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1.
Braz. arch. biol. technol ; 65: e22210711, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1364439

ABSTRACT

Abstract: Microgrids (MD) is a new technology to improve efficiency, resilience, and reliability in the electricity sector. MD are most likely to have a clean energy generation, but the increase of microgrids with this kind of generation brings new challenges for energy management (EMS), especially concerning load uncertainties and variation of energy generation. In this context, this study has the main objective to propose a method of how to attend this matter, verifying the difference between the day before and real-time. The EMS proposed analyses the MD in real-time, calculating the deviation between dispatched and what was predicted to happen in the operation point in a three-dimensional analysis approach, considering renewable energy generation, battery State of Charge (SOC) and load curve. The system categorized the deviation in three possible quantities (small, medium, or high) and it acts accordingly. For the Next Operation Point predictor are used an artificial neural network (ANN) methodology. For the Decision Support System, it's used a fuzzy logic system to adjust the next operation point, and it uses a mixed-integer linear programming (MILP) approach when the deviation is too high, and the dispatched operation is unfeasible. Simulations with real data and information of a pilot project of MD are carried out to test and validate the proposed method. Results show that the methodology used to attend the matters of uncertainties and variation of energy generation. A reduction of operational cost is observed in the simulations.

2.
Braz. arch. biol. technol ; 64(spe): e21210177, 2021. tab, graf
Article in English | LILACS | ID: biblio-1285572

ABSTRACT

Abstract Microgrids (MGs) have increasingly attracted the attention of researchers, government officials, and electricity companies for the values and services they can add to the grid. They can operate independently as a single controllable unit in a coordinated way while connected or islanded, which make them suitable to integrate the growing amount of distributed energy resources (DERs) into the distribution network (DN). An active distribution network with high penetration of DERs could be redefined into a collection of microgrids in different layers, pooling their resources together to enhance the grid's performance in the sense of electricity as a service. However, enabling a microgrid-based power system infrastructure poses challenges concerning operation and control. In this paper, a comprehensive overview of research topics regarding microgrid operation are shown in a hierarchical or stratified manner, looking for a holistic vision of a microgrid-based distribution system. First, multi-objective optimization within one microgrid is formulated aiming to minimize costs and maximize battery life is presented. Second, the interaction among MGs, DERs and the DN was modeled using the OPF technique to represent the operation of the grid as a whole. Following, a methodology for collaborative optimization of multiple MGs operating together is presented and at last a theoretical framework for MG operation through decentralized energy markets is discussed. As a result, this paper aims to contribute to a broad vision of the distribution system based on microgrid operation in all its levels.


Subject(s)
Politics , Electric Wiring , Energy Supply , Brazil
3.
Braz. arch. biol. technol ; 62(spe): e19190019, 2019. graf
Article in English | LILACS | ID: biblio-1055441

ABSTRACT

Abstract In a world where technology is even more essential, quality and reliability of electrical system are fundamental. In Brazil, country where most of the energy is produced thought power plants, the existing distribution network is overwhelmed and the needs for the consolidation of distributed generation is growing. Wind and Solar power generation from biomass and another renewable sources are one alternative to power plants, which requires large areas and massive investment. The renewable energy sources mentioned may be assembled in a way to generate reliable energy to properties far from the cities, such as rural zones, where often energy from power plants doesn't gets to. Distributed generation allows quick development of Brazilian farming and guarantees to the farmer independence from the energy dealerships. Microgrids assembled with renewable sources are one sustainable option and benefits Brazilian economy and society.


Subject(s)
Biomass , Electricity , Renewable Energy , Rural Areas , Sustainable Agriculture
4.
Braz. arch. biol. technol ; 61(spe): e18000030, 2018. tab, graf
Article in English | LILACS | ID: biblio-974151

ABSTRACT

Abstract The electrical sector is under constant evolution. One of the areas refers to the consumers that come to be generators, implementing distributed generation, interconnected to a smart grid. This article discusses the improvement of an algorithm, already presented in the literature, to make the best temporal allocation of loads, electric vehicle, storage and many sources of generation, aiming at the maximum financial performance, that is, the lowest value for the energy invoice The modeling consists of a Mixed Integer Linear Programming (MILP) algorithm, which considers each component of the system and weighs the maintenance and shelf life of storage devices, basically batteries, loads that can be reallocated and the concept of Vehicle-to-grid, performing a daily analysis. The simulation has considered the hypothetical case of a residence, in which are included storage, electric vehicle and redistribution of loads, as well as wind and solar generation. Several scenarios are simulated, with or without the presence of some of the components. The results indicate that the simplest model, only redistributing the loads, can provide a sensible monetary savings of approximately 60%, while with the application of all the components modeled, there can be a reduction in the invoice of 90%.


Subject(s)
Energy-Generating Resources , Wind Energy , Solar Energy , Motor Vehicles
5.
Malaysian Orthopaedic Journal ; : 37-41, 2018.
Article in English | WPRIM | ID: wpr-756919

ABSTRACT

@#Introduction: Microsurgery is a subspecialised field which requires high technical skill. Laboratory training offers good opportunity for novice surgeons to learn and repetitively practise their skills prior to hands-on clinical practice. Commonly, the training programme consists of models in a stepwise increase in fidelity: from latex sheet to anaesthetised rat. We introduce microgrids model as a daily warm up procedure in a 5-day basic microsurgery course. The purpose of this study is to evaluate the correlation between microgrids colouring under magnification with microsuturing proficiency among novice surgeons. Materials and Methods:Participants were required to fill in microgrids under magnification everyday during their 5-day training as a starter test. The number of completely filled in microgrids in 20 seconds was recorded. A simulated cut on latex sheet was sutured and the time taken to apply five sutures was recorded. The sutures were evaluated with modified Global Rating Scale (GRS). Data was analysed with SPSS. Results:There was a statistically significant correlation between the number of microgrids coloured and the time taken to apply five sutures (p<0.01). An increase in number of microgrids coloured was significantly associated with the increase in quality of the suturing technique (p< 0.01). During the 5-day basic microsurgery skills training for novice surgeons, microsuturing skill improvement correlated with microgrid colouring. Conclusion:Microgrids colouring reflected microsuturing proficiency. It is an inexpensive, readily available, and simple model of ‘warm up’ for hand dexterity. The microgrids model can function as a starter test for initial training and a quick screening measure to assess microsurgical skill.

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