Contribution of the losses in the conductors of an installation in the use of electronic ballasts in fluorescent illumination

The global economic and energy situation implies that all contributions for reducing energy consumption are important and relevant in terms of study and investment analysis. In electrical installations, energy consumption can be reduced by reducing losses in the conductors, associated with the use of electronic ballasts in fluorescent illumination, allowing a better use of the energy and of the installed power, which can be an important issue, particularly when using renewable energies. In this sense, this study presents a new software application that compares and chooses the best investment in the acquisition and installation of electronic ballasts in fluorescent illumination

An Advanced LMI-Based-LQR Design for Load Frequency Control of an Autonomous Hybrid Generation System

Part 13: Energy GenerationInternational audienceThis paper proposes a load frequency control scheme for an autonomous hybrid generation system consisting of wind turbine generator (WTG), diesel engine generator (DEG), fuel cell (FC), aquaelectrolyzer (AE) and battery energy storage system (BESS). In wind power generation systems, operating conditions are changing continually due to wind speed and load changes, having an effect on system frequency. Therefore, a robust controller is required for load frequency control. The control scheme is based on Linear Matrix Inequality (LMI)-Linear Quadratic Regulator (LQR). The control optimization problem is obtained in terms of a system of LMI constraints and matrix equations that are simultaneously solved. The proposed load frequency control scheme with the advanced LMI-based-LQR (ALQR) design is applied for the autonomous hybrid generation system. The effectiveness and robustness of the proposed controller is demonstrated for different load and wind power perturbations. The results suggest superior performance of the proposed ALQR controller against an optimal output state feedback controller. The integrated control could be realized though the web by applying Internet of Things technologies within the future smart grid

RadioActive101-Learning through radio, learning for life: an international approach to the inclusion and non-formal learning of socially excluded young people

This article describes an original international approach to inclusion and non-formal learning of socially excluded young people, through participatory internet radio - RadioActive101. First, we critically discuss the social and digital exclusion of young people. We then describe our approach - that includes participatory action research methods that are influenced by the work of Dewey and Freire, and operate as a process of complex intervention. This supports the inclusive co-production of radio content in ways that support non-formal learning in two EU contexts–the UK and Portugal. We then summarise and compare a qualitative investigation of RadioActive101. This showed positive results, with important similarities and differences between the two contexts. Participants reported that RadioActive101 was motivating and contributed to the development of contemporary skills, and also stimulated improvements in psychosocial dimensions such as confidence (self-efficacy) and self-esteem. This investigation informed the development of an original recognition system for non-formal learning that maps EU Key Competences for Lifelong Learning to radio practices and activities that are recognised through electronic badges. Our reflections emphasise that in order to support the non-formal learning of socially excluded young people we must foreground our attention to fostering psychosocial dimensions alongside developing contemporary competences.info:eu-repo/semantics/acceptedVersio

Continuous-time co-operation of integrated electricity and natural gas systems with responsive demands under wind power generation uncertainty

This paper studies the role of electricity demand response program (EDRP) in the co-operation of the electric power systems and the natural gas transmission system to facilitate integration of wind power generation. It is known that time-based uncertainty modeling has a critical role in co-operation of electricity and gas systems. Also, the major limitation of the hourly discrete time model (HDTM) is its inability to handle the fast sub-hourly variations of generation sources. Accordingly, in this paper, this limitation has been solved by the operation of both energy systems with a continuous time model (CTM). Also, a new fuzzy information gap decision theory (IGDT) approach has been proposed to model the uncertainties of the wind energy. Numerical results on the IEEE Reliability Test System (RTS) demonstrate the benefits of applying the continuous-time EDRP to improve the co-scheduling of both natural gas and electricity systems under wind power generation uncertainty.fi=vertaisarvioitu|en=peerReviewed

Control of MMC-based STATCOM as an effective interface between energy sources and the power grid

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This paper presents a dynamic model of modular multilevel converters (MMCs), which are considered as an effective interface between energy sources and the power grid. By improving the converter performance, appropriate reactive power compensation is guaranteed. Modulation indices are calculated based on detailed harmonic evaluations of both dynamic and steady-state operation modes, which is considered as the main contribution of this paper in comparison with other methods. As another novelty of this paper, circulating current control is accomplished by embedding an additional second harmonic component in the modulation process. The proposed control method leads to an effective reduction in capacitor voltage fluctuation and losses. Finally, converter’s maximum stable operation range is modified, which provides efficiency enhancements and also stability assurance. The proficiency and functionality of the proposed controller are demonstrated through detailed theoretical analysis and simulations with MATLAB/Simulink

Tsunami vulnerability assessment of Casablanca-Morocco using numerical modelling and GIS tools

Earthquakes and tsunamis along Morocco's coasts have been reported since historical times. The threat posed by tsunamis must be included in coastal risk studies. This study focuses on the tsunami impact and vulnerability assessment of the Casablanca harbour and surrounding area using a combination of tsunami inundation numerical modelling, field survey data and geographic information system. The tsunami scenario used here is compatible with the 1755 Lisbon event that we considered to be the worst case tsunami scenario. Hydrodynamic modelling was performed with an adapted version of the Cornell Multigrid Coupled Tsunami Model from Cornell University. The simulation covers the eastern domain of the Azores-Gibraltar fracture zone corresponding to the largest tsunamigenic area in the North Atlantic. The proposed vulnerability model attempts to provide an insight into the tsunami vulnerability of building stock. Results in the form of a vulnerability map will be useful for decision makers and local authorities in preventing the community resiliency for tsunami hazards

Operating conditions of lead-acid batteries in the optimization of hybrid energy systems and microgrids

The promotion and deployment of storage technologies in autonomous and grid-connected systems plays a relevant part in the massive integration of renewable power sources required for the worldwide development of a sustainable society. In this regard, analyzing the behavior of electrochemical storage devices such as lead-acid batteries installed on hybrid energy systems and microgrids in terms of their lifetime and economic profitability is an important research topic. Since renewable generation is characterized by its random nature, lead-acid batteries typically work under stress conditions, which directly influence their lifetime in a negative way by increasing the net present cost. Due to the fast growing of renewable sources as a consequence of governmental policies and incentives, the number of manufacturers to be considered worldwide is becoming really high, so that optimization techniques such as genetic algorithms (GAs) are frequently used in order to consider the performance of a high number of manufacturers of wind turbines, photovoltaic panels and lead-acid batteries subject to the environmental conditions of the location under analysis to determine a cost-effective design. In this paper, GA method combined with weighted Ah ageing model is improved by including expert experiences by means of stress factors and the categorization of operating conditions, as a new contribution to earlier studies. The effectiveness of the proposed method is illustrated by analyzing a hybrid energy system to be installed in Zaragoza, Spain, resulting in a near-optimal design in a reduced computational time compared to the enumerative optimization method

Unit Commitment in a Competitive and Emission Constrained Environment

This paper is on the unit commitment problem, considering not only the economic perspective, but also the environmental perspective. We propose a bi-objective approach to handle the problem with conflicting profit and emission objectives. Numerical results based on the standard IEEE 30-bus test system illustrate the proficiency of the proposed approach

Budget impact analysis of cervical cancer screening in Portugal: comparison of cytology and primary HPV screening strategies

BACKGROUND: Primary Human Papilloma Virus (HPV) testing is the currently recommended cervical cancer (CxCa) screening strategy by the Portuguese Society of Gynecology (SPG) clinical consensus. However, primary HPV testing has not yet been adopted by the Portuguese organized screening programs. This modelling study compares clinical benefits and costs of replacing the current practice, namely cytology with ASCUS HPV triage, with 2 comparative strategies: 1) HPV (pooled) test with cytology triage, or 2) HPV test with 16/18 genotyping and cytology triage, in organized CxCa screenings in Portugal. METHODS: A budget impact model compares screening performance, clinical outcomes and budget impact of the 3 screening strategies. A hypothetical cohort of 2,078,039 Portuguese women aged 25-64 years old women is followed for two screening cycles. Screening intervals are 3 years for cytology and 5 years for the HPV strategies. Model inputs include epidemiological, test performance and medical cost data. Clinical impacts are assessed with the numbers of CIN2-3 and CxCa detected. Annual costs, budget impact and cost of detecting one CIN2+ were calculated from a public healthcare payer's perspective. RESULTS: HPV testing with HPV16/18 genotyping and cytology triage (comparator 2) shows the best clinical outcomes at the same cost as comparator 1 and is the most cost-effective CxCa screening strategy in the Portuguese context. Compared to screening with cytology, it would reduce annual CxCa incidence from 9.3 to 5.3 per 100,000, and CxCa mortality from 2.7 to 1.1 per 100,000. Further, it generates substantial cost savings by reducing the annual costs by €9.16 million (- 24%). The cost of detecting CIN2+ decreases from the current €15,845 to €12,795. On the other hand, HPV (pooled) test with cytology triage (comparator 1) reduces annual incidence of CxCa to 6.9 per 100,000 and CxCa mortality to 1.6 per 100,000, with a cost of €13,227 per CIN2+ detected with annual savings of €9.36 million (- 24%). The savings are mainly caused by increasing the length of routine screening intervals from three to five years. CONCLUSION: The results support current clinical recommendations to replace cytology with HPV with 16/18 genotyping with cytology triage as screening algorithm.info:eu-repo/semantics/publishedVersio

A redução das perdas em equipamentos e instalações eléctricas como medida de redução da fatura de energia

A eletricidade e o eletromagnetismo estão presentes no nosso dia-a-dia na quase totalidade dos equipamentos que usamos, quer no trabalho quer em períodos de lazer, desde a máquina mais sofisticada ao mais simples eletrodoméstico. Associado à utilização está o consumo de energia elétrica que pode ser reduzido com uma eficiente escolha e correta utilização. Considerando a atual situação económica mundial, em especial a Portuguesa, e o aumento dos custos de energia elétrica devido à variação da cotação do preço do petróleo e do carvão, todo o contributo para a diminuição do consumo será pertinente, permitindo a diminuição, mesmo que pequena, da fatura de energia das famílias e aumentando o rendimento disponível. Este trabalho tem por objetivo sensibilizar para a necessidade de redução do consumo de energia. Será analisada a eficiência energética dos equipamentos elétricos de uso corrente, sua implicação nos custos energéticos a incluir na fatura doméstica e redução de consumo de energia nas instalações elétricas através da diminuição das perdas nos condutores, associadas à escolha de equipamentos eficientes