yinusa Ademola Adediran; Mary Adebola AjiboyeDynamic Spectrum Access (DSA) is a technology that senses the unused 'free' but allocated portion of the radio frequency spectrum on a non-interfering basis. These unused bands are also known as 'holes' or 'white spaces'. DSA also refers to the time-varying, flexible usage of parts of the radio spectrum under consideration of regulatory and technical restrictions. This type of spectrum access is due to the dynamic behavior that the Secondary User (SU) must employ in order to access the spectrum, while avoiding interfering with a Primary User (PU). Intelligent or Cognitive Radio (CR) is a platform on which the DSA can be implemented. CRs are radio systems that autonomously coordinate the usage of spectrum. They utilize radio spectrum when it is not being used by incumbent (primary) radio systems. Underutilized spectrum can be exploited with the concepts of DSA and CR. This paper reviews the techniques that can be deployed for DSA reliably in a Wireless Cognitive Radio Network (WCRN) and models of network architecture-based DSA in Cognitive Radio Networks (CRN).Item An improved resampling approach for particle filters in tracking(IEEE, 2017-11-06) Yu Gong; Sangarapillai Lambotharan; Abdullahi DaniyanResampling is an essential step in particle filtering (PF) methods in order to avoid degeneracy. Systematic resampling is one of a number of resampling techniques commonly used due to some of its desirable properties such as ease of implementation and low computational complexity. However, it has a tendency of resampling very low weight particles especially when a large number of resampled particles are required which may affect state estimation. In this paper, we propose an improved version of the systematic resampling technique which addresses this problem and demonstrate performance improvement.