1Cape Peninsula University of Technology, Centre of Distributed Power and Electronic Systems (CDPES), Symphony Way, P. O. BOX 1906, Bellville 7535, South Africa
2Mangosuthu University of Technology, Department of Electrical Engineering, P. O. BOX 12363, Jacobs, Durban 4026, South Africa
Optimal exploitation of the costless and self-sustaining solar energy has been a concern of much research in response to pressuring energy demands in one hand and the effects of relying on energy sources which are harmful to the humans and the environment on the other hand. The conversion efficiencies of photovoltaics (PVs) as well as their production costs have therefore been research targets. However, factors such as unsatisfactory exposure to the available sunlight, weather-dependence of the sunlight and shading, temperature rise at cells’ junctions as well as manufacture related-defects still remain major causes of PVs’ underperformance which manifests in lower levels of output power and efficiency. The dynamics of the output power or current with respect to the potential differences at cells’ junctions are usually graphically illustrated with two-axis plots, which imply that only two parameters get evaluated against each other at a time.In this paper, three-axis plots were further used to evaluate the output parameters with respect to a simultaneous change of any other two parameters involved in the model of the PV cells; which gives a more realistic and comprehensive picture of the performance of PV cells. In addition, causes affecting the output and efficiency levels of cells are critically reviewed along with strategies adopted to address them.Ahandful of recommendations concerning optimizing the usage of sunlight at disposal are within provided as well.| Download File
1Research Scholar, 2Associate Professor
1,2Motilal Nehru National Institute of Technology Allahabad, India
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With the beginning of more stringent regulations related to fuel economy, global warming, and emissions as well as conventional energy resource limitations; electric, hybrid, and fuel-cell vehicles have been attracting increasing attention from vehicle constructors, consumers and governments. Especially, Proton exchange membrane fuel cell vehicles (PEMFCVs) based automobile industry has gained attention in the last few years due to rising public concern about urban air pollution and consequent environmental problems. However, design of power trains is difficult in fuel cell electric vehicle and maintaining on board hydrogen tanks as challenge in the system. Alternative power trains for automotive applications aim at improving an emissions and fuel economy. This paper provides an overview of a background of fuel cell vehicles history, different types of fuel cells based on the types of electrolyte used in the membrane electrode assembly (MEA), different types of powertrains have been used in the automobile industry especially in hybrid sector, achievements of fuel cell based automobiles in Indian terrain, various research challenges and comparing among the Internal Combustion Engines (ICE), Battery Electric Vehicles (BEVs), Fuel Cell Vehicles (FCVs), FCHEV. Moreover, fuel cell hybrid electric vehicles (FCHEVs) have huge scope in the Indian terrain because it would be easy to control of emission and global warming with economically suitable powertrain. In order to further promote the sector, initiatives are being undertaken by the Government of India to promote innovation and create a favourable policy regime to make India a prominent manufacturing hub.
Keywords: Energy Storage Subsystems (ESS), Membrane ElectrodeAssembly (MEA), Proton Exchange Membrane Fuel CellVehicles (PEMFCVs), Zero Emission Vehicles (ZEVs).
Department of Electrical and Electronics Engineering, NITK, Surathkal, Mangalore, India
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The increase in demand for electricity coupled with the obligation to use sustainable technologies, has led to research and development in small and medium scale renewable source based electricity generation systems. When it comes to the smaller systems, one of the important criteria in commissioning/ operating is simplicity of the system apart from the systems capability to produce power with acceptable standards. To meet this requirement, a novel switching network referred in this paper as comparator based switching signal selection (CSSS) network, has been proposed for controlling the inverter circuit in the generation system. The network enables the use of any two level inverter modulation schemes to control any levels of series connected inverter. This eliminates the complexity like generation of multiple carrier waveforms, performing complex calculations to generate switching signals. To demonstrate the effectiveness of employing this switching network in a generation system, the performance of a micro wind turbine based energy system has been analyzed using parameters like harmonic distortion of current, voltage and k-factor of the transformer. A comparative study of these parameters has also been performed to understand how comparable the performance of CSSS network is to the existing modulating schemes. The result of analysis and comparison shows that by employing a CSSS network, not only satisfactory performance can be obtained from the system, but also the control algorithm can be simplified.
Keywords: Micro wind turbines, Series connected inverter, Performance analysis of inverter, k-Factor, Multicarrier pwm, CSSS network.
1Department of Electrical and Electronic Engineering, The University of Nottingham Malaysia Campus, 43500, Semenyih, Selangor, Malaysia
2Department of Electrical and Electronic Engineering, University Putra Malaysia, 43400, Serdang, Selangor, Malaysia
Wind turbine can be destroyed when not adequately protected by the receptor. According to recent research, the size of the receptor plays a very important role in its efficiency. The effect of receptor size has not been well considered in literature and standards. This paper investigates six receptor sizes (10 mm, 15 mm, 20 mm, 25 mm, 30mmand 35mmreceptor diameters), encompassing adopted sizes in literature. As the blade is rotated, the interception efficiency of various receptor sizes is evaluated on a modern wind turbine. The vertical tri-pole cloud charge model developed with finite element analysis is used to study the maximum electric field strength required for the initiation of upward leader from the blade surfaces. The interception efficiency of each receptor size is evaluated by comparing the maximum electric field strength. The results of the point of initiation of upward leader match well with those obtained by experimental measurements from lightning discharge attachments.Keywords: Simulation, Lightning protection, Receptor size,Wind turbine| Download File
1Department of Chemical Engineering, University of Seville, C/ Virgen de A´frica, 7, 41011, Seville, Spain
2Grupo TAR RNM159 PAIDI, Department of Applied Physic II, University of Seville, C/ Virgen de A´frica, 7, 41011, Seville, Spain
3Grupo TAR RNM159 PAIDI, University of Seville, C/ Virgen de A´frica, 7, 41011, Seville, Spain
4Grupo TAR RNM159 PAIDI, Department of Chemical Engineering, University of Seville, C/ Virgen de África, 7, 41011, Seville, Spain
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In developed countries the sanitation and treatment of urban wastewater is well sustained and technically solved by means of conventional pipe networks and subsequent centralized treatments. However, developing countries lack these infrastructures and are in need of sustainable, decentralized and economically viable solutions for the disposal of their urban wastewaters. In addition to this, there are situations where the demands of conservation of natural spaces do not allow intensive constructive procedures and which force the implementation of sanitary engineering with less environmental impact. We present the Ecological Wastewater Sewer (EWS), an ecological urban sewerage system that simultaneously transports wastewater and improves its quality. This innovative technology is an alternative to conventional sanitation piping that has minimal environmental impact. It is based on a successful previous work for the improvement of artificial wetlands in a pilot scheme and at full-scale on a test site. The EWS is a channel-shaped device that relies on the application of two key developments: a carefully designed cornered stones layout, and the creation of a natural aeration system. This way, it acts as a separating sewage system that guarantees the presence of a chamber of circulating air within the transportation unit, favouring permanent aerobic conditions in the upper levels of the mass of wastewater. Furthermore, its capacity to settle suspended solids allows the EWS to be used as a sedimentor in water purification processes. A real-life application of this system proved successful in the sanitation of a district of Managua (Nicaragua). Working with a 100-metre-long street of 20 one-story houses, the system is reported to still be in full operating order after six years. The conclusions and results drawn from its monitoring are meticulously explained in our paper, as well as the recommendations & guidelines for the design of more EWS units, with aim to the popularization of this affordable, efficient and green approach to wastewater sanitation.
Keywords: Aeration, Anaerobic, Clogging, Ecological-sewerage, Wastewater management, Constructed wetland, Biofilm processes.