36 research outputs found

    Smart Homes and Sustainable Cities: The Design of a Low-Cost Solution for Comprehensive Home Automation

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    The challenge for smart cities is to connect as many of its inhabitants to technology enabling solutions that improve their lives. Smart homes provide all users a means of interacting and impacting their environment. In developing economies this proves challenging and these challenges are daunting and overwhelming since system costs are always a foreboding factor. The chapter addresses these challenges by providing a low-cost solution for a home energy saving measure. It introduces an overview of enabling technologies for a smart home by considering energy management, energy saving, load management and monitoring and control of living spaces. By leveraging the application of the Internet of Things (IoT) and load management strategies, the realisation of a smart home is made possible. This chapter presents a broad overview of the design and development of a web-enabled smart home solution. Web development and control systems together form the backbone of automation for modern home automation technologies such as the Internet of Things and embedded systems. The developed web-enabled home automation incorporates elements of web developed software application and digital control systems. The web-enabled interface energy saving measure is a networked system that uses web-enabled applications for enabling energy efficiency by incorporating load management, remote power consumption, monitoring and control

    Preventive Maintenance and Fault Detection for Wind Turbine Generators Using a Statistical Model

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    Vigilant fault diagnosis and preventive maintenance has the potential to significantly decrease costs associated with wind generators. As wind energy continues the upward growth in technology and continued worldwide adoption and implementation, the application of fault diagnosis techniques will become more imperative. Fault diagnosis and preventive maintenance techniques for wind turbine generators are still at an early stage compared to matured strategies used for generators in conventional power plants. The cost of wind energy can be further reduced if failures are predicted in advance of a major structural failure, which leads to less unplanned maintenance. High maintenance cost of wind turbines means that predictive strategies like fault diagnosis and preventive maintenance techniques are necessary to manage life cycle costs of critical components. Squirrel-Cage Induction Generators (SCIG) are the prevailing generator type and are more robust and cheaper to manufacturer compared to other generator types used in wind turbines. A statistical model was developed using SCADA data to estimate the relationships between winding temperatures and other variables. Predicting faults in stator windings are challenging because the unhealthy condition rapidly evolves into a functional failure

    STRATEGIC MODULATION OF THERMAL TO ELECTRICAL ENERGY RATIO PRODUCED FROM PV/T MODULE

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    Several strategies have been developed to enhance the performance of a solar photovoltaicthermal (PV/T) system in buildings. However, these systems are limited by the cost, complex structure and power consumed by the pump. This paper proposes an optimisation method conversion strategy that modulates the ratio of thermal to electrical energy from the photovoltaic (PV) cell, to increase the PV/T system’s performance. The design and modelling of a PV cell was developed in MATLAB/Simulink to validate the heat transfer occurring in the PV cell model, which converts the radiation (solar) into heat and electricity. A linear regression equation curve was used to define the ratio of thermal to electrical energy technique, and the behavioural patterns of various types of power (thermal and electrical) as a function of extrinsic cell resistance (Rse). The simulation results show an effective balance of the thermal and electrical power when adjusting the Rse. The strategy to modulate the ratio of thermal to electrical energy from the PV cell may optimise the PV/T system’s performance. A change of Rse might be an effective method of controlling the amount of thermal and electrical energy from the PV cell to support the PV/T system temporally, based on the energy need. The optimisation technique of the PV/T system using the PV cell is particularly useful for households since they require electricity, heating, and cooling. Applying this technique demonstrates the ability of the PV/T system to balance the energy ( thermal and electrical) produced based on the weather conditions and the user’s energy demands

    A PV power supply module for a portable Cubesat satellite ground station

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    This research focuses on the problem of powering a remote and mobile satellite ground station, where utility power is unavailable. It focuses on the use of photovoltaic energy, which is now widely accepted as an alternative source of energy. However, PV suffers from low conversion efficiency, non-linear I-V characteristics, which depend on temperature changes and the earth rotation. The research focuses on accurate determination of the ground station power budget whose total power demand involves an azimuth and rotator function and a current which varies depending on the stages of communication with the satellite. The power budget is used to determine the size, the ratings of solar generators, batteries and the system components. With the aid of a power logger, the PV voltage, the battery voltage, the AC voltage and PV power output is analysed for varying satellite loads. The data is analysed by taking into account the solar irradiation level on the day of measurement and the percentage cloud cover. This method is found to improve the reliability and can be adopted to improve reliability of standalone PV systems. The results are vital in PV power management and design

    Species Composition, Distribution, Biomass Trends and Exploitation of Dominant Fish Species in Manila Bay using Experimental Trawl Survey

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    An experimental trawl fishing survey was conducted in Manila Bay from March 2014 to October 2015 at sixteen (16) pre-established dragging stations adapted from an earlier study (MADECOR, 1995). Using a commercial otter trawl, the average trawling speed during fishing operations was 6-7 km/hour. Analysis of catches focused on biomass trends, species composition, distribution and exploitation of dominant species. A total of 146 fish and invertebrate species belonging to 48 families were recorded during the survey period wherein most of the catches were dominated by small pelagic species such as anchovies and sardines. Exploitation rates (E) for the six (6) dominant species (Sardinella gibbosa, Sardinella fimbriata, Valamugil seheli, Mugil cephalus, Encrasicholina devisi and Stolephorous commersonnii) shows signs of overfishing. The estimated demersal fish biomass of the bay revealed that the relative decline was about 90% from the 1947 baseline study

    An investigation and design of an infrared radiation heat profile controller

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    Thesis (MTech (Electrical Engineering))--Peninsula Technikon, 2002This research outlines the development and design of an infrared radiation heating profile controller. The study includes both the theoretical aspects of the design process as well as giving an overview of the practical facets involved. The controller was subjected to comparative testing with a proportional control model, in order to observe its performance and validate its effectiveness. A need exists for these types of controllers and proved to be the motivation to embark on this investigation. Controllers of this nature that are commercially available either lacks the functionality of this unit or are too expensive to implement for research purposes. This unit was designed with cost effectiveness in mind but still meet the standards required of an industrial style controller. To this end the construction was completed using low cost and affordable electronic components. Heating profiles are necessary and useful tools for the proper processing of a host of materials. The controller developed in this research is able to within a fair degree of accuracy track a heating profile. The results confirm that this programmable control model to be a benefit and a valuable tool in temperature regulation. This means that intensive studies into the effects of infrared radiation on materials are now feasible. Research of this nature could possibly expand the application of infrared as a heating mechanism. Although tests were conducted on this controller, they are not meant to serve as an exhaustive analysis. The conclusions of these examinations do reveal the benefit of such a controller. More rigorous investigation is suggested as a subject for further study

    Geochemistry of volcanic and subvolcanic rocks and biostratigraphy on radiolarian cherts from the Almopias ophiolites and Paikon unit (Western Vardar, Greece)

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    The Almopias and Paikon “sub-zones” in northern Greece represent the easternmost part of the Vardar Domain. Volcanic sequences in the Paikon subzone largely consist of calc-alkaline volcanic rocks with very minor normal-type (N-) mid-ocean ridge basalts (MORB) and boninites. These data confirm that the Paikon volcanics have originated in a volcanic arc setting developed during the Middle to Late Jurassic times on the westernmost continental margin of the European plate. The Almopias “sub-zone” consists of several ophiolite-bearing tectonic units showing a complex combination of different metamorphic, litho-stratigraphical, and age characteristics. The Liki, Nea Zoi, and Vrissi units (central Almopias) are ophiolitic mélanges, the Mavrolakkos and Krania units (eastern Almopias) consist of volcanic sequences, and the Ano Garefi unit (eastern Almopias) includes serpentinized peridotites and overlying basaltic lavas. The Liki unit underwent metamorphism and deformation under amphibolite-facies condition and includes rocks showing N-MORB and low-K island arc tholeiitic affinities. The Nea Zoi unit incorporates N-MORBs of unknown age and Late Triassic calc-alkaline rocks. The Vrissi unit includes an incomplete volcanic sequence consisting of MORB-type volcanics cross cut by arc-type dyke and Middle-Late Jurassic arc-type volcanic rocks. The Mavrolakkos unit consists of sheeted dykes, lavas, and individual dykes with N-MORB affinity, which are crosscut by dykes showing volcanic arc affinity. The Krania unit consists of Middle-Late Jurassic N-MORB series tectonically associated with calc-alkaline volcanics and dykes. Basalts of the Ano Garefi unit have alkaline affinity, whereas dikes cutting the peridotites show enriched-type MORB chemistry. Our data show the occurrence in the Almopias units of Middle-Late Jurassic N-MORB lavas associated with overlying coeval volcanic arc-type lavas and/or intruded by volcanic arc-type dykes. A major point arising from this paper is that some of the Almopias ophiolitic units do not correlate with the other ophiolitic units in the Dinaride-Hellenide belt and some could correlate with the northernmost extension of the Vardar zone in the South Apuseni - Transylvanian ophiolitic belt in Romania

    Analysis of the efficacy of a simplified infrared energy management system.

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    Adonis, M.; and Khan, M. T. E.; (2008). "Analysis of the efficacy of a simplified infrared energy management system". - The definitive, peer-reviewed and edited version of this article is published in Journal of Energy in Southern Africa. [online]. 2008, vol.19, n.2, pp. 14-21. ISSN 2413-3051. link: http://www.scielo.org.za/pdf/jesa/v19n2/02.pdfThis paper summarizes a comparison of an alwayson and a programmable type industrial style infrared dryer. The load power supplied for each kind of dryer is analysed. The design and implementation of an infrared radiation controller is also presented. The study includes both the theoretical aspects of the design process as well as an overview of the practical facets involved. The infrared drying system controller was subjected to comparative testing with an on/off control model, in order to observe the controller’s performance and validate its effectiveness. The proposed controller contributes to a more energy efficient drying system than the always-on techniques that are employed to fluctuate the heater temperature

    Temperature management strategies for a 9kw hybrid FIR-convective fruit dryer

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    A range of infrared heater temperature management mechanisms for a hybrid FIR-convective fruit dryer were designed and tested. The dryer was implemented in order to produce commercial grade apple chips. The infrared heater was subjected to a step-down power converter under current-mode and voltage-mode control. A buck converter was designed and tested to gauge its effectiveness. Simulations were performed on the various system configurations incorporating the buck converter in order to observe their responses to disturbances. In addition these systems were placed under classical control methods and a basic synergetic control scheme
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