Electrical Electronics Engineering

Equipment asset management (EAM) is a branch of reliability engineering that involves formulation of policies that guide the acquisition, operations and maintainability of equipment. Meeting the challenges of business of electricity supply includes having EAM that effectively manage equipment useful life and ensure reliability of supply. In this paper, the impact of EAM on electricity distribution reliability is evaluated using Load Point Reliability Indices. The impact on distribution efficiency and benefit is also discussed. Milsoft Utility Solution software is used to simulate the system reliability analysis that generates Load Point Reliability Indices such as consumer average interruption duration index (CAIDI). The same analysis is repeated using improved equipment reliability data. Comparative analysis of the results shows that EAM policy such as Reliability Centered Asset Management (RCAM) results in improved network equipment failure rate. Improved failure rate in turn improves electricity supply reliability. EAM is also found to positively impact system efficiency and benefit as observed in the Distribution System Benefit and Efficiency analysis (DSBE). Analysis of a survey of maintenance of Nigeria Electricity supply industry is also presented.

Every now and then it is in the news, another market or another office building is gutted by fire, often times the cause of fire is only given by speculations from occupants, eye witnesses and visiting news men. Like many building collapses, road accidents and other accidents that ask critical questions of our public safety, no conclusive investigations are conducted. Hence in these cases of fire accidents as regularly as they occur (even for only the cases reported in major news media) there is hardly any expert opinion that states the cause of fire accidents and no official report is give. And possible prosecution of erring parties whose actions may have resulted in the accidents is out of the equation. Usually, the general public move on from it, including professionals and academics who should show some professional enthusiasm in establishing cause and effect of such accidents to help guide future practices. The dead are buried, the injured languish on hospital beds and survivor simply go on to organize thanks giving ceremonies….no questions asked, not by the authority, not by professional interest groups, not by the victims. Such is the story of accident in Nigeria, it could be believed the situation is so not only because we lack a functional government institutions but more because we lack quality professionals across discipline who should promote public safety and justice. This failure of professional can be traced to many disciplines, engineer who fail to follow through design and construction codes and standards, civil servants who fail to stop impending public danger at design stage when such is presented for approval, insurance brokers who are less than diligent in harnessing the services of requisite expert in risk analysis and management, and lawyers who fail to see litigation opportunities in these accidents as a way of serving justice to the victims and society. As an engineer, I will tilt towards mitigating the menace of fire accident from an engineering perspective and how professionals and government agencies can live up to their bidding in ensuring public safety. Statistics from fire department and national bureau of statistics are hardly concise enough to indicate frequency of building fire accidents and their causes such as electrical faults, explosions etc. Regardless of unavailability and or inaccuracy of national statistics on building fire, fire accidents in buildings could be different if electrical design and installations had been done by qualified engineers and technicians and to relevant codes and standards. For example, many a time explosions and fire result from static electricity around explosive materials in stores, warehouses, and markets, such explosions can be designed against by competent professional either from the inception of the building or at the time the building is to be used for such purpose. This is not the simplest example of causes of fire in buildings, it is an eye saw when one visits many of our markets how they carry out electrical connections; they are, simply put, disasters waiting to happen.

Renewable energy plays a very important role in the improvement and promotion of environmental sustainability in agricultural-related activities. This paper evaluates the techno-economic and environmental benefits of deploying photovoltaic (PV)- battery systems in a livestock farmhouse. For the energy requirements of the farm to be determined, a walkthrough energy audit is conducted on the farmhouse. The farm selected for this study is located in southern Nigeria. The National Renewable Energy Laboratory’s Hybrid Optimization Modeling for Electric Renewable (HOMER) software was adapted for the purpose of the techno-economic analysis. It is found that a standalone PV/battery-powered system in farmhouse applications has higher economic viability when compared to its diesel-powered counterparts in terms of total net present cost (TNPC). A saving of 48% is achievable over the TNPC and Cost of Energy with zero emissions. The results obtained show the numerous benefits of replacing diesel generators with renewable energy sources such as PV-battery systems in farming applications.

Purpose This study aims to analyze the effects of variations in annual real interest rates in the assessment of the techno-economic feasibility of a hybrid renewable energy system (HRES) for an off-grid community. Design/methodology/approach Hybrid Optimization of Multiple Energy Resources (HOMER) software is used to propose an HRES for Abadam community in northern Nigeria. The HRES was designed to meet the basic needs of the community over a 25-year project lifespan. Based on the available energy resources in the community, photovoltaic (PV), wind turbine, diesel generator and battery were suggested for integration to serve the load requirements. Findings When the annual real interest rates were taken as 10 and 8 per cent, the total amount of total energy fraction from PV, wind turbine and the diesel generator is 28, 57 and 15 per cent, respectively. At these interest rates, wind turbines contributed more energy across all months than other energy resources. The energy resource dis...

In this paper, the challenges that slow down the proliferation of much needed renewable microgrids in remote underserved locations in East, West and Southern Africa have been identified. These problems can be grouped as Community/Commercial ownership issues, Economic challenges, Environmental challenges, Technical failures and Policy somersaults (CETEP). Solutions to these problems have also been proffered using successful models within and outside Africa. If these can be adopted by the different governments seeking to grow the renewable energy penetration in their rural electrification goals, Sub-Saharan Africa's rural power schemes will be more sustainable and lasting.

This paper examines the sustainability of utilizing distributed generation (DG) in a reconfigured distribution network. The study is presented as an affordable and clean energy solution suitable for African sustainable development. As a case study, a distribution network (DN) in Northern Nigeria, under the Jos Electricity Distribution Power Company Plc was considered. Particle Swarm Optimization (PSO) - a heuristic algorithm - was employed as solution method. The initiation of network reconfiguration resulted in an improvement of the minimum voltage level by up to 1.2% when the network was loaded to half and full capacities. In addition to improvements in voltage levels, network reconfiguration reduced power losses by 29.36%. These losses decreased by a total of 61.94% when DG's were introduced to the reconfigured DN. With a half-loaded DN, these reductions were 19.78% and 58.37% respectively. When the afore-stated results are put into financial context, annual savings of $100,290 (for a fully loaded network) are realizable and sufficient to recoup the expenditure incurred in installing and maintaining solar photovoltaic distributed generation within a period of six years.

Africa is an import oriented continent with a significant percentage of all electronics and electrical equipment imported, as new or second hand, from other developed nations. The explosion of the telecommunications industry in Africa is an indication of the potential market in this great continent, with an estimated market of 15 million subscribers to GSM technology in Nigeria alone. As Africa increases its participation as users (and most importantly as stakeholders) of technology, the importance of electromagnetic compatibility and bio-electromagnetics increasingly becomes an issue. The paper describes EMC, its potential impact and the need for regulation in an increasing industrialized Africa

Abstract Traditionally, electromagnetic compatibility (EMC) and safety have been viewed as two separate disciplines, however the increase in electronic and electrical apparatus performing safety and control functions is leading to a re-think of this relationship. Safety ...

Modern traction electrification systems are a source of magnetic emissions and possible interference for many internal and external equipment; this is particularly true for light rail or street car systems running through cities and in close proximity to public sensitive installations. In this paper, an analysis of the magnetic field from a light rail is presented. Furthermore potential design mitigations that can be implemented to attenuate the dc component and thus reduce the risk to third party installations are considered with the help of a case study. The average field reduction obtained is in the order of 10 dB.

In view of the many and varied test standards and measurement methods for determining the shielding effectiveness of enclosures, a structured test programme is required from which shielding effectiveness properties of conductive plastic (and indeed other forms of enclosures) can be measured and evaluated effectively. This paper presents a qualification programme for the shielding effectiveness evaluation of conductive plastic enclosures, highlighting the need for an industry-harmonised standard. The suggested programme provides manufacturers and users of conductive plastic enclosures with a testing regime that facilitates the acquisition of meaningful data from which equipment designers and end users can reliably simulate and design equipment enclosures

This paper addresses the problem of robust and accepted methods for the estimation of electromagnetic emissions from electrical machinery and more extensively, Adjustable Speed Drives. Machine emissions can also be considered for diagnostic purposes. In particular, the analysis of the electromagnetic signature of the machine is used for the detection of partial short-circuits inside windings or mechanical unbalancing faults. The focus is on consistent reference data and readily applicable models rather than on theoretical treatment, since the environment in which this apparatus operates is deemed by high levels of electromagnetic noise and propagation conditions far from ideal ones.