Search results for "NEWA"
showing 10 items of 2491 documents
Electrostatic synchronous generator model of an Inverter-Based Distributed Generators
2015
In this paper, the idea of modelling the Inverter-Based Distributed Generators by using the concept of Electrostatic synchronous machines is discussed. A mathematical model of the inverter has been established which depends on the dc bus voltage, modulation index and frequency of the system. Two mathematical models have been developed: a small signal model and a steady-state model. These mathematical models will be helpful in studying the stability of a microgrid; especially when studying the transient stability performance of on-grid operation of converter-based distributed generator with multi-machine microgrid. Simulation results using Matlab/Simulink are carried out.
EABOT – Energetic analysis as a basis for robust optimization of trigeneration systems by linear programming
2008
Abstract The optimization of synthesis, design and operation in trigeneration systems for building applications is a quite complex task, due to the high number of decision variables, the presence of irregular heat, cooling and electric load profiles and the variable electricity price. Consequently, computer-aided techniques are usually adopted to achieve the optimal solution, based either on iterative techniques, linear or non-linear programming or evolutionary search. Large efforts have been made in improving algorithm efficiency, which have resulted in an increasingly rapid convergence to the optimal solution and in reduced calculation time; robust algorithm have also been formulated, ass…
Decentralized price-driven grid balancing via repurposed electric vehicle batteries
2017
Abstract The share of electricity generated from intermittent renewable sources, e.g., wind and solar grows rapidly. This affects grid stability and power quality. If the share of renewable power generation is to be increased further, additional flexibilities must be introduced. Aggregating small, distributed loads and energy storage facilities is a good medium-term option. In this paper, the suitability of decentralized and on-site optimized storage system consisting of repurposed electric vehicle batteries for grid balancing is investigated. Battery operation is controlled via an optimization procedure, which relies on a one-way communicated pseudo-cost function (PCF). Day-ahead electrici…
Grid integration of PEM fuel cell with multiphase switching for maximum power operation
2016
Energy storage in the form of electrolytic Hydrogen can play an important role for integration of intermittent renewable energy sources in the smart grid environment. Electrolytic Hydrogen can be used as a fuel in proton exchange membrane (PEM) fuel cell. In this work, a technique for multiphase switching of a DC-DC converter associated with grid integration of a PEM fuel cell stack for maximum power operation in non-dispatchable mode is proposed. The presented system consists of a PEM fuel cell stack which is operating in non-dispatchable mode of operation, DC-DC multiphase switching boost converter for maximum power operation and a grid tied three phase voltage source inverter (VSI). VSI …
Standard testing of photovoltaic modules for use in renewable energy education
2015
A photovoltaic laboratory exercise has been devised and used in the educational curriculum of the Renewable Energy Programme at the University of Jyväskylä. The purpose of the experimental tasks is to give students of renewable energy a good understanding of standard testing procedures used in industry for characterising photovoltaic modules and to provide practical skills in sizing simple photovoltaic installations. Herein the experimental set-up, basic theory and measurement procedure are described. The experimental apparatus is simple to assemble and uses both standard laboratory equipment and recycled components. From the experimental results, the tested PV cell had a maximum efficiency…
Anaerobic digestion of organic solid poultry slaughterhouse waste – a review
2002
This work reviews the potential of anaerobic digestion for material recovery and energy production from poultry slaughtering by-products and wastes. First, we describe and quantify organic solid by-products and wastes produced in poultry farming and poultry slaughterhouses and discuss their recovery and disposal options. Then we review certain fundamental aspects of anaerobic digestion considered important for the digestion of solid slaughterhouse wastes. Finally, we present an overview of the future potential and current experience of the anaerobic digestion treatment of these materials.
An interpretive framework for assessing and monitoring the sustainability of school gardens
2016
School gardens are, increasingly, an integral part of projects aiming to promote nutritional education and environmental sustainability in many countries throughout the world. In the late 1950s, FAO (Food and Agriculture Organization) and UNICEF (United Nations Children's Fund) had already developed projects to improve the dietary intake and behavior through school and community gardens. However, notwithstanding decades of experience, real proof of how these programs contribute to improving sustainability has not been well-documented, and reported findings have mostly been anecdotal. Therefore, it is important to begin a process of collecting and monitoring data to quantify the results and …
Evaluating the Sustainability in Complex Agri-Food Systems: The SAEMETH Framework
2015
During the last few years, the definition of sustainability and the translation of its general principles into practical and operative tasks have come into the foreground of scientific research and political agendas throughout the world. The understanding and the evaluation of the environmental, social and economic performances of complex agricultural food systems is probably the real challenge, and the design of more sustainable alternatives has been recognized as necessary for a correct territorial management. This study’s primary goal is the proposition of an interpretive structure “Sustainable Agri-Food Evaluation Methodology” (SAEMETH), able to guide the evaluation of the sustainabilit…
Achieving maximum power transfer in a multi-source renewable system
2014
In this paper, a multi-source DC-DC power system is proposed for renewable applications. A multi-input, single inductor power converter controlled by two interacting control loops is designed. The steady-state and small-signal analysis of the designed system is carried out. A battery-photovoltaic system is designed as an application example. Both the output voltage and maximum power point of solar panels are properly controlled to achieve high performances of the whole system. Experimental results on a 48 V laboratory prototype are presented to discuss system performances.
Towards a broader perspective on the forms of eco-industrial networks
2014
Abstract This paper explores various forms of eco-industrial networks in advancing environmental sustainability. Prior research on environmental sustainability primarily identifies industrial actors as autonomous entities or considers the role of networks in advancing environmental sustainability from a rather narrow perspective. However, the networks of ties in which industrial firms are embedded profoundly impacts not only their own performance, but also the natural environment in which they operate. Based on a systematic literature review, we identify four forms of eco-industrial networks that have the potential to advance environmental sustainability: 1) symbiosis networks, 2) sustainab…