1,721,003 research outputs found
Improvement of the dispatching preplanning process in day-ahead electricity market using a sequential method
No full textThis paper proposes a sequential loading method, which finds the hourly changes of frequency and optimal load distribution between power stations. The method solves to minimize the aggregate cost in the electric power system (EPS). The method also calculates the surplus or deficit of an active power in EPS, hourly power flows of each transmission lines, active power losses in the networks. Computed and analyzed the optimal regimes of Mongolian EPS by the proposed method. The result confirmed that the method can potentially benefit to supply of frequency regulation. Developed software allows doing day-ahead market planning and intraday market preplanning in EPS, which improves electricity market model
Integration of BIM and GIS for the digitization of the built environment
Full text linkThe integration of Building Information Modelling (BIM) and Geographic Information Systems (GIS) is a growing reality in the building production sector. Through this integration, it is possible to improve the efficiency of management, maintenance, use and planning of conservation operations, providing an integrated and dynamic vision of the built environment. Simultaneous exchange of BIM-GIS elements in a shared environment facilitates information access and optimizes processes like requalification, activity planning, safety and sustainable urban design. Two alternative strategies are proposed for the multidisciplinary approach, using advanced technologies to acquire, process and manage detailed and georeferenced data. The first one is an open-source environment to guarantee flexibility, customization and accessibility. The second option, in a closed-source environment, provides advanced functionalities and dedicated support. Both require careful planning, detailed analysis and collaboration between the disciplines of architecture, engineering and geoinformatics. The study transcends theoretical analysis by exploring practical implications for real-world systems integration, examining their advantages, limitations and potential synergies in terms of flexibility, security and sustainability. This will enable a more efficient and comprehensive management of the architectural heritage and the built environment, contributing to its preservation and enhancement in the context of the digital transition in a future perspective of smart cities
Energy Transition: Semi-Automatic BIM Tool Approach for Elevating Sustainability in the Maputo Natural History Museum
No full textMozambique is experiencing the consequences of a severe energy crisis with economic and social impacts. Its strict dependence on hydroelectric sources is being severely tested by recent droughts that have drastically reduced water levels in dams. However, Mozambique is addressing energy poverty by exploring renewable energy sources thanks to investments in the sector by the European Union. The research concerns an energy analysis profile of the country and the penetration of renewable energy, presenting an energy upgrading scope through a semi-automatic calculation methodology in a Building Information Modeling (BIM) environment. The building under study, located in Maputo, is the Natural History Museum, which plays an important role in biodiversity conservation. Therefore, this paper proposes a BIM methodology for sizing an environmental control system tailored to serve the museum. The proposed system replaces the previous one and includes a photovoltaic system that not only meets the museum’s load but also supplies electricity to the surrounding area. Energy production from renewable sources with a surplus of 30% has been achieved. The proposed digital methodology has identified a maximum gap of 1.5% between the dimensions of the BIM duct and those of a traditional plant design, meeting ASHRAE requirements for environmental control
Variable-window algorithm for ultra-high-speed distance protection
No full textThis paper presents a new concept in ultra-high speed distance relay for power line protection. The idea is based on the use of a sampling window shorter than usual to speed commutation. The reduction in protection time is obtained through a variable window that is expanded sample by sample until a satisfactory precision is reached in the calculation of fault quantities. The right window length is obtained automatically via software and time-by-time changes depending on the characteristics of the fault. The algorithm is based on the equation associated to the R-L fault circuit, whose solution is obtained using the phase modified Fourier transform. To validate the proposed procedure, a large number of simulations are performed with reference to an existing 150-kV subtransmission line. In comparison with other solutions, the relay proposed here is very cost-effective and makes it possible to achieve ultra-high speed fault localization not only on high-voltage (HV) networks but also on medium-voltage (MV) distribution networks
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A microgrid control strategy to save energy and curb global carbon emissions
No full textThe proposed study concerns the implementation of new strategies aimed at saving energy and reducing the global warming through the reduction of carbon emissions. For this purpose, the implementation of synergic procedures, contemporarily applied to microgrid and prosumers, are proposed and validated in the paper. The main implemented methodologies allow the real time management of different energy flows present inside buildings and, at the same time at higher hierarchic level, enable the supervision and control of the energy managed by the microgrid. The proposed general strategy optimizes contemporarily energy exchanges with the public electricity system, local electrical generation, storage and controllable loads. The developed concepts are valid in general, but also for the port systems where the purpose aims at saving energy and reducing CO2 emissions
Behavior of transformers interconnecting microgrid and prosumers
No full textThe recent evolution in electricity distribution systems has led to the development of new intelligent structures, better known as Smart Grids, Microgrids and Prosumers. The consequent advantages regard mainly both economy aspects and environmental safeguard. In a microgrid, producers and consumers can exchange energy in peer-to-peer way. Normally, the microgrid is connected to a Smart Grid in a single common point. In this case, the microgrid can be easily disconnected from the external grid and continue to work in 'island' mode. In this condition, local production must be equal to the energy consumed, unless local storage systems are installed on site. In case of a bidirectional management, the source may change in load and vice versa. In this situation, a traditional transformer may work in an overload condition and the protection system may trip, provoking, in the worst conditions, a blackout. In order to avoid this condition, some solutions are here proposed and commented. © 2019 IEEE
- …
