Exploring identity within the recovery process of people with serious mental illnesses.

Science.gov (United States)

Buckley-Walker, Kellie; Crowe, Trevor; Caputi, Peter

2010-01-01

To examine self-identity within the recovery processes of people with serious mental illnesses using a repertory grid methodology. Cross-sectional study involving 40 mental health service consumers. Participants rated different "self" and "other" elements on the repertory grid against constructs related to recovery, as well as other recovery focused measures. Perceptions of one's "ideal self" represented more advanced recovery in contrast to perceptions of "a person mentally unwell." Current perceptions of self were most similar to perceptions of "usual self" and least similar to "a person who is mentally unwell." Increased identification with one's "ideal self" reflected increased hopefulness in terms of recovery. The recovery repertory grid shows promise in clinical practice, in terms of exploring identity as a key variable within mental health recovery processes. Distance measures of similarity between various self-elements, including perceptions of others, maps logically against the recovery process of hope.

Level-Set Methodology on Adaptive Octree Grids

Science.gov (United States)

Gibou, Frederic; Guittet, Arthur; Mirzadeh, Mohammad; Theillard, Maxime

2017-11-01

Numerical simulations of interfacial problems in fluids require a methodology capable of tracking surfaces that can undergo changes in topology and capable to imposing jump boundary conditions in a sharp manner. In this talk, we will discuss recent advances in the level-set framework, in particular one that is based on adaptive grids.

SELECTING WORKING TEAMS FOR INFORMATION TECHNOLOGY OUTSOURCING PROJECTS THROUGH A COMBINATION OF METHODOLOGIES

Directory of Open Access Journals (Sweden)

María Alejandra Castellini

Full Text Available ABSTRACT This paper deals with a problem that Information Technology outsourcing suppliers generally face when selecting a working team technically capable for specific roles in software development projects. A combination of methodologies, interactively integrated, is proposed. They are Soft System Methodology to structure the problem, Repertory Grid for individual interviews and elicitation of the selection criteria, DRV Processes to assess the candidates and to generate knowledge and consensus on the selection process and Linear Programming to assign people to each position. This multimethodology allowed finding a more comprehensive solution than that initially requested by the company, since it helped to establish the necessary transformations for the selection model to operate in the right way, set the competencies to be considered as selection criteria, develop a consensus estimate of the weighted criteria, and award global values to candidates, optimizing the assignment of roles in the group for the project.

A simulation methodology of spacer grid residual spring deflection for predictive and interpretative purposes

International Nuclear Information System (INIS)

Kim, K. T.; Kim, H. K.; Yoon, K. H.

1994-01-01

The in-reactor fuel rod support conditions against the fretting wear-induced damage can be evaluated by spacer grid residual spring deflection. In order to predict the spacer grid residual spring deflection as a function of burnup for various spring designs, a simulation methodology of spacer grid residual spring deflection has been developed and implemented in the GRIDFORCE program. The simulation methodology takes into account cladding creep rate, initial spring deflection, initial spring force, and spring force relaxation rate as the key parameters affecting the residual spring deflection. The simulation methodology developed in this study can be utilized as an effective tool in evaluating the capability of a newly designed spacer grid spring to prevent the fretting wear-induced damage

The attitudes of pregnant women and midwives towards raised BMI in a maternity setting: A discussion of two repertory grid studies.

Science.gov (United States)

Hodgkinson, Emma L; Smith, Debbie M; Hare, Dougal J; Wittkowski, Anja

2017-02-01

Weight-related stereotypes may have a detrimental impact on interactions between midwives and pregnant women with a body mass index (BMI) outside the recommended range of 18-30kg/m 2 . This paper explores the reciprocal construal of midwives and pregnant women with a raised BMI and considers the clinical implications of these constructs. Ten pregnant women with a BMI≥30kg/m 2 and 11 midwives and from an inner city maternity service were recruited. Participants provided information that allowed for the creation of a repertory grid; generating psychological constructs (perceptions or attitudes) identifying similarities and differences between pregnant women and midwives across a BMI range. Midwives were extremely conscious of being perceived as judgemental. They construed all pregnant women as anxious and vulnerable, but attributed characteristics such as "less health-conscious" and "complacent" to those with a raised BMI. The ideal pregnant woman and ideal midwife were typically construed as more likely to have a BMI of 18-30kg/m 2 . Pregnant women with a BMI≤18kg/m 2 were construed as lacking warmth. While midwives differentiated between the elements based on role, the pregnant women construed the elements according to their BMI. Similarly, they construed those with a BMI≤18kg/m 2 as having an undesirable personality, and acknowledged weight-related stereotypes for those with a raised BMI. It is possible these constructs impact on the way midwives care for and interact with women. Midwives may be supported through reflective clinical supervision and communication skills training to reduce the perceptions of stigma experienced by women with a raised BMI. It may be beneficial to involve pregnant women with a raised BMI in service development to ensure services meet their needs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Towards Teaching Analytics

DEFF Research Database (Denmark)

Vatrapu, Ravi; Reimann, Peter; Hussain, Abid

2013-01-01

of learners about elements belonging to the topic of study. Repertory Grid and RGFA are a pedagogical method and a computational tool respectively of the NEXT-TELL EU project (www.next-tell-eu) that is concerned with technology enhanced formative assessment and pedagogical decision-making. System description......In this paper, we present a short description of RGFA, a web-based software implementation of the Repertory Grid method. RGFA facilitates the study of the personal constructs of students for spatial diagnosis of their knowledge levels. Repertory Grid is a method for eliciting personal constructs...

A methodology for analysis of impacts of grid integration of renewable energy

International Nuclear Information System (INIS)

George, Mel; Banerjee, Rangan

2011-01-01

Present electricity grids are predominantly thermal (coal, gas) and hydro based. Conventional power planning involves hydro-thermal scheduling and merit order dispatch. In the future, modern renewables (hydro, solar and biomass) are likely to have a significant share in the power sector. This paper presents a method to analyse the impacts of renewables in the electricity grid. A load duration curve based approach has been developed. Renewable energy sources have been treated as negative loads to obtain a modified load duration curve from which capacity savings in terms of base and peak load generation can be computed. The methodology is illustrated for solar, wind and biomass power for Tamil Nadu (a state in India). The trade-offs and interaction between renewable sources are analysed. The impacts on capacity savings by varying the wind regime have also been shown. Scenarios for 2021-22 have been constructed to illustrate the methodology proposed. This technique can be useful for power planners for an analysis of renewables in future electricity grids. - Research highlights: → A new method to analyse impacts of renewables in the electricity grid. → Effects of wind, solar PV and biomass power on load duration curve and capacity savings are shown. → Illustration of intermittent renewables and their interplay for sites in India and the UK. → Future scenarios constructed for generation expansion planning with higher levels of renewable.

Development and Evaluation of a Methodology for the Generation of Gridded Isotopic Datasets

International Nuclear Information System (INIS)

Argiriou, A.A.; Salamalikis, V; Lykoudis, S.P.

2013-01-01

The accurate knowledge of the spatial distribution of stable isotopes in precipitation is necessary for several applications. Since the number of rain sampling stations is small and unevenly distributed around the globe, the global distribution of stable isotopes can be calculated via the generation of gridded isotopic data sets. Several methods have been proposed for this purpose. In this work a methodology is proposed for the development of 10'x 10' gridded isotopic data from precipitation in the central and eastern Mediterranean. Statistical models are developed taking into account geographical and meteorological parameters as regressors. The residuals are interpolated onto the grid using ordinary kriging and thin plate splines. The result is added to the model grids, to obtain the final isotopic gridded data sets. Models are evaluated using an independent data set. the overall performance of the procedure is satisfactory and the obtained gridded data reproduce the isotopic parameters successfully. (author)

Development and Evaluation of a Methodology for the Generation of Gridded Isotopic Datasets

Energy Technology Data Exchange (ETDEWEB)

Argiriou, A. A.; Salamalikis, V [University of Patras, Department of Physics, Laboratory of Atmospheric Physics, Patras (Greece); Lykoudis, S. P. [National Observatory of Athens, Institute of Environmental and Sustainable Development, Athens (Greece)

2013-07-15

The accurate knowledge of the spatial distribution of stable isotopes in precipitation is necessary for several applications. Since the number of rain sampling stations is small and unevenly distributed around the globe, the global distribution of stable isotopes can be calculated via the generation of gridded isotopic data sets. Several methods have been proposed for this purpose. In this work a methodology is proposed for the development of 10'x 10' gridded isotopic data from precipitation in the central and eastern Mediterranean. Statistical models are developed taking into account geographical and meteorological parameters as regressors. The residuals are interpolated onto the grid using ordinary kriging and thin plate splines. The result is added to the model grids, to obtain the final isotopic gridded data sets. Models are evaluated using an independent data set. the overall performance of the procedure is satisfactory and the obtained gridded data reproduce the isotopic parameters successfully. (author)

A three-dimensional electrostatic particle-in-cell methodology on unstructured Delaunay-Voronoi grids

International Nuclear Information System (INIS)

Gatsonis, Nikolaos A.; Spirkin, Anton

2009-01-01

The mathematical formulation and computational implementation of a three-dimensional particle-in-cell methodology on unstructured Delaunay-Voronoi tetrahedral grids is presented. The method allows simulation of plasmas in complex domains and incorporates the duality of the Delaunay-Voronoi in all aspects of the particle-in-cell cycle. Charge assignment and field interpolation weighting schemes of zero- and first-order are formulated based on the theory of long-range constraints. Electric potential and fields are derived from a finite-volume formulation of Gauss' law using the Voronoi-Delaunay dual. Boundary conditions and the algorithms for injection, particle loading, particle motion, and particle tracking are implemented for unstructured Delaunay grids. Error and sensitivity analysis examines the effects of particles/cell, grid scaling, and timestep on the numerical heating, the slowing-down time, and the deflection times. The problem of current collection by cylindrical Langmuir probes in collisionless plasmas is used for validation. Numerical results compare favorably with previous numerical and analytical solutions for a wide range of probe radius to Debye length ratios, probe potentials, and electron to ion temperature ratios. The versatility of the methodology is demonstrated with the simulation of a complex plasma microsensor, a directional micro-retarding potential analyzer that includes a low transparency micro-grid.

An integrative approach to the design methodology for 3-phase power conditioners in Photovoltaic Grid-Connected systems

International Nuclear Information System (INIS)

Rey-Boué, Alexis B.; García-Valverde, Rafael; Ruz-Vila, Francisco de A.; Torrelo-Ponce, José M.

2012-01-01

Highlights: ► A design methodology for Photovoltaic grid-connected systems is presented. ► Models of the Photovoltaic Generator and the 3-phase Inverter are described. ► The power factor and the power quality are regulated with vector control. ► Simulation and experimental results validate the design methodology. ► The proposed methodology can be extended to any Renewable or Industrial System. - Abstract: A novel methodology is presented in this paper, for the design of the Power and Control Subsystems of a 3-phase Photovoltaic Grid-Connected system in an easy and comprehensive way, as an integrative approach. At the DC side of the Power Subsystem, the Photovoltaic Generator modeling is revised and a simple model is proposed, whereas at the AC side, a vector analysis is done to deal with the instantaneous 3-phase variables of the grid-connected Voltage Source Inverter. A d–q control approach is established in the Control Subsystem, along with its specific tuned parameters, as a vector control alternative which will allow the decoupled control of the instantaneous active and reactive powers. A particular Case of Study is presented to illustrate the behavior of the design methodology regarding the fulfillment of the Photovoltaic plant specifications. Some simulations are run to study the performance of the Photovoltaic Generator together with the exerted d–q control to the grid-connected 3-phase inverter, and some experimental results, obtained from a built flexible platform, are also shown. The simulations and the experimental results validate the overall performance of the 3-phase Photovoltaic Grid-Connected system due to the attained unitary power factor operation together with good power quality. The final validation of the proposed design methodology is also achieved.

2011 Population Grid for Spain. Methodological assessment of different construction possibilities

Directory of Open Access Journals (Sweden)

Francisco J. Goerlich Gisbert

2017-08-01

Full Text Available This paper presents an evaluation, from the user point of view, of the regular population grid, with 1 km2 resolution, that the Spanish National Statistical Institute (INE, has released as a product from the last Population and Dwellings Census 2011. This way of disseminating population data is novel, and has a lot of analytical potential uses, since population is no longer linked to administrative divisions. For the first time this information about the population distribution has been generated using a bottom-up approach for the whole of Spain, this is, by georeferencing the population at its place of residence. The availability of another grid at the same spatial resolution, but generated using a top-down approach, this is, by spatial disaggregation methods from administrative population data and other auxiliary land cover information, allow us to explore the benefits associated to georeferencing the population in the context of the methodological changes introduced by the Population and Dwellings Census 2011. At the same time, we are able to evaluate the merits of the census grid .

Differences in body image between anorexics and in-vitro-fertilization patients - a study with Body Grid

Science.gov (United States)

Borkenhagen, Ada; Klapp, Burghard F.; Schoeneich, Frank; Brähler, Elmar

2005-01-01

Objectives: The purpose of the investigation was to explore the body image disturbance of anorexics and in-vitro-fertilization patients (IvF-patients) with Body Grid and Body Identity Plot. Methods: The paper reports on an empirical study conducted with 32 anorexic patients and 30 IvF-patients. The structure of the body image was derived from the Body Grid, an idiographic approach following the Role Repertory Grid developed by George A. Kelly [17]. The representation of the body image and the degree of body-acceptance is represented graphically. Results: By the Body Grid and Body Identity Plot measures we were able to identify important differences in body image between anorexics and IvF-patients. Conclusion: The tendencies of dissociation in the body image of anorexics which we found must be seen in the sense of a specific body image disturbance which differs significantly from the body-experience profile of IvF-patients. With the grid approach it was possible to elicit the inner structure of body image and determine the acceptance of the body and integration of single body parts. PMID:19742059

The Construal of Midwives by Pregnant Women with a Body Mass Index Greater Than or Equal to 30 kg/m2 (BMI ≥ 30 kg/m2 ): A Repertory Grid Study.

Science.gov (United States)

Hodgkinson, Emma L; Smith, Debbie M; Hare, Dougal Julian; Wittkowski, Anja

2017-03-01

To explore the construal of midwives by pregnant women with a body mass index greater than 30 kg/m 2 (BMI ≥ 30 kg/m 2 ). Ten pregnant women with a BMI ≥ 30 kg/m 2 were recruited from antenatal clinics at a maternity hospital in the North West of England. Each participant completed a repertory grid. The participants chose people to match roles including themselves, pregnant women, midwives of different BMIs and hypothetical elements. They also generated psychological constructs to describe them. Pregnant women with a BMI ≥ 30 kg/m 2 construed themselves as vulnerable and self-conscious. Some women endorsed obesity-related stereotypes for themselves and felt responsible for their weight. The midwife with a BMI 18 stereotypes. Copyright © 2016 John Wiley & Sons, Ltd. Pregnant women with a BMI ≥ 30 kg/m 2 construe themselves as vulnerable and self-conscious and perceive themselves responsible for their weight. Pregnant women with a BMI ≥ 30 kg/m 2 construe midwives with a low BMI as having an undesirable, cold, interpersonal style. Midwives with a raised BMI are construed as similar to the women, because they share the uncomfortable psychological consequences of a raised BMI. The nature of pregnant women's construal may affect their engagement and satisfaction with maternity services and midwifery care. Copyright © 2016 John Wiley & Sons, Ltd.

The repertory grid technique as method for the study of cultural differences

NARCIS (Netherlands)

Tomico Plasencia, O.; Karapanos, E.; Levy, P.D.; Mizutani, N.; Yamanaka, T.

2009-01-01

Culture is typically approached in the field of design through generic, cross-domain constructs. In this paper we provide an alternative methodological approach to exploring cross-cultural differences by studying the idiosyncratic views of individuals with regard to existing products. We

A Methodological Inter-Comparison of Gridded Meteorological Products

Science.gov (United States)

Newman, A. J.; Clark, M. P.; Longman, R. J.; Giambelluca, T. W.; Arnold, J.

2017-12-01

Here we present a gridded meteorology inter-comparison using the state of Hawaíi as a testbed. This inter-comparison is motivated by two general goals: 1) the broad user community of gridded observation based meteorological fields should be aware of inter-product differences and the reasons they exist, which allows users to make informed choices on product selection to best meet their specific application(s); 2) we want to demonstrate the utility of inter-comparisons to meet the first goal, yet highlight that they are limited to mostly generic statements regarding attribution of differences that limits our understanding of these complex algorithms and obscures future research directions. Hawaíi is a useful testbed because it is a meteorologically complex region with well-known spatial features that are tied to specific physical processes (e.g. the trade wind inversion). From a practical standpoint, there are now several monthly climatological and daily precipitation and temperature datasets available that are being used for impact modeling. General conclusions that have emerged are: 1) differences in input station data significantly influence product differences; 2) prediction of precipitation occurrence is crucial across multiple metrics; 3) derived temperature statistics (e.g. diurnal temperature range) may have large spatial differences across products; and 4) attribution of differences to methodological choices is difficult and may limit the outcomes of these inter-comparisons, particularly from a development viewpoint. Thus, we want to continue to move the community towards frameworks that allow for multiple options throughout the product generation chain and allow for more systematic testing.

Applying Repertory Grids in Complex Psychological and Psychiatric Expertise in Parents' Legal Disputes over Child Rearing

Directory of Open Access Journals (Sweden)

Safuanov F.S.

2017-08-01

Full Text Available The growing number of dysfunctional families causes the increasing number of civil litigation on the parenting (upbringing of the child. In these families the relationship between the partners are high conflict. The actual problem is the study of the emotional-semantic reactions of wives and husbands on the family traumatic situations. 20 parents of harmonious families and 30 parents of disharmonious families (which are in the process of divorce and determination of the place of residence of the child or the order of meetings of the child with the noncustodial parent were surveyed by the rank grid test. It is shown that the application of the rank grid test in the study of high conflict and harmonious families allows to identify some features of the relationship of spouses to each other and the parents to the child. The specific of emotional response of adult family members to the traumatic situations associated with the behavior of a marriage partner and child is revealed. Types of the selected response: sthenic, ambivalent and asthenic, the latter two types have their substantial options.

Facilitating Teamwork in the Design Process

DEFF Research Database (Denmark)

Bang, Anne Louise; Nissen, Kirsten

2009-01-01

By approaching the Repertory Grid as an exploratory design game and drawing on insight in diagrammatic reasoning we argue that this approach is useful in supporting team work in the design process. In this paper we draw on two courses inviting textile design students to contribute to the developm......By approaching the Repertory Grid as an exploratory design game and drawing on insight in diagrammatic reasoning we argue that this approach is useful in supporting team work in the design process. In this paper we draw on two courses inviting textile design students to contribute...

THE ROMAN FRONTIER IN BISTRIȚA – NĂSĂUD COUNTY. PART I. THE REPERTORY

Directory of Open Access Journals (Sweden)

Radu Iustinian Zăgreanu

2017-07-01

Full Text Available The aim of this paper is to reopen the issues regarding the northern section of the frontiers of Dacia Porolissensis, most of the segment, located on the modern territory of Bistrița – Năsăud County. After almost 40 years, this study is returns to the questions about the watchtowers of the Roman frontier, their locations, their state of preservation and their functionality. The paper is largely an updated repertory of the military structures, with a series of observations regarding their role in the military system of Limes Romanus.

A Root-Locus Design Methodology Derived from the Impedance Stability Criterion and Its Application for LCL Grid-Connected Converters

DEFF Research Database (Denmark)

Diaz, Enrique Rodriguez; Freijedo Fernandez, Francisco Daniel; Golsorkhi, Mohammad

2016-01-01

This paper presents a systematic methodology for design and tuning of the controller of LCL grid-connected converters. The proposed approach is derived from the impedance/admittance stability formulation , which eases the controller modelling of LCL grid-connected systems. After system modelling......, a modified sensitivity function is defined to analyze the closed loop dynamics. For practical development, the control objectives are linked to main requirements in wind turbine applications: 1) the current control time constant should be minimized and 2) active damping actions should effectively mitigate...

Study on the methodology for allocating costs of grid losses

International Nuclear Information System (INIS)

Aalberts, A.; Dekker, G.; Jaarsma, S.; Tieben, B.; Vlug, N.

2011-01-01

The research question in this report: 'Where are grid losses caused and in which (objective) manner can the costs of these grid losses be allocated to the buyers. The key questions answered in the research are: (1) In which locations of the electricity grid are losses caused and what is the volume of these losses?; (2) How are the costs of grid losses allocated to the various groups of end users?; and (3) What are alternative way(s) to allocate the costs of grid losses to the buyers?. [nl

Socioeconomic assessment of smart grids. Summary

International Nuclear Information System (INIS)

2015-07-01

In September of 2013, the President of France identified smart grids as an important part of the country's industrial strategy, given the opportunities and advantages they can offer French industry, and asked the Chairman of the RTE Management Board to prepare a road-map outlining ways to support and accelerate smart grid development. This road-map, prepared in cooperation with stakeholders from the power and smart grids industries, identifies ten actions that can be taken in priority to consolidate the smart grids sector and help French firms play a leading role in the segment. These priorities were presented to the President of France on 7 May 2014. Action items 5 and 6 of the road-map on smart grid development relate, respectively, to the quantification of the value of smart grid functions from an economic, environmental and social (impact on employment) standpoint and to the large-scale deployment of some of the functions. Two tasks were set out in the 'Smart Grids' plan for action item 5: - Create a methodological framework that, for all advanced functions, allows the quantification of benefits and costs from an economic, environmental and social (effect on jobs) standpoint; - Quantify, based on this methodological framework, the potential benefits of a set of smart grid functions considered sufficiently mature to be deployed on a large scale in the near future. Having a methodology that can be applied in the same manner to all solutions, taking into account their impacts on the environment and employment in France, will considerably add to and complement the information drawn from demonstration projects. It will notably enable comparisons of benefits provided by smart grid functions and thus help give rise to a French smart grids industry that is competitive. At first, the smart grids industry was organised around demonstration projects testing different advanced functions within specific geographic areas. These projects covered a wide enough

Socioeconomic assessment of smart grids - Summary

International Nuclear Information System (INIS)

Janssen, Tanguy

2015-07-01

In September of 2013, the President of France identified smart grids as an important part of the country's industrial strategy, given the opportunities and advantages they can offer French industry, and asked the Chairman of the RTE Management Board to prepare a road-map outlining ways to support and accelerate smart grid development. This road-map, prepared in cooperation with stakeholders from the power and smart grids industries, identifies ten actions that can be taken in priority to consolidate the smart grids sector and help French firms play a leading role in the segment. These priorities were presented to the President of France on 7 May 2014. Action items 5 and 6 of the road-map on smart grid development relate, respectively, to the quantification of the value of smart grid functions from an economic, environmental and social (impact on employment) standpoint and to the large-scale deployment of some of the functions. Two tasks were set out in the 'Smart Grids' plan for action item 5: - Create a methodological framework that, for all advanced functions, allows the quantification of benefits and costs from an economic, environmental and social (effect on jobs) standpoint; - Quantify, based on this methodological framework, the potential benefits of a set of smart grid functions considered sufficiently mature to be deployed on a large scale in the near future. Having a methodology that can be applied in the same manner to all solutions, taking into account their impacts on the environment and employment in France, will considerably add to and complement the information drawn from demonstration projects. It will notably enable comparisons of benefits provided by smart grid functions and thus help give rise to a French smart grids industry that is competitive. At first, the smart grids industry was organised around demonstration projects testing different advanced functions within specific geographic areas. These projects covered a wide enough

Behavioral repertory of Trichodactylus panoplus (Crustacea: Trichodactylidae under laboratory conditions

Directory of Open Access Journals (Sweden)

Bianca L. Zimmermann

2009-03-01

Full Text Available This work describes the behavioral repertory of Trichodactylus panoplus von Martens, 1869, based on the animals' diel activity and the possible substrate preference under laboratory experiments. Three experimental replicates were carried out, each using six animals (three males and three females. There were four periods of observation a day, with a total of 864 observation sessions and 144 hours of experiments. A total of 15 behavioral acts divided into five categories were recorded: feeding, exploration of the environment, immobility, social interaction, and self-grooming. The obtained results suggest that T. panoplus has greater activity during the night (p < 0.05, yet without showing an activity peak. In addition, the acceptance of food does not depend on the photoperiod. There was a significant preference for gravel as the chosen substrate. The Morisita index indicates an aggregated distribution of these animals, confirming their preference for substrate with gravel. The increase in activity at night and the preference for substrate with gravel, which can be used to disguise these individuals, would be associated to some anti-predator strategies of these crabs against visually orientated predators.

From the grid to the smart grid, topologically

Science.gov (United States)

Pagani, Giuliano Andrea; Aiello, Marco

2016-05-01

In its more visionary acceptation, the smart grid is a model of energy management in which the users are engaged in producing energy as well as consuming it, while having information systems fully aware of the energy demand-response of the network and of dynamically varying prices. A natural question is then: to make the smart grid a reality will the distribution grid have to be upgraded? We assume a positive answer to the question and we consider the lower layers of medium and low voltage to be the most affected by the change. In our previous work, we analyzed samples of the Dutch distribution grid (Pagani and Aiello, 2011) and we considered possible evolutions of these using synthetic topologies modeled after studies of complex systems in other technological domains (Pagani and Aiello, 2014). In this paper, we take an extra important step by defining a methodology for evolving any existing physical power grid to a good smart grid model, thus laying the foundations for a decision support system for utilities and governmental organizations. In doing so, we consider several possible evolution strategies and apply them to the Dutch distribution grid. We show how increasing connectivity is beneficial in realizing more efficient and reliable networks. Our proposal is topological in nature, enhanced with economic considerations of the costs of such evolutions in terms of cabling expenses and economic benefits of evolving the grid.

Grid Generation Techniques Utilizing the Volume Grid Manipulator

Science.gov (United States)

Alter, Stephen J.

1998-01-01

This paper presents grid generation techniques available in the Volume Grid Manipulation (VGM) code. The VGM code is designed to manipulate existing line, surface and volume grids to improve the quality of the data. It embodies an easy to read rich language of commands that enables such alterations as topology changes, grid adaption and smoothing. Additionally, the VGM code can be used to construct simplified straight lines, splines, and conic sections which are common curves used in the generation and manipulation of points, lines, surfaces and volumes (i.e., grid data). These simple geometric curves are essential in the construction of domain discretizations for computational fluid dynamic simulations. By comparison to previously established methods of generating these curves interactively, the VGM code provides control of slope continuity and grid point-to-point stretchings as well as quick changes in the controlling parameters. The VGM code offers the capability to couple the generation of these geometries with an extensive manipulation methodology in a scripting language. The scripting language allows parametric studies of a vehicle geometry to be efficiently performed to evaluate favorable trends in the design process. As examples of the powerful capabilities of the VGM code, a wake flow field domain will be appended to an existing X33 Venturestar volume grid; negative volumes resulting from grid expansions to enable flow field capture on a simple geometry, will be corrected; and geometrical changes to a vehicle component of the X33 Venturestar will be shown.

Material Implications of Rural Electrification—A Methodological Framework to Assess In-Use Stocks of Off-Grid Solar Products and EEE in Rural Households in Bangladesh

Directory of Open Access Journals (Sweden)

Alexander Batteiger

2018-02-01

Full Text Available “Universal access to electricity” is proclaimed as the seventh sustainable development goal (SDG 7 of the United Nations (UN Sustainable Development Goals list. The achievement of this goal will result in a rapid diffusion of energy technologies that would in turn increase materials stocks, subsequently increase the raw material demand as well as the arising waste flows. This study describes a methodological framework to assess in-use stocks of off-grid solar products and electrical and electronic equipment (EEE for rural communities in developing countries. The methodology is based on energy-access data. Furthermore, the specifics of the characteristics of off-grid solar products are discussed. The methodology is applied to rural Bangladesh and its solar home system (SHS program. By the end of 2016, around 4.1 million SHSs were installed. This type of access to electricity has a significant impact on the in-use stocks, as households add the comparatively heavy SHSs to their in-use stocks. In-use stocks of EEE, in general, are low. Off-grid solar products are lighter than standard EEE, and fewer products types are available. These findings will help to better understand material stocks and future waste flows in the given context and will support the adaption of recycling infrastructures.

Consumer perception of vanilla dairy desserts flavour by Repertory Grid Method and Generalized Procrustes Analysis

OpenAIRE

González Tomás, Luis; Costell, Elvira

2005-01-01

Sensory evaluation of foods and beverages is usually carried out by using conventional techniques such as quantitative descriptive analysis. Most of this techniques imply the use of trained and experienced assessors, who normally tend to generate complex and scientifically orientated vocabulary. In contrast, Free Choice Profile is a sensory methodology that requires little training and allows to gather information about cognitive perception directly from consumers (Moskowitz, 1996). A more st...

Construing Systems of Management among Primary Headteachers: Moving Forward from Work Activity Studies.

Science.gov (United States)

Jones, Norah; Connolly, Michael

2001-01-01

A study used a Personal Construct Theory/Repertory Grid approach to examine the work of 12 Welsh primary headteachers. Analysis of thematic work-activity grids suggests principals have a more coherent view of their work (as centered on children and education) than Henry Mintzberg's observational studies portrayed. (Contains 36 references.) (MLH)

The role of natural gas in smart grids

NARCIS (Netherlands)

Bliek, F.W.; Noort, A. van den; Roossien, B.; Kamphuis, I.G.; Wit, J. de; Velde, J. van der; Eijgelaar, M.

2011-01-01

PowerMatching City (see ref. (Bliek et al., 2010)) is a living lab smart grid demonstration that shows the feasibility of a market based smart grid optimization methodology. It allows simultaneous optimization of multiple goals of the various stakeholders in a smart grid: in-home optimization,

Power fluctuation reduction methodology for the grid-connected renewable power systems

Science.gov (United States)

Aula, Fadhil T.; Lee, Samuel C.

2013-04-01

This paper presents a new methodology for eliminating the influence of the power fluctuations of the renewable power systems. The renewable energy, which is to be considered an uncertain and uncontrollable resource, can only provide irregular electrical power to the power grid. This irregularity creates fluctuations of the generated power from the renewable power systems. These fluctuations cause instability to the power system and influence the operation of conventional power plants. Overall, the power system is vulnerable to collapse if necessary actions are not taken to reduce the impact of these fluctuations. This methodology aims at reducing these fluctuations and makes the generated power capability for covering the power consumption. This requires a prediction tool for estimating the generated power in advance to provide the range and the time of occurrence of the fluctuations. Since most of the renewable energies are weather based, as a result a weather forecast technique will be used for predicting the generated power. The reduction of the fluctuation also requires stabilizing facilities to maintain the output power at a desired level. In this study, a wind farm and a photovoltaic array as renewable power systems and a pumped-storage and batteries as stabilizing facilities are used, since they are best suitable for compensating the fluctuations of these types of power suppliers. As an illustrative example, a model of wind and photovoltaic power systems with battery energy and pumped hydro storage facilities for power fluctuation reduction is included, and its power fluctuation reduction is verified through simulation.

All SiC Grid-Connected PV Supply with HF Link MPPT Converter: System Design Methodology and Development of a 20 kHz, 25 kVA Prototype

Directory of Open Access Journals (Sweden)

Serkan Öztürk

2018-05-01

Full Text Available Design methodology and implementation of an all SiC power semiconductor-based, grid-connected multi-string photovoltaic (PV supply with an isolated high frequency (HF link maximum power point tracker (MPPT have been described. This system configuration makes possible the use of a simple and reliable two-level voltage source inverter (VSI topology for grid connection, owing to the galvanic isolation provided by the HF transformer. This topology provides a viable alternative to the commonly used non-isolated PV supplies equipped with Si-based boost MPPT converters cascaded with relatively more complex inverter topologies, at competitive efficiency figures and a higher power density. A 20 kHz, 25 kVA prototype system was designed based on the dynamic model of the multi-string PV panels obtained from field tests. Design parameters such as input DC link capacitance, switching frequencies of MPPT converter and voltage source inverter, size and performance of HF transformer with nanocrystalline core, DC link voltage, and LCL filter of the VSI were optimized in view of the site dependent parameters such as the variation ranges of solar insolation, module surface temperature, and grid voltage. A modified synchronous reference frame control was implemented in the VSI by applying the grid voltage feedforward to the reference voltages in abc axes directly, so that zero-sequence components of grid voltages are taken into account in the case of an unbalanced grid. The system was implemented and the proposed design methodology verified satisfactorily in the field on a roof-mounted 23.7 kW multi-string PV system.

An overset algorithm for 3D unstructured grids

International Nuclear Information System (INIS)

Pishevar, A.R.; Shateri, A.R.

2004-01-01

In this paper a new methodology is introduced to simulate flows around complex geometries by using overset unstructured grids. The proposed algorithm can also be used for the unsteady flows about objects in relative motions. In such a case since the elements are not deformed during the computation the costly part of conventional methods, re-meshing, is prevented. This method relies on the inter-grid boundary definition to establish communications among independent grids in the overset system. At the end, the Euler set of equations are integrated on several overset systems to examine the capabilities of this methodology. (author)

A methodology toward manufacturing grid-based virtual enterprise operation platform

Science.gov (United States)

Tan, Wenan; Xu, Yicheng; Xu, Wei; Xu, Lida; Zhao, Xianhua; Wang, Li; Fu, Liuliu

2010-08-01

Virtual enterprises (VEs) have become one of main types of organisations in the manufacturing sector through which the consortium companies organise their manufacturing activities. To be competitive, a VE relies on the complementary core competences among members through resource sharing and agile manufacturing capacity. Manufacturing grid (M-Grid) is a platform in which the production resources can be shared. In this article, an M-Grid-based VE operation platform (MGVEOP) is presented as it enables the sharing of production resources among geographically distributed enterprises. The performance management system of the MGVEOP is based on the balanced scorecard and has the capacity of self-learning. The study shows that a MGVEOP can make a semi-automated process possible for a VE, and the proposed MGVEOP is efficient and agile.

Beyond grid security

International Nuclear Information System (INIS)

Hoeft, B; Epting, U; Koenig, T

2008-01-01

While many fields relevant to Grid security are already covered by existing working groups, their remit rarely goes beyond the scope of the Grid infrastructure itself. However, security issues pertaining to the internal set-up of compute centres have at least as much impact on Grid security. Thus, this talk will present briefly the EU ISSeG project (Integrated Site Security for Grids). In contrast to groups such as OSCT (Operational Security Coordination Team) and JSPG (Joint Security Policy Group), the purpose of ISSeG is to provide a holistic approach to security for Grid computer centres, from strategic considerations to an implementation plan and its deployment. The generalised methodology of Integrated Site Security (ISS) is based on the knowledge gained during its implementation at several sites as well as through security audits, and this will be briefly discussed. Several examples of ISS implementation tasks at the Forschungszentrum Karlsruhe will be presented, including segregation of the network for administration and maintenance and the implementation of Application Gateways. Furthermore, the web-based ISSeG training material will be introduced. This aims to offer ISS implementation guidance to other Grid installations in order to help avoid common pitfalls

Standardization in smart grids. Introduction to IT-related methodologies, architectures and standards

Energy Technology Data Exchange (ETDEWEB)

Uslar, Mathias; Specht, Michael; Daenekas, Christian; Trefke, Joern; Rohjans, Sebastian; Gonzalez, Jose M.; Rosinger, Christine; Bleiker, Robert [OFFIS - Institut fuer Informatik, Oldenburg (Germany)

2013-03-01

Introduction to Standardization for Smart Grids. Presents a tutorial and best practice of Smart Grid Prototype Projects. Written by leading experts in the field. Besides the regulatory and market aspects, the technical level dealing with the knowledge from multiple disciplines and the aspects of technical system integration to achieve interoperability and integration has been a strong focus in the Smart Grid. This topic is typically covered by the means of using (technical) standards for processes, data models, functions and communication links. Standardization is a key issue for Smart Grids due to the involvement of many different sectors along the value chain from the generation to the appliances. The scope of Smart Grid is broad, therefore, the standards landscape is unfortunately very large and complex. This is why the three European Standards Organizations ETSI, CEN and CENELEC created a so called Joint Working Group (JWG). This was the first harmonized effort in Europe to bring together the needed disciplines and experts delivering the final report in May 2011. After this approach proved useful, the Commission used the Mandate M/490: Standardization Mandate to European Standardization Organizations (ESOs) to support European Smart Grid deployment. The focal point addressing the ESO's response to M/490 will be the CEN, CENELEC and ETSI Smart Grids Coordination Group (SG-CG). Based on this mandate, meaningful standardization of architectures, use cases, communication technologies, data models and security standards takes place in the four existing working groups. This book provides an overview on the various building blocks and standards identified as the most prominent ones by the JWG report as well as by the first set of standards group - IEC 61850 and CIM, IEC PAS 62559 for documenting Smart Grid use cases, security requirements from the SGIS groups and an introduction on how to apply the Smart Grid Architecture Model SGAM for utilities. In addition

Enhanced Operation of Electricity Distribution Grids Through Smart Metering PLC Network Monitoring, Analysis and Grid Conditioning

Directory of Open Access Journals (Sweden)

Iker Urrutia

2013-01-01

Full Text Available Low Voltage (LV electricity distribution grid operations can be improved through a combination of new smart metering systems’ capabilities based on real time Power Line Communications (PLC and LV grid topology mapping. This paper presents two novel contributions. The first one is a new methodology developed for smart metering PLC network monitoring and analysis. It can be used to obtain relevant information from the grid, thus adding value to existing smart metering deployments and facilitating utility operational activities. A second contribution describes grid conditioning used to obtain LV feeder and phase identification of all connected smart electric meters. Real time availability of such information may help utilities with grid planning, fault location and a more accurate point of supply management.

CFD application to advanced design for high efficiency spacer grid

International Nuclear Information System (INIS)

Ikeda, Kazuo

2014-01-01

Highlights: • A new LDV was developed to investigate the local velocity in a rod bundle and inside a spacer grid. • The design information that utilizes for high efficiency spacer grid has been obtained. • CFD methodology that predicts flow field in a PWR fuel has been developed. • The high efficiency spacer grid was designed using the CFD methodology. - Abstract: Pressurized water reactor (PWR) fuels have been developed to meet the needs of the market. A spacer grid is a key component to improve thermal hydraulic performance of a PWR fuel assembly. Mixing structures (vanes) of a spacer grid promote coolant mixing and enhance heat removal from fuel rods. A larger mixing vane would improve mixing effect, which would increase the departure from nucleate boiling (DNB) benefit for fuel. However, the increased pressure loss at large mixing vanes would reduce the coolant flow at the mixed fuel core, which would reduce the DNB margin. The solution is to develop a spacer grid whose pressure loss is equal to or less than the current spacer grid and that has higher critical heat flux (CHF) performance. For this reason, a requirement of design tool for predicting the pressure loss and CHF performance of spacer grids has been increased. The author and co-workers have been worked for development of high efficiency spacer grid using Computational Fluid Dynamics (CFD) for nearly 20 years. A new laser Doppler velocimetry (LDV), which is miniaturized with fiber optics embedded in a fuel cladding, was developed to investigate the local velocity profile in a rod bundle and inside a spacer grid. The rod-embedded fiber LDV (rod LDV) can be inserted in an arbitrary grid cell instead of a fuel rod, and has the advantage of not disturbing the flow field since it is the same shape as a fuel rod. The probe volume of the rod LDV is small enough to measure spatial velocity profile in a rod gap and inside a spacer grid. According to benchmark experiments such as flow velocity

CFD application to advanced design for high efficiency spacer grid

Energy Technology Data Exchange (ETDEWEB)

Ikeda, Kazuo, E-mail: kazuo3_ikeda@ndc.mhi.co.jp

2014-11-15

Highlights: • A new LDV was developed to investigate the local velocity in a rod bundle and inside a spacer grid. • The design information that utilizes for high efficiency spacer grid has been obtained. • CFD methodology that predicts flow field in a PWR fuel has been developed. • The high efficiency spacer grid was designed using the CFD methodology. - Abstract: Pressurized water reactor (PWR) fuels have been developed to meet the needs of the market. A spacer grid is a key component to improve thermal hydraulic performance of a PWR fuel assembly. Mixing structures (vanes) of a spacer grid promote coolant mixing and enhance heat removal from fuel rods. A larger mixing vane would improve mixing effect, which would increase the departure from nucleate boiling (DNB) benefit for fuel. However, the increased pressure loss at large mixing vanes would reduce the coolant flow at the mixed fuel core, which would reduce the DNB margin. The solution is to develop a spacer grid whose pressure loss is equal to or less than the current spacer grid and that has higher critical heat flux (CHF) performance. For this reason, a requirement of design tool for predicting the pressure loss and CHF performance of spacer grids has been increased. The author and co-workers have been worked for development of high efficiency spacer grid using Computational Fluid Dynamics (CFD) for nearly 20 years. A new laser Doppler velocimetry (LDV), which is miniaturized with fiber optics embedded in a fuel cladding, was developed to investigate the local velocity profile in a rod bundle and inside a spacer grid. The rod-embedded fiber LDV (rod LDV) can be inserted in an arbitrary grid cell instead of a fuel rod, and has the advantage of not disturbing the flow field since it is the same shape as a fuel rod. The probe volume of the rod LDV is small enough to measure spatial velocity profile in a rod gap and inside a spacer grid. According to benchmark experiments such as flow velocity

Deliverable 1.1 Smart grid scenario

DEFF Research Database (Denmark)

Korman, Matus; Ekstedt, Mathias; Gehrke, Oliver

2015-01-01

The purpose of the SALVAGE project is to develop better support for managing and designing a secure future smart grid. This approach includes cyber security technologies dedicated to power grid operation as well as support for the migration to the future smart grid solutions, including the legacy...... of ICT that necessarily will be part of it. The objective is further to develop cyber security technology and methodology optimized with the particular needs and context of the power industry, something that is to a large extent lacking in general cyber security best practices and technologies today...

A Hierarchy of Network Performance Characteristics for Grid Applications and Services

Energy Technology Data Exchange (ETDEWEB)

Lowekamp, B

2004-07-06

This document describes a standard set of network characteristics that are useful for Grid applications and services as well as a classification hierarchy for these characteristics. The goal of this work is to identify the various types of network measurements according to the network characteristic they measure and the network entity on which they are taken. This document defines standard terminology to describe those measurements, but it does not attempt to define new standard measurement methodologies or attempt to define the best measurement methodologies to use for grid applications. However, it does attempt to point out the advantages and disadvantages of different measurement methodologies. This document was motivated by the need for the interchange of measurements taken by various systems in the Grid and to develop a common dictionary to facilitate discussions about and specifications for measurement systems. The application of this naming system will facilitate the creation of common schemata for describing network monitoring data in Grid Monitoring and Discovery Services, and thus help to address portability issues between the wide variety of network measurements used between sites of a Grid.

Feature combination analysis in smart grid based using SOM for Sudan national grid

Science.gov (United States)

Bohari, Z. H.; Yusof, M. A. M.; Jali, M. H.; Sulaima, M. F.; Nasir, M. N. M.

2015-12-01

In the investigation of power grid security, the cascading failure in multicontingency situations has been a test because of its topological unpredictability and computational expense. Both system investigations and burden positioning routines have their limits. In this project, in view of sorting toward Self Organizing Maps (SOM), incorporated methodology consolidating spatial feature (distance)-based grouping with electrical attributes (load) to evaluate the vulnerability and cascading impact of various part sets in the force lattice. Utilizing the grouping result from SOM, sets of overwhelming stacked beginning victimized people to perform assault conspires and asses the consequent falling impact of their failures, and this SOM-based approach viably distinguishes the more powerless sets of substations than those from the conventional burden positioning and other bunching strategies. The robustness of power grids is a central topic in the design of the so called "smart grid". In this paper, to analyze the measures of importance of the nodes in a power grid under cascading failure. With these efforts, we can distinguish the most vulnerable nodes and protect them, improving the safety of the power grid. Also we can measure if a structure is proper for power grids.

Steering the Smart Grid

NARCIS (Netherlands)

Molderink, Albert; Bakker, Vincent; Bosman, M.G.C.; Hurink, Johann L.; Smit, Gerardus Johannes Maria

2010-01-01

Increasing energy prices and the greenhouse effect lead to more awareness of energy efficiency of electricity supply. During the last years, a lot of technologies and optimization methodologies were developed to increase the efficiency, maintain the grid stability and support large scale

Personal Usability Constructs

DEFF Research Database (Denmark)

Hertzum, Morten; Clemmensen, Torkil; Hornbæk, Kasper

2011-01-01

Whereas the concept of usability is predominantly defined analytically, people relate to systems through personal usability constructs. Based on 48 repertory-grid interviews, this study investigates how such personal constructs are affected by two factors crucial to the international development...

MrGrid: a portable grid based molecular replacement pipeline.

Directory of Open Access Journals (Sweden)

Jason W Schmidberger

Full Text Available BACKGROUND: The crystallographic determination of protein structures can be computationally demanding and for difficult cases can benefit from user-friendly interfaces to high-performance computing resources. Molecular replacement (MR is a popular protein crystallographic technique that exploits the structural similarity between proteins that share some sequence similarity. But the need to trial permutations of search models, space group symmetries and other parameters makes MR time- and labour-intensive. However, MR calculations are embarrassingly parallel and thus ideally suited to distributed computing. In order to address this problem we have developed MrGrid, web-based software that allows multiple MR calculations to be executed across a grid of networked computers, allowing high-throughput MR. METHODOLOGY/PRINCIPAL FINDINGS: MrGrid is a portable web based application written in Java/JSP and Ruby, and taking advantage of Apple Xgrid technology. Designed to interface with a user defined Xgrid resource the package manages the distribution of multiple MR runs to the available nodes on the Xgrid. We evaluated MrGrid using 10 different protein test cases on a network of 13 computers, and achieved an average speed up factor of 5.69. CONCLUSIONS: MrGrid enables the user to retrieve and manage the results of tens to hundreds of MR calculations quickly and via a single web interface, as well as broadening the range of strategies that can be attempted. This high-throughput approach allows parameter sweeps to be performed in parallel, improving the chances of MR success.

The North Seas Countries' Offshore Grid Initiative. Initial Findings. Final Report. Working Group 1 - Grid Configuration

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-11-15

This report focuses on the tasks and results from Working Group 1 (WG1), grid configuration and integration, chaired jointly by representatives from Denmark and the Netherlands. The methodology, assumptions concerning generation portfolio, load situation, available technology and results are presented. This report presents the WG1 Offshore Grid Study that supports the North Seas Countries' Offshore Grid Initiative (NSCOGI) final report. The information contained in this report aims to evaluate the long-term development of an offshore grid structure in the North Seas by providing a view on how such a grid may possibly develop in the future, based on the assumptions made for this study. The report aims to compare and evaluate the possible advantages and disadvantages of the long term development of an optimised, integrated (or meshed) offshore grid in the North Seas by providing a view of how that possible grid might develop in the future against changes to the electricity energy requirements. To evaluate basic variants, different transmission design topologies (radial and meshed) were compared and analysed with respect to various aspects, such as cost/benefits, import and export levels and the systems' CO2 emissions.

Three-Phase Grid-Connected of Photovoltaic Generator Using Nonlinear Control

DEFF Research Database (Denmark)

Yahya, A.; El Fadil, H.; Guerrero, Josep M.

2014-01-01

This paper proposes a nonlinear control methodology for three phase grid connected of PV generator. It consists of a PV arrays; a voltage source inverter, a grid filter and an electric grid. The controller objectives are threefold: i) ensuring the Maximum power point tracking (MPPT) in the side...... stability analysis and simulation results that the proposed controller meets all the objectives....

Methodology to determine the technical performance and value proposition for grid-scale energy storage systems :

Energy Technology Data Exchange (ETDEWEB)

Byrne, Raymond Harry; Loose, Verne William; Donnelly, Matthew K.; Trudnowski, Daniel J.

2012-12-01

As the amount of renewable generation increases, the inherent variability of wind and photovoltaic systems must be addressed in order to ensure the continued safe and reliable operation of the nation's electricity grid. Grid-scale energy storage systems are uniquely suited to address the variability of renewable generation and to provide other valuable grid services. The goal of this report is to quantify the technical performance required to provide di erent grid bene ts and to specify the proper techniques for estimating the value of grid-scale energy storage systems.

Assessing Personal Constructs of Adolescents with Autism Spectrum Disorder: A Person-Centered Measure of Social Cognition

Science.gov (United States)

Hess, Sean; Self, Trisha; DiLollo, Anthony

2018-01-01

Many protocols assessing social communication skills of adolescents with autism spectrum disorder (ASD) are based on behavioral observations. It has been suggested, however, that social cognition encompasses processes underlying observable behaviors. Such processes include personal constructs, which can be assessed using repertory grids. Personal…

Communication challenges and solutions in the smart grid

CERN Document Server

Bouhafs, Fayçal; Merabti, Madjid

2014-01-01

This SpringerBrief discusses the rise of the smart grid from the perspective of computing and communications. It explains how current and next-generation network technology and methodologies help recognize the potential that the smart grid initiative promises.Chapters provide context on the smart grid before exploring specific challenges related to communication control and energy management. Topics include control in heterogeneous power supply, solutions for backhaul and wide area networks, home energy management systems, and technologies for smart energy management systems.Designed for resea

The North Seas Countries' Offshore Grid Initiative. Initial Findings. Final Report. Working Group 1 - Grid Configuration

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-11-15

This report focuses on the tasks and results from Working Group 1 (WG1), grid configuration and integration, chaired jointly by representatives from Denmark and the Netherlands. The methodology, assumptions concerning generation portfolio, load situation, available technology and results are presented. This report presents the WG1 Offshore Grid Study that supports the North Seas Countries' Offshore Grid Initiative (NSCOGI) final report. The information contained in this report aims to evaluate the long-term development of an offshore grid structure in the North Seas by providing a view on how such a grid may possibly develop in the future, based on the assumptions made for this study. The report aims to compare and evaluate the possible advantages and disadvantages of the long term development of an optimised, integrated (or meshed) offshore grid in the North Seas by providing a view of how that possible grid might develop in the future against changes to the electricity energy requirements. To evaluate basic variants, different transmission design topologies (radial and meshed) were compared and analysed with respect to various aspects, such as cost/benefits, import and export levels and the systems' CO2 emissions.

Integrating the Differentiated: A Review of the Personal Construct Approach to Cognitive Complexity

Czech Academy of Sciences Publication Activity Database

Kovářová, Marie; Filip, Miroslav

2015-01-01

Roč. 28, č. 4 (2015), s. 342-366 ISSN 1072-0537 R&D Projects: GA ČR(CZ) GAP407/12/2432 Institutional support: RVO:68081740 Keywords : cognitive complexity * psychology of personal constructs * repertory grid technique Subject RIV: AN - Psychology Impact factor: 0.333, year: 2015

A Commentary by Chinese Hotel Workers on the Value of Vocational Education.

Science.gov (United States)

Huyton, Jeremy R.; Ingold, Anthony

1999-01-01

An adaptation of Kelly's Repertory Grid was completed by Chinese hotel staff. Results showed they revered higher education qualifications for the prestige and respect they commanded; secondary vocational-technical education was viewed very negatively. However, higher education is typically better funded and staffed than vocational education. (SK)

Cost-Benefit Analysis of Smart Grids Implementation

International Nuclear Information System (INIS)

Tomsic, Z.; Pongrasic, M.

2014-01-01

Paper presents guidelines for conducting the cost-benefit analysis of Smart Grid projects connected to the implementation of advanced technologies in electric power system. Restrictions of presented electric power networks are also mentioned along with solutions that are offered by advanced electric power network. From an economic point of view, the main characteristic of advanced electric power network is big investment, and benefits are seen after some time with risk of being smaller than expected. Therefore it is important to make a comprehensive analysis of those projects which consist of economic and qualitative analysis. This report relies on EPRI methodology developed in American institute for energy. The methodology is comprehensive and useful, but also simple and easy to understand. Steps of this methodology and main characteristics of methodologies which refer to EPRI methodology: methodology developed in Joint Research Center and methodologies for analysing implementation of smart meters in electricity power network are explained. Costs, benefits and categories in which they can be classified are also defined. As a part of qualitative analysis, social aspect of Smart Grid projects is described. In cost defining, special attention has to be paid to projects of integrating electricity from variable renewable energy sources into the power system because of additional costs. This work summarized categories of additional costs. In the end of this report, an overview is given of what has been done and what will be done in European Union. (author).

Study of Swept Angle Effects on Grid Fins Aerodynamics Performance

Science.gov (United States)

Faza, G. A.; Fadillah, H.; Silitonga, F. Y.; Agoes Moelyadi, Mochamad

2018-04-01

Grid fin is an aerodynamic control surface that usually used on missiles and rockets. In the recent several years many researches have conducted to develop a more efficient grid fins. There are many possibilities of geometric combination could be done to improve aerodynamics characteristic of a grid fin. This paper will only discuss about the aerodynamics characteristics of grid fins compared by another grid fins with different swept angle. The methodology that used to compare the aerodynamics is Computational Fluid Dynamics (CFD). The result of this paper might be used for future studies to answer our former question or as a reference for related studies.

Facilitating Teamwork in the Design Process

DEFF Research Database (Denmark)

Bang, Anne Louise; Nissen, Kirsten

2009-01-01

By approaching the Repertory Grid as an exploratory design game and drawing on insight in diagrammatic reasoning we argue that this approach is useful in supporting team work in the design process. In this paper we draw on two courses inviting textile design students to contribute to the developm...

What do Polish and Dutch consumers think about dried fruit and products with them - creaiwe group discussions as a means of recognittion consumers'perception

NARCIS (Netherlands)

Jesionkowska, K.; Konopacka, D.; P¿ocharski, W.; Sijtsema, S.J.; Zimmermann, K.L.

2007-01-01

The main aim of the study was to get insight into consumers' perception towards dried fruit and products with them, thus the exploratory study designed as a group discussion took place. While group discussions association (as one of the projective technique) and Kelly repertory grid were used to

Smart Grid Constraint Violation Management for Balancing and Regulating Purposes

DEFF Research Database (Denmark)

Bhattarai, Bishnu Prasad; Kouzelis, Konstantinos; Mendaza, Iker Diaz de Cerio

2017-01-01

The gradual active load penetration in low voltage distribution grids is expected to challenge their network capacity in the near future. Distribution system operators should for this reason resort to either costly grid reinforcements, use of low voltage boosters, or demand response mechanisms. S...... of utilization of demand flexibility among the customers is incorporated. It is demonstrated that the proposed methodology aids in keeping the grid status within preset limits while utilizing flexibility from all flexibility participants....

National assessment study in Armenia using innovative nuclear reactors and fuel cycles methodology for an innovative nuclear systems in a country with small grid

International Nuclear Information System (INIS)

Sargsyan, V.H.; Galstyan, A.A.; Gevorgyan, A.A.

2010-01-01

The International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) was launched in November 2000 under the aegis of the IAEA. Phases 1A and IB (first Part) of the Project were dedicated to elaboration, testing and validation of the INPRO Methodology. At the Technical Meeting in Vienna (13-15 October 2004) Armenia has proposed an assessment using the INPRO Methodology for an Innovative Nuclear Energy System in a country with a small electrical grid. Such kind of study helps Armenia in analysis of Innovative Nuclear Energy System (INS), including fuel cycle options, as well as shows applicability of INPRO methodology for small countries, like Armenia. This study was based on the results given in [3] and [4], and also on the main objectives, declared by the Government of Armenia in the paper 'Energy Sector Development Strategies in the Context of Economic Development in Armenia'

Fabrics in Function

DEFF Research Database (Denmark)

Bang, Anne Louise

2007-01-01

sensing of fabrics in function. It is proposed that tactile and visual sensing of fabrics is a way to investigate and express emotional utility values. The further purpose is to use experiments with repertory grid models as part of the mapping of the entire research project and also as a basis...

Taxonomy of Payments

DEFF Research Database (Denmark)

Hedman, Jonas; Tan, Felix B.; Holst, Jacques

2017-01-01

that impact payers’ choice of payment instruments. Design/methodology/approach: Through in-depth interviews using the repertory grid technique, the authors explored 15 payers’ perceptions of six payment instruments, including coins, banknotes, debit cards, credit cards, mobile payments, and online banking....... The approach draws heavily on organizational systematics to better understand payers’ choice of payment instruments. Findings: A four-category taxonomy of payments was developed. The authors refer to the taxonomy as the 4Ps: the purchase, the payer, the payment instrument, and the physical technology...... or checks. Research limitations/implications: The findings suggest that payers view payment instruments in a much broader sense, including context, control, or cultural beliefs. Consequently, the authors suggest that researchers try to understand the essence of an innovation before assuming any economic...

Assessing the Value Dimensions of Outsourced Maintenance Services

DEFF Research Database (Denmark)

Toossi, Amir; Lockett, Helen Louise; Raja, Jawwad

2013-01-01

Purpose – The purpose of this paper is to investigate the diverse nature of tangible and intangible value dimensions that contribute to customers’ perception of value from outsourced maintenance services. Design/methodology/approach – A multiple case study approach has been adopted. Repertory grid......, an in-depth structured interviewing technique, has been used in order to draw out the respondents’ hidden constructs in evaluating outsourced maintenance services. Data have been collected from four customer organizations of outsourced maintenance services, and a total of 33 interviews have been...... undertaken. Findings – The paper has identified a range of tangible and intangible value dimensions that are of importance in maintenance outsourcing decision making. The most important value dimensions for maintenance outsourcing were found to be specialist knowledge, accessibility (of the service provider...

Cultural Differences and Students' Spontaneous Models of the Water Cycle: A Case Study of Jewish and Bedouin Children in Israel

Science.gov (United States)

Ben-Zvi Assaraf, Orit; Eshach, Haim; Orion, Nir; Alamour, Yousif

2012-01-01

The present research aims at pinpointing differences in spontaneous and non-spontaneous mental models of water cycle conceptions of two 4th grade student groups: the Jewish residents of a small provincial town and a group of students from an indigenous Bedouin community. Students' conceptions were elicited using the Repertory Grid technique as…

Evaluation of Smart Grid Technologies Employed for System Reliability Improvement: Pacific Northwest Smart Grid Demonstration Experience

Energy Technology Data Exchange (ETDEWEB)

Agalgaonkar, Yashodhan P.; Hammerstrom, Donald J.

2017-06-01

The Pacific Northwest Smart Grid Demonstration (PNWSGD) was a smart grid technology performance evaluation project that included multiple U.S. states and cooperation from multiple electric utilities in the northwest region. One of the local objectives for the project was to achieve improved distribution system reliability. Toward this end, some PNWSGD utilities automated their distribution systems, including the application of fault detection, isolation, and restoration and advanced metering infrastructure. In light of this investment, a major challenge was to establish a correlation between implementation of these smart grid technologies and actual improvements of distribution system reliability. This paper proposes using Welch’s t-test to objectively determine and quantify whether distribution system reliability is improving over time. The proposed methodology is generic, and it can be implemented by any utility after calculation of the standard reliability indices. The effectiveness of the proposed hypothesis testing approach is demonstrated through comprehensive practical results. It is believed that wider adoption of the proposed approach can help utilities to evaluate a realistic long-term performance of smart grid technologies.

Improving Grid Resilience through Informed Decision-making (IGRID)

Energy Technology Data Exchange (ETDEWEB)

Burnham, Laurie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Power Systems Research; Stamber, Kevin L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Systems Research, Analysis and Applications; Jeffers, Robert Fredric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Resilience and Regulatory Effects; Stevens-Adams, Susan Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Human Factors; Verzi, Stephen Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Systems Research, Analysis and Applications; Galiardi, Meghan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Systems Research, Analysis and Applications; Haass, Michael Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Cognitive Systems; Cauthen, Katherine Regina [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Systems Research, Analysis and Applications

2016-09-01

The transformation of the distribution grid from a centralized to decentralized architecture, with bi-directional power and data flows, is made possible by a surge in network intelligence and grid automation. While changes are largely beneficial, the interface between grid operator and automated technologies is not well understood, nor are the benefits and risks of automation. Quantifying and understanding the latter is an important facet of grid resilience that needs to be fully investigated. The work described in this document represents the first empirical study aimed at identifying and mitigating the vulnerabilities posed by automation for a grid that for the foreseeable future will remain a human-in-the-loop critical infrastructure. Our scenario-based methodology enabled us to conduct a series of experimental studies to identify causal relationships between grid-operator performance and automated technologies and to collect measurements of human performance as a function of automation. Our findings, though preliminary, suggest there are predictive patterns in the interplay between human operators and automation, patterns that can inform the rollout of distribution automation and the hiring and training of operators, and contribute in multiple and significant ways to the field of grid resilience.

Cognitive conflicts in major depression: Between desired change and personal coherence

Science.gov (United States)

Feixas, Guillem; Montesano, Adrián; Compañ, Victoria; Salla, Marta; Dada, Gloria; Pucurull, Olga; Trujillo, Adriana; Paz, Clara; Muñoz, Dámaris; Gasol, Miquel; Saúl, Luis Ángel; Lana, Fernando; Bros, Ignasi; Ribeiro, Eugenia; Winter, David; Carrera-Fernández, María Jesús; Guàrdia, Joan

2014-01-01

Objectives The notion of intrapsychic conflict has been present in psychopathology for more than a century within different theoretical orientations. However, internal conflicts have not received enough empirical attention, nor has their importance in depression been fully elaborated. This study is based on the notion of cognitive conflict, understood as implicative dilemma (ID), and on a new way of identifying these conflicts by means of the Repertory Grid Technique. Our aim was to explore the relevance of cognitive conflicts among depressive patients. Design Comparison between persons with a diagnosis of major depressive disorder and community controls. Methods A total of 161 patients with major depression and 110 non-depressed participants were assessed for presence of IDs and level of symptom severity. The content of these cognitive conflicts was also analysed. Results Repertory grid analysis indicated conflict (presence of ID/s) in a greater proportion of depressive patients than in controls. Taking only those grids with conflict, the average number of IDs per person was higher in the depression group. In addition, participants with cognitive conflicts displayed higher symptom severity. Within the clinical sample, patients with IDs presented lower levels of global functioning and a more frequent history of suicide attempts. Conclusions Cognitive conflicts were more prevalent in depressive patients and were associated with clinical severity. Conflict assessment at pre-therapy could aid in treatment planning to fit patient characteristics. Practitioner points Internal conflicts have been postulated in clinical psychology for a long time but there is little evidence about its relevance due to the lack of methods to measure them. We developed a method for identifying conflicts using the Repertory Grid Technique. Depressive patients have higher presence and number of conflicts than controls. Conflicts (implicative dilemmas) can be a new target for intervention in

Reliability analysis of HVDC grid combined with power flow simulations

Energy Technology Data Exchange (ETDEWEB)

Yang, Yongtao; Langeland, Tore; Solvik, Johan [DNV AS, Hoevik (Norway); Stewart, Emma [DNV KEMA, Camino Ramon, CA (United States)

2012-07-01

Based on a DC grid power flow solver and the proposed GEIR, we carried out reliability analysis for a HVDC grid test system proposed by CIGRE working group B4-58, where the failure statistics are collected from literature survey. The proposed methodology is used to evaluate the impact of converter configuration on the overall reliability performance of the HVDC grid, where the symmetrical monopole configuration is compared with the bipole with metallic return wire configuration. The results quantify the improvement on reliability by using the later alternative. (orig.)

Understanding What It Means for Older Students to Learn Basic Musical Skills on a Keyboard Instrument

Science.gov (United States)

Taylor, Angela; Hallam, Susan

2008-01-01

Although many adults take up or return to instrumental and vocal tuition every year, we know very little about how they experience it. As part of ongoing case study research, eight older learners with modest keyboard skills explored what their musical skills meant to them during conversation-based repertory grid interviews. The data were…

A Root-Locus Design Methodology Derived from the Impedance/Admittance Stability Formulation and Its Application for LCL Grid-Connected Converters in Wind Turbines

DEFF Research Database (Denmark)

Freijedo Fernandez, Francisco Daniel; Diaz, Enrique Rodriguez; Golsorkhi, Mohammad

2017-01-01

This paper presents a systematic methodology for design and tuning of the current controller in LCL gridconnected converters for wind turbine applications. The design target is formulated as a minimization of the current loop dominant time constant, which is in accordance with standard design......, it has been also proved to be very suitable for system level studies in applications with a high penetration of renewable energy resources. The tuning methodology is as follows: firstly, the physical system is modelled in terms of the converter admittance and its equivalent grid impedance; then......, a sensitivity transfer function is derived, from which the closed-loop eigenvalues can be calculated; finally, the set of control gains that minimize the dominant time constant are obtained by direct search optimization. A case study that models the target system in a low power scale is provided...

Matching indices taking the dynamic hybrid electrical and thermal grids information into account for the decision-making of nZEB on-site renewable energy systems

International Nuclear Information System (INIS)

Cao, Sunliang; Sirén, Kai

2015-01-01

Highlights: • Use dynamic hourly-based grid information (PEF/CEF/tariffs) in nZEB control. • Hourly dynamic primary energy factor, CO 2 factor and tariffs for hybrid grids. • Methodology which links the on-site matching with dynamic grid information. • Multi-objective control indicators reflects both matching and grid information. • The influence of the dynamic grid information on the energy/environment/cost. - Abstract: Future nearly-zero energy buildings (nZEBs) will be involved with the twofold problem of on-site matching and hybrid–grid interactions. Theoretically, the hybrid grids’ information is dynamic, such as primary energy factors, equivalent CO 2 emission factors, and grid tariffs. Regarding primary energy consumption, equivalent CO 2 emissions or the grid cost of the nZEB, the significance of specific aspects of the matching capability, such as on-site energy faction (OEF) and on-site energy matching (OEM), will also become dynamic and variable with respect to the evolution of the grid information. Therefore, the primary goal is to develop a methodology as a multi-objective control criterion for the nZEB energy system, which can reflect both the on-site matching capability and dynamic grid information of environmental or economic impacts. The developed methodology is to quantitatively link the dynamic grid information with the weighting factors of the weighted matching index (WMI), following the monotone relationships between the extended matching indices and grid information. The methodology is implemented in this study to control an nZEB energy system with hybrid grid connections. The results show that the developed methodology can seek an optimised balance between the objectives of maximising the matching capability and minimising the environmental/economic load

Trends in life science grid: from computing grid to knowledge grid

Directory of Open Access Journals (Sweden)

Konagaya Akihiko

2006-12-01

Full Text Available Abstract Background Grid computing has great potential to become a standard cyberinfrastructure for life sciences which often require high-performance computing and large data handling which exceeds the computing capacity of a single institution. Results This survey reviews the latest grid technologies from the viewpoints of computing grid, data grid and knowledge grid. Computing grid technologies have been matured enough to solve high-throughput real-world life scientific problems. Data grid technologies are strong candidates for realizing "resourceome" for bioinformatics. Knowledge grids should be designed not only from sharing explicit knowledge on computers but also from community formulation for sharing tacit knowledge among a community. Conclusion Extending the concept of grid from computing grid to knowledge grid, it is possible to make use of a grid as not only sharable computing resources, but also as time and place in which people work together, create knowledge, and share knowledge and experiences in a community.

Impact of Smart Grid Technologies on Peak Load to 2050

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

The IEA's Smart Grids Technology Roadmap identified five global trends that could be effectively addressed by deploying smart grids. These are: increasing peak load (the maximum power that the grid delivers during peak hours), rising electricity consumption, electrification of transport, deployment of variable generation technologies (e.g. wind and solar PV) and ageing infrastructure. Along with this roadmap, a new working paper -- Impact of Smart Grid Technologies on Peak Load to 2050 -- develops a methodology to estimate the evolution of peak load until 2050. It also analyses the impact of smart grid technologies in reducing peak load for four key regions; OECD North America, OECD Europe, OECD Pacific and China. This working paper is a first IEA effort in an evolving modelling process of smart grids that is considering demand response in residential and commercial sectors as well as the integration of electric vehicles.

Grid interoperability: joining grid information systems

International Nuclear Information System (INIS)

Flechl, M; Field, L

2008-01-01

A grid is defined as being 'coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organizations'. Over recent years a number of grid projects, many of which have a strong regional presence, have emerged to help coordinate institutions and enable grids. Today, we face a situation where a number of grid projects exist, most of which are using slightly different middleware. Grid interoperation is trying to bridge these differences and enable Virtual Organizations to access resources at the institutions independent of their grid project affiliation. Grid interoperation is usually a bilateral activity between two grid infrastructures. Recently within the Open Grid Forum, the Grid Interoperability Now (GIN) Community Group is trying to build upon these bilateral activities. The GIN group is a focal point where all the infrastructures can come together to share ideas and experiences on grid interoperation. It is hoped that each bilateral activity will bring us one step closer to the overall goal of a uniform grid landscape. A fundamental aspect of a grid is the information system, which is used to find available grid services. As different grids use different information systems, interoperation between these systems is crucial for grid interoperability. This paper describes the work carried out to overcome these differences between a number of grid projects and the experiences gained. It focuses on the different techniques used and highlights the important areas for future standardization

Performance and Feasibility Analysis of a Grid Interactive Large Scale Wind/PV Hybrid System based on Smart Grid Methodology Case Study South Part – Jordan

Directory of Open Access Journals (Sweden)

Qais H. Alsafasfeh

2015-02-01

Full Text Available Most recent research on renewable energy resources main one goal to make Jordan less dependent on imported energy with locally developed and produced solar power, this paper discussed the efficient system of Wind/ PV Hybrid System to be than main power sources for south part of Jordan, the proposed hybrid system design based on Smart Grid Methodology,  the solar energy will be installed on top roof of  electricity subscribers across the Governorate of Maan, Tafila, Karak and Aqaba and the wind energy will set in one site by this way the capital cost for project will be reduced also the  simulation result show   the feasibility  is a very competitive and feasible cost . Economics analysis of a proposed renewable energy system was made using HOMER simulation and evaluation was completed with the cost per kilowatt of EDCO company, the net present cost is $2,551,676,416, the cost of energy is 0.07kWhr with a renewable fraction of 86.6 %.

The Knowledge Grid

CERN Document Server

Zhuge, Hai

2004-01-01

The Knowledge Grid is an intelligent and sustainable interconnection environment that enables people and machines to effectively capture, publish, share and manage knowledge resources. It also provides appropriate on-demand services to support scientific research, technological innovation, cooperative teamwork, problem solving, and decision making. It incorporates epistemology and ontology to reflect human cognitive characteristics; exploits social, ecological and economic principles; and adopts techniques and standards developed during work toward the future web. This book presents its methodology, theory, models and applications systematically for the first time.

Macedonian transmission grid capability and development

International Nuclear Information System (INIS)

Naumoski, K.; Achkoska, E.; Paunoski, A.

2015-01-01

The main task of the transmission grid is to guarantee evacuation of electricity from production facilities and, at the same time, supply the electricity to all customers, in a secure, reliable and qualitative manner. During the last years, transmission grid goes through the period of fast and important development, as a result of implementation of renewable and new technologies and creation of internal European electricity market. Due to these reasons, capacity of the existing grid needs to be upgraded either with optimization of existing infrastructure or constructing the new transmission projects. Among the various solutions for strengthening the grid, the one with the minimal investment expenses for construction is selected. While planning the national transmission grid, MEPSO planners apply multi-scenarios analyses, in order to handle all uncertainties, particularly in the forecasts on loads, production and exchange of electricity, location and size of the new power plants, hydrological conditions, integration of renewable sources and the evolution of the electricity market. Visions for development of European transmission grid are also considered. Special attention in the development plan is paid to modelling of power systems in the region of South-Eastern Europe and covering a wider area of the regional transmission grid with simulations of various market transactions. Macedonian transmission grid is developed to satisfy all requirements for electricity production/supply and transits, irrespective which scenario will be realized on long-term basis. Transmission development plan gives the road map for grid evolution from short-term and mid-term period towards long-term horizons (15-20 years ahead). While creating long-term visions, a big challenge in front of transmission planners is implementation of NPP. The paper gives overview of the planning process of Macedonian transmission grid,comprising: definition of scenarios,planning methodology and assessment of

The complexity and challenges of determining GHG (greenhouse gas) emissions from grid electricity consumption and conservation in LCA (life cycle assessment) – A methodological review

International Nuclear Information System (INIS)

Soimakallio, Sampo; Kiviluoma, Juha; Saikku, Laura

2011-01-01

The way in which GHG (greenhouse gas) emissions associated with grid electricity consumption is handled in different LCA (life cycle assessment) studies, varies significantly. Apart from differences in actual research questions, methodological choices and data set selection have a significant impact on the outcomes. These inconsistencies result in difficulties to compare the findings of various LCA studies. This review paper explores the issue from a methodological point of view. The perspectives of ALCA (attributional life cycle assessment) and CLCA (consequential life cycle assessment) are reflected. Finally, the paper summarizes the key issues and provides suggestions on the way forward. The major challenge related to both of the LCA categories is to determine the GHG emissions of the power production technologies under consideration. Furthermore, the specific challenge in ALCA is to determine the appropriate electricity production mix, and in CLCA, to identify the marginal technologies affected and related consequences. Significant uncertainties are involved, particularly in future-related LCAs, and these should not be ignored. Harmonization of the methods and data sets for various purposes is suggested, acknowledging that selections might be subjective. -- Highlights: ► Methods to assess GHG emissions from grid electricity consumption in LCA vary. ► We explored the major challenges related to various methods. ► Significant uncertainties are involved particularly in future-related GHG emissions. ► The most appropriate method depends on the equity viewpoints.

Automatic Overset Grid Generation with Heuristic Feedback Control

Science.gov (United States)

Robinson, Peter I.

2001-01-01

An advancing front grid generation system for structured Overset grids is presented which automatically modifies Overset structured surface grids and control lines until user-specified grid qualities are achieved. The system is demonstrated on two examples: the first refines a space shuttle fuselage control line until global truncation error is achieved; the second advances, from control lines, the space shuttle orbiter fuselage top and fuselage side surface grids until proper overlap is achieved. Surface grids are generated in minutes for complex geometries. The system is implemented as a heuristic feedback control (HFC) expert system which iteratively modifies the input specifications for Overset control line and surface grids. It is developed as an extension of modern control theory, production rules systems and subsumption architectures. The methodology provides benefits over the full knowledge lifecycle of an expert system for knowledge acquisition, knowledge representation, and knowledge execution. The vector/matrix framework of modern control theory systematically acquires and represents expert system knowledge. Missing matrix elements imply missing expert knowledge. The execution of the expert system knowledge is performed through symbolic execution of the matrix algebra equations of modern control theory. The dot product operation of matrix algebra is generalized for heuristic symbolic terms. Constant time execution is guaranteed.

Smart Grid Research: Control Systems - IEEE Vision for Smart Grid Controls

DEFF Research Database (Denmark)

Aho, Jacob; Arnold, George; Buckspan, Andrew

This document highlights the role of control systems in the evolution of the Smart Grid. It includes an overview of research investigations that are needed for renewable integration, reliability, self-healing, energy efficiency, and resilience to physical and cyber attacks. These investigations...... are encapsulated in several loci of control including: new methodologies for transmission, distribution, and renewable energy, and storage; new roles in emerging topics such as electricity markets, demand-response, microgrids, and virtual power plants; and new solutions for efficiency, heating and cooling...

Schwarz-Christoffel Conformal Mapping based Grid Generation for Global Oceanic Circulation Models

Science.gov (United States)

Xu, Shiming

2015-04-01

We propose new grid generation algorithms for global ocean general circulation models (OGCMs). Contrary to conventional, analytical forms based dipolar or tripolar grids, the new algorithm are based on Schwarz-Christoffel (SC) conformal mapping with prescribed boundary information. While dealing with the conventional grid design problem of pole relocation, it also addresses more advanced issues of computational efficiency and the new requirements on OGCM grids arisen from the recent trend of high-resolution and multi-scale modeling. The proposed grid generation algorithm could potentially achieve the alignment of grid lines to coastlines, enhanced spatial resolution in coastal regions, and easier computational load balance. Since the generated grids are still orthogonal curvilinear, they can be readily 10 utilized in existing Bryan-Cox-Semtner type ocean models. The proposed methodology can also be applied to the grid generation task for regional ocean modeling when complex land-ocean distribution is present.

Towards A Genetic Business Code For Growth in the South African Transport Industry

Directory of Open Access Journals (Sweden)

J.H. Vermeulen

2003-11-01

Full Text Available As with each living organism, it is proposed that an organisation possesses a genetic code. In the fast-changing business environment it would be invaluable to know what constitutes organisational growth and success in terms of such a code. To identify this genetic code a quantitative methodological framework, supplemented by a qualitative approach, was used and the views of top management in the Transport Industry were solicited. The Repertory Grid was used as the primary data-collection method. Through a phased data-analysis process an integrated profile of first- and second-order constructs, and opposite poles, was compiled. By utilising deductive and inductive strategies three strands of a Genetic Business Growth Code were identified, namely a Leadership Strand, Organisational Architecture Strand and Internal Orientation Strand. The study confirmed the value of a Genetic Business Code for growth in the Transport Industry. Opsomming Daar word voorgestel dat ’n organisasie, soos elke lewende organisme, oor ’n genetiese kode beskik. In die snelveranderende sake-omgewing sal dit onskatbaar wees om te weet wat organisasiegroei en –sukses veroorsaak. ’n Kwantitatiewe metodologie-raamwerk, aangevul deur ’n kwalitatiewe benadering is gebruik om hierdie genetiese kode te identifiseer, en die menings van topbestuur in die Vervoerbedryf is ingewin met behulp van die “Repertory Grid" as die vernaamste metode van data-insameling. ’n Geïntegreerde profiel van eerste- en tweedeordekonstrukte, met hulle teenoorgestelde pole, is opgestel. Drie stringe van ’n Genetiese Sakegroeikode, nl. ’n Leierskapstring, die Organisasieargitektuur-string en die Innerlike-ingesteldheidstring is geïdentifiseer deur deduktiewe en induktiewe strategieë te gebruik. Die studie bevestig die waarde van ’n Genetiese Sakekode vir groei in die Vervoerbedryf.

Envers un repertori conceptual de la poesia de Narcís Vinyoles

Directory of Open Access Journals (Sweden)

Salvador Cuenca Almenar

2013-12-01

Full Text Available L’obra lírica de Narcís Vinyoles es pot caracteritzar pel sincretisme formal i temàtic, típic de la València del pas del segle XV al XVI, un espai eclèctic on s’unien influències diverses. En aquest espai receptor Vinyoles construí la seua obra amb tres llengües: català, castellà i italià, i amb inspiracions temàtiques divergents. Des del punt de vista temàtic, un dels elements barrejats pel poeta valencià fou el filosoficoconceptual. En aquest treball detectaré els conceptes i, sense explicar-los en profunditat, explicitaré l’ús que en fa el poeta valencià. Dividiré el repertori conceptual en cinc apartats, segons la disciplina a la qual pertanguen: epistemologia, filosofia de la natura, metafísica, filosofia moral i teologia. Narcís Vinyoles’s poetry can be depicted by its formal and thematic syncretism, representative of Valencia at the turn of the 15th and 16th centuries, an eclectic city where diverse influences inextricably merged. In this receiving place Vinyoles built up his works with three languages, namely, Catalan, Castilian and Italian, and with different thematic inspirations. Thematically speaking, philosophical concepts are one of the elements mingled by the Valencian poet. In this paper I will only detect these concepts and specify the use made by Vinyoles without the explanation. The repertoire will be divided in five parts, according to the discipline to which concepts belong: epistemology, philosophy of nature, metaphysics, moral philosophy and theology

Scoping paper on new CDM baseline methodology for cross-border power trade

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

Poeyry has been sub-contracted by Carbon Limits, under the African Development Bank CDM Support Programme, to prepare a new CDM baseline methodology for cross border trade, based on a transmission line from Ethiopia to Kenya. The first step in that process is to review the response of the UNFCCC, particularly the Methodologies Panel ('Meth Panel') of the CDM Executive Board, to the various proposals on cross-border trade and interconnection of grids. This report reviews the Methodology Panel and Executive Board decisions on 4 requests for revisions of ACM2 'Consolidated baseline methodology for grid-connected electricity generation from renewable sources', and 5 proposed new baseline methodologies (NM255, NM269, NM272, NM318, NM342), all of which were rejected. We analyse the reasons the methodologies were rejected, and whether the proposed draft Approved Methodology (AM) that the Methodology Panel created in response to NM269 and NM272 is a suitable basis for a new methodology proposal.(auth)

Design of High-Fidelity Testing Framework for Secure Electric Grid Control

Energy Technology Data Exchange (ETDEWEB)

Yoginath, Srikanth B [ORNL; Perumalla, Kalyan S [ORNL

2014-01-01

A solution methodology and implementation components are presented that can uncover unwanted, unintentional or unanticipated effects on electric grids from changes to actual electric grid control software. A new design is presented to leapfrog over the limitations of current modeling and testing techniques for cyber technologies in electric grids. We design a fully virtualized approach in which actual, unmodified operational software under test is enabled to interact with simulated surrogates of electric grids. It enables the software to influence the (simulated) grid operation and vice versa in a controlled, high fidelity environment. Challenges in achieving such capability include achieving low-overhead time control mechanisms in hypervisor schedulers, network capture and time-stamping, translation of network packets emanating from grid software into discrete events of virtual grid models, translation back from virtual sensors/actuators into data packets to control software, and transplanting the entire system onto an accurately and efficiently maintained virtual-time plane.

Design optimization of transformerless grid-connected PV inverters including reliability

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2012-01-01

Of the Electricity (LCOE) generated during the PV system lifetime period is minimized. The LCOE is calculated also considering the failure rates of the components, which affect the reliability performance and lifetime maintenance cost of the PV inverter. A design example is presented, demonstrating that compared...... to the non-optimized PV inverter structures, the PV inverters designed using the proposed optimization methodology exhibit lower total manufacturing and lifetime maintenance cost and inject more energy into the electric-grid and by that minimizing LCOE.......This paper presents a new methodology for optimal design of transformerless Photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal values and types of the PV inverter components are calculated such that the PV inverter Levelized Cost...

Design Optimization of Transformerless Grid-Connected PV Inverters Including Reliability

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

such that the PV inverter LCOE generated during the PV system lifetime period is minimized. The LCOE is also calculated considering the failure rates of the components, which affect the reliability performance and lifetime maintenance cost of the PV inverter. A design example is presented, demonstrating...... that compared to the nonoptimized PV inverter structures, the PV inverters designed using the proposed optimization methodology exhibit lower total manufacturing and lifetime maintenance cost and inject more energy into the electric-grid and by that minimizing LCOE.......This paper presents a new methodology for optimal design of transformerless photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal switching frequency as well as the optimal values and types of the PV inverter components is calculated...

Renewable energy integration in smart grids-multicriteria assessment using the fuzzy analytical hierarchy process

OpenAIRE

JANJIC, ALEKSANDAR; SAVIC, SUZANA; VELIMIROVIC, LAZAR; NIKOLIC, VESNA

2015-01-01

Unlike the traditional way of efficiency assessment of renewable energy sources integration, the smart grid concept is introducing new goals and objectives regarding increased use of renewable electricity sources, grid security, energy conservation, energy efficiency, and deregulated energy market. Possible benefits brought by renewable sources integration are evaluated by the degree of the approach to the ideal smart grid. In this paper, fuzzy analytical hierarchy process methodology for the...

Strategic Energy Management (SEM) in a micro grid with modern grid interactive electric vehicle

International Nuclear Information System (INIS)

Panwar, Lokesh Kumar; Reddy, K. Srikanth; Kumar, Rajesh; Panigrahi, B.K.; Vyas, Shashank

2015-01-01

Highlights: • System: Modelling of energy and storage systems for micro grid. • Target: Co-ordination of unitized regenerative fuel cell (URFC) and electric vehicle (EV). • Energy management strategies: Only URFC, URFC–EV charging, URFC-V2G with enabled. • Multi-objective approach: loss, cost minimization, maximization of stored energy. • Proposed Solution: Intelligent co-ordination of URFC and EV with V2G with most effective strategy. - Abstract: In this paper, strategic energy management in a micro grid is proposed incorporating two types of storage elements viz. unitised regenerative fuel cell (URFC) and electric vehicle (EV). Rather than a simple approach of optimizing micro grid operation to minimize line loss in the micro grid, this paper deals with multi objective optimization to minimize line loss, operational cost and maximize the value of stored energy of URFC and EV simultaneously. Apart from URFC, two operation strategies are proposed for EV enabling V2G operation to reduce overall system cost of operation. To address the complexity, non-linearity and multi dimensionality of the objective function, particle swarm optimization-a heuristic approach based solution methodology along with forward and back sweep algorithm based load flow solution technique is developed. Combined with particle swarm optimization (PSO), forward and backward sweep algorithm resolves the complexity and multi dimensionality of the load flow analysis and optimizes the operational cost of micro grid. The simulation results are presented and discussed which are promising with regard to reduction in line loss as well as cost of operation. Scheduling strategy of the micro grid with both URFC and EV enabling V2G operation presents a promising approach to minimize line loss and cost of operation.

Modeling of GE Appliances in GridLAB-D: Peak Demand Reduction

Energy Technology Data Exchange (ETDEWEB)

Fuller, Jason C.; Vyakaranam, Bharat GNVSR; Prakash Kumar, Nirupama; Leistritz, Sean M.; Parker, Graham B.

2012-04-29

The widespread adoption of demand response enabled appliances and thermostats can result in significant reduction to peak electrical demand and provide potential grid stabilization benefits. GE has developed a line of appliances that will have the capability of offering several levels of demand reduction actions based on information from the utility grid, often in the form of price. However due to a number of factors, including the number of demand response enabled appliances available at any given time, the reduction of diversity factor due to the synchronizing control signal, and the percentage of consumers who may override the utility signal, it can be difficult to predict the aggregate response of a large number of residences. The effects of these behaviors can be modeled and simulated in open-source software, GridLAB-D, including evaluation of appliance controls, improvement to current algorithms, and development of aggregate control methodologies. This report is the first in a series of three reports describing the potential of GE's demand response enabled appliances to provide benefits to the utility grid. The first report will describe the modeling methodology used to represent the GE appliances in the GridLAB-D simulation environment and the estimated potential for peak demand reduction at various deployment levels. The second and third reports will explore the potential of aggregated group actions to positively impact grid stability, including frequency and voltage regulation and spinning reserves, and the impacts on distribution feeder voltage regulation, including mitigation of fluctuations caused by high penetration of photovoltaic distributed generation and the effects on volt-var control schemes.

Usability Constructs

DEFF Research Database (Denmark)

Hertzum, Morten; Clemmesen, Torkil; Hornbæk, Kasper Anders Søren

2007-01-01

Whereas research on usability predominantly employs universal definitions of the aspects that comprise usability, people experience their use of information systems through personal constructs. Based on 48 repertory-grid interviews, this study investigates how such personal constructs are affected...... use of constructs traditionally associated with usability (e.g., easy-to-use, intuitive, and liked). Further analysis of the data is ongoing...

Discrete Adjoint-Based Design Optimization of Unsteady Turbulent Flows on Dynamic Unstructured Grids

Science.gov (United States)

Nielsen, Eric J.; Diskin, Boris; Yamaleev, Nail K.

2009-01-01

An adjoint-based methodology for design optimization of unsteady turbulent flows on dynamic unstructured grids is described. The implementation relies on an existing unsteady three-dimensional unstructured grid solver capable of dynamic mesh simulations and discrete adjoint capabilities previously developed for steady flows. The discrete equations for the primal and adjoint systems are presented for the backward-difference family of time-integration schemes on both static and dynamic grids. The consistency of sensitivity derivatives is established via comparisons with complex-variable computations. The current work is believed to be the first verified implementation of an adjoint-based optimization methodology for the true time-dependent formulation of the Navier-Stokes equations in a practical computational code. Large-scale shape optimizations are demonstrated for turbulent flows over a tiltrotor geometry and a simulated aeroelastic motion of a fighter jet.

Near-Body Grid Adaption for Overset Grids

Science.gov (United States)

Buning, Pieter G.; Pulliam, Thomas H.

2016-01-01

A solution adaption capability for curvilinear near-body grids has been implemented in the OVERFLOW overset grid computational fluid dynamics code. The approach follows closely that used for the Cartesian off-body grids, but inserts refined grids in the computational space of original near-body grids. Refined curvilinear grids are generated using parametric cubic interpolation, with one-sided biasing based on curvature and stretching ratio of the original grid. Sensor functions, grid marking, and solution interpolation tasks are implemented in the same fashion as for off-body grids. A goal-oriented procedure, based on largest error first, is included for controlling growth rate and maximum size of the adapted grid system. The adaption process is almost entirely parallelized using MPI, resulting in a capability suitable for viscous, moving body simulations. Two- and three-dimensional examples are presented.

The MammoGrid Project Grids Architecture

CERN Document Server

McClatchey, Richard; Hauer, Tamas; Estrella, Florida; Saiz, Pablo; Rogulin, Dmitri; Buncic, Predrag; Clatchey, Richard Mc; Buncic, Predrag; Manset, David; Hauer, Tamas; Estrella, Florida; Saiz, Pablo; Rogulin, Dmitri

2003-01-01

The aim of the recently EU-funded MammoGrid project is, in the light of emerging Grid technology, to develop a European-wide database of mammograms that will be used to develop a set of important healthcare applications and investigate the potential of this Grid to support effective co-working between healthcare professionals throughout the EU. The MammoGrid consortium intends to use a Grid model to enable distributed computing that spans national borders. This Grid infrastructure will be used for deploying novel algorithms as software directly developed or enhanced within the project. Using the MammoGrid clinicians will be able to harness the use of massive amounts of medical image data to perform epidemiological studies, advanced image processing, radiographic education and ultimately, tele-diagnosis over communities of medical "virtual organisations". This is achieved through the use of Grid-compliant services [1] for managing (versions of) massively distributed files of mammograms, for handling the distri...

TRIANA. A control strategy for Smart Grids. Forecasting, planning and real-time control

International Nuclear Information System (INIS)

Bakker, V.

2012-01-01

Increasing demand, extra fluctuation and a large share of distributed electricity generation will put more stress on the electricity supply chain. Therefore, changes are required in the supply chain to maintain a properly functioning, stable and affordable grid. Currently the supply chain is completely driven by demand by constantly adapting the production to the demand. The exploitation of flexibility on the demand side of the supply chain allows for a more efficient and sustainable electricity production. Techniques like controllable distributed generation, distributed storage, and smart appliances can introduce this required flexibility. To exploit the new flexibility, the grid has to become more intelligent, i.e. become a Smart Grid. In this thesis TRIANA, a three step control strategy for the Smart Grid is presented. In the first step of TRIANA, the forecasting step, the scheduling freedom (flexibility) of a device is determined for each individual device by a local controller. In the second step, a (central) planner tries to exploit the freedom of the devices determined in the first step for his objective. The last step of TRIANA is the real-time control step performed by the local controller achieving the planning in the best possible way. In order to analyze the impact of control methodologies for Smart Grid, a simulator based on an energy model has been built. The basic elements of the model are individual devices and between devices energy streams are defined. The energy streams are connected via so called pools, which represent the physical connections between the devices. To study the effectiveness of the control methodology and study the most economic use of the flexibility of devices, multiple scenarios have been simulated. Simulations show that TRIANA can optimize the energy flows and can control the operation of the domestic devices in an economic manner without discomfort for the residents. TRIANA is a methodology capable of adjusting the energy

Discrete Adjoint-Based Design for Unsteady Turbulent Flows On Dynamic Overset Unstructured Grids

Science.gov (United States)

Nielsen, Eric J.; Diskin, Boris

2012-01-01

A discrete adjoint-based design methodology for unsteady turbulent flows on three-dimensional dynamic overset unstructured grids is formulated, implemented, and verified. The methodology supports both compressible and incompressible flows and is amenable to massively parallel computing environments. The approach provides a general framework for performing highly efficient and discretely consistent sensitivity analysis for problems involving arbitrary combinations of overset unstructured grids which may be static, undergoing rigid or deforming motions, or any combination thereof. General parent-child motions are also accommodated, and the accuracy of the implementation is established using an independent verification based on a complex-variable approach. The methodology is used to demonstrate aerodynamic optimizations of a wind turbine geometry, a biologically-inspired flapping wing, and a complex helicopter configuration subject to trimming constraints. The objective function for each problem is successfully reduced and all specified constraints are satisfied.

Integration of electric vehicles with optimum sized storage for grid connected photo-voltaic system

OpenAIRE

Sulabh Sachan

2017-01-01

The necessity of energy storage by means of battery/EV is exceedingly expected in event of energy blackouts. Different advantages incorporate sparing the cash in purchasing top time power and support the grid when grid power is deficit against the load demand. In this paper, ideal size of energy storage in a grid associated photovoltaic (PV) framework is proposed. The methodology of energy flow choice is produced with the appraisal on accessibility of PV yield control and the load demand. The...

Implementation of grid-connected to/from off-grid transference for micro-grid inverters

OpenAIRE

Heredero Peris, Daniel; Chillón Antón, Cristian; Pages Gimenez, Marc; Gross, Gabriel Igor; Montesinos Miracle, Daniel

2013-01-01

This paper presents the transfer of a microgrid converter from/to on-grid to/from off-grid when the converter is working in two different modes. In the first transfer presented method, the converter operates as a Current Source Inverter (CSI) when on-grid and as a Voltage Source Inverter (VSI) when off-grid. In the second transfer method, the converter is operated as a VSI both, when operated on-grid and off-grid. The two methods are implemented successfully in a real pla...

Energy revolution and citizens' protests. A study of the communication of citizens' initiatives concerning grid expension

International Nuclear Information System (INIS)

Braeuer, Marco

2017-01-01

The extension of the German high voltage power grid has recently caused intense resistance in the affected regions. Publicly visible protests are mainly organised by citizen action groups. These groups act from the position of the periphery of the political system. Hence, they need to communicate their concerns and aims in order to influence the political and administrative decision-making system. In general they have the option to gain access to the mass media agenda. In addition protest groups can also create own media products (from leaflets to social media represenations). The theoretical points of departure of this study are social movement theories and the theory of the public sphere. An inclusive theoretical model, explaining the choice of protest repertories by citizen action groups, is developed. Furthermore, eight comprehensive case studies of citizen action groups in the conflict field of the extension of the German high voltage power grid were conducted. The results of the case studies reveal that the citizen action groups act strategically. They observe and assess the political and mass-mediated discourses and respectively develop their own frames. Although critical and sceptical towards the institutional practices and the actions of political representatives, the political system is perceived as legitimate and remains the main addressee. In addition, the mass media system is in general accepted, even though a (at least partially deliberate) negative bias and sometimes oven hostility against their own position is perceived. The creation of alternative media products is not a mere reaction with regard to the perceived mass media bias. It can be better understood as a result of the integration of the protest groups in local and regional communication structures (neighbourhoods, hobby networks, professional networks etc.). The study closes with recommendations for the improvement of consultation processes in the field of infrastructure protests.

Computer Network Operations Methodology

Science.gov (United States)

2004-03-01

means of their computer information systems. Disrupt - This type of attack focuses on disrupting as “attackers might surreptitiously reprogram enemy...by reprogramming the computers that control distribution within the power grid. A disruption attack introduces disorder and inhibits the effective...between commanders. The use of methodologies is widespread and done subconsciously to assist individuals in decision making. The processes that

Smart grid

International Nuclear Information System (INIS)

Choi, Dong Bae

2001-11-01

This book describes press smart grid from basics to recent trend. It is divided into ten chapters, which deals with smart grid as green revolution in energy with introduction, history, the fields, application and needed technique for smart grid, Trend of smart grid in foreign such as a model business of smart grid in foreign, policy for smart grid in U.S.A, Trend of smart grid in domestic with international standard of smart grid and strategy and rood map, smart power grid as infrastructure of smart business with EMS development, SAS, SCADA, DAS and PQMS, smart grid for smart consumer, smart renewable like Desertec project, convergence IT with network and PLC, application of an electric car, smart electro service for realtime of electrical pricing system, arrangement of smart grid.

GridCom, Grid Commander: graphical interface for Grid jobs and data management

International Nuclear Information System (INIS)

Galaktionov, V.V.

2011-01-01

GridCom - the software package for maintenance of automation of access to means of distributed system Grid (jobs and data). The client part, executed in the form of Java-applets, realises the Web-interface access to Grid through standard browsers. The executive part Lexor (LCG Executor) is started by the user in UI (User Interface) machine providing performance of Grid operations

Smart Grid Development Issues for Terrestrial and Space Applications

Science.gov (United States)

Soeder, James F.

2014-01-01

The development of the so called Smart Grid has as many definitions as individuals working in the area. Based on the technology or technologies that are of interest, be it high speed communication, renewable generation, smart meters, energy storage, advanced sensors, etc. they can become the individual defining characteristic of the Smart Grid. In reality the smart grid encompasses all of these items and quite at bit more. This discussion attempts to look at what the needs are for the grid of the future, such as the issues of increased power flow capability, use of renewable energy, increased security and efficiency and common power and data standards. It also shows how many of these issues are common with the needs of NASA for future exploration programs. A common theme to address both terrestrial and space exploration issues is to develop micro-grids that advertise the ability to enable the load leveling of large power generation facilities. However, for microgrids to realize their promise there needs to a holistic systems approach to their development and integration. The overall system integration issues are presented along with potential solution methodologies.

Croatia's rural areas - renewable energy based electricity generation for isolated grids

Directory of Open Access Journals (Sweden)

Protic Sonja Maria

2014-01-01

Full Text Available Several Western Balkan states face the consequences of the Yugoslavian war, which left hometowns with dilapidated electricity grid connections, a high average age of power plant capacities and low integration of renewable energy sources, grid bottlenecks and a lack of competition. In order to supply all households with electricity, UNDP Croatia did a research on decentralized supply systems based on renewable energy sources. Decentralized supply systems offer cheaper electricity connections and provide faster support to rural development. This paper proposes a developed methodology to financially compare isolated grid solutions that primarily use renewable energies to an extension of the public electricity network to small regions in Croatia. Isolated grid supply proves to be very often a preferable option. Furthermore, it points out the lack of a reliable evaluation of non-monetizable aspects and promotes a new interdisciplinary approach.

Net load forecasting for high renewable energy penetration grids

International Nuclear Information System (INIS)

Kaur, Amanpreet; Nonnenmacher, Lukas; Coimbra, Carlos F.M.

2016-01-01

We discuss methods for net load forecasting and their significance for operation and management of power grids with high renewable energy penetration. Net load forecasting is an enabling technology for the integration of microgrid fleets with the macrogrid. Net load represents the load that is traded between the grids (microgrid and utility grid). It is important for resource allocation and electricity market participation at the point of common coupling between the interconnected grids. We compare two inherently different approaches: additive and integrated net load forecast models. The proposed methodologies are validated on a microgrid with 33% annual renewable energy (solar) penetration. A heuristics based solar forecasting technique is proposed, achieving skill of 24.20%. The integrated solar and load forecasting model outperforms the additive model by 10.69% and the uncertainty range for the additive model is larger than the integrated model by 2.2%. Thus, for grid applications an integrated forecast model is recommended. We find that the net load forecast errors and the solar forecasting errors are cointegrated with a common stochastic drift. This is useful for future planning and modeling because the solar energy time-series allows to infer important features of the net load time-series, such as expected variability and uncertainty. - Highlights: • Net load forecasting methods for grids with renewable energy generation are discussed. • Integrated solar and load forecasting outperforms the additive model by 10.69%. • Net load forecasting reduces the uncertainty between the interconnected grids.

Grid for Earth Science Applications

Science.gov (United States)

Petitdidier, Monique; Schwichtenberg, Horst

2013-04-01

The civil society at large has addressed to the Earth Science community many strong requirements related in particular to natural and industrial risks, climate changes, new energies. The main critical point is that on one hand the civil society and all public ask for certainties i.e. precise values with small error range as it concerns prediction at short, medium and long term in all domains; on the other hand Science can mainly answer only in terms of probability of occurrence. To improve the answer or/and decrease the uncertainties, (1) new observational networks have been deployed in order to have a better geographical coverage and more accurate measurements have been carried out in key locations and aboard satellites. Following the OECD recommendations on the openness of research and public sector data, more and more data are available for Academic organisation and SMEs; (2) New algorithms and methodologies have been developed to face the huge data processing and assimilation into simulations using new technologies and compute resources. Finally, our total knowledge about the complex Earth system is contained in models and measurements, how we put them together has to be managed cleverly. The technical challenge is to put together databases and computing resources to answer the ES challenges. However all the applications are very intensive computing. Different compute solutions are available and depend on the characteristics of the applications. One of them is Grid especially efficient for independent or embarrassingly parallel jobs related to statistical and parametric studies. Numerous applications in atmospheric chemistry, meteorology, seismology, hydrology, pollution, climate and biodiversity have been deployed successfully on Grid. In order to fulfill requirements of risk management, several prototype applications have been deployed using OGC (Open geospatial Consortium) components with Grid middleware. The Grid has permitted via a huge number of runs to

Enabling Campus Grids with Open Science Grid Technology

International Nuclear Information System (INIS)

Weitzel, Derek; Fraser, Dan; Pordes, Ruth; Bockelman, Brian; Swanson, David

2011-01-01

The Open Science Grid is a recognized key component of the US national cyber-infrastructure enabling scientific discovery through advanced high throughput computing. The principles and techniques that underlie the Open Science Grid can also be applied to Campus Grids since many of the requirements are the same, even if the implementation technologies differ. We find five requirements for a campus grid: trust relationships, job submission, resource independence, accounting, and data management. The Holland Computing Center's campus grid at the University of Nebraska-Lincoln was designed to fulfill the requirements of a campus grid. A bridging daemon was designed to bring non-Condor clusters into a grid managed by Condor. Condor features which make it possible to bridge Condor sites into a multi-campus grid have been exploited at the Holland Computing Center as well.

Assessment of grid optimisation measures for the German transmission grid using open source grid data

Science.gov (United States)

Böing, F.; Murmann, A.; Pellinger, C.; Bruckmeier, A.; Kern, T.; Mongin, T.

2018-02-01

The expansion of capacities in the German transmission grid is a necessity for further integration of renewable energy sources into the electricity sector. In this paper, the grid optimisation measures ‘Overhead Line Monitoring’, ‘Power-to-Heat’ and ‘Demand Response in the Industry’ are evaluated and compared against conventional grid expansion for the year 2030. Initially, the methodical approach of the simulation model is presented and detailed descriptions of the grid model and the used grid data, which partly originates from open-source platforms, are provided. Further, this paper explains how ‘Curtailment’ and ‘Redispatch’ can be reduced by implementing grid optimisation measures and how the depreciation of economic costs can be determined considering construction costs. The developed simulations show that the conventional grid expansion is more efficient and implies more grid relieving effects than the evaluated grid optimisation measures.

Enabling campus grids with open science grid technology

Energy Technology Data Exchange (ETDEWEB)

Weitzel, Derek [Nebraska U.; Bockelman, Brian [Nebraska U.; Swanson, David [Nebraska U.; Fraser, Dan [Argonne; Pordes, Ruth [Fermilab

2011-01-01

The Open Science Grid is a recognized key component of the US national cyber-infrastructure enabling scientific discovery through advanced high throughput computing. The principles and techniques that underlie the Open Science Grid can also be applied to Campus Grids since many of the requirements are the same, even if the implementation technologies differ. We find five requirements for a campus grid: trust relationships, job submission, resource independence, accounting, and data management. The Holland Computing Center's campus grid at the University of Nebraska-Lincoln was designed to fulfill the requirements of a campus grid. A bridging daemon was designed to bring non-Condor clusters into a grid managed by Condor. Condor features which make it possible to bridge Condor sites into a multi-campus grid have been exploited at the Holland Computing Center as well.

IDENTIFYING COMPETENCIES OF VOLUNTEER BOARD MEMBERS OF COMMUNITY SPORTS CLUBS

OpenAIRE

A. BALDUCK; A. VAN ROSSEM; M. BUELENS

2009-01-01

This study contributes to the emerging empirical studies on roles and responsibilities of boards in nonprofit organizations by identifying competencies of volunteer board members. We identified how two types of constituents—volunteer board members and sports members—perceived competencies of volunteer board members in community sports clubs. We used the repertory grid technique to draw cognitive maps and to reveal the perceived reality of these constituents. Our results suggest that constitue...

Recruiting for diversity: Sex differences in undergraduates’ choices of potential employers

OpenAIRE

Freeman, Cheryl

2003-01-01

The aim of this research is to explore sex differences in undergraduates’ choices of potential employers. It focuses on a major employer (‘the Firm’), wishing to increase the number of job applications it receives from female undergraduates, and comprises three linked projects. No previous research was found that addresses sex differences in organisational choice. In the first project, a contribution is made by identifying, using Repertory Grids, eightyfour organisational at...

The Improvement of Kansei Engineering by Using the Repertory Grid Technique

Directory of Open Access Journals (Sweden)

Steinberg Falk

2015-09-01

Full Text Available A customer-oriented approach to product development with particular consideration of emotions is represented by Kansei Engineering. Developed by Mitsuo Nagamachi, Kansei Engineering is characterized by the possibility to capture customer perceptions and to translate them into product features. In order to assess these perceptions, a semantic space is generated. For this purpose it is necessary to identify Kansei words that are gathered up through research in marketing concepts, scientific journals and service reports. This procedure though displays the disadvantage of not being able to identify all emotions referring to the investigated product.

A Generic Framework for the Evaluation of the Benefits Expected from the Smart Grid

Directory of Open Access Journals (Sweden)

Panayotis G. Cottis

2013-02-01

Full Text Available The Smart Grid has the potential to bring significant value to the various stakeholders of the electricity market. A methodology for the evaluation of the smart grid benefits is required to facilitate the decision making by quantifying the benefits expected from a smart grid project. The present paper proposes a generic framework to assess these expected benefits taking into account the regulatory, business and technical challenges focusing particularly on Distributed Systems Operators (DSOs and end users. An indicative study case is presented where the proposed cost-benefit approach assesses the expected value of DSOs from the Smart Grid and determines whether and under what conditions such an investment should be initiated.

Numerical analysis of the spacer grids' compression strength

International Nuclear Information System (INIS)

Schettino, C.F.M.; Gouvea, J.P.; Medeiros, N.

2013-01-01

Among the components of the fuel assembly, the spacer grids play an important structural role during the energy generation process, mainly for their requirement to have enough structural strength to withstand lateral impact loads, due to fuel assembly shipping/handling and due to forces outcome from postulated accidents (earthquake and LOCA). This requirement ensures a proper geometry for cooling and for guide thimble straightness in the fuel assembly. In this way, the understanding of the macroscopic mechanical behavior of this component becomes essential even to any subsequent geometrical modifications to optimize the flue assemblies' structural behavior. In the present work, three-dimensional finite element models destined to provide consistent predictions of 16X16-type spacer grids lateral strength were proposed. Firstly, buckling tests based on results available in the literature were performed to establish a methodology for spacer grid finite element-based modeling. The, by considering a spacer grid interesting geometry and some possible variations associated to its fabrication, tolerance, the proposed numerical models were submitted to compression conditions to calculate the buckling force. Also, these models were validated for comparison with experimental buckling load results. Comparison of buckling predictions combined to observations of actual and simulated deformed spacer grids geometries permitted to verify the consistency and applicability of the proposed models. Thus, these numerical results show a good agreement between the and the experimental results. (author)

Transcultural Adaptation of GRID Hamilton Rating Scale For Depression (GRID-HAMD) to Brazilian Portuguese and Evaluation of the Impact of Training Upon Inter-Rater Reliability.

Science.gov (United States)

Henrique-Araújo, Ricardo; Osório, Flávia L; Gonçalves Ribeiro, Mônica; Soares Monteiro, Ivandro; Williams, Janet B W; Kalali, Amir; Alexandre Crippa, José; Oliveira, Irismar Reis De

2014-07-01

GRID-HAMD is a semi-structured interview guide developed to overcome flaws in HAM-D, and has been incorporated into an increasing number of studies. Carry out the transcultural adaptation of GRID-HAMD into the Brazilian Portuguese language, evaluate the inter-rater reliability of this instrument and the training impact upon this measure, and verify the raters' opinions of said instrument. The transcultural adaptation was conducted by appropriate methodology. The measurement of inter-rater reliability was done by way of videos that were evaluated by 85 professionals before and after training for the use of this instrument. The intraclass correlation coefficient (ICC) remained between 0.76 and 0.90 for GRID-HAMD-21 and between 0.72 and 0.91 for GRID-HAMD-17. The training did not have an impact on the ICC, except for a few groups of participants with a lower level of experience. Most of the participants showed high acceptance of GRID-HAMD, when compared to other versions of HAM-D. The scale presented adequate inter-rater reliability even before training began. Training did not have an impact on this measure, except for a few groups with less experience. GRID-HAMD received favorable opinions from most of the participants.

Avaliação do repertório de habilidades sociais de adolescentes com Síndrome de Down Assessment of the social skills repertory of adolescents with Down's Syndrome

Directory of Open Access Journals (Sweden)

Antonio Paulo Angélico

2011-01-01

Full Text Available Objetivou-se investigar, a partir da metodologia observacional direta (filmagens, o repertório de habilidades sociais de um grupo de dez adolescentes com síndrome de Down. A classe de desempenhos pró-sociais predominou no repertório dos sujeitos em relação à classe de respostas de enfrentamento exibidas, não havendo, portanto, uma associação significativa entre estas duas classes de habilidades. Este fato pode ser explicado por se tratar de comportamentos distintos adquiridos em contingências específicas de aprendizagem e pelo número maior de categorias que compuseram a primeira classe. A maioria dos sujeitos apresentou déficit de respostas de enfrentamento, o que poderia ser indicativo da necessidade de intervenções preventivas e educacionais que contribuam para um melhor desempenho em situações com essas demandas.Direct observational methodology (video recordings was used to investigate the social abilities of a group of ten adolescents with Down's syndrome. Pro-social performance prevailed in the repertory of the individuals as compared to the coping responses presented. Therefore, there was no significant relation between those two classes of abilities. This result can be explained by the fact that those are different behaviors which are acquired in specific learning contingencies, and by the larger number of categories that composed the first class. Most of the subjects showed deficit in the coping responses, suggesting the need of educational and preventive interventions which contribute to improve the performance in situations with such demands.

Smart electric grids. Economic and environmental value, general implementation. September 2017. Contribution by RTE - Full report

International Nuclear Information System (INIS)

2017-09-01

This report is the RTE's contribution to studies commissions by public authorities on the social and economic valorisation of smart grids for the different actors. It first proposes an overview of the various considered technical and technological solutions: storage, active management of residential, tertiary and industrial demand, and steerability of renewable energies. After a recall of objectives related to the development of smart grids, the report reviews the methodological framework adopted for a previous study (general principles, modelling principles for the electricity system operation, use of the Flexis model, economic and environmental assessment), and proposes an overview of methodological developments achieved since 2015. It discusses how this study compares with others related to smart grid flexibility published in France and in Europe. Then, after having stated some hypotheses, the report presents the analytical framework for quantitative results, discusses economic and environmental assessments performed for each solution (storage, active management for different sectors, and steerability of wind energy production). The next part presents different global economically relevant scenarios of smart grid deployment, with assessments by 2030

GridCom, Grid Commander: graphical interface for Grid jobs and data management; GridCom, Grid Commander: graficheskij interfejs dlya raboty s zadachami i dannymi v gride

Energy Technology Data Exchange (ETDEWEB)

Galaktionov, V V

2011-07-01

GridCom - the software package for maintenance of automation of access to means of distributed system Grid (jobs and data). The client part, executed in the form of Java-applets, realises the Web-interface access to Grid through standard browsers. The executive part Lexor (LCG Executor) is started by the user in UI (User Interface) machine providing performance of Grid operations

Input-Admittance Passivity Compliance for Grid-Connected Converters with LCL Filter

DEFF Research Database (Denmark)

Diaz, Enrique Rodriguez; Freijedo, Francisco D.; Guerrero, Josep M.

2018-01-01

This work presents a design methodology and its experimental validation for the input-admittance passivity compliance of LCL grid-connected converters. The designs of the LCL filter parameters and discrete controller are addressed systematically, and suitable design guidelines are provided......-admittance passivity compliance....

Progress in Grid Generation: From Chimera to DRAGON Grids

Science.gov (United States)

Liou, Meng-Sing; Kao, Kai-Hsiung

1994-01-01

Hybrid grids, composed of structured and unstructured grids, combines the best features of both. The chimera method is a major stepstone toward a hybrid grid from which the present approach is evolved. The chimera grid composes a set of overlapped structured grids which are independently generated and body-fitted, yielding a high quality grid readily accessible for efficient solution schemes. The chimera method has been shown to be efficient to generate a grid about complex geometries and has been demonstrated to deliver accurate aerodynamic prediction of complex flows. While its geometrical flexibility is attractive, interpolation of data in the overlapped regions - which in today's practice in 3D is done in a nonconservative fashion, is not. In the present paper we propose a hybrid grid scheme that maximizes the advantages of the chimera scheme and adapts the strengths of the unstructured grid while at the same time keeps its weaknesses minimal. Like the chimera method, we first divide up the physical domain by a set of structured body-fitted grids which are separately generated and overlaid throughout a complex configuration. To eliminate any pure data manipulation which does not necessarily follow governing equations, we use non-structured grids only to directly replace the region of the arbitrarily overlapped grids. This new adaptation to the chimera thinking is coined the DRAGON grid. The nonstructured grid region sandwiched between the structured grids is limited in size, resulting in only a small increase in memory and computational effort. The DRAGON method has three important advantages: (1) preserving strengths of the chimera grid; (2) eliminating difficulties sometimes encountered in the chimera scheme, such as the orphan points and bad quality of interpolation stencils; and (3) making grid communication in a fully conservative and consistent manner insofar as the governing equations are concerned. To demonstrate its use, the governing equations are

Factors influencing societal response of nanotechnology: an expert stakeholder analysis

International Nuclear Information System (INIS)

Gupta, Nidhi; Fischer, Arnout R. H.; Lans, Ivo A. van der; Frewer, Lynn J.

2012-01-01

Nanotechnology can be described as an emerging technology and, as has been the case with other emerging technologies such as genetic modification, different socio-psychological factors will potentially influence societal responses to its development and application. These factors will play an important role in how nanotechnology is developed and commercialised. This article aims to identify expert opinion on factors influencing societal response to applications of nanotechnology. Structured interviews with experts on nanotechnology from North West Europe were conducted using repertory grid methodology in conjunction with generalized Procrustes analysis to examine the psychological constructs underlying societal uptake of 15 key applications of nanotechnology drawn from different areas (e.g. medicine, agriculture and environment, chemical, food, military, sports, and cosmetics). Based on expert judgement, the main factors influencing societal response to different applications of nanotechnology will be the extent to which applications are perceived to be beneficial, useful, and necessary, and how 'real' and physically close to the end-user these applications are perceived to be by the public.

Factors influencing societal response of nanotechnology: an expert stakeholder analysis

Science.gov (United States)

Gupta, Nidhi; Fischer, Arnout R. H.; van der Lans, Ivo A.; Frewer, Lynn J.

2012-05-01

Nanotechnology can be described as an emerging technology and, as has been the case with other emerging technologies such as genetic modification, different socio-psychological factors will potentially influence societal responses to its development and application. These factors will play an important role in how nanotechnology is developed and commercialised. This article aims to identify expert opinion on factors influencing societal response to applications of nanotechnology. Structured interviews with experts on nanotechnology from North West Europe were conducted using repertory grid methodology in conjunction with generalized Procrustes analysis to examine the psychological constructs underlying societal uptake of 15 key applications of nanotechnology drawn from different areas (e.g. medicine, agriculture and environment, chemical, food, military, sports, and cosmetics). Based on expert judgement, the main factors influencing societal response to different applications of nanotechnology will be the extent to which applications are perceived to be beneficial, useful, and necessary, and how 'real' and physically close to the end-user these applications are perceived to be by the public.

MICROARRAY IMAGE GRIDDING USING GRID LINE REFINEMENT TECHNIQUE

Directory of Open Access Journals (Sweden)

V.G. Biju

2015-05-01

Full Text Available An important stage in microarray image analysis is gridding. Microarray image gridding is done to locate sub arrays in a microarray image and find co-ordinates of spots within each sub array. For accurate identification of spots, most of the proposed gridding methods require human intervention. In this paper a fully automatic gridding method which enhances spot intensity in the preprocessing step as per a histogram based threshold method is used. The gridding step finds co-ordinates of spots from horizontal and vertical profile of the image. To correct errors due to the grid line placement, a grid line refinement technique is proposed. The algorithm is applied on different image databases and results are compared based on spot detection accuracy and time. An average spot detection accuracy of 95.06% depicts the proposed method’s flexibility and accuracy in finding the spot co-ordinates for different database images.

Integration of electric vehicles with optimum sized storage for grid connected photo-voltaic system

Directory of Open Access Journals (Sweden)

Sulabh Sachan

2017-12-01

Full Text Available The necessity of energy storage by means of battery/EV is exceedingly expected in event of energy blackouts. Different advantages incorporate sparing the cash in purchasing top time power and support the grid when grid power is deficit against the load demand. In this paper, ideal size of energy storage in a grid associated photovoltaic (PV framework is proposed. The methodology of energy flow choice is produced with the appraisal on accessibility of PV yield control and the load demand. The energy flow decision is changed by peak and off peak hours to shorten the functional cost of the grid associated PV framework with storage. Naturally, the quantities of electric vehicles that can be associated are resolved.

Grid3: An Application Grid Laboratory for Science

CERN Multimedia

CERN. Geneva

2004-01-01

level services required by the participating experiments. The deployed infrastructure has been operating since November 2003 with 27 sites, a peak of 2800 processors, work loads from 10 different applications exceeding 1300 simultaneous jobs, and data transfers among sites of greater than 2 TB/day. The Grid3 infrastructure was deployed from grid level services provided by groups and applications within the collaboration. The services were organized into four distinct "grid level services" including: Grid3 Packaging, Monitoring and Information systems, User Authentication and the iGOC Grid Operatio...

Grid-connected to/from off-grid transference for micro-grid inverters

OpenAIRE

Heredero Peris, Daniel; Chillón Antón, Cristian; Pages Gimenez, Marc; Gross, Gabriel Igor; Montesinos Miracle, Daniel

2013-01-01

This paper compares two methods for controlling the on-line transference from connected to stand-alone mode and vice versa in converters for micro-grids. The first proposes a method where the converter changes from CSI (Current Source Inverter) in grid-connected mode to VSI (Voltage Source Inverter) in off-grid. In the second method, the inverter always works as a non-ideal voltage source, acting as VSI, using AC droop control strategy.

Potential and cost-effectiveness of off-grid PV systems in Indonesia - An evaluation on a provincial level

NARCIS (Netherlands)

Veldhuis, A.J.; Reinders, Angelina H.M.E.

2014-01-01

In this study we estimate the potential of off-grid PV systems in Indonesia at a provincial level as a follow-up of a study on the potential of grid-connected PV systems in Indonesia which we executed in 2012 [1]. For this study we use an adapted methodology leading to cumulative numbers for the

The GridSite Web/Grid security system

International Nuclear Information System (INIS)

McNab, Andrew; Li Yibiao

2010-01-01

We present an overview of the current status of the GridSite toolkit, describing the security model for interactive and programmatic uses introduced in the last year. We discuss our experiences of implementing these internal changes and how they and previous rounds of improvements have been prompted by requirements from users and wider security trends in Grids (such as CSRF). Finally, we explain how these have improved the user experience of GridSite-based websites, and wider implications for portals and similar web/grid sites.

SAGE - MULTIDIMENSIONAL SELF-ADAPTIVE GRID CODE

Science.gov (United States)

Davies, C. B.

1994-01-01

SAGE, Self Adaptive Grid codE, is a flexible tool for adapting and restructuring both 2D and 3D grids. Solution-adaptive grid methods are useful tools for efficient and accurate flow predictions. In supersonic and hypersonic flows, strong gradient regions such as shocks, contact discontinuities, shear layers, etc., require careful distribution of grid points to minimize grid error and produce accurate flow-field predictions. SAGE helps the user obtain more accurate solutions by intelligently redistributing (i.e. adapting) the original grid points based on an initial or interim flow-field solution. The user then computes a new solution using the adapted grid as input to the flow solver. The adaptive-grid methodology poses the problem in an algebraic, unidirectional manner for multi-dimensional adaptations. The procedure is analogous to applying tension and torsion spring forces proportional to the local flow gradient at every grid point and finding the equilibrium position of the resulting system of grid points. The multi-dimensional problem of grid adaption is split into a series of one-dimensional problems along the computational coordinate lines. The reduced one dimensional problem then requires a tridiagonal solver to find the location of grid points along a coordinate line. Multi-directional adaption is achieved by the sequential application of the method in each coordinate direction. The tension forces direct the redistribution of points to the strong gradient region. To maintain smoothness and a measure of orthogonality of grid lines, torsional forces are introduced that relate information between the family of lines adjacent to one another. The smoothness and orthogonality constraints are direction-dependent, since they relate only the coordinate lines that are being adapted to the neighboring lines that have already been adapted. Therefore the solutions are non-unique and depend on the order and direction of adaption. Non-uniqueness of the adapted grid is

Current Grid operation and future role of the Grid

Science.gov (United States)

Smirnova, O.

2012-12-01

Grid-like technologies and approaches became an integral part of HEP experiments. Some other scientific communities also use similar technologies for data-intensive computations. The distinct feature of Grid computing is the ability to federate heterogeneous resources of different ownership into a seamless infrastructure, accessible via a single log-on. Like other infrastructures of similar nature, Grid functioning requires not only technologically sound basis, but also reliable operation procedures, monitoring and accounting. The two aspects, technological and operational, are closely related: weaker is the technology, more burden is on operations, and other way around. As of today, Grid technologies are still evolving: at CERN alone, every LHC experiment uses an own Grid-like system. This inevitably creates a heavy load on operations. Infrastructure maintenance, monitoring and incident response are done on several levels, from local system administrators to large international organisations, involving massive human effort worldwide. The necessity to commit substantial resources is one of the obstacles faced by smaller research communities when moving computing to the Grid. Moreover, most current Grid solutions were developed under significant influence of HEP use cases, and thus need additional effort to adapt them to other applications. Reluctance of many non-HEP researchers to use Grid negatively affects the outlook for national Grid organisations, which strive to provide multi-science services. We started from the situation where Grid organisations were fused with HEP laboratories and national HEP research programmes; we hope to move towards the world where Grid will ultimately reach the status of generic public computing and storage service provider and permanent national and international Grid infrastructures will be established. How far will we be able to advance along this path, depends on us. If no standardisation and convergence efforts will take place

Current Grid operation and future role of the Grid

International Nuclear Information System (INIS)

Smirnova, O

2012-01-01

Grid-like technologies and approaches became an integral part of HEP experiments. Some other scientific communities also use similar technologies for data-intensive computations. The distinct feature of Grid computing is the ability to federate heterogeneous resources of different ownership into a seamless infrastructure, accessible via a single log-on. Like other infrastructures of similar nature, Grid functioning requires not only technologically sound basis, but also reliable operation procedures, monitoring and accounting. The two aspects, technological and operational, are closely related: weaker is the technology, more burden is on operations, and other way around. As of today, Grid technologies are still evolving: at CERN alone, every LHC experiment uses an own Grid-like system. This inevitably creates a heavy load on operations. Infrastructure maintenance, monitoring and incident response are done on several levels, from local system administrators to large international organisations, involving massive human effort worldwide. The necessity to commit substantial resources is one of the obstacles faced by smaller research communities when moving computing to the Grid. Moreover, most current Grid solutions were developed under significant influence of HEP use cases, and thus need additional effort to adapt them to other applications. Reluctance of many non-HEP researchers to use Grid negatively affects the outlook for national Grid organisations, which strive to provide multi-science services. We started from the situation where Grid organisations were fused with HEP laboratories and national HEP research programmes; we hope to move towards the world where Grid will ultimately reach the status of generic public computing and storage service provider and permanent national and international Grid infrastructures will be established. How far will we be able to advance along this path, depends on us. If no standardisation and convergence efforts will take place

A data grid for imaging-based clinical trials

Science.gov (United States)

Zhou, Zheng; Chao, Sander S.; Lee, Jasper; Liu, Brent; Documet, Jorge; Huang, H. K.

2007-03-01

Clinical trials play a crucial role in testing new drugs or devices in modern medicine. Medical imaging has also become an important tool in clinical trials because images provide a unique and fast diagnosis with visual observation and quantitative assessment. A typical imaging-based clinical trial consists of: 1) A well-defined rigorous clinical trial protocol, 2) a radiology core that has a quality control mechanism, a biostatistics component, and a server for storing and distributing data and analysis results; and 3) many field sites that generate and send image studies to the radiology core. As the number of clinical trials increases, it becomes a challenge for a radiology core servicing multiple trials to have a server robust enough to administrate and quickly distribute information to participating radiologists/clinicians worldwide. The Data Grid can satisfy the aforementioned requirements of imaging based clinical trials. In this paper, we present a Data Grid architecture for imaging-based clinical trials. A Data Grid prototype has been implemented in the Image Processing and Informatics (IPI) Laboratory at the University of Southern California to test and evaluate performance in storing trial images and analysis results for a clinical trial. The implementation methodology and evaluation protocol of the Data Grid are presented.

An exploratory study of global leaders' and Chinese managers' leadership constructs in multinational corporations in China

OpenAIRE

Wang, Lake

2012-01-01

This research explores the leadership constructs of global leaders and Chinese managers in multi-national corporations (MNCs) in order to understand whether their constructs are misaligned, and if so, in what ways. To address these questions, data was gathered via repertory grid test interviews with 31 global leaders and 59 Chinese managers in six MNCs’ China organizations. Analysis subsequently revealed that global leaders rely upon twelve key constructs to define global leaders...

OGC and Grid Interoperability in enviroGRIDS Project

Science.gov (United States)

Gorgan, Dorian; Rodila, Denisa; Bacu, Victor; Giuliani, Gregory; Ray, Nicolas

2010-05-01

EnviroGRIDS (Black Sea Catchment Observation and Assessment System supporting Sustainable Development) [1] is a 4-years FP7 Project aiming to address the subjects of ecologically unsustainable development and inadequate resource management. The project develops a Spatial Data Infrastructure of the Black Sea Catchment region. The geospatial technologies offer very specialized functionality for Earth Science oriented applications as well as the Grid oriented technology that is able to support distributed and parallel processing. One challenge of the enviroGRIDS project is the interoperability between geospatial and Grid infrastructures by providing the basic and the extended features of the both technologies. The geospatial interoperability technology has been promoted as a way of dealing with large volumes of geospatial data in distributed environments through the development of interoperable Web service specifications proposed by the Open Geospatial Consortium (OGC), with applications spread across multiple fields but especially in Earth observation research. Due to the huge volumes of data available in the geospatial domain and the additional introduced issues (data management, secure data transfer, data distribution and data computation), the need for an infrastructure capable to manage all those problems becomes an important aspect. The Grid promotes and facilitates the secure interoperations of geospatial heterogeneous distributed data within a distributed environment, the creation and management of large distributed computational jobs and assures a security level for communication and transfer of messages based on certificates. This presentation analysis and discusses the most significant use cases for enabling the OGC Web services interoperability with the Grid environment and focuses on the description and implementation of the most promising one. In these use cases we give a special attention to issues such as: the relations between computational grid and

Numerical analysis of the spacer grids' compression strength

Energy Technology Data Exchange (ETDEWEB)

Schettino, C.F.M.; Gouvea, J.P.; Medeiros, N., E-mail: carlosschettino@inb.gov.br, E-mail: jpg@metal.eeimvr.uff.br [Universidade Federal Fluminense (UFF), Volta Redonda, RJ (Brazil). Programa de Engenharia Metalurgica

2013-07-01

Among the components of the fuel assembly, the spacer grids play an important structural role during the energy generation process, mainly for their requirement to have enough structural strength to withstand lateral impact loads, due to fuel assembly shipping/handling and due to forces outcome from postulated accidents (earthquake and LOCA). This requirement ensures a proper geometry for cooling and for guide thimble straightness in the fuel assembly. In this way, the understanding of the macroscopic mechanical behavior of this component becomes essential even to any subsequent geometrical modifications to optimize the flue assemblies' structural behavior. In the present work, three-dimensional finite element models destined to provide consistent predictions of 16X16-type spacer grids lateral strength were proposed. Firstly, buckling tests based on results available in the literature were performed to establish a methodology for spacer grid finite element-based modeling. The, by considering a spacer grid interesting geometry and some possible variations associated to its fabrication, tolerance, the proposed numerical models were submitted to compression conditions to calculate the buckling force. Also, these models were validated for comparison with experimental buckling load results. Comparison of buckling predictions combined to observations of actual and simulated deformed spacer grids geometries permitted to verify the consistency and applicability of the proposed models. Thus, these numerical results show a good agreement between the and the experimental results. (author)

caGrid 1.0: a Grid enterprise architecture for cancer research.

Science.gov (United States)

Oster, Scott; Langella, Stephen; Hastings, Shannon; Ervin, David; Madduri, Ravi; Kurc, Tahsin; Siebenlist, Frank; Covitz, Peter; Shanbhag, Krishnakant; Foster, Ian; Saltz, Joel

2007-10-11

caGrid is the core Grid architecture of the NCI-sponsored cancer Biomedical Informatics Grid (caBIG) program. The current release, caGrid version 1.0, is developed as the production Grid software infrastructure of caBIG. Based on feedback from adopters of the previous version (caGrid 0.5), it has been significantly enhanced with new features and improvements to existing components. This paper presents an overview of caGrid 1.0, its main components, and enhancements over caGrid 0.5.

Intelligent Scheduling of a Grid-Connected Heat Pump in a Danish Detached House

DEFF Research Database (Denmark)

Gianniou, Panagiota; Foteinaki, Kyriaki; Heller, Alfred

This study proposes a methodology for intelligent scheduling of a heat pump installed in a refurbished grid-connected detached house in Denmark. This scheduling is conducted through the coupling of a dynamic building simulation tool with an optimization tool. The optimization of the operation of ...... thermal comfort conditions. The proposed methodology bridges dynamic building modelling with optimization of real-time operation of HVAC systems offering a detailed model for building physics, especially regarding thermal mass and a stochastic price-based control....... of the system is based on a price-signal considering a three-day period for different weather cases. The results show that the optimal scheduling of the system is successful in terms of reducing the peak load during times when electricity prices are high, thus achieving cost savings as well as maintaining good......This study proposes a methodology for intelligent scheduling of a heat pump installed in a refurbished grid-connected detached house in Denmark. This scheduling is conducted through the coupling of a dynamic building simulation tool with an optimization tool. The optimization of the operation...

Imagining Homeland: Identity and Repertories of a Greek Labour-immigrant Musician in Germany

Directory of Open Access Journals (Sweden)

Smaragdi Boura

2006-05-01

Full Text Available Migration has always played an important and determinative role in the formation of the Greek life-cycle, since the existence of a Greek Diaspora originates back to the institution of the Greek nation. However, whether the migration phenomenon represents a typical and integral part of the Greek cultural tradition or mentality, or appears as a forced consequence of specific economic or political circumstances, it should be pointed out that it has proved to be a transformative factor for the lives of people involved in it. The fate of "metanastes" (immigrants and the life in "xenitia" (foreign host land appear to be a very common and prominent topic elaborated in the poetic texts of the Greek "dimotika tragoudia" (traditional songs and "laika tragoudia" (folk-popular songs. Through these repertoires, music reveals its power in conveying and symbolically communicating and expressing public notions, feelings and cultural messages that acquire a particular significance for immigrant communities. Furthermore, diasporic music—along with dance—constitutes one of the basic components of the immigrant's cultural heritage, representing: an expressive way of maintaining cultural identity; a fixed, however metaphorical, conjunctional link between the mother country and the host land; and, a fundamental context through which the migratory community identifies or reconstitutes itself in relation to the majority and other surrounding groups. The author uses fieldwork from a year spent amongst Greek immigrant communities in the Stuttgart region of Germany to address and reflect on issues around the role of music in identity construction and the way in which this connects with processes of integration, assimilation and transnationalism. Specifically, the paper explores the multiple identities and repertories of a Greek musician in Germany, by focusing on several aspects of the musician's life-portrait and providing both emic and etic interpretations. This

Assessment of the Unstructured Grid Software TetrUSS for Drag Prediction of the DLR-F4 Configuration

Science.gov (United States)

Pirzadeh, Shahyar Z.; Frink, Neal T.

2002-01-01

An application of the NASA unstructured grid software system TetrUSS is presented for the prediction of aerodynamic drag on a transport configuration. The paper briefly describes the underlying methodology and summarizes the results obtained on the DLR-F4 transport configuration recently presented in the first AIAA computational fluid dynamics (CFD) Drag Prediction Workshop. TetrUSS is a suite of loosely coupled unstructured grid CFD codes developed at the NASA Langley Research Center. The meshing approach is based on the advancing-front and the advancing-layers procedures. The flow solver employs a cell-centered, finite volume scheme for solving the Reynolds Averaged Navier-Stokes equations on tetrahedral grids. For the present computations, flow in the viscous sublayer has been modeled with an analytical wall function. The emphasis of the paper is placed on the practicality of the methodology for accurately predicting aerodynamic drag data.

Leaving the grid: An ambition or a real choice?

International Nuclear Information System (INIS)

Khalilpour, Rajab; Vassallo, Anthony

2015-01-01

The recent rapid decline in PV prices has brought grid parity, or near grid parity for PV in many countries. This, together with an expectation of a similar reduction for battery prices has prompted a new wave of social and academic discussions about the possibility of installing PV–battery systems and “leaving the grid” or “living off-grid”. This, if uncontrolled, has been termed the “death spiral” for utility companies. We have developed a decision support tool for rigorous assessment of the feasibility of leaving the grid. Numerous sensitivity analyses are carried out over critical parameters such as technology costs, system size, consumer load, and feed-in-tariff. The results show that, in most cases, leaving-the-grid is not the best economic option and it might be more beneficial to keep the connection with the grid, but minimize the electricity purchased by installation of an optimized size of PV-battery systems. The policy implication of this study is that, from an economic perspective, widespread disconnection might not be a realistic projection of the future. Rather, a notable reduction of energy demand per connection point is a more realistic option as PV–battery system prices decline further. Therefore, policies could be devised to help electricity network operators develop other sources of revenue rather than increasing energy prices, which have been assumed to be the key driver of the death spiral. -- Highlights: •There is an increasing public and academic interest in “leaving the grid” or “living off-grid”. •Grid defection is argued as a “death spiral” for transmission and distribution industries. •An optimization methodology is developed for assessing the feasibility of leaving the grid. •Leaving the grid with PV–battery is found to be infeasible due to large system requirements. •The best is to preserve connection with the grid, but minimize the electricity purchase

Laboratory infrastructure driven key performance indicator development using the smart grid architecture model

DEFF Research Database (Denmark)

Syed, Mazheruddin H.; Guillo-Sansano, Efren; Blair, Steven M.

2017-01-01

This study presents a methodology for collaboratively designing laboratory experiments and developing key performance indicators for the testing and validation of novel power system control architectures in multiple laboratory environments. The contribution makes use of the smart grid architecture...

Including threat actor capability and motivation in risk assessment for Smart GRIDs

NARCIS (Netherlands)

Rossebo, J.E.Y.; Fransen, F.; Luiijf, H.A.M.

2016-01-01

The SEGRID (Security for Smart Electricity GRIDs) collaboration project, funded by the EU under the FP7 program investigates risk assessment methodologies and their possible need for enhancement. In this paper we discuss the need to include threat actor analysis in threat, vulnerability and risk

Gridded Species Distribution, Version 1: Global Amphibians Presence Grids

Data.gov (United States)

National Aeronautics and Space Administration — The Global Amphibians Presence Grids of the Gridded Species Distribution, Version 1 is a reclassified version of the original grids of amphibian species distribution...

Smart grids and e-mobility

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

integration of electric vehicles and plug-in-vehicles in the power system (H. Seljeseth); (21) Implications of vehicle-to-grid strategies on lithium-ion batteries and grids (M. Hackmann); (22) A methodology for evaluating the hosting capacity margins for PEVs on distribution grids (I.M. Gianinoni); (23) Integration of fast EV charging systems into the distribution grid (M. Zamalloa); (24) The need for innovative functionalities for on-board electrical vehicle chargers (J.A. Pecas Lopes); (25) Towards a system for accessing real-time, cross-provider electric mobility charging station information (T. Lutz); (26) Concept evaluation of an inductive charging system for electric vehicles (H. Barth); (27) System integrated testing of EV batteries (O. Gehrke); (28) Requirements analysis for a smart charging infrastructure enabling maximum use of renewable energy (R. Ponnette); (29) The hybrid power supply system for Truong Sa Islands using solar and wind energy (T.Q. Vinh); (30) Intelligent local network management for the integration of distributed generation and storage systems (W. Heckmann); (31) Network of value creation networks for e-mobility - An analysis of the collaboration competitive advantage (R. Colmom); (32) Project netquality (R. Witzmann); (33) The interdependences between electric vehicles and offshore wind energy - An investigation for the North-Western Region of Germany (M. Buchmann); (34) Testing platform for e-mobility (TPE) (J. Prior); (35) Experiences from integrating DG in rural MV networks (M.K. Istad); (36) MUGIELEC: A comprehensive approach to EV recharge infrastructure (A. Arzuaga); (37) Model region electric mobility Munich - Drive eCharged (W. vom Eyser).

Analysis of the World Experience of Smart Grid Deployment: Economic Effectiveness Issues

Science.gov (United States)

Ratner, S. V.; Nizhegorodtsev, R. M.

2018-06-01

Despite the positive dynamics in the growth of RES-based power production in electric power systems of many countries, the further development of commercially mature technologies of wind and solar generation is often constrained by the existing grid infrastructure and conventional energy supply practices. The integration of large wind and solar power plants into a single power grid and the development of microgeneration require the widespread introduction of a new smart grid technology cluster (smart power grids), whose technical advantages over the conventional ones have been fairly well studied, while issues of their economic effectiveness remain open. Estimation and forecasting potential economic effects from the introduction of innovative technologies in the power sector during the stage preceding commercial development is a methodologically difficult task that requires the use of knowledge from different sciences. This paper contains the analysis of smart grid project implementation in Europe and the United States. Interval estimates are obtained for their basic economic parameters. It was revealed that the majority of smart grid implemented projects are not yet commercially effective, since their positive externalities are usually not recognized on the revenue side due to the lack of universal methods for public benefits monetization. The results of the research can be used in modernization and development planning for the existing grid infrastructure both at the federal level and at the level of certain regions and territories.

Chimera Grid Tools

Science.gov (United States)

Chan, William M.; Rogers, Stuart E.; Nash, Steven M.; Buning, Pieter G.; Meakin, Robert

2005-01-01

Chimera Grid Tools (CGT) is a software package for performing computational fluid dynamics (CFD) analysis utilizing the Chimera-overset-grid method. For modeling flows with viscosity about geometrically complex bodies in relative motion, the Chimera-overset-grid method is among the most computationally cost-effective methods for obtaining accurate aerodynamic results. CGT contains a large collection of tools for generating overset grids, preparing inputs for computer programs that solve equations of flow on the grids, and post-processing of flow-solution data. The tools in CGT include grid editing tools, surface-grid-generation tools, volume-grid-generation tools, utility scripts, configuration scripts, and tools for post-processing (including generation of animated images of flows and calculating forces and moments exerted on affected bodies). One of the tools, denoted OVERGRID, is a graphical user interface (GUI) that serves to visualize the grids and flow solutions and provides central access to many other tools. The GUI facilitates the generation of grids for a new flow-field configuration. Scripts that follow the grid generation process can then be constructed to mostly automate grid generation for similar configurations. CGT is designed for use in conjunction with a computer-aided-design program that provides the geometry description of the bodies, and a flow-solver program.

Grid: From EGEE to EGI and from INFN-Grid to IGI

International Nuclear Information System (INIS)

Giselli, A.; Mazzuccato, M.

2009-01-01

In the last fifteen years the approach of the computational Grid has changed the way to use computing resources. Grid computing has raised interest worldwide in academia, industry, and government with fast development cycles. Great efforts, huge funding and resources have been made available through national, regional and international initiatives aiming at providing Grid infrastructures, Grid core technologies, Grid middle ware and Grid applications. The Grid software layers reflect the architecture of the services developed so far by the most important European and international projects. In this paper Grid e-Infrastructure story is given, detailing European, Italian and international projects such as EGEE, INFN-Grid and NAREGI. In addition the sustainability issue in the long-term perspective is described providing plans by European and Italian communities with EGI and IGI.

Study on Behavior Value Analysis and Decision Methodology of Grid Corporations in China

Directory of Open Access Journals (Sweden)

Jiang Yuanbin

2017-01-01

Full Text Available Based on grid corporations, business environment and value characteristics in China, the article analyzes its behavior value factors, and then divides its behavior into three categories: the behavior only affecting the current Economic Value Added(EVA, the behavior affecting both the current and future EVA, and the behavior only affecting future EVA. Finally, the article studies such corporations, behavior value decision making based upon analyses and classifications above.

Drought and Heat Wave Impacts on Electricity Grid Reliability in Illinois

Science.gov (United States)

Stillwell, A. S.; Lubega, W. N.

2016-12-01

A large proportion of thermal power plants in the United States use cooling systems that discharge large volumes of heated water into rivers and cooling ponds. To minimize thermal pollution from these discharges, restrictions are placed on temperatures at the edge of defined mixing zones in the receiving waters. However, during extended hydrological droughts and heat waves, power plants are often granted thermal variances permitting them to exceed these temperature restrictions. These thermal variances are often deemed necessary for maintaining electricity reliability, particularly as heat waves cause increased electricity demand. Current practice, however, lacks tools for the development of grid-scale operational policies specifying generator output levels that ensure reliable electricity supply while minimizing thermal variances. Such policies must take into consideration characteristics of individual power plants, topology and characteristics of the electricity grid, and locations of power plants within the river basin. In this work, we develop a methodology for the development of these operational policies that captures necessary factors. We develop optimal rules for different hydrological and meteorological conditions, serving as rule curves for thermal power plants. The rules are conditioned on leading modes of the ambient hydrological and meteorological conditions at the different power plant locations, as the locations are geographically close and hydrologically connected. Heat dissipation in the rivers and cooling ponds is modeled using the equilibrium temperature concept. Optimal rules are determined through a Monte Carlo sampling optimization framework. The methodology is applied to a case study of eight power plants in Illinois that were granted thermal variances in the summer of 2012, with a representative electricity grid model used in place of the actual electricity grid.

The Grid

CERN Document Server

Klotz, Wolf-Dieter

2005-01-01

Grid technology is widely emerging. Grid computing, most simply stated, is distributed computing taken to the next evolutionary level. The goal is to create the illusion of a simple, robust yet large and powerful self managing virtual computer out of a large collection of connected heterogeneous systems sharing various combinations of resources. This talk will give a short history how, out of lessons learned from the Internet, the vision of Grids was born. Then the extensible anatomy of a Grid architecture will be discussed. The talk will end by presenting a selection of major Grid projects in Europe and US and if time permits a short on-line demonstration.

gLExec: gluing grid computing to the Unix world

Science.gov (United States)

Groep, D.; Koeroo, O.; Venekamp, G.

2008-07-01

The majority of compute resources in todays scientific grids are based on Unix and Unix-like operating systems. In this world, user and user-group management are based around the concepts of a numeric 'user ID' and 'group ID' that are local to the resource. In contrast, grid concepts of user and group management are centered around globally assigned identifiers and VO membership, structures that are independent of any specific resource. At the fabric boundary, these 'grid identities' have to be translated to Unix user IDs. New job submission methodologies, such as job-execution web services, community-deployed local schedulers, and the late binding of user jobs in a grid-wide overlay network of 'pilot jobs', push this fabric boundary ever further down into the resource. gLExec, a light-weight (and thereby auditable) credential mapping and authorization system, addresses these issues. It can be run both on fabric boundary, as part of an execution web service, and on the worker node in a late-binding scenario. In this contribution we describe the rationale for gLExec, how it interacts with the site authorization and credential mapping frameworks such as LCAS, LCMAPS and GUMS, and how it can be used to improve site control and traceability in a pilot-job system.

gLExec: gluing grid computing to the Unix world

International Nuclear Information System (INIS)

Groep, D; Koeroo, O; Venekamp, G

2008-01-01

The majority of compute resources in todays scientific grids are based on Unix and Unix-like operating systems. In this world, user and user-group management are based around the concepts of a numeric 'user ID' and 'group ID' that are local to the resource. In contrast, grid concepts of user and group management are centered around globally assigned identifiers and VO membership, structures that are independent of any specific resource. At the fabric boundary, these 'grid identities' have to be translated to Unix user IDs. New job submission methodologies, such as job-execution web services, community-deployed local schedulers, and the late binding of user jobs in a grid-wide overlay network of 'pilot jobs', push this fabric boundary ever further down into the resource. gLExec, a light-weight (and thereby auditable) credential mapping and authorization system, addresses these issues. It can be run both on fabric boundary, as part of an execution web service, and on the worker node in a late-binding scenario. In this contribution we describe the rationale for gLExec, how it interacts with the site authorization and credential mapping frameworks such as LCAS, LCMAPS and GUMS, and how it can be used to improve site control and traceability in a pilot-job system

Parallel grid population

Science.gov (United States)

Wald, Ingo; Ize, Santiago

2015-07-28

Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

Development of analysis methodology on turbulent thermal stripping

Energy Technology Data Exchange (ETDEWEB)

Yoo, Geun Jong; Jeon, Won Dae; Han, Jin Woo; Gu, Byong Kook [Changwon National University, Changwon(Korea)

2001-03-01

For developing analysis methodology, important governing factors of thermal stripping phenomena are identified as geometric configuration and flow characteristics such as velocity. Along these factors, performance of turbulence models in existing analysis methodology are evaluated against experimental data. Status of DNS application is also accessed based on literature. Evaluation results are reflected in setting up the new analysis methodology. From the evaluation of existing analysis methodology, Full Reynolds Stress model is identified as best one among other turbulence models. And LES is found to be able to provide time dependent turbulence values. Further improvements in near-wall region and temperature variance equation are required for FRS and implementation of new sub-grid scale models is also required for LES. Through these improvements, new reliable analysis methodology for thermal stripping can be developed. 30 refs., 26 figs., 6 tabs. (Author)

The MicroGrid: A Scientific Tool for Modeling Computational Grids

Directory of Open Access Journals (Sweden)

H.J. Song

2000-01-01

Full Text Available The complexity and dynamic nature of the Internet (and the emerging Computational Grid demand that middleware and applications adapt to the changes in configuration and availability of resources. However, to the best of our knowledge there are no simulation tools which support systematic exploration of dynamic Grid software (or Grid resource behavior. We describe our vision and initial efforts to build tools to meet these needs. Our MicroGrid simulation tools enable Globus applications to be run in arbitrary virtual grid resource environments, enabling broad experimentation. We describe the design of these tools, and their validation on micro-benchmarks, the NAS parallel benchmarks, and an entire Grid application. These validation experiments show that the MicroGrid can match actual experiments within a few percent (2% to 4%.

Modelling noise propagation using Grid Resources. Progress within GDI-Grid

Science.gov (United States)

Kiehle, Christian; Mayer, Christian; Padberg, Alexander; Stapelfeld, Hartmut

2010-05-01

Modelling noise propagation using Grid Resources. Progress within GDI-Grid. GDI-Grid (english: SDI-Grid) is a research project funded by the German Ministry for Science and Education (BMBF). It aims at bridging the gaps between OGC Web Services (OWS) and Grid infrastructures and identifying the potential of utilizing the superior storage capacities and computational power of grid infrastructures for geospatial applications while keeping the well-known service interfaces specified by the OGC. The project considers all major OGC webservice interfaces for Web Mapping (WMS), Feature access (Web Feature Service), Coverage access (Web Coverage Service) and processing (Web Processing Service). The major challenge within GDI-Grid is the harmonization of diverging standards as defined by standardization bodies for Grid computing and spatial information exchange. The project started in 2007 and will continue until June 2010. The concept for the gridification of OWS developed by lat/lon GmbH and the Department of Geography of the University of Bonn is applied to three real-world scenarios in order to check its practicability: a flood simulation, a scenario for emergency routing and a noise propagation simulation. The latter scenario is addressed by the Stapelfeldt Ingenieurgesellschaft mbH located in Dortmund adapting their LimA software to utilize grid resources. Noise mapping of e.g. traffic noise in urban agglomerates and along major trunk roads is a reoccurring demand of the EU Noise Directive. Input data requires road net and traffic, terrain, buildings and noise protection screens as well as population distribution. Noise impact levels are generally calculated in 10 m grid and along relevant building facades. For each receiver position sources within a typical range of 2000 m are split down into small segments, depending on local geometry. For each of the segments propagation analysis includes diffraction effects caused by all obstacles on the path of sound propagation

RANS based CFD methodology for a real scale 217-pin wire-wrapped fuel assembly of KAERI PGSFR

Energy Technology Data Exchange (ETDEWEB)

Jeong, Jae-Ho, E-mail: jhjeong@kaeri.re.kr [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseoung-gu, Daejeon (Korea, Republic of); Song, Min-Seop [Department of Nuclear Engineering, Seoul National University, 559 Gwanak-ro, Gwanak-gu, Seoul (Korea, Republic of); Lee, Kwi-Lim [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseoung-gu, Daejeon (Korea, Republic of)

2017-03-15

Highlights: • This paper presents a suitable way for a practical RANS based CFD methodology which is applicable to real scale 217-pin wire-wrapped fuel assembly of KAERI PGSFR. • A key point of differentiation of the RANS based CFD methodology in this study is adapting an innovative grid generation method using a fortran based in-house code with a GGI function in a general-purpose commercial CFD code, CFX. • The RANS based CFD methodology is implemented with high resolution scheme and SST turbulence model in the 7-pin 37-pin, and 127-pin wire-wrapped fuel assembly of PNC and JNC. Furthermore, the RANS based CFD methodology can be successfully extended to the real scale 217-pin wire-wrapped fuel bundles of KAERI PGSFR. • Three-dimensional thermal-hydraulic characteristics have been also investigated briefly. - Abstract: This paper presents a suitable way for a practical RANS (Reynolds Averaged Navier-Stokes simulation) based CFD (Computational Fluid Dynamics) methodology which is applicable to real scale 217-pin wire-wrapped fuel assembly of KAERI (Korea Atomic Energy Research Institute) PGSFR (Prototype Gen-IV Sodium-cooled Fast Reactor). The main purpose of the current study is to support license issue for the KAERI PGSFR core safety and to elucidate thermal-hydraulic characteristics in a 217-pin wire-wrapped fuel assembly of KAERI PGSFR. A key point of differentiation of the RANS based CFD methodology in this study is adapting an innovative grid generation method using a fortran based in-house code with a GGI (General Grid Interface) function in a general-purpose commercial CFD code, CFX. The innovative grid generation method with GGI function can achieve to simulate a real wire shape with minimizing cell skewness. The RANS based CFD methodology is implemented with high resolution scheme in convection term and SST (Shear Stress Transport) turbulence model in the 7-pin 37-pin, and 127-pin wire-wrapped fuel assembly of PNC (Power reactor and Nuclear fuel

Smart grid security

Energy Technology Data Exchange (ETDEWEB)

Cuellar, Jorge (ed.) [Siemens AG, Muenchen (Germany). Corporate Technology

2013-11-01

The engineering, deployment and security of the future smart grid will be an enormous project requiring the consensus of many stakeholders with different views on the security and privacy requirements, not to mention methods and solutions. The fragmentation of research agendas and proposed approaches or solutions for securing the future smart grid becomes apparent observing the results from different projects, standards, committees, etc, in different countries. The different approaches and views of the papers in this collection also witness this fragmentation. This book contains the following papers: 1. IT Security Architecture Approaches for Smart Metering and Smart Grid. 2. Smart Grid Information Exchange - Securing the Smart Grid from the Ground. 3. A Tool Set for the Evaluation of Security and Reliability in Smart Grids. 4. A Holistic View of Security and Privacy Issues in Smart Grids. 5. Hardware Security for Device Authentication in the Smart Grid. 6. Maintaining Privacy in Data Rich Demand Response Applications. 7. Data Protection in a Cloud-Enabled Smart Grid. 8. Formal Analysis of a Privacy-Preserving Billing Protocol. 9. Privacy in Smart Metering Ecosystems. 10. Energy rate at home Leveraging ZigBee to Enable Smart Grid in Residential Environment.

The island dynamics model on parallel quadtree grids

Science.gov (United States)

Mistani, Pouria; Guittet, Arthur; Bochkov, Daniil; Schneider, Joshua; Margetis, Dionisios; Ratsch, Christian; Gibou, Frederic

2018-05-01

We introduce an approach for simulating epitaxial growth by use of an island dynamics model on a forest of quadtree grids, and in a parallel environment. To this end, we use a parallel framework introduced in the context of the level-set method. This framework utilizes: discretizations that achieve a second-order accurate level-set method on non-graded adaptive Cartesian grids for solving the associated free boundary value problem for surface diffusion; and an established library for the partitioning of the grid. We consider the cases with: irreversible aggregation, which amounts to applying Dirichlet boundary conditions at the island boundary; and an asymmetric (Ehrlich-Schwoebel) energy barrier for attachment/detachment of atoms at the island boundary, which entails the use of a Robin boundary condition. We provide the scaling analyses performed on the Stampede supercomputer and numerical examples that illustrate the capability of our methodology to efficiently simulate different aspects of epitaxial growth. The combination of adaptivity and parallelism in our approach enables simulations that are several orders of magnitude faster than those reported in the recent literature and, thus, provides a viable framework for the systematic study of mound formation on crystal surfaces.

Thinking About Challenging Behavior: A Repertory Grid Study of Inpatient Staff Beliefs

Science.gov (United States)

Hare, Dougal Julian; Durand, Marianne; Hendy, Steve; Wittkowski, Anja

2012-01-01

Studies examining staff attitudes toward people with intellectual disability have traditionally used pre-determined categories and models or been open to researcher bias. The use of methods derived from personal construct psychology permits an objective investigation of staff views and attitudes without such limitations. Fourteen staff from an…

Synchronization in single-phase grid-connected photovoltaic systems under grid faults

DEFF Research Database (Denmark)

Yang, Yongheng; Blaabjerg, Frede

2012-01-01

The highly increasing penetration of single-phase photovoltaic (PV) systems pushes the grid requirements related to the integration of PV power systems to be updated. These upcoming regulations are expected to direct the grid-connected renewable generators to support the grid operation and stabil......The highly increasing penetration of single-phase photovoltaic (PV) systems pushes the grid requirements related to the integration of PV power systems to be updated. These upcoming regulations are expected to direct the grid-connected renewable generators to support the grid operation...

Grid generation methods

CERN Document Server

Liseikin, Vladimir D

2010-01-01

This book is an introduction to structured and unstructured grid methods in scientific computing, addressing graduate students, scientists as well as practitioners. Basic local and integral grid quality measures are formulated and new approaches to mesh generation are reviewed. In addition to the content of the successful first edition, a more detailed and practice oriented description of monitor metrics in Beltrami and diffusion equations is given for generating adaptive numerical grids. Also, new techniques developed by the author are presented, in particular a technique based on the inverted form of Beltrami’s partial differential equations with respect to control metrics. This technique allows the generation of adaptive grids for a wide variety of computational physics problems, including grid clustering to given function values and gradients, grid alignment with given vector fields, and combinations thereof. Applications of geometric methods to the analysis of numerical grid behavior as well as grid ge...

Smart grid technologies in local electric grids

Science.gov (United States)

Lezhniuk, Petro D.; Pijarski, Paweł; Buslavets, Olga A.

2017-08-01

The research is devoted to the creation of favorable conditions for the integration of renewable sources of energy into electric grids, which were designed to be supplied from centralized generation at large electric power stations. Development of distributed generation in electric grids influences the conditions of their operation - conflict of interests arises. The possibility of optimal functioning of electric grids and renewable sources of energy, when complex criterion of the optimality is balance reliability of electric energy in local electric system and minimum losses of electric energy in it. Multilevel automated system for power flows control in electric grids by means of change of distributed generation of power is developed. Optimization of power flows is performed by local systems of automatic control of small hydropower stations and, if possible, solar power plants.

5 X 5 rod bundle flow field measurements downstream a PWR spacer grid

Energy Technology Data Exchange (ETDEWEB)

Castro, Higor F.P.; Silva, Vitor V A.; Santos, André A.C.; Veloso, Maria A.F., E-mail: higorfabiano@gmail.com, E-mail: mdora@nuclear.ufmg.br, E-mail: vitors@cdtn.br, E-mail: aacs@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

The spacer grids are structures present in nuclear fuel assembly of Pressurized Water Reactors (PWR). They play an important structural role and also assist in heat removal through the assembly by promoting increased turbulence of the flow. Understanding the flow dynamics downstream the spacer grid is paramount for fuel element design and analysis. This paper presents water flow velocity profiles measurements downstream a spacer grid in a 5 x 5 rod bundle test rig with the objective of highlighting important fluid dynamic behavior near the grid and supplying data for CFD simulation validation. These velocity profiles were obtained at two different heights downstream the spacer grid using a LDV (Laser Doppler Velocimetry) through the top of test rig. The turbulence intensities and patterns of the swirl and cross flow were evaluated. The tests were conducted for Reynolds numbers ranging from 1.8 x 10{sup 4} to 5.4 x 10{sup 4}. This experimental research was carried out in thermo-hydraulics laboratory of Nuclear Technology Development Center – CDTN. Results show great repeatability and low uncertainties (< 1.24 %). Details of the flow field show how the mixture and turbulence induced by the spacer grid quickly decays downstream the spacer grid. It is shown that the developed methodology can supply high resolution low uncertainty results that can be used for validation of CFD simulations. (author)

5 X 5 rod bundle flow field measurements downstream a PWR spacer grid

International Nuclear Information System (INIS)

Castro, Higor F.P.; Silva, Vitor V A.; Santos, André A.C.; Veloso, Maria A.F.

2017-01-01

The spacer grids are structures present in nuclear fuel assembly of Pressurized Water Reactors (PWR). They play an important structural role and also assist in heat removal through the assembly by promoting increased turbulence of the flow. Understanding the flow dynamics downstream the spacer grid is paramount for fuel element design and analysis. This paper presents water flow velocity profiles measurements downstream a spacer grid in a 5 x 5 rod bundle test rig with the objective of highlighting important fluid dynamic behavior near the grid and supplying data for CFD simulation validation. These velocity profiles were obtained at two different heights downstream the spacer grid using a LDV (Laser Doppler Velocimetry) through the top of test rig. The turbulence intensities and patterns of the swirl and cross flow were evaluated. The tests were conducted for Reynolds numbers ranging from 1.8 x 10"4 to 5.4 x 10"4. This experimental research was carried out in thermo-hydraulics laboratory of Nuclear Technology Development Center – CDTN. Results show great repeatability and low uncertainties (< 1.24 %). Details of the flow field show how the mixture and turbulence induced by the spacer grid quickly decays downstream the spacer grid. It is shown that the developed methodology can supply high resolution low uncertainty results that can be used for validation of CFD simulations. (author)

Greening the Grid - Advancing Solar, Wind, and Smart Grid Technologies (Spanish Version)

Energy Technology Data Exchange (ETDEWEB)

2016-04-01

This is the Spanish version of 'Greening the Grid - Advancing Solar, Wind, and Smart Grid Technologies'. Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid.

Micro grids toward the smart grid

International Nuclear Information System (INIS)

Guerrero, J.

2011-01-01

Worldwide electrical grids are expecting to become smarter in the near future, with interest in Microgrids likely to grow. A microgrid can be defined as a part of the grid with elements of prime energy movers, power electronics converters, distributed energy storage systems and local loads, that can operate autonomously but also interacting with main grid. Thus, the ability of intelligent Microgrids to operate in island mode or connected to the grid will be a keypoint to cope with new functionalities and the integration of renewable energy resources. The functionalities expected for these small grids are: black start operation, frequency and voltage stability, active and reactive power flow control, active power filter capabilities, and storage energy management. In this presentation, a review of the main concepts related to flexible Microgrids will be introduced, with examples of real Microgrids. AC and DC Microgrids to integrate renewable and distributed energy resources will also be presented, as well as distributed energy storage systems, and standardization issues of these Microgrids. Finally, Microgrid hierarchical control will be analyzed looking at three different levels: i) a primary control based on the droop method, including an output impedance virtual loop; ii) a secondary control, which enables restoring any deviations produced by the primary control; and iii) a tertiary control to manage the power flow between the microgrid and the external electrical distribution system.

Performance Parameters for Grid-Connected PV Systems

Energy Technology Data Exchange (ETDEWEB)

Marion, B.; Adelstein, J.; Boyle, K.; Hayden, H.; Hammond, B.; Fletcher, T.; Canada, B.; Narang, D.; Shugar, D.; Wenger, H.; Kimber, A.; Mitchell, L.; Rich, G.; Townsend, T.

2005-02-01

The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.

Content Analysis of the Construction of Self and Others in Women with Bulimia Nervosa

OpenAIRE

Dada, Gloria; Izu, Sheila; Montebruno, Claudia; Grau, Antoni; Feixas, Guillem

2017-01-01

The purpose of this study was to explore the content of personal constructs in people diagnosed with bulimia nervosa (BN). We expected to find differences in the predominant content of the construct systems between women with and without BN. We analyzed the constructs elicited using the repertory grid technique from 120 women aged between 18 to 45 years, divided into two groups: a clinical group of women diagnosed with bulimia (n = 62) and a control group of university students (n = 58). The ...

Smart grid security

CERN Document Server

Goel, Sanjay; Papakonstantinou, Vagelis; Kloza, Dariusz

2015-01-01

This book on smart grid security is meant for a broad audience from managers to technical experts. It highlights security challenges that are faced in the smart grid as we widely deploy it across the landscape. It starts with a brief overview of the smart grid and then discusses some of the reported attacks on the grid. It covers network threats, cyber physical threats, smart metering threats, as well as privacy issues in the smart grid. Along with the threats the book discusses the means to improve smart grid security and the standards that are emerging in the field. The second part of the b

The Grid2003 Production Grid Principles and Practice

CERN Document Server

Foster, I; Gose, S; Maltsev, N; May, E; Rodríguez, A; Sulakhe, D; Vaniachine, A; Shank, J; Youssef, S; Adams, D; Baker, R; Deng, W; Smith, J; Yu, D; Legrand, I; Singh, S; Steenberg, C; Xia, Y; Afaq, A; Berman, E; Annis, J; Bauerdick, L A T; Ernst, M; Fisk, I; Giacchetti, L; Graham, G; Heavey, A; Kaiser, J; Kuropatkin, N; Pordes, R; Sekhri, V; Weigand, J; Wu, Y; Baker, K; Sorrillo, L; Huth, J; Allen, M; Grundhoefer, L; Hicks, J; Luehring, F C; Peck, S; Quick, R; Simms, S; Fekete, G; Van den Berg, J; Cho, K; Kwon, K; Son, D; Park, H; Canon, S; Jackson, K; Konerding, D E; Lee, J; Olson, D; Sakrejda, I; Tierney, B; Green, M; Miller, R; Letts, J; Martin, T; Bury, D; Dumitrescu, C; Engh, D; Gardner, R; Mambelli, M; Smirnov, Y; Voeckler, J; Wilde, M; Zhao, Y; Zhao, X; Avery, P; Cavanaugh, R J; Kim, B; Prescott, C; Rodríguez, J; Zahn, A; McKee, S; Jordan, C; Prewett, J; Thomas, T; Severini, H; Clifford, B; Deelman, E; Flon, L; Kesselman, C; Mehta, G; Olomu, N; Vahi, K; De, K; McGuigan, P; Sosebee, M; Bradley, D; Couvares, P; De Smet, A; Kireyev, C; Paulson, E; Roy, A; Koranda, S; Moe, B; Brown, B; Sheldon, P

2004-01-01

The Grid2003 Project has deployed a multi-virtual organization, application-driven grid laboratory ("GridS") that has sustained for several months the production-level services required by physics experiments of the Large Hadron Collider at CERN (ATLAS and CMS), the Sloan Digital Sky Survey project, the gravitational wave search experiment LIGO, the BTeV experiment at Fermilab, as well as applications in molecular structure analysis and genome analysis, and computer science research projects in such areas as job and data scheduling. The deployed infrastructure has been operating since November 2003 with 27 sites, a peak of 2800 processors, work loads from 10 different applications exceeding 1300 simultaneous jobs, and data transfers among sites of greater than 2 TB/day. We describe the principles that have guided the development of this unique infrastructure and the practical experiences that have resulted from its creation and use. We discuss application requirements for grid services deployment and configur...

Mapping of grid faults and grid codes

DEFF Research Database (Denmark)

Iov, F.; Hansen, Anca Daniela; Sørensen, Poul Ejnar

loads of wind turbines. The goal is also to clarify and define possible new directions in the certification process of power plant wind turbines, namely wind turbines, which participate actively in the stabilisation of power systems. Practical experience shows that there is a need...... challenges for the design of both the electrical system and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries is done in this report. The most relevant study cases for the quantification of the loads......The present report is a part of the research project ''Grid fault and designbasis for wind turbine'' supported by Energinet.dk through the grant PSO F&U 6319. The objective of this project is to investigate into the consequences of the new grid connection requirements for the fatigue and extreme...

Ancillary reactive power service allocation cost in deregulated markets: a methodology

International Nuclear Information System (INIS)

Hernandez, J. Horacio Tovar; Jimenez-Guzman, Miguel; Gutierrez-Alcaraz, Guillermo

2005-01-01

This paper presents a methodology to allocate reactive power costs in deregulated markets. Reactive power supply service is decomposed into voltage regulation and reactive power spinning reserve. The proposed methodology is based on sensitivities and the postage-stamp method in order to allocate the total costs service among all participants. With the purpose of achieving this goal, the system operator identifies voltage support and/or reactive power requirements, and looks out for suitable providers. One case study is presented here to illustrate the methodology over a simplified southeastern Mexican grid. (Author)

A Stationary Reference Frame Grid Synchronization System for Three-Phase Grid-Connected Power Converters Under Adverse Grid Conditions

DEFF Research Database (Denmark)

Rodríguez, P.; Luna, A.; Muñoz-Aguilar, R. S.

2012-01-01

synchronization method for three-phase three-wire networks, namely dual second-order generalized integrator (SOGI) frequency-locked loop. The method is based on two adaptive filters, implemented by using a SOGI on the stationary αβ reference frame, and it is able to perform an excellent estimation......Grid synchronization algorithms are of great importance in the control of grid-connected power converters, as fast and accurate detection of the grid voltage parameters is crucial in order to implement stable control strategies under generic grid conditions. This paper presents a new grid...

Multi-objective parallel particle swarm optimization for day-ahead Vehicle-to-Grid scheduling

DEFF Research Database (Denmark)

Soares, Joao; Vale, Zita; Canizes, Bruno

2013-01-01

This paper presents a methodology for multi-objective day-ahead energy resource scheduling for smart grids considering intensive use of distributed generation and Vehicle-To-Grid (V2G). The main focus is the application of weighted Pareto to a multi-objective parallel particle swarm approach aiming...... to solve the dual-objective V2G scheduling: minimizing total operation costs and maximizing V2G income. A realistic mathematical formulation, considering the network constraints and V2G charging and discharging efficiencies is presented and parallel computing is applied to the Pareto weights. AC power flow...

GridICE: monitoring the user/application activities on the grid

International Nuclear Information System (INIS)

Aiftimiei, C; Pra, S D; Andreozzi, S; Fattibene, E; Misurelli, G; Cuscela, G; Donvito, G; Dudhalkar, V; Maggi, G; Pierro, A; Fantinel, S

2008-01-01

The monitoring of the grid user activity and application performance is extremely useful to plan resource usage strategies particularly in cases of complex applications. Large VOs, such as the LHC VOs, do their monitoring by means of dashboards. Other VOs or communities, like for example the BioinfoGRID one, are characterized by a greater diversification of the application types: so the effort to provide a dashboard like monitor is particularly heavy. The main theme of this paper is to show the improvements introduced in GridICE, a web tool built to provides an almost complete grid monitoring. These recent improvements allows GridICE to provide new reports on the resources usage with details of the VOMS groups, roles and users. By accessing the GridICE web pages, the grid user can get all information that is relevant to keep track of his activity on the grid. In the same way, the activity of a VOMS group can be distinguished from the activity of the entire VO. In this paper we briefly talk about the features and advantages of this approach and, after discussing the requirements, we describe the software solutions, middleware and prerequisite to manage and retrieve the user's credentials

Mapping of grid faults and grid codes

DEFF Research Database (Denmark)

Iov, Florin; Hansen, A.D.; Sørensen, P.

loads of wind turbines. The goal is also to clarify and define possible new directions in the certification process of power plant wind turbines, namely wind turbines, which participate actively in the stabilisation of power systems. Practical experience shows that there is a need...... challenges for the design of both the electrical system and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries is done in this report. The most relevant study cases for the quantification of the loads......The present report is a part of the research project "Grid fault and design basis for wind turbine" supported by Energinet.dk through the grant PSO F&U 6319. The objective of this project is to investigate into the consequences of the new grid connection requirements for the fatigue and extreme...

A unified grid current control for grid-interactive DG inverters in microgrids

DEFF Research Database (Denmark)

Wang, Xiongfei; Loh, Poh Chiang; Blaabjerg, Frede

2015-01-01

This paper proposes a unified grid current control for grid-interactive distributed generation inverters. In the approach, the grid-side current, instead of inverter-side current, is controlled as an inner loop, while the filter capacitor voltage is indirectly regulated through a virtual admittan...... locus analyses in the discrete z-domain are performed for elaborating the controller design. Simulations and experimental results demonstrate the performances of the proposed approach.......This paper proposes a unified grid current control for grid-interactive distributed generation inverters. In the approach, the grid-side current, instead of inverter-side current, is controlled as an inner loop, while the filter capacitor voltage is indirectly regulated through a virtual admittance...... in the outer loop. It, therefore, provides several superior features over traditional control schemes: 1) high-quality grid current in the grid-connected mode, 2) inherent derivative-less virtual output impedance control, and 3) the unified active damping for both grid-connected and islanded operations. Root...

Grid-Voltage-Feedforward Active Damping for Grid-Connected Inverter with LCL Filter

DEFF Research Database (Denmark)

Lu, Minghui; Wang, Xiongfei; Blaabjerg, Frede

2016-01-01

For the grid-connected voltage source inverters, the feedforward scheme of grid voltage is commonly adopted to mitigate the current distortion caused by grid background voltages harmonics. This paper investigates the grid-voltage-feedforward active damping for grid connected inverter with LCL...... filter. It reveals that proportional feedforward control can not only fulfill the mitigation of grid disturbance, but also offer damping effects on the LCL filter resonance. Digital delays are intrinsic to digital controlled inverters; with these delays, the feedforward control can be equivalent...

A roadmap for caGrid, an enterprise Grid architecture for biomedical research.

Science.gov (United States)

Saltz, Joel; Hastings, Shannon; Langella, Stephen; Oster, Scott; Kurc, Tahsin; Payne, Philip; Ferreira, Renato; Plale, Beth; Goble, Carole; Ervin, David; Sharma, Ashish; Pan, Tony; Permar, Justin; Brezany, Peter; Siebenlist, Frank; Madduri, Ravi; Foster, Ian; Shanbhag, Krishnakant; Mead, Charlie; Chue Hong, Neil

2008-01-01

caGrid is a middleware system which combines the Grid computing, the service oriented architecture, and the model driven architecture paradigms to support development of interoperable data and analytical resources and federation of such resources in a Grid environment. The functionality provided by caGrid is an essential and integral component of the cancer Biomedical Informatics Grid (caBIG) program. This program is established by the National Cancer Institute as a nationwide effort to develop enabling informatics technologies for collaborative, multi-institutional biomedical research with the overarching goal of accelerating translational cancer research. Although the main application domain for caGrid is cancer research, the infrastructure provides a generic framework that can be employed in other biomedical research and healthcare domains. The development of caGrid is an ongoing effort, adding new functionality and improvements based on feedback and use cases from the community. This paper provides an overview of potential future architecture and tooling directions and areas of improvement for caGrid and caGrid-like systems. This summary is based on discussions at a roadmap workshop held in February with participants from biomedical research, Grid computing, and high performance computing communities.

Design and evaluation of a grid reciprocation scheme for use in digital breast tomosynthesis

Science.gov (United States)

Patel, Tushita; Sporkin, Helen; Peppard, Heather; Williams, Mark B.

2016-03-01

This work describes a methodology for efficient removal of scatter radiation during digital breast tomosynthesis (DBT). The goal of this approach is to enable grid image obscuration without a large increase in radiation dose by minimizing misalignment of the grid focal point (GFP) and x-ray focal spot (XFS) during grid reciprocation. Hardware for the motion scheme was built and tested on the dual modality breast tomosynthesis (DMT) scanner, which combines DBT and molecular breast tomosynthesis (MBT) on a single gantry. The DMT scanner uses fully isocentric rotation of tube and x-ray detector for maintaining a fixed tube-detector alignment during DBT imaging. A cellular focused copper prototype grid with 80 cm focal length, 3.85 mm height, 0.1 mm thick lamellae, and 1.1 mm hole pitch was tested. Primary transmission of the grid at 28 kV tube voltage was on average 74% with the grid stationary and aligned for maximum transmission. It fell to 72% during grid reciprocation by the proposed method. Residual grid line artifacts (GLAs) in projection views and reconstructed DBT images are characterized and methods for reducing the visibility of GLAs in the reconstructed volume through projection image flat-field correction and spatial frequency-based filtering of the DBT slices are described and evaluated. The software correction methods reduce the visibility of these artifacts in the reconstructed volume, making them imperceptible both in the reconstructed DBT images and their Fourier transforms.

Urban micro-grids

International Nuclear Information System (INIS)

Faure, Maeva; Salmon, Martin; El Fadili, Safae; Payen, Luc; Kerlero, Guillaume; Banner, Arnaud; Ehinger, Andreas; Illouz, Sebastien; Picot, Roland; Jolivet, Veronique; Michon Savarit, Jeanne; Strang, Karl Axel

2017-02-01

ENEA Consulting published the results of a study on urban micro-grids conducted in partnership with the Group ADP, the Group Caisse des Depots, ENEDIS, Omexom, Total and the Tuck Foundation. This study offers a vision of the definition of an urban micro-grid, the value brought by a micro-grid in different contexts based on real case studies, and the upcoming challenges that micro-grid stakeholders will face (regulation, business models, technology). The electric production and distribution system, as the backbone of an increasingly urbanized and energy dependent society, is urged to shift towards a more resilient, efficient and environment-friendly infrastructure. Decentralisation of electricity production into densely populated areas is a promising opportunity to achieve this transition. A micro-grid enhances local production through clustering electricity producers and consumers within a delimited electricity network; it has the ability to disconnect from the main grid for a limited period of time, offering an energy security service to its customers during grid outages for example. However: The islanding capability is an inherent feature of the micro-grid concept that leads to a significant premium on electricity cost, especially in a system highly reliant on intermittent electricity production. In this case, a smart grid, with local energy production and no islanding capability, can be customized to meet relevant sustainability and cost savings goals at lower costs For industrials, urban micro-grids can be economically profitable in presence of high share of reliable energy production and thermal energy demand micro-grids face strong regulatory challenges that should be overcome for further development Whether islanding is or is not implemented into the system, end-user demand for a greener, more local, cheaper and more reliable energy, as well as additional services to the grid, are strong drivers for local production and consumption. In some specific cases

Grid Architecture 2

Energy Technology Data Exchange (ETDEWEB)

Taft, Jeffrey D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-01-01

The report describes work done on Grid Architecture under the auspices of the Department of Electricity Office of Electricity Delivery and Reliability in 2015. As described in the first Grid Architecture report, the primary purpose of this work is to provide stakeholder insight about grid issues so as to enable superior decision making on their part. Doing this requires the creation of various work products, including oft-times complex diagrams, analyses, and explanations. This report provides architectural insights into several important grid topics and also describes work done to advance the science of Grid Architecture as well.

GridOrbit public display

DEFF Research Database (Denmark)

Ramos, Juan David Hincapie; Tabard, Aurélien; Bardram, Jakob

2010-01-01

We introduce GridOrbit, a public awareness display that visualizes the activity of a community grid used in a biology laboratory. This community grid executes bioin-formatics algorithms and relies on users to donate CPU cycles to the grid. The goal of GridOrbit is to create a shared awareness about...

Smart Grid: Network simulator for smart grid test-bed

International Nuclear Information System (INIS)

Lai, L C; Ong, H S; Che, Y X; Do, N Q; Ong, X J

2013-01-01

Smart Grid become more popular, a smaller scale of smart grid test-bed is set up at UNITEN to investigate the performance and to find out future enhancement of smart grid in Malaysia. The fundamental requirement in this project is design a network with low delay, no packet drop and with high data rate. Different type of traffic has its own characteristic and is suitable for different type of network and requirement. However no one understands the natural of traffic in smart grid. This paper presents the comparison between different types of traffic to find out the most suitable traffic for the optimal network performance.

Factors influencing societal response of nanotechnology: an expert stakeholder analysis

Energy Technology Data Exchange (ETDEWEB)

Gupta, Nidhi, E-mail: nidhi.gupta@wur.nl; Fischer, Arnout R. H., E-mail: arnout.fischer@wur.nl; Lans, Ivo A. van der, E-mail: Ivo.vanderLans@wur.nl [Wageningen University, Marketing and Consumer Behaviour Group (Netherlands); Frewer, Lynn J., E-mail: lynn.frewer@newcastle.ac.uk [Newcastle University, School of Agriculture, Food and Rural Development (United Kingdom)

2012-05-15

Nanotechnology can be described as an emerging technology and, as has been the case with other emerging technologies such as genetic modification, different socio-psychological factors will potentially influence societal responses to its development and application. These factors will play an important role in how nanotechnology is developed and commercialised. This article aims to identify expert opinion on factors influencing societal response to applications of nanotechnology. Structured interviews with experts on nanotechnology from North West Europe were conducted using repertory grid methodology in conjunction with generalized Procrustes analysis to examine the psychological constructs underlying societal uptake of 15 key applications of nanotechnology drawn from different areas (e.g. medicine, agriculture and environment, chemical, food, military, sports, and cosmetics). Based on expert judgement, the main factors influencing societal response to different applications of nanotechnology will be the extent to which applications are perceived to be beneficial, useful, and necessary, and how 'real' and physically close to the end-user these applications are perceived to be by the public.

Grid Voltage Modulated Control of Grid-Connected Voltage Source Inverters under Unbalanced Grid Conditions

DEFF Research Database (Denmark)

Li, Mingshen; Gui, Yonghao; Quintero, Juan Carlos Vasquez

2017-01-01

In this paper, an improved grid voltage modulated control (GVM) with power compensation is proposed for grid-connected voltage inverters when the grid voltage is unbalanced. The objective of the proposed control is to remove the power ripple and to improve current quality. Three power compensation...... objectives are selected to eliminate the negative sequence components of currents. The modified GVM method is designed to obtain two separate second-order systems for not only the fast convergence rate of the instantaneous active and reactive powers but also the robust performance. In addition, this method...

EASE-Grid 2.0: Incremental but Significant Improvements for Earth-Gridded Data Sets

Directory of Open Access Journals (Sweden)

Matthew H. Savoie

2012-03-01

Full Text Available Defined in the early 1990s for use with gridded satellite passive microwave data, the Equal-Area Scalable Earth Grid (EASE-Grid was quickly adopted and used for distribution of a variety of satellite and in situ data sets. Conceptually easy to understand, EASE-Grid suffers from limitations that make it impossible to format in the widely popular GeoTIFF convention without reprojection. Importing EASE-Grid data into standard mapping software packages is nontrivial and error-prone. This article defines a standard for an improved EASE-Grid 2.0 definition, addressing how the changes rectify issues with the original grid definition. Data distributed using the EASE-Grid 2.0 standard will be easier for users to import into standard software packages and will minimize common reprojection errors that users had encountered with the original EASE-Grid definition.

Ambiguities in the grid-inefficiency correction for Frisch-Grid Ionization Chambers

International Nuclear Information System (INIS)

Al-Adili, A.; Hambsch, F.-J.; Bencardino, R.; Oberstedt, S.; Pomp, S.

2012-01-01

Ionization chambers with Frisch grids have been very successfully applied to neutron-induced fission-fragment studies during the past 20 years. They are radiation resistant and can be easily adapted to the experimental conditions. The use of Frisch grids has the advantage to remove the angular dependency from the charge induced on the anode plate. However, due to the Grid Inefficiency (GI) in shielding the charges, the anode signal remains slightly angular dependent. The correction for the GI is, however, essential to determine the correct energy of the ionizing particles. GI corrections can amount to a few percent of the anode signal. Presently, two contradicting correction methods are considered in literature. The first method adding the angular-dependent part of the signal to the signal pulse height; the second method subtracting the former from the latter. Both additive and subtractive approaches were investigated in an experiment where a Twin Frisch-Grid Ionization Chamber (TFGIC) was employed to detect the spontaneous fission fragments (FF) emitted by a 252 Cf source. Two parallel-wire grids with different wire spacing (1 and 2 mm, respectively), were used individually, in the same chamber side. All the other experimental conditions were unchanged. The 2 mm grid featured more than double the GI of the 1 mm grid. The induced charge on the anode in both measurements was compared, before and after GI correction. Before GI correction, the 2 mm grid resulted in a lower pulse-height distribution than the 1 mm grid. After applying both GI corrections to both measurements only the additive approach led to consistent grid independent pulse-height distributions. The application of the subtractive correction on the contrary led to inconsistent, grid-dependent results. It is also shown that the impact of either of the correction methods is small on the FF mass distributions of 235 U(n th , f).

Isostatic lines’ study to optimize steel space grid envelope structures for tall buildings according to their solicitations

OpenAIRE

Señís López, Roger

2013-01-01

Based on the first study completed with wind tunnel tests, the aim of this paper is to define a second methodology for the optimization of steel space grid envelope structures for tall buildings according to their isostatic lines according to their solicitations. It is by means of the comparison NatHaz online database and numerical simulation research of wind flow repercussion in buildings, through Computational Fluid Dynamics (CDF), that we can understand and analyse the grid ...

Payment Instrument Characteristics

DEFF Research Database (Denmark)

Holst, Jacques; Kjeldsen, Martin; Hedman, Jonas

2015-01-01

Over the last decade, we have witnessed payment innovations that fundamentally have changed the ways we pay. Payment innovations, such as mobile payments and on-line banking, include characteristics or features that are essential to understand if we want to know how and why payers choose among...... payment innovations. Using the Repertory Grid technique to explore 15 payers’ perception of six payment instruments, including coins, banknotes, debit cards, credit cards, mobile payments, and on-line banking, we identify 16 payment characteristics. The characteristics aggregate seventy-six unique...

How do Usability Professionals Construe Usability?

DEFF Research Database (Denmark)

Hertzum, Morten; Clemmensen, Torkil

2012-01-01

distinguishing it from user experience. On the basis of repertory-grid interviews with 24 Chinese, Danish, and Indian usability professionals we find that they make use of more utilitarian than experiential, i.e. user-experience related, constructs. This indicates that goal-related performance is central......’ constructs, particularly their experiential constructs, go considerably beyond ISO 9241 usability, indicating a discrepancy between this definition of usability and the thinking of the professionals concerned with delivering usability. Finally, usability is construed rather similarly across the three...

Enhancing the Professional Vision of Teachers

DEFF Research Database (Denmark)

Pantazos, Kostas; Vatrapu, Ravi

2016-01-01

by students for given topics of study at the individual student, group or classroom levels of analysis. The pedagogical objective of the dashboards is to facilitate formative assessment feedback to students and feed-forward refinements to ongoing instructional practices. The teaching analytics dashboards were......This paper reports on a study of the design, development and evaluation of two teaching analytics dashboards that visualize students’ repertory grid exercise data. The technical objective of the dashboards is to support teachers to investigate and compare personal constructs and element ratings...

Coarse-grid-CFD. An advantageous alternative to subchannel analysis

International Nuclear Information System (INIS)

Class, A.G.; Himmel, S.R.; Viellieber, M.O.

2011-01-01

In the 1960 th to 80 th when current GEN II reactor technology was developed, the only possible approach was to use one-dimensional subchannel analysis to compute the flow inside a fuel bundle so that the subchannel scale could be resolved. For simulations of the whole reactor core either system codes or homogenization were employed. In system codes resolution of individual assemblies was the state of the art. Homogenization used porous media equations simulations and averaged the thermohydraulics on reactor core scale. Current potent computing power allows using Computational Fluid Dynamics (CFD) to simulate individual fuel assemblies. Yet the large number of fuel assemblies within the core forbids exploiting CFD for core wide simulation. We propose to combine ideas of subchannel analysis and CFD to develop a new methodology which takes advantage of the fast development of commercial CFD software and the efficiency of subchannel analysis. In this methodology was first applied to simulate a wire-wrap fuel bundle of the High Performance Light Water Reactor (HPLWR). Computations using an inviscid Euler solver on an extremely coarse grid were tuned to predict the true thermohydraulics by adding volumetric forces. These forces represent the non-resolved sub-grid physics. The volumetric forces cannot be measured directly. However, they can be accessed from detailed CFD simulations resolving all relevant physics. Parameterization of these subgrid forces can be realized analogous to models in subchannel codes. In the present work we extend the methodology to the open source solver OpenFOAM and a specific hexagonal fuel assembly which is studied in the framework of liquid metal cooled GEN IV reactor concepts. (orig.)

Grid Transmission Expansion Planning Model Based on Grid Vulnerability

Science.gov (United States)

Tang, Quan; Wang, Xi; Li, Ting; Zhang, Quanming; Zhang, Hongli; Li, Huaqiang

2018-03-01

Based on grid vulnerability and uniformity theory, proposed global network structure and state vulnerability factor model used to measure different grid models. established a multi-objective power grid planning model which considering the global power network vulnerability, economy and grid security constraint. Using improved chaos crossover and mutation genetic algorithm to optimize the optimal plan. For the problem of multi-objective optimization, dimension is not uniform, the weight is not easy given. Using principal component analysis (PCA) method to comprehensive assessment of the population every generation, make the results more objective and credible assessment. the feasibility and effectiveness of the proposed model are validated by simulation results of Garver-6 bus system and Garver-18 bus.

Gridded uncertainty in fossil fuel carbon dioxide emission maps, a CDIAC example

Science.gov (United States)

Andres, Robert J.; Boden, Thomas A.; Higdon, David M.

2016-12-01

Due to a current lack of physical measurements at appropriate spatial and temporal scales, all current global maps and distributions of fossil fuel carbon dioxide (FFCO2) emissions use one or more proxies to distribute those emissions. These proxies and distribution schemes introduce additional uncertainty into these maps. This paper examines the uncertainty associated with the magnitude of gridded FFCO2 emissions. This uncertainty is gridded at the same spatial and temporal scales as the mass magnitude maps. This gridded uncertainty includes uncertainty contributions from the spatial, temporal, proxy, and magnitude components used to create the magnitude map of FFCO2 emissions. Throughout this process, when assumptions had to be made or expert judgment employed, the general tendency in most cases was toward overestimating or increasing the magnitude of uncertainty. The results of the uncertainty analysis reveal a range of 4-190 %, with an average of 120 % (2σ) for populated and FFCO2-emitting grid spaces over annual timescales. This paper also describes a methodological change specific to the creation of the Carbon Dioxide Information Analysis Center (CDIAC) FFCO2 emission maps: the change from a temporally fixed population proxy to a temporally varying population proxy.

A Systems Approach to Analyzing Cyber-Physical Threats in the Smart Grid

Energy Technology Data Exchange (ETDEWEB)

Almajali, Anas; Rice, Eric; Viswanathan, Arun; Tan, Kymie; Neuman, Clifford

2016-10-01

This paper presents a systems analysis approach to characterizing the risk of a Smart Grid to a load-drop attack. A characterization of the risk is necessary for the design of detection and remediation strategies to address the consequences of such attacks. Using concepts from systems health management and system engineering, this work (a) first identifies metrics that can be used to generate constraints for security features, and (b) lays out an end-to-end integrated methodology using separate network and power simulations to assess system risk. We demonstrate our approach by performing a systems-style analysis of a load-drop attack implemented over the AMI subsystem and targeted at destabilizing the underlying power grid.

Towards resiliency with micro-grids: Portfolio optimization and investment under uncertainty

Science.gov (United States)

Gharieh, Kaveh

Energy security and sustained supply of power are critical for community welfare and economic growth. In the face of the increased frequency and intensity of extreme weather conditions which can result in power grid outage, the value of micro-grids to improve the communities' power reliability and resiliency is becoming more important. Micro-grids capability to operate in islanded mode in stressed-out conditions, dramatically decreases the economic loss of critical infrastructure in power shortage occasions. More wide-spread participation of micro-grids in the wholesale energy market in near future, makes the development of new investment models necessary. However, market and price risks in short term and long term along with risk factors' impacts shall be taken into consideration in development of new investment models. This work proposes a set of models and tools to address different problems associated with micro-grid assets including optimal portfolio selection, investment and financing in both community and a sample critical infrastructure (i.e. wastewater treatment plant) levels. The models account for short-term operational volatilities and long-term market uncertainties. A number of analytical methodologies and financial concepts have been adopted to develop the aforementioned models as follows. (1) Capital budgeting planning and portfolio optimization models with Monte Carlo stochastic scenario generation are applied to derive the optimal investment decision for a portfolio of micro-grid assets considering risk factors and multiple sources of uncertainties. (2) Real Option theory, Monte Carlo simulation and stochastic optimization techniques are applied to obtain optimal modularized investment decisions for hydrogen tri-generation systems in wastewater treatment facilities, considering multiple sources of uncertainty. (3) Public Private Partnership (PPP) financing concept coupled with investment horizon approach are applied to estimate public and private

Grid Databases for Shared Image Analysis in the MammoGrid Project

CERN Document Server

Amendolia, S R; Hauer, T; Manset, D; McClatchey, R; Odeh, M; Reading, T; Rogulin, D; Schottlander, D; Solomonides, T

2004-01-01

The MammoGrid project aims to prove that Grid infrastructures can be used for collaborative clinical analysis of database-resident but geographically distributed medical images. This requires: a) the provision of a clinician-facing front-end workstation and b) the ability to service real-world clinician queries across a distributed and federated database. The MammoGrid project will prove the viability of the Grid by harnessing its power to enable radiologists from geographically dispersed hospitals to share standardized mammograms, to compare diagnoses (with and without computer aided detection of tumours) and to perform sophisticated epidemiological studies across national boundaries. This paper outlines the approach taken in MammoGrid to seamlessly connect radiologist workstations across a Grid using an "information infrastructure" and a DICOM-compliant object model residing in multiple distributed data stores in Italy and the UK

Multigrid on unstructured grids using an auxiliary set of structured grids

Energy Technology Data Exchange (ETDEWEB)

Douglas, C.C.; Malhotra, S.; Schultz, M.H. [Yale Univ., New Haven, CT (United States)

1996-12-31

Unstructured grids do not have a convenient and natural multigrid framework for actually computing and maintaining a high floating point rate on standard computers. In fact, just the coarsening process is expensive for many applications. Since unstructured grids play a vital role in many scientific computing applications, many modifications have been proposed to solve this problem. One suggested solution is to map the original unstructured grid onto a structured grid. This can be used as a fine grid in a standard multigrid algorithm to precondition the original problem on the unstructured grid. We show that unless extreme care is taken, this mapping can lead to a system with a high condition number which eliminates the usefulness of the multigrid method. Theorems with lower and upper bounds are provided. Simple examples show that the upper bounds are sharp.

Asymmetrical Grid Fault Ride-Through Strategy of Three-phase Grid-connected Inverter Considering Network Impedance Impact in Low Voltage Grid

DEFF Research Database (Denmark)

Guo, Xiaoqiang; Zhang, Xue; Wang, Baocheng

2014-01-01

This letter presents a new control strategy of threephase grid-connected inverter for the positive sequence voltage recovery and negative sequence voltage reduction under asymmetrical grid faults. Unlike the conventional control strategy based on an assumption that the network impedance is mainly...... of the proposed solution for the flexible voltage support in a low-voltage grid, where thenetwork impedance is mainly resistive.......This letter presents a new control strategy of threephase grid-connected inverter for the positive sequence voltage recovery and negative sequence voltage reduction under asymmetrical grid faults. Unlike the conventional control strategy based on an assumption that the network impedance is mainly...... inductive, the proposed control strategy is more flexible and effective by considering the network impedance impact, which is of great importance for the high penetration of grid-connected renewable energy systems into low-voltage grids. The experimental tests are carried out to validate the effectiveness...

Towards risk-based management of critical infrastructures : enabling insights and analysis methodologies from a focused study of the bulk power grid.

Energy Technology Data Exchange (ETDEWEB)

Richardson, Bryan T.; LaViolette, Randall A.; Cook, Benjamin Koger

2008-02-01

This report summarizes research on a holistic analysis framework to assess and manage risks in complex infrastructures, with a specific focus on the bulk electric power grid (grid). A comprehensive model of the grid is described that can approximate the coupled dynamics of its physical, control, and market components. New realism is achieved in a power simulator extended to include relevant control features such as relays. The simulator was applied to understand failure mechanisms in the grid. Results suggest that the implementation of simple controls might significantly alter the distribution of cascade failures in power systems. The absence of cascade failures in our results raises questions about the underlying failure mechanisms responsible for widespread outages, and specifically whether these outages are due to a system effect or large-scale component degradation. Finally, a new agent-based market model for bilateral trades in the short-term bulk power market is presented and compared against industry observations.

The GRID seminar

CERN Multimedia

CERN. Geneva HR-RFA

2006-01-01

The Grid infrastructure is a key part of the computing environment for the simulation, processing and analysis of the data of the LHC experiments. These experiments depend on the availability of a worldwide Grid infrastructure in several aspects of their computing model. The Grid middleware will hide much of the complexity of this environment to the user, organizing all the resources in a coherent virtual computer center. The general description of the elements of the Grid, their interconnections and their use by the experiments will be exposed in this talk. The computational and storage capability of the Grid is attracting other research communities beyond the high energy physics. Examples of these applications will be also exposed during the presentation.

Importance of Grid Center Arrangement

Science.gov (United States)

Pasaogullari, O.; Usul, N.

2012-12-01

In Digital Elevation Modeling, grid size is accepted to be the most important parameter. Despite the point density and/or scale of the source data, it is freely decided by the user. Most of the time, arrangement of the grid centers are ignored, even most GIS packages omit the choice of grid center coordinate selection. In our study; importance of the arrangement of grid centers is investigated. Using the analogy between "Raster Grid DEM" and "Bitmap Image", importance of placement of grid centers in DEMs are measured. The study has been conducted on four different grid DEMs obtained from a half ellipsoid. These grid DEMs are obtained in such a way that they are half grid size apart from each other. Resulting grid DEMs are investigated through similarity measures. Image processing scientists use different measures to investigate the dis/similarity between the images and the amount of different information they carry. Grid DEMs are projected to a finer grid in order to co-center. Similarity measures are then applied to each grid DEM pairs. These similarity measures are adapted to DEM with band reduction and real number operation. One of the measures gives function graph and the others give measure matrices. Application of similarity measures to six grid DEM pairs shows interesting results. These four different grid DEMs are created with the same method for the same area, surprisingly; thirteen out of 14 measures state that, the half grid size apart grid DEMs are different from each other. The results indicated that although grid DEMs carry mutual information, they have also additional individual information. In other words, half grid size apart constructed grid DEMs have non-redundant information.; Joint Probability Distributions Function Graphs

Initial results of local grid control using wind farms with grid support

Energy Technology Data Exchange (ETDEWEB)

Soerensen, Poul; Hansen, Anca D.; Iov, F.; Blaabjerg, F.

2005-09-01

This report describes initial results with simulation of local grid control using wind farms with grid support. The focus is on simulation of the behaviour of the wind farms when they are isolated from the main grid and establish a local grid together with a few other grid components. The isolated subsystems used in the work presented in this report do not intend to simulate a specific subsystem, but they are extremely simplified single bus bar systems using only a few more components than the wind farm. This approach has been applied to make it easier to understand the dynamics of the subsystem. The main observation is that the fast dynamics of the wind turbines seem to be able to contribute significantly to the grid control, which can be useful where the wind farm is isolated with a subsystem from the main grid with surplus of generation. Thus, the fast down regulation of the wind farm using automatic frequency control can keep the subsystem in operation and thereby improve the reliability of the grid. (LN)

How should grid operators govern smart grid innovation projects? An embedded case study approach

International Nuclear Information System (INIS)

Reuver, Mark de; Lei, Telli van der; Lukszo, Zofia

2016-01-01

Grid operators increasingly have to collaborate with other actors in order to realize smart grid innovations. For routine maintenance, grid operators typically acquire technologies in one-off transactions, but the innovative nature of smart grid projects may require more collaborate relationships. This paper studies how a transactional versus relational approach to governing smart grid innovation projects affects incentives for other actors to collaborate. We analyse 34 cases of smart grid innovation projects based on extensive archival data as well as interviews. We find that projects relying on relational governance are more likely to provide incentives for collaboration. Especially non-financial incentives such as reputational benefits and shared intellectual property rights are more likely to be found in projects relying on relational governance. Policy makers that wish to stimulate smart grid innovation projects should consider stimulating long-term relationships between grid operators and third parties, because such relationships are more likely to produce incentives for collaboration. - Highlights: • Smart grids require collaboration between grid operators and other actors. • We contrast transactional and relational governance of smart grid projects. • Long-term relations produce more incentives for smart grid collaboration. • Non-financial incentives are more important in long-term relations. • Policy makers should stimulate long-term relations to stimulate smart grids.

Characterization of Slosh Damping for Ortho-Grid and Iso-Grid Internal Tank Structures

Science.gov (United States)

Westra, Douglas G.; Sansone, Marco D.; Eberhart, Chad J.; West, Jeffrey S.

2016-01-01

Grid stiffened tank structures such as Ortho-Grid and Iso-Grid are widely used in cryogenic tanks for providing stiffening to the tank while reducing mass, compared to tank walls of constant cross-section. If the structure is internal to the tank, it will positively affect the fluid dynamic behavior of the liquid propellant, in regard to fluid slosh damping. As NASA and commercial companies endeavor to explore the solar system, vehicles will by necessity become more mass efficient, and design margin will be reduced where possible. Therefore, if the damping characteristics of the Ortho-Grid and Iso-Grid structure is understood, their positive damping effect can be taken into account in the systems design process. Historically, damping by internal structures has been characterized by rules of thumb and for Ortho-Grid, empirical design tools intended for slosh baffles of much larger cross-section have been used. There is little or no information available to characterize the slosh behavior of Iso-Grid internal structure. Therefore, to take advantage of these structures for their positive damping effects, there is much need for obtaining additional data and tools to characterize them. Recently, the NASA Marshall Space Flight Center conducted both sub-scale testing and computational fluid dynamics (CFD) simulations of slosh damping for Ortho-Grid and Iso-Grid tanks for cylindrical tanks containing water. Enhanced grid meshing techniques were applied to the geometrically detailed and complex Ortho-Grid and Iso-Grid structures. The Loci-STREAM CFD program with the Volume of Fluid Method module for tracking and locating the water-air fluid interface was used to conduct the simulations. The CFD simulations were validated with the test data and new empirical models for predicting damping and frequency of Ortho-Grid and Iso-Grid structures were generated.

Design Optimization of Transformerless Grid-Connected PV Inverters Including Reliability

OpenAIRE

Koutroulis, Eftichios; Blaabjerg, Frede

2013-01-01

This paper presents a new methodology for optimal design of transformerless photovoltaic (PV) inverters targeting a cost-effective deployment of grid-connected PV systems. The optimal switching frequency as well as the optimal values and types of the PV inverter components is calculated such that the PV inverter LCOE generated during the PV system lifetime period is minimized. The LCOE is also calculated considering the failure rates of the components, which affect the reliability performance...

Robust Grid-Current-Feedback Resonance Suppression Method for LCL-Type Grid-Connected Inverter Connected to Weak Grid

DEFF Research Database (Denmark)

Zhou, Xiaoping; Zhou, Leming; Chen, Yandong

2018-01-01

In this paper, a robust grid-current-feedback reso-nance suppression (GCFRS) method for LCL-type grid-connected inverter is proposed to enhance the system damping without introducing the switching noise and eliminate the impact of control delay on system robustness against grid-impedance variation....... It is composed of GCFRS method, the full duty-ratio and zero-beat-lag PWM method, and the lead-grid-current-feedback-resonance-suppression (LGCFRS) method. Firstly, the GCFRS is used to suppress the LCL-resonant peak well and avoid introducing the switching noise. Secondly, the proposed full duty-ratio and zero......-beat-lag PWM method is used to elimi-nate the one-beat-lag computation delay without introducing duty cycle limitations. Moreover, it can also realize the smooth switching from positive to negative half-wave of the grid current and improve the waveform quality. Thirdly, the proposed LGCFRS is used to further...

Grid connectivity issues and the importance of GCC. [GCC - Grid Code Compliance

Energy Technology Data Exchange (ETDEWEB)

Das, A.; Schwartz, M.-K. [GL Renewable Certification, Malleswaram, Bangalore (India)

2012-07-01

In India, the wind energy is concentrated in rural areas with a very high penetration. In these cases, the wind power has an increasing influence on the power quality on the grids. Another aspect is the influence of weak grids on the operation of wind turbines. Hence it becomes very much essential to introduce such a strong grid code which is particularly applicable to wind sector and suitable for Indian environmental grid conditions. This paper focuses on different international grid codes and their requirement with regard to the connection of wind farms to the electric power systems to mitigate the grid connectivity issues. The requirements include the ways to achieve voltage and frequency stability in the grid-tied wind power system. In this paper, comparative overview and analysis of the main grid connecting requirements will be conducted, comprising several national and regional codes from many countries where high wind penetration levels have been achieved or are expected in the future. The objective of these requirements is to provide wind farms with the control and regulation capabilities encountered in conventional power plants and are necessary for the safe, reliable and economic operation of the power system. This paper also provides a brief idea on the Grid Code Compliance (GCC) certification procedure implemented by the leading accredited certifying body like Germanischer Lloyd Renewables Certification (GL RC), who checks the conformity of the wind turbines as per region specific grid codes. (Author)

The GridShare solution: a smart grid approach to improve service provision on a renewable energy mini-grid in Bhutan

International Nuclear Information System (INIS)

Quetchenbach, T G; Harper, M J; Jacobson, A E; Robinson IV, J; Hervin, K K; Chase, N A; Dorji, C

2013-01-01

This letter reports on the design and pilot installation of GridShares, devices intended to alleviate brownouts caused by peak power use on isolated, village-scale mini-grids. A team consisting of the authors and partner organizations designed, built and field-tested GridShares in the village of Rukubji, Bhutan. The GridShare takes an innovative approach to reducing brownouts by using a low cost device that communicates the state of the grid to its users and regulates usage before severe brownouts occur. This demand-side solution encourages users to distribute the use of large appliances more evenly throughout the day, allowing power-limited systems to provide reliable, long-term renewable electricity to these communities. In the summer of 2011, GridShares were installed in every household and business connected to the Rukubji micro-hydro mini-grid, which serves approximately 90 households with a 40 kW nominal capacity micro-hydro system. The installation was accompanied by an extensive education program. Following the installation of the GridShares, the occurrence and average length of severe brownouts, which had been caused primarily by the use of electric cooking appliances during meal preparation, decreased by over 92%. Additionally, the majority of residents surveyed stated that now they are more certain that their rice will cook well and that they would recommend installing GridShares in other villages facing similar problems. (letter)

Bayesian grid matching

DEFF Research Database (Denmark)

Hartelius, Karsten; Carstensen, Jens Michael

2003-01-01

A method for locating distorted grid structures in images is presented. The method is based on the theories of template matching and Bayesian image restoration. The grid is modeled as a deformable template. Prior knowledge of the grid is described through a Markov random field (MRF) model which r...

SALVAGE Report D2.1 Description of existing and extended smart grid component models for use in the intrusion detection system

DEFF Research Database (Denmark)

Kosek, Anna Magdalena; Heussen, Kai

2015-01-01

The purpose of the SALVAGE project is to develop better support for managing and designing a secure future smart grid. This approach includes cyber security technologies dedicated to power grid operation as well as support for the migration to the future smart grid solutions, including the legacy...... of ICT that necessarily will be part of it. The objective is further to develop cyber security technology and methodology optimized with the particular needs and context of the power industry, something that is to a large extent lacking in general cyber security best practices and technologies today...

The LHCb Grid Simulation

CERN Multimedia

Baranov, Alexander

2016-01-01

The LHCb Grid access if based on the LHCbDirac system. It provides access to data and computational resources to researchers with different geographical locations. The Grid has a hierarchical topology with multiple sites distributed over the world. The sites differ from each other by their number of CPUs, amount of disk storage and connection bandwidth. These parameters are essential for the Grid work. Moreover, job scheduling and data distribution strategy have a great impact on the grid performance. However, it is hard to choose an appropriate algorithm and strategies as they need a lot of time to be tested on the real grid. In this study, we describe the LHCb Grid simulator. The simulator reproduces the LHCb Grid structure with its sites and their number of CPUs, amount of disk storage and bandwidth connection. We demonstrate how well the simulator reproduces the grid work, show its advantages and limitations. We show how well the simulator reproduces job scheduling and network anomalies, consider methods ...

Smart grid in Denmark 2.0. Implementing three key recommendations from the Smart Grid Network. [DanGrid]; Smart Grid i Danmark 2.0. Implementering af tre centrale anbefalinger fra Smart Grid netvaerket

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-11-01

In 2011 the Smart Grid Network, established by the Danish Climate and Energy minister in 2010, published a report which identifies 35 recommendations for implementing smart grid in Denmark. The present report was prepared by the Danish Energy Association and Energinet.dk and elaborates three of these recommendations: Concept for controlling the power system; Information model for the dissemination of data; Roadmap for deployment of smart grid. Concept of Smart Grid: The concept mobilizes and enables electric power demand response and production from smaller customers. This is done by customers or devices connected to the power system modify their behavior to meet the needs of the power system. The concept basically distinguishes between two different mechanisms to enable flexibility. One is the use of price signals (variable network tariffs and electricity prices), which gives customers a financial incentive to move their electricity consumption and production to times when it is of less inconvenience to the power system. The second is flexibility products, where a pre-arranged and well-specified performance - for example, a load reduction in a defined network area - can be activated as required by grid operators and / or Energinet.dk at an agreed price. Information Model for Disseminating Data: The future power system is complex with a large number of physical units, companies and individuals are actively involved in the power system. Similarly, the amount of information needed to be collected, communicated and processed grows explosively, and it is therefore essential to ensure a well-functioning IT infrastructure. A crucial element is a standardized information model in the Danish power system. The concept therefore indicates to use international standards to define an information model. Roadmap Focusing on Grid Companies' Role: There is a need to remove two key barriers. The first barrier is that the existing regulation does not support the grid using

Synchronization method for grid integrated battery storage systems during asymmetrical grid faults

Directory of Open Access Journals (Sweden)

Popadić Bane

2017-01-01

Full Text Available This paper aims at presenting a robust and reliable synchronization method for battery storage systems during asymmetrical grid faults. For this purpose, a Matlab/Simulink based model for testing of the power electronic interface between the grid and the battery storage systems has been developed. The synchronization method proposed in the paper is based on the proportional integral resonant controller with the delay signal cancellation. The validity of the synchronization method has been verified using the advanced laboratory station for the control of grid connected distributed energy sources. The proposed synchronization method has eliminated unfavourable components from the estimated grid angular frequency, leading to the more accurate and reliable tracking of the grid voltage vector positive sequence during both the normal operation and the operation during asymmetrical grid faults. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 042004: Integrated and Interdisciplinary Research entitled: Smart Electricity Distribution Grids Based on Distribution Management System and Distributed Generation

Optimal Wind Energy Integration in Large-Scale Electric Grids

Science.gov (United States)

Albaijat, Mohammad H.

The major concern in electric grid operation is operating under the most economical and reliable fashion to ensure affordability and continuity of electricity supply. This dissertation investigates the effects of such challenges, which affect electric grid reliability and economic operations. These challenges are: 1. Congestion of transmission lines, 2. Transmission lines expansion, 3. Large-scale wind energy integration, and 4. Phaser Measurement Units (PMUs) optimal placement for highest electric grid observability. Performing congestion analysis aids in evaluating the required increase of transmission line capacity in electric grids. However, it is necessary to evaluate expansion of transmission line capacity on methods to ensure optimal electric grid operation. Therefore, the expansion of transmission line capacity must enable grid operators to provide low-cost electricity while maintaining reliable operation of the electric grid. Because congestion affects the reliability of delivering power and increases its cost, the congestion analysis in electric grid networks is an important subject. Consequently, next-generation electric grids require novel methodologies for studying and managing congestion in electric grids. We suggest a novel method of long-term congestion management in large-scale electric grids. Owing to the complication and size of transmission line systems and the competitive nature of current grid operation, it is important for electric grid operators to determine how many transmission lines capacity to add. Traditional questions requiring answers are "Where" to add, "How much of transmission line capacity" to add, and "Which voltage level". Because of electric grid deregulation, transmission lines expansion is more complicated as it is now open to investors, whose main interest is to generate revenue, to build new transmission lines. Adding a new transmission capacity will help the system to relieve the transmission system congestion, create

Flexible operation of parallel grid-connecting converters under unbalanced grid voltage

DEFF Research Database (Denmark)

Lu, Jinghang; Savaghebi, Mehdi; Guerrero, Josep M.

2017-01-01

-link voltage ripple, and overloading. Moreover, under grid voltage unbalance, the active power delivery ability is decreased due to the converter's current rating limitation. In this paper, a thorough study on the current limitation of the grid-connecting converter under grid voltage unbalance is conducted....... In addition, based on the principle that total output active power should be oscillation free, a coordinated control strategy is proposed for the parallel grid-connecting converters. The case study has been conducted to demonstrate the effectiveness of this proposed control strategy....

Phase-lock loop of Grid-connected Voltage Source Converter under non-ideal grid condition

DEFF Research Database (Denmark)

Wang, Haojie; Sun, Hai; Han, Minxiao

2015-01-01

It is a normal practice that the DC micro-grid is connected to AC main grid through Grid-connected Voltage Source Converter (G-VSC) for voltage support. Accurate control of DC micro-grid voltage is difficult for G-VSC under unbalanced grid condition as the fundamental positive-sequence component...... and distorted system voltage the proposed PLL can accurately detect the fundamental positive-sequence component of grid voltage thus accurate control of DC micro-grid voltage can be realized....... phase information cannot be accurately tracked. Based on analysis of the cause of double-frequency ripple when unbalance exists in main grid, a phase-locked loop (PLL) detection technique is proposed. Under the conditions of unsymmetrical system voltage, varying system frequency, single-phase system...

Smart grid security innovative solutions for a modernized grid

CERN Document Server

Skopik, Florian

2015-01-01

The Smart Grid security ecosystem is complex and multi-disciplinary, and relatively under-researched compared to the traditional information and network security disciplines. While the Smart Grid has provided increased efficiencies in monitoring power usage, directing power supplies to serve peak power needs and improving efficiency of power delivery, the Smart Grid has also opened the way for information security breaches and other types of security breaches. Potential threats range from meter manipulation to directed, high-impact attacks on critical infrastructure that could bring down regi

Grid Integration Research | Wind | NREL

Science.gov (United States)

Grid Integration Research Grid Integration Research Researchers study grid integration of wind three wind turbines with transmission lines in the background. Capabilities NREL's grid integration electric power system operators to more efficiently manage wind grid system integration. A photo of

EASE-Grid 2.0: Incremental but Significant Improvements for Earth-Gridded Data Sets

OpenAIRE

Brodzik, Mary J.; Billingsley, Brendan; Haran, Terry; Raup, Bruce; Savoie, Matthew H.

2012-01-01

Defined in the early 1990s for use with gridded satellite passive microwave data, the Equal-Area Scalable Earth Grid (EASE-Grid) was quickly adopted and used for distribution of a variety of satellite and in situ data sets. Conceptually easy to understand, EASE-Grid suffers from limitations that make it impossible to format in the widely popular GeoTIFF convention without reprojection. Importing EASE-Grid data into standard mapping software packages is nontrivial and error-prone. This article...

Energy Non-Availability in Distribution Grids with Heavy Penetration of Solar Power: Assessment and Mitigation through Solar Smoother

Directory of Open Access Journals (Sweden)

Tathagata Sarkar

2018-03-01

Full Text Available Rapid fluctuation of solar irradiance due to cloud passage causes corresponding variations in the power output of solar PV power plants. This leads to rapid voltage instability at the point of common coupling (PCC of the connected grid which may cause temporary shutdown of the plant leading to non-availability of energy in the connected load and distribution grid. An estimate of the duration and frequency of this outage is important for solar energy generators to ensure the generation and performance of the solar power plant. A methodology using PVsyst (6.6.4, University of Geneva, Geneva, Switzerland and PSCAD (4.5, Manitoba HVDC Research Centre, Winnipeg, MB, Canada simulation has been developed to estimate the duration and frequency of power outages due to rapid fluctuation of solar irradiance throughout the year. It is shown that the outage depends not only on the solar irradiance fluctuation, but also on the grid parameters of the connected distribution grid. A practical case study has been done on a 500 kilo Watt peak (kWp solar PV power plant for validation of the proposed methodology. It is observed that the energy non-availability for this plant is about 13% per year. This can be reduced to 8% by incorporating a solar smoother. A financial analysis of this outage and its mitigation has also been carried out.

NEMO. A novel techno-economic tool suite for simulating and optimizing solutions for grid integration of electric vehicles and charging stations

Energy Technology Data Exchange (ETDEWEB)

Erge, Thomas; Stillahn, Thies; Dallmer-Zerbe, Kilian; Wille-Haussmann, Bernhard [Frauenhofer Institut for Solar Energy Systems ISE, Freiburg (Germany)

2013-07-01

With an increasing use of electric vehicles (EV) grid operators need to predict energy flows depending on electromobility use profiles to accordingly adjust grid infrastructure and operation control accordingly. Tools and methodologies are required to characterize grid problems resulting from the interconnection of EV with the grid. The simulation and optimization tool suite NEMO (Novel E-MObility grid model) was developed within a European research project and is currently being tested using realistic showcases. It is a combination of three professional tools. One of the tools aims at a combined techno-economic design and operation, primarily modeling plants on contracts or the spot market, at the same time participating in balancing markets. The second tool is designed for planning grid extension or reinforcement while the third tool is mainly used to quickly discover potential conflicts of grid operation approaches through load flow analysis. The tool suite is used to investigate real showcases in Denmark, Germany and the Netherlands. First studies show that significant alleviation of stress on distribution grid lines could be achieved by few but intelligent restrictions to EV charging procedures.

NEMO. A novel techno-economic tool suite for simulating and optimizing solutions for grid integration of electric vehicles and charging stations

International Nuclear Information System (INIS)

Erge, Thomas; Stillahn, Thies; Dallmer-Zerbe, Kilian; Wille-Haussmann, Bernhard

2013-01-01

With an increasing use of electric vehicles (EV) grid operators need to predict energy flows depending on electromobility use profiles to accordingly adjust grid infrastructure and operation control accordingly. Tools and methodologies are required to characterize grid problems resulting from the interconnection of EV with the grid. The simulation and optimization tool suite NEMO (Novel E-MObility grid model) was developed within a European research project and is currently being tested using realistic showcases. It is a combination of three professional tools. One of the tools aims at a combined techno-economic design and operation, primarily modeling plants on contracts or the spot market, at the same time participating in balancing markets. The second tool is designed for planning grid extension or reinforcement while the third tool is mainly used to quickly discover potential conflicts of grid operation approaches through load flow analysis. The tool suite is used to investigate real showcases in Denmark, Germany and the Netherlands. First studies show that significant alleviation of stress on distribution grid lines could be achieved by few but intelligent restrictions to EV charging procedures.

SuperGrid or SmartGrid: Competing strategies for large-scale integration of intermittent renewables?

International Nuclear Information System (INIS)

Blarke, Morten B.; Jenkins, Bryan M.

2013-01-01

This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts of interest between the two. The article identifies differences between a domestic strategy for the integration of intermittent renewables, vis-à-vis the SmartGrid, and a cross-system strategy, vis-à-vis the SuperGrid. Policy makers and transmission system operators must understand the need for both strategies to evolve in parallel, but in different territories, or with strategic integration, avoiding for one strategy to undermine the feasibility of the other. A strategic zoning strategy is introduced from which attentive societies as well as the global community stand to benefit. The analysis includes a paradigmatic case study from West Denmark which supports the hypothesis that these strategies are mutually exclusive. The case study shows that increasing cross-system transmission capacity jeopardizes the feasibility of SmartGrid technology investments. A political effort is required for establishing dedicated SmartGrid innovation zones, while also redefining infrastructure to avoid the narrow focus on grids and cables. SmartGrid Investment Trusts could be supported from reallocation of planned transmission grid investments to provide for the equitable development of SmartGrid strategies. - Highlights: • Compares SuperGrid and SmartGrid strategies for integrating intermittent renewables. • Identifies technological and socio-economic conflicts of interest between the two. • Proposes a strategic zoning strategy allowing for both strategies to evolve. • Presents a paradigmatic case study showing that strategies are mutually exclusive. • Proposes dedicated SmartGrid innovation zones and SmartGrid investment trusts

Mapping of grid faults and grid codes[Wind turbines

Energy Technology Data Exchange (ETDEWEB)

Iov, F. [Aalborg Univ., Inst. of Energy Technology (Denmark); Hansen, Anca D.; Soerensen, Poul; Cutululis, N.A. [Risoe National Lab. - DTU, Wind Enegy Dept., Roskilde (Denmark)

2007-06-15

The objective of this project is to investigate into the consequences of the new grid connection requirements for the fatigue and extreme loads of wind turbines. The goal is also to clarify and define possible new directions in the certification process of power plant wind turbines, namely wind turbines, which participate actively in the stabilisation of power systems. Practical experience shows that there is a need for such investigations. The grid connection requirements for wind turbines have increased significantly during the last 5-10 years. Especially the requirements for wind turbines to stay connected to the grid during and after voltage sags, imply potential challenges in the design of wind turbines. These requirements pose challenges for the design of both the electrical system and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries is done in this report. The most relevant study cases for the quantification of the loads' impact on the wind turbines' lifetime are defined. The goal of this report is to present a mapping of different grid fault types and their frequency in different countries. The report provides also a detailed overview of the Low Voltage Ride-Through Capabilities for wind turbines in different relevant countries. The most relevant study cases for the quantification of the loads' impact on the wind turbines' lifetime are defined. (au)

Bus.py: A GridLAB-D Communication Interface for Smart Distribution Grid Simulations

Energy Technology Data Exchange (ETDEWEB)

Hansen, Timothy M.; Palmintier, Bryan; Suryanarayanan, Siddharth; Maciejewski, Anthony A.; Siegel, Howard Jay

2015-07-03

As more Smart Grid technologies (e.g., distributed photovoltaic, spatially distributed electric vehicle charging) are integrated into distribution grids, static distribution simulations are no longer sufficient for performing modeling and analysis. GridLAB-D is an agent-based distribution system simulation environment that allows fine-grained end-user models, including geospatial and network topology detail. A problem exists in that, without outside intervention, once the GridLAB-D simulation begins execution, it will run to completion without allowing the real-time interaction of Smart Grid controls, such as home energy management systems and aggregator control. We address this lack of runtime interaction by designing a flexible communication interface, Bus.py (pronounced bus-dot-pie), that uses Python to pass messages between one or more GridLAB-D instances and a Smart Grid simulator. This work describes the design and implementation of Bus.py, discusses its usefulness in terms of some Smart Grid scenarios, and provides an example of an aggregator-based residential demand response system interacting with GridLAB-D through Bus.py. The small scale example demonstrates the validity of the interface and shows that an aggregator using said interface is able to control residential loads in GridLAB-D during runtime to cause a reduction in the peak load on the distribution system in (a) peak reduction and (b) time-of-use pricing cases.

Profitability of smart grid solutions applied in power grid

Directory of Open Access Journals (Sweden)

Katić Nenad A.

2016-01-01

Full Text Available The idea of a Smart Grid solution has been developing for years, as complete solution for a power utility, consisting of different advanced technologies aimed at improving of the efficiency of operation. The trend of implementing various smart systems continues, e.g. Energy Management Systems, Grid Automation Systems, Advanced Metering Infrastructure, Smart power equipment, Distributed Energy Resources, Demand Response systems, etc. Futhermore, emerging technologies, such as energy storages, electrical vehicles or distributed generators, become integrated in distribution networks and systems. Nowadays, the idea of a Smart Grid solution becomes more realistic by full integration of all advanced operation technologies (OT within IT environment, providing the complete digitalization of an Utility (IT/OT integration. The overview of smart grid solutions, estimation of investments, operation costs and possible benefits are presented in this article, with discusison about profitability of such systems.

Application of synchronous grid-connected controller in the wind-solar-storage micro grid

OpenAIRE

Li, Hua; Ren, Yongfeng; Li, Le; Luo, Zhenpeng

2016-01-01

Recently, there has been an increasing interest in using distributed generators (DG) not only to inject power into the grid, but also to enhance the power quality. In this study, a space voltage pulse width modulation (SVPWM) control method is proposed for a synchronous grid-connected controller in a wind-solar-storage micro grid. This method is based on the appropriate topology of the synchronous controller. The wind-solar-storage micro grid is controlled to reconnect to the grid synchronous...

Analysis of turbine-grid interaction of grid-connected wind turbine using HHT

Science.gov (United States)

Chen, A.; Wu, W.; Miao, J.; Xie, D.

2018-05-01

This paper processes the output power of the grid-connected wind turbine with the denoising and extracting method based on Hilbert Huang transform (HHT) to discuss the turbine-grid interaction. At first, the detailed Empirical Mode Decomposition (EMD) and the Hilbert Transform (HT) are introduced. Then, on the premise of decomposing the output power of the grid-connected wind turbine into a series of Intrinsic Mode Functions (IMFs), energy ratio and power volatility are calculated to detect the unessential components. Meanwhile, combined with vibration function of turbine-grid interaction, data fitting of instantaneous amplitude and phase of each IMF is implemented to extract characteristic parameters of different interactions. Finally, utilizing measured data of actual parallel-operated wind turbines in China, this work accurately obtains the characteristic parameters of turbine-grid interaction of grid-connected wind turbine.

What Is the Function of a Figurine? Can the Repertory Grid Technique Tell?

Science.gov (United States)

Persson, Helena Isakssson

2016-01-01

Teaching design and product development at upper secondary school level in Sweden is a matter of interdisciplinary considerations. Education in product development, at this level, prepares students for further studies and career in engineering or industrial design. Knowledge of artefacts is an important element in the education. In coherence with…

Grid generation methods

CERN Document Server

Liseikin, Vladimir D

2017-01-01

This new edition provides a description of current developments relating to grid methods, grid codes, and their applications to actual problems. Grid generation methods are indispensable for the numerical solution of differential equations. Adaptive grid-mapping techniques, in particular, are the main focus and represent a promising tool to deal with systems with singularities. This 3rd edition includes three new chapters on numerical implementations (10), control of grid properties (11), and applications to mechanical, fluid, and plasma related problems (13). Also the other chapters have been updated including new topics, such as curvatures of discrete surfaces (3). Concise descriptions of hybrid mesh generation, drag and sweeping methods, parallel algorithms for mesh generation have been included too. This new edition addresses a broad range of readers: students, researchers, and practitioners in applied mathematics, mechanics, engineering, physics and other areas of applications.

Coarse Grid Modeling of Turbine Film Cooling Flows Using Volumetric Source Terms

Science.gov (United States)

Heidmann, James D.; Hunter, Scott D.

2001-01-01

The recent trend in numerical modeling of turbine film cooling flows has been toward higher fidelity grids and more complex geometries. This trend has been enabled by the rapid increase in computing power available to researchers. However, the turbine design community requires fast turnaround time in its design computations, rendering these comprehensive simulations ineffective in the design cycle. The present study describes a methodology for implementing a volumetric source term distribution in a coarse grid calculation that can model the small-scale and three-dimensional effects present in turbine film cooling flows. This model could be implemented in turbine design codes or in multistage turbomachinery codes such as APNASA, where the computational grid size may be larger than the film hole size. Detailed computations of a single row of 35 deg round holes on a flat plate have been obtained for blowing ratios of 0.5, 0.8, and 1.0, and density ratios of 1.0 and 2.0 using a multiblock grid system to resolve the flows on both sides of the plate as well as inside the hole itself. These detailed flow fields were spatially averaged to generate a field of volumetric source terms for each conservative flow variable. Solutions were also obtained using three coarse grids having streamwise and spanwise grid spacings of 3d, 1d, and d/3. These coarse grid solutions used the integrated hole exit mass, momentum, energy, and turbulence quantities from the detailed solutions as volumetric source terms. It is shown that a uniform source term addition over a distance from the wall on the order of the hole diameter is able to predict adiabatic film effectiveness better than a near-wall source term model, while strictly enforcing correct values of integrated boundary layer quantities.

Smart grids in the colombian electric system: Current situation and potential opportunities

Directory of Open Access Journals (Sweden)

William Mauricio Giral Ramírez

2017-07-01

Full Text Available Context: This paper focuses on providing a functional analysis of smart grids, with the purpose of establishing a framework to identify the main characteristics of the current electric interconnection system in Colombia. It also names the positive incentives proposed by the Colombian government to support both research and development projects that implement non-conventional energy sources and promoting energy management based on efficiency. Method: An architecture model that describes the components interoperability of a smart grid is presented using a descriptive methodology. Results: The results include a list of the objectives established by the Colombian public and private entities related to energy development, specially focusing on the opportunities to provide some kind of artificial intelligence to the current electrical system. Conclusions: It is necessary for the Colombian energy system to supply the energy demand considering electrical safety, social equity, and the minimum environmental impact. These restrictions impose new challenges for the energy system itself: From a technical point of view, the traditional electrical grid must be outfitted with the characteristics of a smart grid, and from a legal perspective, it is essential to generate a clear regulatory framework that promotes the development of this type of technology.

Gridded uncertainty in fossil fuel carbon dioxide emission maps, a CDIAC example

Directory of Open Access Journals (Sweden)

R. J. Andres

2016-12-01

Full Text Available Due to a current lack of physical measurements at appropriate spatial and temporal scales, all current global maps and distributions of fossil fuel carbon dioxide (FFCO2 emissions use one or more proxies to distribute those emissions. These proxies and distribution schemes introduce additional uncertainty into these maps. This paper examines the uncertainty associated with the magnitude of gridded FFCO2 emissions. This uncertainty is gridded at the same spatial and temporal scales as the mass magnitude maps. This gridded uncertainty includes uncertainty contributions from the spatial, temporal, proxy, and magnitude components used to create the magnitude map of FFCO2 emissions. Throughout this process, when assumptions had to be made or expert judgment employed, the general tendency in most cases was toward overestimating or increasing the magnitude of uncertainty. The results of the uncertainty analysis reveal a range of 4–190 %, with an average of 120 % (2σ for populated and FFCO2-emitting grid spaces over annual timescales. This paper also describes a methodological change specific to the creation of the Carbon Dioxide Information Analysis Center (CDIAC FFCO2 emission maps: the change from a temporally fixed population proxy to a temporally varying population proxy.

Suburban Housing Development and Off-Grid Electric Power Supply Assessment for North-Central Nigeria

Directory of Open Access Journals (Sweden)

Ibikunle Olalekan Ogundari

2017-01-01

Full Text Available Energy infrastructures in North-Central Nigeria are inadequate and grid electricity is unable to meet suburban housing electricity demand. The alternative power-supply options proposed by government for the region require appropriation analysis for selection. Four public housing estates in suburban Abuja are selected for electricity demand analysis under conventional and energy-efficient lighting scenarios; then techno-economic parameters of two off-grid electric power supply systems (PV and Diesel-powered generation to meet these electricity demands are evaluated. An energy techno-economic assessment methodology is used. The study determines the energy-efficient lighting system is appropriate with 40% energy savings relative to the Conventional Lighting Systems. The diesel generator alternative power-supply option has Life Cycle Costs almost 4 times those of the PV option. The study established the PV-energy-efficient lighting system as the most feasible off-grid electric power supply alternative for implementation.

Potential carbon impacts of smart grid development in six European countries

Energy Technology Data Exchange (ETDEWEB)

Darby, S. [Lower Carbon Futures, Environmental Change Institute, Oxford University, South Parks Road, Oxford, OX1 3QY (United Kingdom); Stroembaeck, J. [VaasaETT Global Energy Think Tank, Itaemerenkatu 5, 2nd floor, 00180 Helsinki (Finland); Wilks, M. [Poyry Management Consulting, King Charles House, Park End Street, Oxford, OX1 1JD (United Kingdom)

2013-11-15

This paper examines reports on work carried out for the European Commission to devise a methodology for estimating the potential impact of smart grids on carbon emissions. It first identifies functionalities that enable carbon benefits to be realised. Each functionality on the demand side is assumed to be mirrored on the supply side, as when dynamic peak shifting 'replaces' flexible peak generation. Metrics are developed to describe the state of markets and to estimate customer response to demand response initiatives. Quantitative analysis identifies where the greatest scope for emissions reduction lies, while qualitative assessment indicates where to expect more or less impact from smart grid deployment. The impact of smart grid functionalities by 2020 is then modelled for six representative EU markets (Austria, France, Germany, Great Britain, Portugal and Spain), using a detailed pan-European market model and also a high-level ancillary services model. Three scenarios are developed: baseline, in which no smart grid rollout is assumed; feasible, based on what could be achievable in the light of technology developments and with supportive legislation; and an intermediate expected scenario, in which new technologies are introduced but nothing else changes. The findings indicate the potential for emissions reductions by 2020. They also show that the potential is very unlikely to be reached without regulatory support for user engagement in demand response and demand reduction, along with enabling technology and programmes. Development of regulatory frameworks that allow full advantage to be taken of the new technologies emerges as a challenge for smart grid development.

A Generic Danish Distribution Grid Model for Smart Grid Technology Testing

DEFF Research Database (Denmark)

Cha, Seung-Tae; Wu, Qiuwei; Østergaard, Jacob

2012-01-01

This paper describes the development of a generic Danish distribution grid model for smart grid technology testing based on the Bornholm power system. The frequency dependent network equivalent (FDNE) method has been used in order to accurately preserve the desired properties and characteristics...... as a generic Smart Grid benchmark model for testing purposes....... by comparing the transient response of the original Bornholm power system model and the developed generic model under significant fault conditions. The results clearly show that the equivalent generic distribution grid model retains the dynamic characteristics of the original system, and can be used...

Impact of grid impedance variations on harmonic emission of grid-connected inverters

DEFF Research Database (Denmark)

Hoseinzadeh, Bakhtyar; Bak, Claus Leth; Blaabjerg, Frede

2017-01-01

This paper addresses harmonic magnification due to resonance circuits resulting from interaction between uncertain grid impedance and converter. The source of harmonic may be either the grid or inverter. It is demonstrated that unknown and unpredictable grid impedance may result in variable...

A methodology for the evaluation of the collective dose from radioactivity in terrestrial food chains

International Nuclear Information System (INIS)

Simmonds, J.R.; Linsley, G.S.

1980-02-01

A methodology is described for the evaluation of the collective dose from radioactivity in the terrestrial food chains. It involves the use of an agricultural grid for Great Britain from which the geographical distribution of each of the main cereal, vegetable, fruit and animal products around any given point can be evaluated. A description is given of the procedure by which the grid was assembled. The use of the grid is demonstrated in an example in which the collective doses associated with the milk pathway to man following the routine discharge to air of iodine-131 are compared for two coastal sites in markedly different agricultural regions. (author)

Risk management of smart grids based on managed charging of PHEVs and vehicle-to-grid strategy using Monte Carlo simulation

International Nuclear Information System (INIS)

Hashemi-Dezaki, Hamed; Hamzeh, Mohsen; Askarian-Abyaneh, Hossein; Haeri-Khiavi, Homayoun

2015-01-01

Highlights: • Actual distribution system is used to analyze the proposed methodology. • A novel charging management method for PHEVs has been introduced. • The well-being criteria have been provided in addition to reliability indices. • The uncertainty of results is analyzed in addition to expected average results. • System effects due to charging and penetration level of PHEVs are analyzed. - Abstract: The unmanaged charging of plug-in-hybrid-electric vehicles (PHEVs) may adversely affect electric grid reliability because a large amount of additional electrical energy is required to charge the PHEVs. In this paper, a comprehensive method to evaluate the system reliability concerning the stochastic modeling of PHEVs, renewable resources, availability of devices, etc. is proposed. In addition, a novel risk management method in order to reduce the negative PHEVs effects is introduced. This method, which consists of managed charging and vehicle-to-grid (V2G) scenarios, can be practically implemented in smart grids because the bidirectional-power-conversion technologies and two-way of both the power and data are applicable. The introduced method was applied to a real 20 kV network of the Hormozgan Regional Electric Company (HREC) of Iran which is considered as a pilot system for upgrading to smart distribution grid. The results showed that the smart grid’s adequacy was jeopardized by using the PHEVs without any managed charging schedule. The sensitivity analyses results illustrated that by using the risk management scenarios, not only did the PHEVs not compromise the system reliability, but also in the V2G scenario acted as storage systems and improved the well-being criteria and adequacy indices. The comparison between the results based on the proposed method and the other conventional approaches in addition to study of various parameters uncertainty emphasized the advantages of the proposed method

Grid simulator for power quality assessment of micro-grids

DEFF Research Database (Denmark)

Carrasco, Joaquin Eloy Garcia; Vasquez, Juan Carlos; Guerrero, Josep M.

2013-01-01

voltages, low-order harmonics and flicker. The aim of this equipment is to test the performance of a given system under such distorted voltages. A prototype of the simulator, consisting of two inverters connected back-to-back to a 380 V three-phase grid and feeding a micro-grid composed of two......-inverter interfaced distributed generators and a critical load was built and tested. A set of experimental results for linear purely resistive loads, non-linear loads and current-controlled inverters is presented to prove the capabilities of the simulator. Finally, a case study is presented by testing a micro-grid.......In this study, a grid simulator based on a back-to-back inverter topology with resonant controllers is presented. The simulator is able to generate three-phase voltages for a range of amplitudes and frequencies with different types of perturbations, such as voltage sags, steady-state unbalanced...

Method for Assessing Grid Frequency Deviation Due to Wind Power Fluctuation Based on “Time-Frequency Transformation”

DEFF Research Database (Denmark)

Jin, Lin; Yuan-zhang, Sun; Sørensen, Poul Ejnar

2012-01-01

published studies are based entirely on deterministic methodology. This paper presents a novel assessment method based on Time-Frequency Transformation to overcome shortcomings of existing methods. The main contribution of the paper is to propose a stochastic process simulation model which is a better...... alternative of the existing dynamic frequency deviation simulation model. In this way, the method takes the stochastic wind power fluctuation into full account so as to give a quantitative risk assessment of grid frequency deviation to grid operators, even without using any dynamic simulation tool. The case...

Back-to-back converter control of grid-connected wind turbine to mitigate voltage drop caused by faults

DEFF Research Database (Denmark)

Hassanzadeh, Fattah; Sangrody, Hossein; Hajizadeh, Amin

2017-01-01

Power electronic converters enable wind turbines, operating at variable speed, to generate electricity more efficiently. Among variable speed operating turbine generators, permanent magnetic synchronous generator (PMSG) has got more attentions due to low cost and maintenance requirements...... side converter is designed to improve voltage drop caused by the fault in the grid while maximum available active power of wind turbine system is injected to the grid and the DC link voltage in the converter is regulated. The methodology of the converter control is elaborated in details and its...

Smart grids - French Expertise

International Nuclear Information System (INIS)

2015-11-01

The adaptation of electrical systems is the focus of major work worldwide. Bringing electricity to new territories, modernizing existing electricity grids, implementing energy efficiency policies and deploying renewable energies, developing new uses for electricity, introducing electric vehicles - these are the challenges facing a multitude of regions and countries. Smart Grids are the result of the convergence of electrical systems technologies with information and communications technologies. They play a key role in addressing the above challenges. Smart Grid development is a major priority for both public and private-sector actors in France. The experience of French companies has grown with the current French electricity system, a system that already shows extensive levels of 'intelligence', efficiency and competitiveness. French expertise also leverages substantial competence in terms of 'systems engineering', and can provide a tailored response to meet all sorts of needs. French products and services span all the technical and commercial building blocks that make up the Smart Grid value chain. They address the following issues: Improving the use and valuation of renewable energies and decentralized means of production, by optimizing the balance between generation and consumption. Strengthening the intelligence of the transmission and distribution grids: developing 'Supergrid', digitizing substations in transmission networks, and automating the distribution grids are the focus of a great many projects designed to reinforce the 'self-healing' capacity of the grid. Improving the valuation of decentralized flexibilities: this involves, among others, deploying smart meters, reinforcing active energy efficiency measures, and boosting consumers' contribution to grid balancing, via practices such as demand response which implies the aggregation of flexibility among residential, business, and/or industrial sites. Addressing current technological challenges, in

Power grid complex network evolutions for the smart grid

NARCIS (Netherlands)

Pagani, Giuliano Andrea; Aiello, Marco

2014-01-01

The shift towards an energy grid dominated by prosumers (consumers and producers of energy) will inevitably have repercussions on the electricity distribution infrastructure. Today the grid is a hierarchical one delivering energy from large scale facilities to end-users. Tomorrow it will be a

Utilizing data grid architecture for the backup and recovery of clinical image data.

Science.gov (United States)

Liu, Brent J; Zhou, M Z; Documet, J

2005-01-01

Grid Computing represents the latest and most exciting technology to evolve from the familiar realm of parallel, peer-to-peer and client-server models. However, there has been limited investigation into the impact of this emerging technology in medical imaging and informatics. In particular, PACS technology, an established clinical image repository system, while having matured significantly during the past ten years, still remains weak in the area of clinical image data backup. Current solutions are expensive or time consuming and the technology is far from foolproof. Many large-scale PACS archive systems still encounter downtime for hours or days, which has the critical effect of crippling daily clinical operations. In this paper, a review of current backup solutions will be presented along with a brief introduction to grid technology. Finally, research and development utilizing the grid architecture for the recovery of clinical image data, in particular, PACS image data, will be presented. The focus of this paper is centered on applying a grid computing architecture to a DICOM environment since DICOM has become the standard for clinical image data and PACS utilizes this standard. A federation of PACS can be created allowing a failed PACS archive to recover its image data from others in the federation in a seamless fashion. The design reflects the five-layer architecture of grid computing: Fabric, Resource, Connectivity, Collective, and Application Layers. The testbed Data Grid is composed of one research laboratory and two clinical sites. The Globus 3.0 Toolkit (Co-developed by the Argonne National Laboratory and Information Sciences Institute, USC) for developing the core and user level middleware is utilized to achieve grid connectivity. The successful implementation and evaluation of utilizing data grid architecture for clinical PACS data backup and recovery will provide an understanding of the methodology for using Data Grid in clinical image data backup for

Grid interoperability: the interoperations cookbook

Energy Technology Data Exchange (ETDEWEB)

Field, L; Schulz, M [CERN (Switzerland)], E-mail: Laurence.Field@cern.ch, E-mail: Markus.Schulz@cern.ch

2008-07-01

Over recent years a number of grid projects have emerged which have built grid infrastructures that are now the computing backbones for various user communities. A significant number of these communities are limited to one grid infrastructure due to the different middleware and procedures used in each grid. Grid interoperation is trying to bridge these differences and enable virtual organizations to access resources independent of the grid project affiliation. This paper gives an overview of grid interoperation and describes the current methods used to bridge the differences between grids. Actual use cases encountered during the last three years are discussed and the most important interfaces required for interoperability are highlighted. A summary of the standardisation efforts in these areas is given and we argue for moving more aggressively towards standards.

Grid interoperability: the interoperations cookbook

International Nuclear Information System (INIS)

Field, L; Schulz, M

2008-01-01

Over recent years a number of grid projects have emerged which have built grid infrastructures that are now the computing backbones for various user communities. A significant number of these communities are limited to one grid infrastructure due to the different middleware and procedures used in each grid. Grid interoperation is trying to bridge these differences and enable virtual organizations to access resources independent of the grid project affiliation. This paper gives an overview of grid interoperation and describes the current methods used to bridge the differences between grids. Actual use cases encountered during the last three years are discussed and the most important interfaces required for interoperability are highlighted. A summary of the standardisation efforts in these areas is given and we argue for moving more aggressively towards standards

Calculation approaches for grid usage fees to influence the load curve in the distribution grid level

International Nuclear Information System (INIS)

Illing, Bjoern

2014-01-01

Dominated by the energy policy the decentralized German energy market is changing. One mature target of the government is to increase the contribution of renewable generation to the gross electricity consumption. In order to achieve this target disadvantages like an increased need for capacity management occurs. Load reduction and variable grid fees offer the grid operator solutions to realize capacity management by influencing the load profile. The evolution of the current grid fees towards more causality is required to adapt these approaches. Two calculation approaches are developed in this assignment. On the one hand multivariable grid fees keeping the current components demand and energy charge. Additional to the grid costs grid load dependent parameters like the amount of decentralized feed-ins, time and local circumstances as well as grid capacities are considered. On the other hand the grid fee flat-rate which represents a demand based model on a monthly level. Both approaches are designed to meet the criteria for future grid fees. By means of a case study the effects of the grid fees on the load profile at the low voltage grid is simulated. Thereby the consumption is represented by different behaviour models and the results are scaled at the benchmark grid area. The resulting load curve is analyzed concerning the effects of peak load reduction as well as the integration of renewable energy sources. Additionally the combined effect of grid fees and electricity tariffs is evaluated. Finally the work discusses the launching of grid fees in the tense atmosphere of politics, legislation and grid operation. Results of this work are two calculation approaches designed for grid operators to define the grid fees. Multivariable grid fees are based on the current calculation scheme. Hereby demand and energy charges are weighted by time, locational and load related dependencies. The grid fee flat-rate defines a limitation in demand extraction. Different demand levels

Grid Security

CERN Multimedia

CERN. Geneva

2004-01-01

The aim of Grid computing is to enable the easy and open sharing of resources between large and highly distributed communities of scientists and institutes across many independent administrative domains. Convincing site security officers and computer centre managers to allow this to happen in view of today's ever-increasing Internet security problems is a major challenge. Convincing users and application developers to take security seriously is equally difficult. This paper will describe the main Grid security issues, both in terms of technology and policy, that have been tackled over recent years in LCG and related Grid projects. Achievements to date will be described and opportunities for future improvements will be addressed.

Emissions & Generation Resource Integrated Database (eGRID), eGRID2012

Data.gov (United States)

U.S. Environmental Protection Agency — The Emissions emissions rates; net generation; resource mix; and many other attributes. eGRID2012 Version 1.0 is the eighth edition of eGRID, which contains the...

Analysis of aggregation and disaggregation effects for grid-based hydrological models and the development of improved precipitation disaggregation procedures for GCMs

Directory of Open Access Journals (Sweden)

H. S. Wheater

1999-01-01

Full Text Available Appropriate representation of hydrological processes within atmospheric General Circulation Models (GCMs is important with respect to internal model dynamics (e.g. surface feedback effects on atmospheric fluxes, continental runoff production and to simulation of terrestrial impacts of climate change. However, at the scale of a GCM grid-square, several methodological problems arise. Spatial disaggregation of grid-square average climatological parameters is required in particular to produce appropriate point intensities from average precipitation. Conversely, aggregation of land surface heterogeneity is necessary for grid-scale or catchment scale application. The performance of grid-based hydrological models is evaluated for two large (104km2 UK catchments. Simple schemes, using sub-grid average of individual land use at 40 km scale and with no calibration, perform well at the annual time-scale and, with the addition of a (calibrated routing component, at the daily and monthly time-scale. Decoupling of hillslope and channel routing does not necessarily improve performance or identifiability. Scale dependence is investigated through application of distribution functions for rainfall and soil moisture at 100 km scale. The results depend on climate, but show interdependence of the representation of sub-grid rainfall and soil moisture distribution. Rainfall distribution is analysed directly using radar rainfall data from the UK and the Arkansas Red River, USA. Among other properties, the scale dependence of spatial coverage upon radar pixel resolution and GCM grid-scale, as well as the serial correlation of coverages are investigated. This leads to a revised methodology for GCM application, as a simple extension of current procedures. A new location-based approach using an image processing technique is then presented, to allow for the preservation of the spatial memory of the process.

Analysis of Electric Vehicle Charging Impact on the Electric Power Grid

Energy Technology Data Exchange (ETDEWEB)

Jiang, Zeming [Ming Hsieh Department of Electrical Engineering; Tian, Hao [Ming Hsieh Department of Electrical Engineering; Beshir, Mohammed J. [Ming Hsieh Department of Electrical Engineering; Vohra, Surendra [Los Angeles Department of Water and Power; Mazloomzadeh, Ali [Smart Utility Systems

2016-09-24

In order to evaluate the impact of electric vehicles (EVs) on the distribution grid and assess their potential benefits to the future smart grid, it is crucial to study the EV charging patterns and the usage charging station. Though EVs are not yet widely adopted nationwide, a valuable methodology to conduct such studies is the statistical analysis of real-world charging data. This paper presents actual EV charging behavior of 64 EVs (5 brands, 8 models) from EV users and charging stations at Los Angeles Department of Water and Power for more than one year. Twenty-four-hour EV charging load curves have been generated and studied for various load periods: daily, monthly, seasonally and yearly. Finally, the effect and impact of EV load on the California distribution network are evaluated at different EV penetration rates.

A network approach to decentralized coordination of energy production-consumption grids.

Science.gov (United States)

Omodei, Elisa; Arenas, Alex

2018-01-01

Energy grids are facing a relatively new paradigm consisting in the formation of local distributed energy sources and loads that can operate in parallel independently from the main power grid (usually called microgrids). One of the main challenges in microgrid-like networks management is that of self-adapting to the production and demands in a decentralized coordinated way. Here, we propose a stylized model that allows to analytically predict the coordination of the elements in the network, depending on the network topology. Surprisingly, almost global coordination is attained when users interact locally, with a small neighborhood, instead of the obvious but more costly all-to-all coordination. We compute analytically the optimal value of coordinated users in random homogeneous networks. The methodology proposed opens a new way of confronting the analysis of energy demand-side management in networked systems.

LHC computing grid

International Nuclear Information System (INIS)

Novaes, Sergio

2011-01-01

Full text: We give an overview of the grid computing initiatives in the Americas. High-Energy Physics has played a very important role in the development of grid computing in the world and in Latin America it has not been different. Lately, the grid concept has expanded its reach across all branches of e-Science, and we have witnessed the birth of the first nationwide infrastructures and its use in the private sector. (author)

High density grids

Energy Technology Data Exchange (ETDEWEB)

Cohen, Aina E.; Baxter, Elizabeth L.

2018-01-16

An X-ray data collection grid device is provided that includes a magnetic base that is compatible with robotic sample mounting systems used at synchrotron beamlines, a grid element fixedly attached to the magnetic base, where the grid element includes at least one sealable sample window disposed through a planar synchrotron-compatible material, where the planar synchrotron-compatible material includes at least one automated X-ray positioning and fluid handling robot fiducial mark.

Comparison tomography relocation hypocenter grid search and guided grid search method in Java island

International Nuclear Information System (INIS)

Nurdian, S. W.; Adu, N.; Palupi, I. R.; Raharjo, W.

2016-01-01

The main data in this research is earthquake data recorded from 1952 to 2012 with 9162 P wave and 2426 events are recorded by 30 stations located around Java island. Relocation hypocenter processed using grid search and guidded grid search method. Then the result of relocation hypocenter become input for tomography pseudo bending inversion process. It can be used to identification the velocity distribution in subsurface. The result of relocation hypocenter by grid search and guided grid search method after tomography process shown in locally and globally. In locally area grid search method result is better than guided grid search according to geological reseach area. But in globally area the result of guided grid search method is better for a broad area because the velocity variation is more diverse than the other one and in accordance with local geological research conditions. (paper)

Examining inter-family differences in intra-family (parent-adolescent) dynamics using grid-sequence analysis.

Science.gov (United States)

Brinberg, Miriam; Fosco, Gregory M; Ram, Nilam

2017-12-01

Family systems theorists have forwarded a set of theoretical principles meant to guide family scientists and practitioners in their conceptualization of patterns of family interaction-intra-family dynamics-that, over time, give rise to family and individual dysfunction and/or adaptation. In this article, we present an analytic approach that merges state space grid methods adapted from the dynamic systems literature with sequence analysis methods adapted from molecular biology into a "grid-sequence" method for studying inter-family differences in intra-family dynamics. Using dyadic data from 86 parent-adolescent dyads who provided up to 21 daily reports about connectedness, we illustrate how grid-sequence analysis can be used to identify a typology of intrafamily dynamics and to inform theory about how specific types of intrafamily dynamics contribute to adolescent behavior problems and family members' mental health. Methodologically, grid-sequence analysis extends the toolbox of techniques for analysis of family experience sampling and daily diary data. Substantively, we identify patterns of family level microdynamics that may serve as new markers of risk/protective factors and potential points for intervention in families. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Framing the grid: effect of boundaries on grid cells and navigation.

Science.gov (United States)

Krupic, Julija; Bauza, Marius; Burton, Stephen; O'Keefe, John

2016-11-15

Cells in the mammalian hippocampal formation subserve neuronal representations of environmental location and support navigation in familiar environments. Grid cells constitute one of the main cell types in the hippocampal formation and are widely believed to represent a universal metric of space independent of external stimuli. Recent evidence showing that grid symmetry is distorted in non-symmetrical environments suggests that a re-examination of this hypothesis is warranted. In this review we will discuss behavioural and physiological evidence for how environmental shape and in particular enclosure boundaries influence grid cell firing properties. We propose that grid cells encode the geometric layout of enclosures. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Neural network algorithm for image reconstruction using the grid friendly projections

International Nuclear Information System (INIS)

Cierniak, R.

2011-01-01

Full text: The presented paper describes a development of original approach to the reconstruction problem using a recurrent neural network. Particularly, the 'grid-friendly' angles of performed projections are selected according to the discrete Radon transform (DRT) concept to decrease the number of projections required. The methodology of our approach is consistent with analytical reconstruction algorithms. Reconstruction problem is reformulated in our approach to optimization problem. This problem is solved in present concept using method based on the maximum likelihood methodology. The reconstruction algorithm proposed in this work is consequently adapted for more practical discrete fan beam projections. Computer simulation results show that the neural network reconstruction algorithm designed to work in this way improves obtained results and outperforms conventional methods in reconstructed image quality. (author)

The open science grid

International Nuclear Information System (INIS)

Pordes, R.

2004-01-01

The U.S. LHC Tier-1 and Tier-2 laboratories and universities are developing production Grids to support LHC applications running across a worldwide Grid computing system. Together with partners in computer science, physics grid projects and active experiments, we will build a common national production grid infrastructure which is open in its architecture, implementation and use. The Open Science Grid (OSG) model builds upon the successful approach of last year's joint Grid2003 project. The Grid3 shared infrastructure has for over eight months provided significant computational resources and throughput to a range of applications, including ATLAS and CMS data challenges, SDSS, LIGO, and biology analyses, and computer science demonstrators and experiments. To move towards LHC-scale data management, access and analysis capabilities, we must increase the scale, services, and sustainability of the current infrastructure by an order of magnitude or more. Thus, we must achieve a significant upgrade in its functionalities and technologies. The initial OSG partners will build upon a fully usable, sustainable and robust grid. Initial partners include the US LHC collaborations, DOE and NSF Laboratories and Universities and Trillium Grid projects. The approach is to federate with other application communities in the U.S. to build a shared infrastructure open to other sciences and capable of being modified and improved to respond to needs of other applications, including CDF, D0, BaBar, and RHIC experiments. We describe the application-driven, engineered services of the OSG, short term plans and status, and the roadmap for a consortium, its partnerships and national focus

Porting of Scientific Applications to Grid Computing on GridWay

Directory of Open Access Journals (Sweden)

J. Herrera

2005-01-01

Full Text Available The expansion and adoption of Grid technologies is prevented by the lack of a standard programming paradigm to port existing applications among different environments. The Distributed Resource Management Application API has been proposed to aid the rapid development and distribution of these applications across different Distributed Resource Management Systems. In this paper we describe an implementation of the DRMAA standard on a Globus-based testbed, and show its suitability to express typical scientific applications, like High-Throughput and Master-Worker applications. The DRMAA routines are supported by the functionality offered by the GridWay2 framework, which provides the runtime mechanisms needed for transparently executing jobs on a dynamic Grid environment based on Globus. As cases of study, we consider the implementation with DRMAA of a bioinformatics application, a genetic algorithm and the NAS Grid Benchmarks.

FermiGrid - experience and future plans

International Nuclear Information System (INIS)

Chadwick, K.; Berman, E.; Canal, P.; Hesselroth, T.; Garzoglio, G.; Levshina, T.; Sergeev, V.; Sfiligoi, I.; Timm, S.; Yocum, D.

2007-01-01

Fermilab supports a scientific program that includes experiments and scientists located across the globe. In order to better serve this community, Fermilab has placed its production computer resources in a Campus Grid infrastructure called 'FermiGrid'. The FermiGrid infrastructure allows the large experiments at Fermilab to have priority access to their own resources, enables sharing of these resources in an opportunistic fashion, and movement of work (jobs, data) between the Campus Grid and National Grids such as Open Science Grid and the WLCG. FermiGrid resources support multiple Virtual Organizations (VOs), including VOs from the Open Science Grid (OSG), EGEE and the Worldwide LHC Computing Grid Collaboration (WLCG). Fermilab also makes leading contributions to the Open Science Grid in the areas of accounting, batch computing, grid security, job management, resource selection, site infrastructure, storage management, and VO services. Through the FermiGrid interfaces, authenticated and authorized VOs and individuals may access our core grid services, the 10,000+ Fermilab resident CPUs, near-petabyte (including CMS) online disk pools and the multi-petabyte Fermilab Mass Storage System. These core grid services include a site wide Globus gatekeeper, VO management services for several VOs, Fermilab site authorization services, grid user mapping services, as well as job accounting and monitoring, resource selection and data movement services. Access to these services is via standard and well-supported grid interfaces. We will report on the user experience of using the FermiGrid campus infrastructure interfaced to a national cyberinfrastructure--the successes and the problems

Smart grid in China

DEFF Research Database (Denmark)

Sommer, Simon; Ma, Zheng; Jørgensen, Bo Nørregaard

2015-01-01

China is planning to transform its traditional power grid in favour of a smart grid, since it allows a more economically efficient and a more environmentally friendly transmission and distribution of electricity. Thus, a nationwide smart grid is likely to save tremendous amounts of resources...

A measurement method for micro 3D shape based on grids-processing and stereovision technology

International Nuclear Information System (INIS)

Li, Chuanwei; Xie, Huimin; Liu, Zhanwei

2013-01-01

An integrated measurement method for micro 3D surface shape by a combination of stereovision technology in a scanning electron microscope (SEM) and grids-processing methodology is proposed. The principle of the proposed method is introduced in detail. By capturing two images of the tested specimen with grids on the surface at different tilt angles in an SEM, the 3D surface shape of the specimen can be obtained. Numerical simulation is applied to analyze the feasibility of the proposed method. A validation experiment is performed here. The surface shape of the metal-wire/polymer-membrane structures with thermal deformation is reconstructed. By processing the surface grids of the specimen, the out-of-plane displacement field of the specimen surface is also obtained. Compared with the measurement results obtained by a 3D digital microscope, the experimental error of the proposed method is discussed (paper)

Thermal Management of Battery Systems in EV and Smart Grid Application

DEFF Research Database (Denmark)

Khan, Mohammad Rezwan

The principal outcome of the research is to deliver experimental and modelling framework targeted for both EV and next-generation smart grid application developer. The results of the research assist in providing a correct datasheet for a battery cell. It is a result of an experimental framework t...... methodology, it enables to determine how the current input affects the heat flux generation inside a battery cell and how it is possible to find the key performance indicator (KPI) efficiency....

Decentral Smart Grid Control

Science.gov (United States)

Schäfer, Benjamin; Matthiae, Moritz; Timme, Marc; Witthaut, Dirk

2015-01-01

Stable operation of complex flow and transportation networks requires balanced supply and demand. For the operation of electric power grids—due to their increasing fraction of renewable energy sources—a pressing challenge is to fit the fluctuations in decentralized supply to the distributed and temporally varying demands. To achieve this goal, common smart grid concepts suggest to collect consumer demand data, centrally evaluate them given current supply and send price information back to customers for them to decide about usage. Besides restrictions regarding cyber security, privacy protection and large required investments, it remains unclear how such central smart grid options guarantee overall stability. Here we propose a Decentral Smart Grid Control, where the price is directly linked to the local grid frequency at each customer. The grid frequency provides all necessary information about the current power balance such that it is sufficient to match supply and demand without the need for a centralized IT infrastructure. We analyze the performance and the dynamical stability of the power grid with such a control system. Our results suggest that the proposed Decentral Smart Grid Control is feasible independent of effective measurement delays, if frequencies are averaged over sufficiently large time intervals.

Decentral Smart Grid Control

International Nuclear Information System (INIS)

Schäfer, Benjamin; Matthiae, Moritz; Timme, Marc; Witthaut, Dirk

2015-01-01

Stable operation of complex flow and transportation networks requires balanced supply and demand. For the operation of electric power grids—due to their increasing fraction of renewable energy sources—a pressing challenge is to fit the fluctuations in decentralized supply to the distributed and temporally varying demands. To achieve this goal, common smart grid concepts suggest to collect consumer demand data, centrally evaluate them given current supply and send price information back to customers for them to decide about usage. Besides restrictions regarding cyber security, privacy protection and large required investments, it remains unclear how such central smart grid options guarantee overall stability. Here we propose a Decentral Smart Grid Control, where the price is directly linked to the local grid frequency at each customer. The grid frequency provides all necessary information about the current power balance such that it is sufficient to match supply and demand without the need for a centralized IT infrastructure. We analyze the performance and the dynamical stability of the power grid with such a control system. Our results suggest that the proposed Decentral Smart Grid Control is feasible independent of effective measurement delays, if frequencies are averaged over sufficiently large time intervals. (paper)

QoS Differential Scheduling in Cognitive-Radio-Based Smart Grid Networks: An Adaptive Dynamic Programming Approach.

Science.gov (United States)

Yu, Rong; Zhong, Weifeng; Xie, Shengli; Zhang, Yan; Zhang, Yun

2016-02-01

As the next-generation power grid, smart grid will be integrated with a variety of novel communication technologies to support the explosive data traffic and the diverse requirements of quality of service (QoS). Cognitive radio (CR), which has the favorable ability to improve the spectrum utilization, provides an efficient and reliable solution for smart grid communications networks. In this paper, we study the QoS differential scheduling problem in the CR-based smart grid communications networks. The scheduler is responsible for managing the spectrum resources and arranging the data transmissions of smart grid users (SGUs). To guarantee the differential QoS, the SGUs are assigned to have different priorities according to their roles and their current situations in the smart grid. Based on the QoS-aware priority policy, the scheduler adjusts the channels allocation to minimize the transmission delay of SGUs. The entire transmission scheduling problem is formulated as a semi-Markov decision process and solved by the methodology of adaptive dynamic programming. A heuristic dynamic programming (HDP) architecture is established for the scheduling problem. By the online network training, the HDP can learn from the activities of primary users and SGUs, and adjust the scheduling decision to achieve the purpose of transmission delay minimization. Simulation results illustrate that the proposed priority policy ensures the low transmission delay of high priority SGUs. In addition, the emergency data transmission delay is also reduced to a significantly low level, guaranteeing the differential QoS in smart grid.

A Grid Voltage Measurement Method for Wind Power Systems during Grid Fault Conditions

OpenAIRE

Yoo, Cheol-Hee; Chung, Il-Yop; Yoo, Hyun-Jae; Hong, Sung-Soo

2014-01-01

Grid codes in many countries require low-voltage ride-through (LVRT) capability to maintain power system stability and reliability during grid fault conditions. To meet the LVRT requirement, wind power systems must stay connected to the grid and also supply reactive currents to the grid to support the recovery from fault voltages. This paper presents a new fault detection method and inverter control scheme to improve the LVRT capability for full-scale permanent magnet synchronous generator (P...

Benchmarking of Grid Fault Modes in Single-Phase Grid-Connected Photovoltaic Systems

DEFF Research Database (Denmark)

Yang, Yongheng; Blaabjerg, Frede; Zou, Zhixiang

2013-01-01

Pushed by the booming installations of singlephase photovoltaic (PV) systems, the grid demands regarding the integration of PV systems are expected to be modified. Hence, the future PV systems should become more active with functionalities of Low Voltage Ride-Through (LVRT) and grid support...... phase systems under grid faults. The intent of this paper is to present a benchmarking of grid fault modes that might come in future single-phase PV systems. In order to map future challenges, the relevant synchronization and control strategies are discussed. Some faulty modes are studied experimentally...... and provided at the end of this paper. It is concluded that there are extensive control possibilities in single-phase PV systems under grid faults. The Second Order General Integral based PLL technique might be the most promising candidate for future single-phase PV systems because of its fast adaptive...

Determining Maximum Photovoltaic Penetration in a Distribution Grid considering Grid Operation Limits

DEFF Research Database (Denmark)

Kordheili, Reza Ahmadi; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

2014-01-01

High penetration of photovoltaic panels in distribution grid can bring the grid to its operation limits. The main focus of the paper is to determine maximum photovoltaic penetration level in the grid. Three main criteria were investigated for determining maximum penetration level of PV panels...... for this grid: even distribution of PV panels, aggregation of panels at the beginning of each feeder, and aggregation of panels at the end of each feeder. Load modeling is done using Velander formula. Since PV generation is highest in the summer due to irradiation, a summer day was chosen to determine maximum......; maximum voltage deviation of customers, cables current limits, and transformer nominal value. Voltage deviation of different buses was investigated for different penetration levels. The proposed model was simulated on a Danish distribution grid. Three different PV location scenarios were investigated...

Study of the integration of distributed generation systems in the grid: application in micro-grids

International Nuclear Information System (INIS)

Gaztanaga Arantzamendi, H.

2006-12-01

The present PhD deals with an original micro-grid concept and its application as a Renewable Energy Source's (RES) grid integration scheme. This micro-grid is composed of RES generators as well as support systems that incorporate additional functionalities in order to improve RES integration into the grid. According to this concept, two practical micro-grid applications have been studied in detail: a residential micro-grid and a wind farm supported by DFACTS systems (STATCOM and DVR). In both applications, the control structures which are implemented at different levels and applied to the different micro-grid elements have been developed, analyzed by means of off-line simulations and finally validated in real-time conditions with physical reduced-scale prototypes. (author)

Cosmos++: relativistic magnetohydrodynamics on unstructured grids with local adaptive refinement

International Nuclear Information System (INIS)

Salmonson, Jay D; Anninos, Peter; Fragile, P Chris; Camarda, Karen

2007-01-01

A code and methodology are introduced for solving the fully general relativistic magnetohydrodynamic (GRMHD) equations using time-explicit, finite-volume discretization. The code has options for solving the GRMHD equations using traditional artificial-viscosity (AV) or non-oscillatory central difference (NOCD) methods, or a new extended AV (eAV) scheme using artificial-viscosity together with a dual energy-flux-conserving formulation. The dual energy approach allows for accurate modeling of highly relativistic flows at boost factors well beyond what has been achieved to date by standard artificial viscosity methods. It provides the benefit of Godunov methods in capturing high Lorentz boosted flows but without complicated Riemann solvers, and the advantages of traditional artificial viscosity methods in their speed and flexibility. Additionally, the GRMHD equations are solved on an unstructured grid that supports local adaptive mesh refinement using a fully threaded oct-tree (in three dimensions) network to traverse the grid hierarchy across levels and immediate neighbors. Some recent studies will be summarized

FermiGrid-experience and future plans

International Nuclear Information System (INIS)

Chadwick, K; Berman, E; Canal, P; Hesselroth, T; Garzoglio, G; Levshina, T; Sergeev, V; Sfiligoi, I; Sharma, N; Timm, S; Yocum, D R

2008-01-01

Fermilab supports a scientific program that includes experiments and scientists located across the globe. In order to better serve this community, Fermilab has placed its production computer resources in a Campus Grid infrastructure called 'FermiGrid'. The FermiGrid infrastructure allows the large experiments at Fermilab to have priority access to their own resources, enables sharing of these resources in an opportunistic fashion, and movement of work (jobs, data) between the Campus Grid and National Grids such as Open Science Grid (OSG) and the Worldwide LHC Computing Grid Collaboration (WLCG). FermiGrid resources support multiple Virtual Organizations (VOs), including VOs from the OSG, EGEE, and the WLCG. Fermilab also makes leading contributions to the Open Science Grid in the areas of accounting, batch computing, grid security, job management, resource selection, site infrastructure, storage management, and VO services. Through the FermiGrid interfaces, authenticated and authorized VOs and individuals may access our core grid services, the 10,000+ Fermilab resident CPUs, near-petabyte (including CMS) online disk pools and the multi-petabyte Fermilab Mass Storage System. These core grid services include a site wide Globus gatekeeper, VO management services for several VOs, Fermilab site authorization services, grid user mapping services, as well as job accounting and monitoring, resource selection and data movement services. Access to these services is via standard and well-supported grid interfaces. We will report on the user experience of using the FermiGrid campus infrastructure interfaced to a national cyberinfrastructure - the successes and the problems

A comparative analysis of dynamic grids vs. virtual grids using the A3pviGrid framework.

Science.gov (United States)

Shankaranarayanan, Avinas; Amaldas, Christine

2010-11-01

With the proliferation of Quad/Multi-core micro-processors in mainstream platforms such as desktops and workstations; a large number of unused CPU cycles can be utilized for running virtual machines (VMs) as dynamic nodes in distributed environments. Grid services and its service oriented business broker now termed cloud computing could deploy image based virtualization platforms enabling agent based resource management and dynamic fault management. In this paper we present an efficient way of utilizing heterogeneous virtual machines on idle desktops as an environment for consumption of high performance grid services. Spurious and exponential increases in the size of the datasets are constant concerns in medical and pharmaceutical industries due to the constant discovery and publication of large sequence databases. Traditional algorithms are not modeled at handing large data sizes under sudden and dynamic changes in the execution environment as previously discussed. This research was undertaken to compare our previous results with running the same test dataset with that of a virtual Grid platform using virtual machines (Virtualization). The implemented architecture, A3pviGrid utilizes game theoretic optimization and agent based team formation (Coalition) algorithms to improve upon scalability with respect to team formation. Due to the dynamic nature of distributed systems (as discussed in our previous work) all interactions were made local within a team transparently. This paper is a proof of concept of an experimental mini-Grid test-bed compared to running the platform on local virtual machines on a local test cluster. This was done to give every agent its own execution platform enabling anonymity and better control of the dynamic environmental parameters. We also analyze performance and scalability of Blast in a multiple virtual node setup and present our findings. This paper is an extension of our previous research on improving the BLAST application framework

Desktop grid computing

CERN Document Server

Cerin, Christophe

2012-01-01

Desktop Grid Computing presents common techniques used in numerous models, algorithms, and tools developed during the last decade to implement desktop grid computing. These techniques enable the solution of many important sub-problems for middleware design, including scheduling, data management, security, load balancing, result certification, and fault tolerance. The book's first part covers the initial ideas and basic concepts of desktop grid computing. The second part explores challenging current and future problems. Each chapter presents the sub-problems, discusses theoretical and practical

Mini-grid Policy Tool-kit. Policy and business frameworks for successful mini-grid roll-outs

International Nuclear Information System (INIS)

Franz, Michael; Hayek, Niklas; Peterschmidt, Nico; Rohrer, Michael; Kondev, Bozhil; Adib, Rana; Cader, Catherina; Carter, Andrew; George, Peter; Gichungi, Henry; Hankins, Mark; Kappiah, Mahama; Mangwengwende, Simbarashe E.

2014-01-01

The Mini-grid Policy Tool-kit is for policy makers to navigate the mini-grid policy design process. It contains information on mini-grid operator models, the economics of mini-grids, and necessary policy and regulation that must be considered for successful implementation. The publication specifically focuses on Africa. Progress on extending the electricity grid in many countries has remained slow because of high costs of gird-extension and limited utility/state budgets for electrification. Mini-grids provide an affordable and cost-effective option to extend needed electricity services. Putting in place the right policy for min-grid deployment requires considerable effort but can yield significant improvement in electricity access rates as examples from Kenya, Senegal and Tanzania illustrate. The tool-kit is available in English, French and Portuguese

Smart grid communication-enabled intelligence for the electric power grid

CERN Document Server

Bush, Stephen F

2014-01-01

This book bridges the divide between the fields of power systems engineering and computer communication through the new field of power system information theory. Written by an expert with vast experience in the field, this book explores the smart grid from generation to consumption, both as it is planned today and how it will evolve tomorrow. The book focuses upon what differentiates the smart grid from the ""traditional"" power grid as it has been known for the last century. Furthermore, the author provides the reader with a fundamental understanding of both power systems and communication ne

Challenges facing production grids

Energy Technology Data Exchange (ETDEWEB)

Pordes, Ruth; /Fermilab

2007-06-01

Today's global communities of users expect quality of service from distributed Grid systems equivalent to that their local data centers. This must be coupled to ubiquitous access to the ensemble of processing and storage resources across multiple Grid infrastructures. We are still facing significant challenges in meeting these expectations, especially in the underlying security, a sustainable and successful economic model, and smoothing the boundaries between administrative and technical domains. Using the Open Science Grid as an example, I examine the status and challenges of Grids operating in production today.

Computational fluid dynamics for propulsion technology: Geometric grid visualization in CFD-based propulsion technology research

Science.gov (United States)

Ziebarth, John P.; Meyer, Doug

1992-01-01

The coordination is examined of necessary resources, facilities, and special personnel to provide technical integration activities in the area of computational fluid dynamics applied to propulsion technology. Involved is the coordination of CFD activities between government, industry, and universities. Current geometry modeling, grid generation, and graphical methods are established to use in the analysis of CFD design methodologies.

Online grid impedance estimation for single-phase grid-connected systems using PQ variations

DEFF Research Database (Denmark)

Ciobotaru, Mihai; Teodorescu, Remus; Rodriguez, Pedro

2007-01-01

algorithms are used in order to estimate the value of the grid impedance. The online grid impedance estimation method can be used for compliance with the anti-islanding standard requirements (IEEE1574, IEEE929 and VDE0126) and for adaptive control of the grid-connected converters. The proposed method...

The Benefits of Grid Networks

Science.gov (United States)

Tennant, Roy

2005-01-01

In the article, the author talks about the benefits of grid networks. In speaking of grid networks the author is referring to both networks of computers and networks of humans connected together in a grid topology. Examples are provided of how grid networks are beneficial today and the ways in which they have been used.

Energy revolution and citizens' protests. A study of the communication of citizens' initiatives concerning grid expension; Energiewende und Buergerproteste. Eine Untersuchung der Kommunikation von Buergerinitiativen im Themenfeld Netzausbau

Energy Technology Data Exchange (ETDEWEB)

Braeuer, Marco

2017-08-01

The extension of the German high voltage power grid has recently caused intense resistance in the affected regions. Publicly visible protests are mainly organised by citizen action groups. These groups act from the position of the periphery of the political system. Hence, they need to communicate their concerns and aims in order to influence the political and administrative decision-making system. In general they have the option to gain access to the mass media agenda. In addition protest groups can also create own media products (from leaflets to social media represenations). The theoretical points of departure of this study are social movement theories and the theory of the public sphere. An inclusive theoretical model, explaining the choice of protest repertories by citizen action groups, is developed. Furthermore, eight comprehensive case studies of citizen action groups in the conflict field of the extension of the German high voltage power grid were conducted. The results of the case studies reveal that the citizen action groups act strategically. They observe and assess the political and mass-mediated discourses and respectively develop their own frames. Although critical and sceptical towards the institutional practices and the actions of political representatives, the political system is perceived as legitimate and remains the main addressee. In addition, the mass media system is in general accepted, even though a (at least partially deliberate) negative bias and sometimes oven hostility against their own position is perceived. The creation of alternative media products is not a mere reaction with regard to the perceived mass media bias. It can be better understood as a result of the integration of the protest groups in local and regional communication structures (neighbourhoods, hobby networks, professional networks etc.). The study closes with recommendations for the improvement of consultation processes in the field of infrastructure protests.

Power grids

International Nuclear Information System (INIS)

Viterbo, J.

2012-01-01

The implementation of renewable energies represents new challenges for electrical systems. The objective: making power grids smarter so they can handle intermittent production. The advent of smart grids will allow flexible operations like distributing energy in a multidirectional manner instead of just one way and it will make electrical systems capable of integrating actions by different users, consumers and producers in order to maintain efficient, sustainable, economical and secure power supplies. Practically speaking, they associate sensors, instrumentation and controls with information processing and communication systems in order to create massively automated networks. Smart grids require huge investments: for example more than 7 billion dollars have been invested in China and in the Usa in 2010 and France is ranked 9. worldwide with 265 million dollars invested. It is expected that smart grids will promote the development of new business models and a change in the value chain for energy. Decentralized production combined with the probable introduction of more or less flexible rates for sales or purchases and of new supplier-customer relationships will open the way to the creation of new businesses. (A.C.)

Recent trends in grid computing

International Nuclear Information System (INIS)

Miura, Kenichi

2004-01-01

Grid computing is a technology which allows uniform and transparent access to geographically dispersed computational resources, such as computers, databases, experimental and observational equipment etc. via high-speed, high-bandwidth networking. The commonly used analogy is that of electrical power grid, whereby the household electricity is made available from outlets on the wall, and little thought need to be given to where the electricity is generated and how it is transmitted. The usage of grid also includes distributed parallel computing, high through-put computing, data intensive computing (data grid) and collaborative computing. This paper reviews the historical background, software structure, current status and on-going grid projects, including applications of grid technology to nuclear fusion research. (author)

GRID and FMPhI-UNIBA

International Nuclear Information System (INIS)

Babik, M.; Daranyi, T.; Fekete, V.; Stavina, P.; Zagiba, M.; Zenis, T.

2008-01-01

The word GRID has several meanings, so it is not an abbreviation. All of them have in common description of GRID as a form of hardware and software and software solution for distributive computing. Additionally, word GRID is also used for distributive computing of many computers and not one super computer with several processors. It, of course, does not mean that such a supercomputer cannot be a part of the GRID. Typical task for GRID is computer programs execution and to data storage. (Authors)

Probabilistic Learning by Rodent Grid Cells.

Science.gov (United States)

Cheung, Allen

2016-10-01

Mounting evidence shows mammalian brains are probabilistic computers, but the specific cells involved remain elusive. Parallel research suggests that grid cells of the mammalian hippocampal formation are fundamental to spatial cognition but their diverse response properties still defy explanation. No plausible model exists which explains stable grids in darkness for twenty minutes or longer, despite being one of the first results ever published on grid cells. Similarly, no current explanation can tie together grid fragmentation and grid rescaling, which show very different forms of flexibility in grid responses when the environment is varied. Other properties such as attractor dynamics and grid anisotropy seem to be at odds with one another unless additional properties are assumed such as a varying velocity gain. Modelling efforts have largely ignored the breadth of response patterns, while also failing to account for the disastrous effects of sensory noise during spatial learning and recall, especially in darkness. Here, published electrophysiological evidence from a range of experiments are reinterpreted using a novel probabilistic learning model, which shows that grid cell responses are accurately predicted by a probabilistic learning process. Diverse response properties of probabilistic grid cells are statistically indistinguishable from rat grid cells across key manipulations. A simple coherent set of probabilistic computations explains stable grid fields in darkness, partial grid rescaling in resized arenas, low-dimensional attractor grid cell dynamics, and grid fragmentation in hairpin mazes. The same computations also reconcile oscillatory dynamics at the single cell level with attractor dynamics at the cell ensemble level. Additionally, a clear functional role for boundary cells is proposed for spatial learning. These findings provide a parsimonious and unified explanation of grid cell function, and implicate grid cells as an accessible neuronal population

A Theorem on Grid Access Control

Institute of Scientific and Technical Information of China (English)

XU ZhiWei(徐志伟); BU GuanYing(卜冠英)

2003-01-01

The current grid security research is mainly focused on the authentication of grid systems. A problem to be solved by grid systems is to ensure consistent access control. This problem is complicated because the hosts in a grid computing environment usually span multiple autonomous administrative domains. This paper presents a grid access control model, based on asynchronous automata theory and the classic Bell-LaPadula model. This model is useful to formally study the confidentiality and integrity problems in a grid computing environment. A theorem is proved, which gives the necessary and sufficient conditions to a grid to maintain confidentiality.These conditions are the formalized descriptions of local (node) relations or relationship between grid subjects and node subjects.

Transmission grid security

CERN Document Server

Haarla, Liisa; Hirvonen, Ritva; Labeau, Pierre-Etienne

2011-01-01

In response to the growing importance of power system security and reliability, ""Transmission Grid Security"" proposes a systematic and probabilistic approach for transmission grid security analysis. The analysis presented uses probabilistic safety assessment (PSA) and takes into account the power system dynamics after severe faults. In the method shown in this book the power system states (stable, not stable, system breakdown, etc.) are connected with the substation reliability model. In this way it is possible to: estimate the system-wide consequences of grid faults; identify a chain of eve

Pyramid solar micro-grid

Science.gov (United States)

Huang, Bin-Juine; Hsu, Po-Chien; Wang, Yi-Hung; Tang, Tzu-Chiao; Wang, Jia-Wei; Dong, Xin-Hong; Hsu, Hsin-Yi; Li, Kang; Lee, Kung-Yen

2018-03-01

A novel pyramid solar micro-grid is proposed in the present study. All the members within the micro-grid can mutually share excess solar PV power each other through a binary-connection hierarchy. The test results of a 2+2 pyramid solar micro-grid consisting of 4 individual solar PV systems for self-consumption are reported.

Smart Solar Grid. Integration of high penetration of photovoltaic in municipal low voltage distribution grids; Smart Solar Grid. Integration hoher Anteile von Photovoltaik in kommunalen Niederspannungsverteilnetzen

Energy Technology Data Exchange (ETDEWEB)

Ruf, Holger; Heilscher, Gerd [Hochschule Ulm (Germany); Meier, Florian [SWU Netze GmbH, Ulm (Germany)

2012-07-01

The high rate of decentralized generation in low voltage grids especially photovoltaic (PV) put the distribution grid operators to new challenges. Grid operation and grid planning have to respect the volatility and dynamic of decentralized generation now and in the future and adapt their previous proceedings. In the frame of the project Smart Solar Grid was a test site defined in the grid area of the DSO Stadtwerke Ulm/Neu-Ulm GmbH (SWU) to analyze the impact of the PV rise and possible solutions for the grid planning in the future. The first analysis based upon secondly measurements of the first test site. From this were statistical evaluation of the load flows and power variations done. Furthermore were the roof potential analysis results of the test site validated. These data are the base for the development of a forecast system for grid condition parameter. (orig.)

Scaling Up Renewable Energy Generation: Aligning Targets and Incentives with Grid Integration Considerations, Greening The Grid

Energy Technology Data Exchange (ETDEWEB)

Katz, Jessica; Cochran, Jaquelin

2015-05-27

Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid. This document, part of a Greening the Grid toolkit, provides power system planners with tips to help secure and sustain investment in new renewable energy generation by aligning renewable energy policy targets and incentives with grid integration considerations.

Robust Multi-Objective PQ Scheduling for Electric Vehicles in Flexible Unbalanced Distribution Grids

DEFF Research Database (Denmark)

Knezovic, Katarina; Soroudi, Alireza; Marinelli, Mattia

2017-01-01

With increased penetration of distributed energy resources and electric vehicles (EVs), different EV management strategies can be used for mitigating adverse effects and supporting the distribution grid. This paper proposes a robust multi-objective methodology for determining the optimal day...... demand response programs. The method is tested on a real Danish unbalanced distribution grid with 35% EV penetration to demonstrate the effectiveness of the proposed approach. It is shown that the proposed formulation guarantees an optimal EV cost as long as the price uncertainties are lower than....... The robust formulation effectively considers the errors in the electricity price forecast and its influence on the EV schedule. Moreover, the impact of EV reactive power support on objective values and technical parameters is analysed both when EVs are the only flexible resources and when linked with other...

Neural Model with Particle Swarm Optimization Kalman Learning for Forecasting in Smart Grids

Directory of Open Access Journals (Sweden)

Alma Y. Alanis

2013-01-01

Full Text Available This paper discusses a novel training algorithm for a neural network architecture applied to time series prediction with smart grids applications. The proposed training algorithm is based on an extended Kalman filter (EKF improved using particle swarm optimization (PSO to compute the design parameters. The EKF-PSO-based algorithm is employed to update the synaptic weights of the neural network. The size of the regression vector is determined by means of the Cao methodology. The proposed structure captures more efficiently the complex nature of the wind speed, energy generation, and electrical load demand time series that are constantly monitorated in a smart grid benchmark. The proposed model is trained and tested using real data values in order to show the applicability of the proposed scheme.

Impact of Considering 110 kV Grid Structures on the Congestion Management in the German Transmission Grid

Science.gov (United States)

Hoffrichter, André; Barrios, Hans; Massmann, Janek; Venkataramanachar, Bhavasagar; Schnettler, Armin

2018-02-01

The structural changes in the European energy system lead to an increase of renewable energy sources that are primarily connected to the distribution grid. Hence the stationary analysis of the transmission grid and the regionalization of generation capacities are strongly influenced by subordinate grid structures. To quantify the impact on the congestion management in the German transmission grid, a 110 kV grid model is derived using publicly available data delivered by Open Street Map and integrated into an existing model of the European transmission grid. Power flow and redispatch simulations are performed for three different regionalization methods and grid configurations. The results show a significant impact of the 110 kV system and prove an overestimation of power flows in the transmission grid when neglecting subordinate grids. Thus, the redispatch volume in Germany to dissolve bottlenecks in case of N-1 contingencies decreases by 38 % when considering the 110 kV grid.

Stability of Grid-Connected PV Inverters with Large Grid Impedance Variation

DEFF Research Database (Denmark)

Liserre, Marco; Teodorescu, Remus; Blaabjerg, Frede

2004-01-01

Photovoltaic (PV) inverters used in dispersed power generation of houses in the range of 1-5 kW are currently available from several manufactures. However, large grid impedance variation is challenging the control and the grid filter design in terms of stability. In fact the PV systems are well...... suited for loads connected in a great distance to the transformer (long wires) and the situation becomes even more difficult in low-developed remote areas characterized by low power transformers and long distribution wires with high grid impedance. Hence a theoretical analysis is needed because the grid...... impedance variation leads to dynamic and stability problems both in the low frequency range (around the current controller bandwidth frequency) as well as in the high frequency range (around the LCL-filter resonance frequency). In the low frequency range the possible variation of the impedance challenges...

TIGER: Turbomachinery interactive grid generation

Science.gov (United States)

Soni, Bharat K.; Shih, Ming-Hsin; Janus, J. Mark

1992-01-01

A three dimensional, interactive grid generation code, TIGER, is being developed for analysis of flows around ducted or unducted propellers. TIGER is a customized grid generator that combines new technology with methods from general grid generation codes. The code generates multiple block, structured grids around multiple blade rows with a hub and shroud for either C grid or H grid topologies. The code is intended for use with a Euler/Navier-Stokes solver also being developed, but is general enough for use with other flow solvers. TIGER features a silicon graphics interactive graphics environment that displays a pop-up window, graphics window, and text window. The geometry is read as a discrete set of points with options for several industrial standard formats and NASA standard formats. Various splines are available for defining the surface geometries. Grid generation is done either interactively or through a batch mode operation using history files from a previously generated grid. The batch mode operation can be done either with a graphical display of the interactive session or with no graphics so that the code can be run on another computer system. Run time can be significantly reduced by running on a Cray-YMP.

New grid-planning and certification approaches for the large-scale offshore-wind farm grid-connection systems

Energy Technology Data Exchange (ETDEWEB)

Heising, C.; Bartelt, R. [Avasition GmbH, Dortmund (Germany); Zadeh, M. Koochack; Lebioda, T.J.; Jung, J. [TenneT Offshore GmbH, Bayreuth (Germany)

2012-07-01

Stable operation of the offshore-wind farms (OWF) and stable grid connection under stationary and dynamic conditions are essential to achieve a stable public power supply. To reach this aim, adequate grid-planning and certification approaches are a major advantage. Within this paper, the fundamental characteristics of the offshore-wind farms and their grid-connection systems are given. The main goal of this research project is to study the stability of the offshore grid especially in terms of subharmonic stability for the likely future extension stage of the offshore grids i.e. having parallel connection of two or more HVDC links and for certain operating scenarios e.g. overload scenario. The current requirements according to the grid code are not the focus of this research project. The goal is to study and define potential additional grid code requirements, simulations, tests and grid planning methods for the future. (orig.)

Online Grid Measurement and ENS Detection for PV Inverter Running on Highly Inductive Grid

DEFF Research Database (Denmark)

Timbus, Adrian Vasile; Teodorescu, Remus; Blaabjerg, Frede

2004-01-01

Photovoltaic (PV) and other sources of renewable energy are being used increasingly in grid-connected systems, for which stronger power quality requirements are being issued. Continuous grid monitoring should be considered so as to provide safe connections and disconnections from the grid...

NetJobs: A new approach to network monitoring for the Grid using Grid jobs

OpenAIRE

Pagano, Alfredo

2011-01-01

With grid computing, the far-fl�ung and disparate IT resources act as a single "virtual datacenter". Grid computing interfaces heterogeneous IT resources so they are available when and where we need them. Grid allows us to provision applications and allocate capacity among research and business groups that are geographically and organizationally dispersed. Building a high availability Grid is hold as the next goal to achieve: protecting against computer failures and site failures to avoid dow...

Wireless Communications in Smart Grid

Science.gov (United States)

Bojkovic, Zoran; Bakmaz, Bojan

Communication networks play a crucial role in smart grid, as the intelligence of this complex system is built based on information exchange across the power grid. Wireless communications and networking are among the most economical ways to build the essential part of the scalable communication infrastructure for smart grid. In particular, wireless networks will be deployed widely in the smart grid for automatic meter reading, remote system and customer site monitoring, as well as equipment fault diagnosing. With an increasing interest from both the academic and industrial communities, this chapter systematically investigates recent advances in wireless communication technology for the smart grid.

Fuel Cell Backup Power System for Grid Service and Micro-Grid in Telecommunication Applications: Preprint

Energy Technology Data Exchange (ETDEWEB)

Ma, Zhiwen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eichman, Joshua D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kurtz, Jennifer M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-03-22

This paper presents the feasibility and economics of using fuel cell backup power systems in telecommunication cell towers to provide grid services (e.g., ancillary services, demand response). The fuel cells are able to provide power for the cell tower during emergency conditions. This study evaluates the strategic integration of clean, efficient, and reliable fuel cell systems with the grid for improved economic benefits. The backup systems have potential as enhanced capability through information exchanges with the power grid to add value as grid services that depend on location and time. The economic analysis has been focused on the potential revenue for distributed telecommunications fuel cell backup units to provide value-added power supply. This paper shows case studies on current fuel cell backup power locations and regional grid service programs. The grid service benefits and system configurations for different operation modes provide opportunities for expanding backup fuel cell applications responsive to grid needs.

THE STRATEGIST THOUGHT: GRANTED FACTORS IN THE STRATEGIC DECISION MAKING OF THE SMALL AND MEDIUM ENTERPRISES DOI: 10.5585/riae.v8i2.1641

Directory of Open Access Journals (Sweden)

Werner Duarte Dalla

2009-12-01

Full Text Available The organizational behavior is linked to the strategic decision-making, carried through its main decision-makers, called "strategists". This behavior, in organizational daily actions or planning, shifts its performance to consider market and tangible and intangible resources. The present study aimed to contribute in the understanding of how these actors formulate their strategies, build their heuristics, to manage their firms to improve organizational performance. The RepGrid - Repertory Grid (Kelly, 1955 was chosen as the method, which was undertaken with the Small and Medium Enterprises (SMEs owners of the footwear area of a relevant cluster production of Nova Serrana-MG - Brazil. The results appointed agent factors of attention, which centralize the decision in the managers or owners, base on financial results, asses actual internal factors so that external sales, and lead to a emergent and less formalized process.

Probabilistic methods in grid planning ''low voltage''; Probabilistische Methoden in der Netzplanung ''Niederspannung''

Energy Technology Data Exchange (ETDEWEB)

Schmidtner, Theo [LEW Verteilnetz GmbH, Augsburg (Germany)

2012-07-01

With the penetration of the grids with renewable energy sources, approaches for planning based on standardized customer behavior run to their limits. In addition to the energy supply based on profiles at the network nodes, additional power requirements must be considered (photovoltaic power, micro-CHP, controlled hot water preparation, E-Mobility memory, etc.). The consequence of this is, that the grid requirements are to determine for each grid node individually. These tasks could be accompolished by probabilistic methods. This methodology is emerging over discrete process by the following results. Unlike discrete methods, not only the possible operation points of a subnetwork are determined, but also the probability of occurrence will be calculated. (orig.)

The DataGrid Project

CERN Document Server

Ruggieri, F

2001-01-01

An overview of the objectives and status of the DataGrid Project is presented, together with a brief introduction to the Grid metaphor and some references to the Grid activities and initiatives related to DataGrid. High energy physics experiments have always requested state of the art computing facilities to efficiently perform several computing activities related with the handling of large amounts of data and fairly large computing resources. Some of the ideas born inside the community to enhance the user friendliness of all the steps in the computing chain have been, sometimes, successfully applied also in other contexts: one bright example is the World Wide Web. The LHC computing challenge has triggered inside the high energy physics community, the start of the DataGrid Project. The objective of the project is to enable next generation scientific exploration requiring intensive computation and analysis of shared large-scale databases. (12 refs).

gCube Grid services

CERN Document Server

Andrade, Pedro

2008-01-01

gCube is a service-based framework for eScience applications requiring collaboratory, on-demand, and intensive information processing. It provides to these communities Virtual Research Environments (VREs) to support their activities. gCube is build on top of standard technologies for computational Grids, namely the gLite middleware. The software was produced by the DILIGENT project and will continue to be supported and further developed by the D4Science project. gCube reflects within its name a three-sided interpretation of the Grid vision of resource sharing: sharing of computational resources, sharing of structured data, and sharing of application services. As such, gCube embodies the defining characteristics of computational Grids, data Grids, and virtual data Grids. Precisely, it builds on gLite middleware for managing distributed computations and unstructured data, includes dedicated services for managing data and metadata, provides services for distributed information retrieval, allows the orchestration...

Research on wind power grid-connected operation and dispatching strategies of Liaoning power grid

Science.gov (United States)

Han, Qiu; Qu, Zhi; Zhou, Zhi; He, Xiaoyang; Li, Tie; Jin, Xiaoming; Li, Jinze; Ling, Zhaowei

2018-02-01

As a kind of clean energy, wind power has gained rapid development in recent years. Liaoning Province has abundant wind resources and the total installed capacity of wind power is in the forefront. With the large-scale wind power grid-connected operation, the contradiction between wind power utilization and peak load regulation of power grid has been more prominent. To this point, starting with the power structure and power grid installation situation of Liaoning power grid, the distribution and the space-time output characteristics of wind farm, the prediction accuracy, the curtailment and the off-grid situation of wind power are analyzed. Based on the deep analysis of the seasonal characteristics of power network load, the composition and distribution of main load are presented. Aiming at the problem between the acceptance of wind power and power grid adjustment, the scheduling strategies are given, including unit maintenance scheduling, spinning reserve, energy storage equipment settings by the analysis of the operation characteristics and the response time of thermal power units and hydroelectric units, which can meet the demand of wind power acceptance and provide a solution to improve the level of power grid dispatching.

Grid cut-off-effect

International Nuclear Information System (INIS)

Fischer, U.; Vosshenrich, R.; Grabbe, E.

1992-01-01

Tilting of a grid during portable radiography leads to uneven exposures, and errors greater than 3 0 can lead to errors in interpretation. Differentiation from abnormal findings can be made by recognising exposure difference of extrathoracic comparable areas. The difficulties caused by tilting of the grid can be reduced by increasing the film focus distance and by using suitable grids. A new cassette holder with an integrated balance makes it possible to correct tilting of the grid rapidly and effectively. This results in improved image quality which can be applied not only to conventional exposure systems but is also of advantage when using digital methods. (orig.) [de

Gridded Data in the Arctic; Benefits and Perils of Publicly Available Grids

Science.gov (United States)

Coakley, B.; Forsberg, R.; Gabbert, R.; Beale, J.; Kenyon, S. C.

2015-12-01

Our understanding of the Arctic Ocean has been hugely advanced by release of gridded bathymetry and potential field anomaly grids. The Arctic Gravity Project grid achieves excellent, near-isotropic coverage of the earth north of 64˚N by combining land, satellite, airborne, submarine, surface ship and ice set-out measurements of gravity anomalies. Since the release of the V 2.0 grid in 2008, there has been extensive icebreaker activity across the Amerasia Basin due to mapping of the Arctic coastal nation's Extended Continental Shelves (ECS). While grid resolution has been steadily improving over time, addition of higher resolution and better navigated data highlights some distortions in the grid that may influence interpretation. In addition to the new ECS data sets, gravity anomaly data has been collected from other vessels; notably the Korean Icebreaker Araon, the Japanese icebreaker Mirai and the German icebreaker Polarstern. Also the GRAV-D project of the US National Geodetic Survey has flown airborne surveys over much of Alaska. These data will be Included in the new AGP grid, which will result in a much improved product when version 3.0 is released in 2015. To make use of these measurements, it is necessary to compile them into a continuous spatial representation. Compilation is complicated by differences in survey parameters, gravimeter sensitivity and reduction methods. Cross-over errors are the classic means to assess repeatability of track measurements. Prior to the introduction of near-universal GPS positioning, positional uncertainty was evaluated by cross-over analysis. GPS positions can be treated as more or less true, enabling evaluation of differences due to contrasting sensitivity, reference and reduction techniques. For the most part, cross-over errors for racks of gravity anomaly data collected since 2008 are less than 0.5 mGals, supporting the compilation of these data with only slight adjustments. Given the different platforms used for various

Optimizing solar-cell grid geometry

Science.gov (United States)

Crossley, A. P.

1969-01-01

Trade-off analysis and mathematical expressions calculate optimum grid geometry in terms of various cell parameters. Determination of the grid geometry provides proper balance between grid resistance and cell output to optimize the energy conversion process.

Communication and Networking in Smart Grids

CERN Document Server

Xiao, Yang

2012-01-01

Appropriate for researchers, practitioners, and students alike, Communication and Networking in Smart Grids presents state-of-the-art approaches and novel technologies for communication networks in smart grids. It explains how contemporary grid networks are developed and deployed and presents a collection of cutting-edge advances to help improve current practice. Prominent researchers working on smart grids and in related fields around the world explain the fundamental aspects and applications of smart grids. Describing the role that communication and networking will play in future smart grids

The play grid

DEFF Research Database (Denmark)

Fogh, Rune; Johansen, Asger

2013-01-01

In this paper we propose The Play Grid, a model for systemizing different play types. The approach is psychological by nature and the actual Play Grid is based, therefore, on two pairs of fundamental and widely acknowledged distinguishing characteristics of the ego, namely: extraversion vs. intro...

Synchronization of grid-connected renewable energy sources under highly distorted voltages and unbalanced grid faults

DEFF Research Database (Denmark)

Hadjidemetriou, Lenos; Kyriakides, Elias; Blaabjerg, Frede

2013-01-01

Renewable energy sources require accurate and appropriate performance not only under normal grid operation but also under abnormal and faulty grid conditions according to the modern grid codes. This paper proposes a novel phase-locked loop algorithm (MSHDC-PLL), which can enable the fast...... and dynamic synchronization of the interconnected renewable energy system under unbalanced grid faults and under highly harmonic distorted voltage. The outstanding performance of the suggested PLL is achieved by implementing an innovative multi-sequence/harmonic decoupling cell in order to dynamically cancel...... renewable energy systems. Therefore, the performance of the new PLL can increase the quality of the injected power under abnormal conditions and in addition enable the renewable energy systems to provide the appropriate support to the grid under balanced and unbalanced grid faults....

A Multi-layer, Hierarchical Information Management System for the Smart Grid

Energy Technology Data Exchange (ETDEWEB)

Lu, Ning; Du, Pengwei; Paulson, Patrick R.; Greitzer, Frank L.; Guo, Xinxin; Hadley, Mark D.

2011-10-10

This paper presents the modeling approach, methodologies, and initial results of setting up a multi-layer, hierarchical information management system (IMS) for the smart grid. The IMS allows its users to analyze the data collected by multiple control and communication networks to characterize the states of the smart grid. Abnormal, corrupted, or erroneous measurement data and outliers are detected and analyzed to identify whether they are caused by random equipment failures, unintentional human errors, or deliberate tempering attempts. Data collected from different information networks are crosschecked for data integrity based on redundancy, dependency, correlation, or cross-correlations, which reveal the interdependency between data sets. A hierarchically structured reasoning mechanism is used to rank possible causes of an event to aid the system operators to proactively respond or provide mitigation recommendations to remove or neutralize the threats. The model provides satisfactory performance on identifying the cause of an event and significantly reduces the need of processing myriads of data collected.

Additional Security Considerations for Grid Management

Science.gov (United States)

Eidson, Thomas M.

2003-01-01

The use of Grid computing environments is growing in popularity. A Grid computing environment is primarily a wide area network that encompasses multiple local area networks, where some of the local area networks are managed by different organizations. A Grid computing environment also includes common interfaces for distributed computing software so that the heterogeneous set of machines that make up the Grid can be used more easily. The other key feature of a Grid is that the distributed computing software includes appropriate security technology. The focus of most Grid software is on the security involved with application execution, file transfers, and other remote computing procedures. However, there are other important security issues related to the management of a Grid and the users who use that Grid. This note discusses these additional security issues and makes several suggestions as how they can be managed.

Unavailability of critical SCADA communication links interconnecting a power grid and a Telco network

International Nuclear Information System (INIS)

Bobbio, A.; Bonanni, G.; Ciancamerla, E.; Clemente, R.; Iacomini, A.; Minichino, M.; Scarlatti, A.; Terruggia, R.; Zendri, E.

2010-01-01

The availability of power supply to power grid customers depends upon the availability of services of supervision, control and data acquisition (SCADA) system, which constitutes the nervous system of a power grid. In turn, SCADA services depend on the availability of the interconnected networks supporting such services. We propose a service oriented stochastic modelling methodology to investigate the availability of large interconnected networks, based on the hierarchical application of different modelling formalisms to different parts of the networks. Interconnected networks are decomposed according to the specific services delivered until the failure and repair mechanisms of the decomposed elementary blocks can be identified. We represent each network by a convenient stochastic modelling formalism, able to capture the main technological issues and to cope with realistic assumptions about failure and recovery mechanisms. This procedure confines the application of the more intensive computational techniques to those subsystems that actually require it. The paper concentrates on an actual failure scenario, occurred in Rome in January 2004 that involved the outage of critical SCADA communication links, interconnecting a power grid and a Telco network.

Unavailability of critical SCADA communication links interconnecting a power grid and a Telco network

Energy Technology Data Exchange (ETDEWEB)

Bobbio, A. [Dipartimento di Informatica, Universita del Piemonte Orientale, Viale Michel 11, 15121 Alessandria (Italy); Bonanni, G.; Ciancamerla, E. [ENEA - CRE Casaccia, Via Anguillarese 301, 00060 Roma (Italy); Clemente, R. [Telecom Italia Mobile, Via Isonzo112, 10141 Torino (Italy); Iacomini, A. [ACEA, Pl. Ostiense 2, 00154 Roma (Italy); Minichino, M., E-mail: minichino@casaccia.enea.i [ENEA - CRE Casaccia, Via Anguillarese 301, 00060 Roma (Italy); Scarlatti, A. [ACEA, Pl. Ostiense 2, 00154 Roma (Italy); Terruggia, R. [Dipartimento di Informatica, Universita del Piemonte Orientale, Viale Michel 11, 15121 Alessandria (Italy); Zendri, E. [ACEA, Pl. Ostiense 2, 00154 Roma (Italy)

2010-12-15

The availability of power supply to power grid customers depends upon the availability of services of supervision, control and data acquisition (SCADA) system, which constitutes the nervous system of a power grid. In turn, SCADA services depend on the availability of the interconnected networks supporting such services. We propose a service oriented stochastic modelling methodology to investigate the availability of large interconnected networks, based on the hierarchical application of different modelling formalisms to different parts of the networks. Interconnected networks are decomposed according to the specific services delivered until the failure and repair mechanisms of the decomposed elementary blocks can be identified. We represent each network by a convenient stochastic modelling formalism, able to capture the main technological issues and to cope with realistic assumptions about failure and recovery mechanisms. This procedure confines the application of the more intensive computational techniques to those subsystems that actually require it. The paper concentrates on an actual failure scenario, occurred in Rome in January 2004 that involved the outage of critical SCADA communication links, interconnecting a power grid and a Telco network.

GridPP returns to CERN

CERN Document Server

Neasan O'Neill

2011-01-01

In early September, GridPP, the collaboration that manages the UK’s contribution to the worldwide LHC Computing Grid (wLCG), celebrated a decade of work by holding its twenty-seventh collaboration meeting at CERN.   Officially launched in September 2001, GridPP was one of the original partners in wLCG, funding much of the early work at CERN. Over the last decade GridPP has gone from a mere proposal to almost 30,000 CPUs working for researchers scattered across the globe. Twice a year, GridPP meets to discuss the progress and future plans of the community and this year, for the first time since 2004, decamped to CERN for this biannual meeting on the theme “GridPP in the International Context”. The main meeting was held over 2 days in the IT auditorium and was the perfect opportunity to have contributions from experts based at CERN, alongside those from within GridPP. Opening with a welcome from Frederic Hemmer, Head of the IT Department at CERN, the meeting began with...

Observability of Low Voltage grids

DEFF Research Database (Denmark)

Martin-Loeches, Ruben Sánchez; Iov, Florin; Kemal, Mohammed Seifu

2017-01-01

Low Voltage (LV) distribution power grids are experiencing a transformation from a passive to a more active role due to the increasing penetration of distributed generation, heat pumps and electrical vehicles. The first step towards a smarter operation of LV electrical systems is to provide grid ...... an updated state of the art on DSSE-AMI based, adaptive data collection techniques and database management system types. Moreover, the ongoing Danish RemoteGRID project is presented as a realistic case study.......Low Voltage (LV) distribution power grids are experiencing a transformation from a passive to a more active role due to the increasing penetration of distributed generation, heat pumps and electrical vehicles. The first step towards a smarter operation of LV electrical systems is to provide grid....... It becomes unrealistic to provide near real time full observability of the LV grid by applying Distribution System State Estimation (DSSE) utilizing the classical data collection and storage/preprocessing techniques. This paper investigates up-todate the observability problem in LV grids by providing...

A methodology to leverage cross-sectional accelerometry to capture weather's influence in active living research.

Science.gov (United States)

Katapally, Tarun R; Rainham, Daniel; Muhajarine, Nazeem

2016-06-27

While active living interventions focus on modifying urban design and built environment, weather variation, a phenomenon that perennially interacts with these environmental factors, is consistently underexplored. This study's objective is to develop a methodology to link weather data with existing cross-sectional accelerometry data in capturing weather variation. Saskatoon's neighbourhoods were classified into grid-pattern, fractured grid-pattern and curvilinear neighbourhoods. Thereafter, 137 Actical accelerometers were used to derive moderate to vigorous physical activity (MVPA) and sedentary behaviour (SB) data from 455 children in 25 sequential one-week cycles between April and June, 2010. This sequential deployment was necessary to overcome the difference in the ratio between the sample size and the number of accelerometers. A data linkage methodology was developed, where each accelerometry cycle was matched with localized (Saskatoon-specific) weather patterns derived from Environment Canada. Statistical analyses were conducted to depict the influence of urban design on MVPA and SB after factoring in localized weather patterns. Integration of cross-sectional accelerometry with localized weather patterns allowed the capture of weather variation during a single seasonal transition. Overall, during the transition from spring to summer in Saskatoon, MVPA increased and SB decreased during warmer days. After factoring in localized weather, a recurring observation was that children residing in fractured grid-pattern neighbourhoods accumulated significantly lower MVPA and higher SB. The proposed methodology could be utilized to link globally available cross-sectional accelerometry data with place-specific weather data to understand how built and social environmental factors interact with varying weather patterns in influencing active living.

Workshop on Future Generation Grids

CERN Document Server

Laforenza, Domenico; Reinefeld, Alexander

2006-01-01

The Internet and the Web continue to have a major impact on society. By allowing us to discover and access information on a global scale, they have created entirely new businesses and brought new meaning to the term surf. In addition, however, we want processing, and increasingly, we want collaborative processing within distributed teams. This need has led to the creation of the Grid - an infrastructure that enables us to share capabilities, and integrate services and resources within and across enterprises. "Future Generation Grids" is the second in the "CoreGRID" series. This edited volume brings together contributed articles by scientists and researchers in the Grid community in an attempt to draw a clearer picture of the future generation Grids. This book also identifies some of the most challenging problems on the way to achieving the invisible Grid ideas

Communication technologies in smart grid

Directory of Open Access Journals (Sweden)

Miladinović Nikola

2013-01-01

Full Text Available The role of communication technologies in Smart Grid lies in integration of large number of devices into one telecommunication system. This paper provides an overview of the technologies currently in use in electric power grid, that are not necessarily in compliance with the Smart Grid concept. Considering that the Smart Grid is open to the flow of information in all directions, it is necessary to provide reliability, protection and security of information.

Grid and Entrepreneurship Workshop

CERN Multimedia

2006-01-01

The CERN openlab is organising a special workshop about Grid opportunities for entrepreneurship. This one-day event will provide an overview of what is involved in spin-off technology, with a special reference to the context of computing and data Grids. Lectures by experienced entrepreneurs will introduce the key concepts of entrepreneurship and review, in particular, the industrial potential of EGEE (the EU co-funded Enabling Grids for E-sciencE project, led by CERN). Case studies will be given by CEOs of European start-ups already active in the Grid and computing cluster area, and regional experts will provide an overview of efforts in several European regions to stimulate entrepreneurship. This workshop is designed to encourage students and researchers involved or interested in Grid technology to consider the entrepreneurial opportunities that this technology may create in the coming years. This workshop is organized as part of the CERN openlab student programme, which is co-sponsored by CERN, HP, ...

Balancing Area Coordination: Efficiently Integrating Renewable Energy Into the Grid, Greening the Grid

Energy Technology Data Exchange (ETDEWEB)

Katz, Jessica; Denholm, Paul; Cochran, Jaquelin

2015-06-01

Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid. Coordinating balancing area operation can promote more cost and resource efficient integration of variable renewable energy, such as wind and solar, into power systems. This efficiency is achieved by sharing or coordinating balancing resources and operating reserves across larger geographic boundaries.

A Communication and Resources Management Scheme to Support the Smart Grid Integration of Multiplayers Access to Resources Information

DEFF Research Database (Denmark)

Vale, Zita; Morais, Hugo; Faria, Pedro

2014-01-01

The increasing and i ntensive integration of distributed energy resources into distribution systems requires adequate methodologies to ensure a secure operation according to the smart grid paradigm. In this context, SCADA (Supervisory Control and Data Acquisition) systems are an essential...... considering all the involved costs, power flows, and electricity prices leading to the network reconfiguration . The methodology also addresses the definition of the information access permissio ns of each player to each resource. The paper includes a 33 - bus network used in a case study that considers...

Technology Roadmaps: Smart Grids

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

The development of Technology Roadmaps: Smart Grids -- which the IEA defines as an electricity network that uses digital and other advanced technologies to monitor and manage the transport of electricity from all generation sources to meet the varying electricity demands of end users -- is essential if the global community is to achieve shared goals for energy security, economic development and climate change mitigation. Unfortunately, existing misunderstandings of exactly what smart grids are and the physical and institutional complexity of electricity systems make it difficult to implement smart grids on the scale that is needed. This roadmap sets out specific steps needed over the coming years to achieve milestones that will allow smart grids to deliver a clean energy future.

Synergisms between smart metering and smart grid; Synergien zwischen Smart Metering und Smart Grid

Energy Technology Data Exchange (ETDEWEB)

Maas, Peter [IDS GmbH, Ettlingen (Germany)

2010-04-15

With the implementation of a smart metering solution, it is not only possible to acquire consumption data for billing but also to acquire relevant data of the distribution grid for grid operation. There is still a wide gap between the actual condition and the target condition. Synergies result from the use of a common infrastructure which takes account both of the requirements of smart metering and of grid operation. An open architecture also enables the future integration of further applications of the fields of smart grid and smart home. (orig.)

Securing the smart grid information exchange

Energy Technology Data Exchange (ETDEWEB)

Fries, Steffen; Falk, Rainer [Siemens AG, Corporate Technology, Muenchen (Germany)

2012-07-01

The smart grid is based on information exchange between various stakeholders using open communication technologies, to control the physical electric grid through the information grid. Protection against cyber attacks is essential to ensure a reliable operation of the smart grid. This challenge is addressed by various regulatory, standardization, and research activities. After giving an overview of the security demand of a smart grid, existing and appearing standardization activities are described. (orig.)

Monitoring the EGEE/WLCG grid services

International Nuclear Information System (INIS)

Duarte, A; Nyczyk, P; Retico, A; Vicinanza, D

2008-01-01

Grids have the potential to revolutionise computing by providing ubiquitous, on demand access to computational services and resources. They promise to allow for on demand access and composition of computational services provided by multiple independent sources. Grids can also provide unprecedented levels of parallelism for high-performance applications. On the other hand, grid characteristics, such as high heterogeneity, complexity and distribution create many new technical challenges. Among these technical challenges, failure management is a key area that demands much progress. A recent survey revealed that fault diagnosis is still a major problem for grid users. When a failure appears at the user screen, it becomes very difficult for the user to identify whether the problem is in the application, somewhere in the grid middleware, or even lower in the fabric that comprises the grid. In this paper we present a tool able to check if a given grid service works as expected for a given set of users (Virtual Organisation) on the different resources available on a grid. Our solution deals with grid services as single components that should produce an expected output to a pre-defined input, what is quite similar to unit testing. The tool, called Service Availability Monitoring or SAM, is being currently used by several different Virtual Organizations to monitor more than 300 grid sites belonging to the largest grids available today. We also discuss how this tool is being used by some of those VOs and how it is helping in the operation of the EGEE/WLCG grid

DIGRD: an interactive grid generating program

International Nuclear Information System (INIS)

Foote, H.P.; Rice, W.A.; Kincaid, C.T.

1982-11-01

Pacific Northwest Laboratory has completed the development and documentation of an interactive grid generating program (DIGRD, digitize grid). This program is designed to rapidly generate or modify grids necessary for the unsaturated flow code TRUST. In addition to the code, a user's manual was prepared. Unfortunately, the computer hardware that comprises the PNL interactive graphics capability is unique. Direct technology transfer is not possible, therefore, this report is intended to convey the utility of interactive graphics in supplying a grid generating capability. DIGRD has already been effectively used in the preparation of grids for the analysis of leachate movement from uranium mill tailings. The principal conclusion is that the interactive graphics employed in DIGRD are useful and economical in the development of complex grids. Grid generation activities that previously took between a half- and a full-man month can now be completed in less than a week. DIGRD users have recommended development of an uniform grid of either rectangles or equilateral triangles, which could be superimposed on any domain and then adjusted through the DIGRD program to match the boundaries of a tailings disposal facility. This improvement to the DIGRD package could further reduce the effort in grid generation while providing more optimal grids

Smart Grid Integration Laboratory

Energy Technology Data Exchange (ETDEWEB)

Troxell, Wade [Colorado State Univ., Fort Collins, CO (United States)

2011-12-22

The initial federal funding for the Colorado State University Smart Grid Integration Laboratory is through a Congressionally Directed Project (CDP), DE-OE0000070 Smart Grid Integration Laboratory. The original program requested in three one-year increments for staff acquisition, curriculum development, and instrumentation all which will benefit the Laboratory. This report focuses on the initial phase of staff acquisition which was directed and administered by DOE NETL/ West Virginia under Project Officer Tom George. Using this CDP funding, we have developed the leadership and intellectual capacity for the SGIC. This was accomplished by investing (hiring) a core team of Smart Grid Systems engineering faculty focused on education, research, and innovation of a secure and smart grid infrastructure. The Smart Grid Integration Laboratory will be housed with the separately funded Integrid Laboratory as part of CSU's overall Smart Grid Integration Center (SGIC). The period of performance of this grant was 10/1/2009 to 9/30/2011 which included one no cost extension due to time delays in faculty hiring. The Smart Grid Integration Laboratory's focus is to build foundations to help graduate and undergraduates acquire systems engineering knowledge; conduct innovative research; and team externally with grid smart organizations. Using the results of the separately funded Smart Grid Workforce Education Workshop (May 2009) sponsored by the City of Fort Collins, Northern Colorado Clean Energy Cluster, Colorado State University Continuing Education, Spirae, and Siemens has been used to guide the hiring of faculty, program curriculum and education plan. This project develops faculty leaders with the intellectual capacity to inspire its students to become leaders that substantially contribute to the development and maintenance of Smart Grid infrastructure through topics such as: (1) Distributed energy systems modeling and control; (2) Energy and power conversion; (3

SuperGrid or SmartGrid: Competing strategies for large-scale integration of intermittent renewables?

DEFF Research Database (Denmark)

Blarke, Morten; M. Jenkins, Bryan

2013-01-01

This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts...... of interest between the two. The article identifies differences between a domestic strategy for the integration of intermittent renewables, vis-à-vis the SmartGrid, and a cross-system strategy, vis-à-vis the SuperGrid. Policy makers and transmission system operators must understand the need for both...... a paradigmatic case study from West Denmark which supports the hypothesis that these strategies are mutually exclusive. The case study shows that increasing cross-system transmission capacity jeopardizes the feasibility of SmartGrid technology investments. A political effort is required for establishing...

Methodology development for estimating support behavior of spacer grid spring in core

International Nuclear Information System (INIS)

Yoon, Kyung Ho; Kang, Heung Seok; Kim, Hyung Kyu; Song, Kee Nam

1998-04-01

The fuel rod (FR) support behavior is changed during operation resulting from effects such as clad creep-down, spring force relaxation due to irradiation, and irradiation growth of spacer straps in accordance with time or increase of burnup. The FR support behavior is closely associated with time or increase of burnup. The FR support behavior is closely associated with FR damage due to fretting, therefore the analysis on the FR support behavior is normally required to minimize the damage. The characteristics of the parameters, which affect the FR support behavior, and the methodology developed for estimating the FR support behavior in the reactor core are described in this work. The FR support condition for the KOFA (KOrean Fuel Assembly) fuel has been analyzed by this method, and the results of the analysis show that the fuel failure due to the fuel rod fretting wear is closely related to the support behavior of FR in the core. Therefore, the present methodology for estimating the FR support condition seems to be useful for estimating the actual FR support condition. In addition, the optimization seems to be a reliable tool for establishing the optimal support condition on the basis of these results. (author). 15 refs., 3 tabs., 26 figs

Gridded Population of the World, Version 3 (GPWv3): Population Count Grid

Data.gov (United States)

National Aeronautics and Space Administration — Gridded Population of the World, Version 3 (GPWv3) consists of estimates of human population for the years 1990, 1995, and 2000 by 2.5 arc-minute grid cells and...

Smart Grid: Smart Customer Policy Needs

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

In September 2010, the International Energy Agency (IEA) held a workshop on the regulatory, market and consumer policies necessary to ensure that smart grids are deployed with adequate consideration of their risks and benefits to all stakeholders. This was one of several workshops that brought together energy providers, network operators, technology developers, regulators, customers and government policy makers to discuss smart grid technology and policy. The Smart Grid - Smart Customer Policies workshop allowed stakeholders to: gain a perspective on key issues and barriers facing early deployment of smart grids; hear expert opinion on regulatory, consumer and market challenges to smart grids; discuss smart grid-smart customer policy priorities; and build consensus on the technology and policy ingredients needed for customer-friendly smart grid deployments. Drawing on workshop discussions, the following paper lays out a logical framework to maximise the benefits and minimise the risks that smart grids pose for customers. The paper also describes key policy research questions that will guide future IEA research on this topic.

Production grid systems and their programming

CERN Document Server

Kacsuk, P; Stefan, P

2004-01-01

Summary form only given. There are a large variety of grid test-beds that can be used for experimental purposes by a small community. However, the number of production grid systems that can be used as a service for a large community is very limited. The current tutorial provides introduction to three of these very few production grid systems. They represent different models and policies of using grid resources and hence understanding and comparing them is an extremely useful exercise to everyone interested in grid technology. The Hungarian ClusterGrid infrastructure connects clusters during the nights and weekends. These clusters are used during the day for educational purposes at the Hungarian universities and polytechnics. Therefore, a unique feature of this grid is the switching mechanism by which the day time and night time working modes are loaded to the computers. In order to manage the system as a production, one, the system is homogeneous, all the machines should install the same grid software package...

Recent Developments in Grid Generation and Force Integration Technology for Overset Grids

Science.gov (United States)

Chan, William M.; VanDalsem, William R. (Technical Monitor)

1994-01-01

Recent developments in algorithms and software tools for generating overset grids for complex configurations are described. These include the overset surface grid generation code SURGRD and version 2.0 of the hyperbolic volume grid generation code HYPGEN. The SURGRD code is in beta test mode where the new features include the capability to march over a collection of panel networks, a variety of ways to control the side boundaries and the marching step sizes and distance, a more robust projection scheme and an interpolation option. New features in version 2.0 of HYPGEN include a wider range of boundary condition types. The code also allows the user to specify different marching step sizes and distance for each point on the surface grid. A scheme that takes into account of the overlapped zones on the body surface for the purpose of forces and moments computation is also briefly described, The process involves the following two software modules: MIXSUR - a composite grid generation module to produce a collection of quadrilaterals and triangles on which pressure and viscous stresses are to be integrated, and OVERINT - a forces and moments integration module.

Smart Grids. Innovators talking; Smart Grids. Innovators aan het woord

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-02-15

Qualitative studies have been conducted of the results of completed projects focused on energy innovation, spread over the seven themes of the top sector Energy: Energy saving in industry, Energy conservation in the built environment, Gas, Bio-energy, Smart grids, Offshore Wind, Solar PV. This provides insight into the follow-up activities and lessons of some EOS (Energy Research Subsidy) completed projects with the aim to inspire, connect and strengthen the TKIs (Topconsortia for Knowledge and Innovation) and individual companies and researchers working on energy innovation. This report concerns the research on Smart Grids [Dutch] Er is een kwalitatief onderzoek uitgevoerd naar de resultaten van afgeronde projecten gericht op energie-innovatie, verdeeld over de zeven thema's van de topsector Energie: Energiebesparing in de industrie; Energiebesparing in de gebouwde omgeving; Gas; Bio-energie; Smart grids; Wind op zee; Zon-pv. Daarmee wordt inzicht gegeven in de vervolgactiviteiten en lessen van een aantal afgesloten EOS-projecten (Energie Onderzoek Subsidie) met het oog op het inspireren, verbinden en versterken van de TKI's (Topconsortia voor Kennis en Innovatie) en individuele bedrijven en onderzoekers die werken aan energie-innovatie. Dit rapport betreft het onderzoek naar Smart Grids.

Smart Grids. Innovators talking; Smart Grids. Innovators aan het woord

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-02-15

Qualitative studies have been conducted of the results of completed projects focused on energy innovation, spread over the seven themes of the top sector Energy: Energy saving in industry, Energy conservation in the built environment, Gas, Bio-energy, Smart grids, Offshore Wind, Solar PV. This provides insight into the follow-up activities and lessons of some EOS (Energy Research Subsidy) completed projects with the aim to inspire, connect and strengthen the TKIs (Topconsortia for Knowledge and Innovation) and individual companies and researchers working on energy innovation. This report concerns the research on Smart Grids [Dutch] Er is een kwalitatief onderzoek uitgevoerd naar de resultaten van afgeronde projecten gericht op energie-innovatie, verdeeld over de zeven thema's van de topsector Energie: Energiebesparing in de industrie; Energiebesparing in de gebouwde omgeving; Gas; Bio-energie; Smart grids; Wind op zee; Zon-pv. Daarmee wordt inzicht gegeven in de vervolgactiviteiten en lessen van een aantal afgesloten EOS-projecten (Energie Onderzoek Subsidie) met het oog op het inspireren, verbinden en versterken van de TKI's (Topconsortia voor Kennis en Innovatie) en individuele bedrijven en onderzoekers die werken aan energie-innovatie. Dit rapport betreft het onderzoek naar Smart Grids.

Agent-Based Smart Grid Market Simulation with Connection to Real Infrastructures

DEFF Research Database (Denmark)

Santos, Gabriel; Pinto, Tiago; Gomes, Luis

2015-01-01

The consensus behind Smart Grids (SG) as one of the most promising solutions for the massive integration of renewable energy sources in power systems has led to the practical implementation of several prototypes and pilots that aim at testing and validating SG methodologies. The urgent need...... to accommodate such resources of distributed and intermittent nature and the impact that a deficient management of energy sources has on the global population require that alternative solutions are experimented. This paper presents a multi-agent based SG simulation platform that is connected to physical...

Trends and Potentials of the Smart Grid Infrastructure: From ICT Sub-System to SDN-Enabled Smart Grid Architecture

Directory of Open Access Journals (Sweden)

Jaebeom Kim

2015-10-01

Full Text Available Context and situational awareness are key features and trends of the smart grid and enable adaptable, flexible and extendable smart grid services. However, the traditional hardware-dependent communication infrastructure is not designed to identify the flow and context of data, and it focuses only on packet forwarding using a pre-defined network configuration profile. Thus, the current network infrastructure may not dynamically adapt the various business models and services of the smart grid system. To solve this problem, software-defined networking (SDN is being considered in the smart grid, but the design, architecture and system model need to be optimized for the smart grid environment. In this paper, we investigate the state-of-the-art smart grid information subsystem, communication infrastructure and its emerging trends and potentials, called an SDN-enabled smart grid. We present an abstract business model, candidate SDN applications and common architecture of the SDN-enabled smart grid. Further, we compare recent studies into the SDN-enabled smart grid depending on its service functionalities, and we describe further challenges of the SDN-enabled smart grid network infrastructure.

Study on methodologies for establishing a system for cross-border tariffication in the internal electricity market

International Nuclear Information System (INIS)

Glavitsch, H.

2001-01-01

This reports for the Swiss Federal Office of Energy (SFOE) presents the results of a study made by a working group on the costs and the billing of electrical power transfer across national borders in Europe. On the basis of present-day concepts and operating conditions, new methodologies were developed that were oriented towards the responsible parties, that were non-discriminating and that were based on physical energy flow. The results obtained with prototype calculation programs using test data are discussed and a cost-model that was intensively discussed in the working group is introduced. The software was developed far enough as to be able to perform simulations using a real-life set of data from the European grid. Together with the grid regulator in Belgium, a concept paper was developed that presents the targets and principal procedures involved in the new methodology developed in the project

An Evaluation of Alternative Designs for a Grid Information Service

Science.gov (United States)

Smith, Warren; Waheed, Abdul; Meyers, David; Yan, Jerry; Kwak, Dochan (Technical Monitor)

2001-01-01

The Globus information service wasn't working well. There were many updates of data from Globus daemons which saturated the single server and users couldn't retrieve information. We created a second server for NASA and Alliance. Things were great on that server, but a bit slow on the other server. We needed to know exactly how the information service was being used. What were the best servers and configurations? This viewgraph presentation gives an overview of the evaluation of alternative designs for a Grid Information Service. Details are given on the workload characterization, methodology used, and the performance evaluation.

Integrating Variable Renewable Energy into the Grid: Key Issues, Greening the Grid (Spanish Version)

Energy Technology Data Exchange (ETDEWEB)

2016-04-01

This is the Spanish version of 'Greening the Grid - Integrating Variable Renewable Energy into the Grid: Key Issues'. To foster sustainable, low-emission development, many countries are establishing ambitious renewable energy targets for their electricity supply. Because solar and wind tend to be more variable and uncertain than conventional sources, meeting these targets will involve changes to power system planning and operations. Grid integration is the practice of developing efficient ways to deliver variable renewable energy (VRE) to the grid. Good integration methods maximize the cost-effectiveness of incorporating VRE into the power system while maintaining or increasing system stability and reliability. When considering grid integration, policy makers, regulators, and system operators consider a variety of issues, which can be organized into four broad topics: New Renewable Energy Generation, New Transmission, Increased System Flexibility, and Planning for a High RE Future.

Grid Integration | Water Power | NREL

Science.gov (United States)

Grid Integration Grid Integration For marine and hydrokinetic technologies to play a larger role in supplying the nation's energy needs, integration into the U.S. power grid is an important challenge to address. Efficient integration of variable power resources like water power is a critical part of the

What is a smart grid?

NARCIS (Netherlands)

Kumar, A.

2017-01-01

The Indian Smart Grid Forum defines a smart grid as "a power system capable of two-way communication between all the entities of the network-generation, transmission, distribution and the consumers". Like most work on smart grids, this view is also mainly technical. This paper aims to progress the

Kids Enjoy Grids

CERN Multimedia

2007-01-01

I want to come back and work here when I'm older,' was the spontaneous reaction of one of the children invited to CERN by the Enabling Grids for E-sciencE project for a 'Grids for Kids' day at the end of January. The EGEE project is led by CERN, and the EGEE gender action team organized the day to introduce children to grid technology at an early age. The school group included both boys and girls, aged 9 to 11. All of the presenters were women. 'In general, before this visit, the children thought that scientists always wore white coats and were usually male, with wild Einstein-like hair,' said Jackie Beaver, the class's teacher at the Institut International de Lancy, a school near Geneva. 'They were surprised and pleased to see that women became scientists, and that scientists were quite 'normal'.' The half-day event included presentations about why Grids are needed, a visit of the computer centre, some online games, and plenty of time for questions. In the end, everyone agreed that it was a big success a...

Mesoscale Climate Evaluation Using Grid Computing

Science.gov (United States)

Campos Velho, H. F.; Freitas, S. R.; Souto, R. P.; Charao, A. S.; Ferraz, S.; Roberti, D. R.; Streck, N.; Navaux, P. O.; Maillard, N.; Collischonn, W.; Diniz, G.; Radin, B.

2012-04-01

The CLIMARS project is focused to establish an operational environment for seasonal climate prediction for the Rio Grande do Sul state, Brazil. The dynamical downscaling will be performed with the use of several software platforms and hardware infrastructure to carry out the investigation on mesoscale of the global change impact. The grid computing takes advantage of geographically spread out computer systems, connected by the internet, for enhancing the power of computation. The ensemble climate prediction is an appropriated application for processing on grid computing, because the integration of each ensemble member does not have a dependency on information from another ensemble members. The grid processing is employed to compute the 20-year climatology and the long range simulations under ensemble methodology. BRAMS (Brazilian Regional Atmospheric Model) is a mesoscale model developed from a version of the RAMS (from the Colorado State University - CSU, USA). BRAMS model is the tool for carrying out the dynamical downscaling from the IPCC scenarios. Long range BRAMS simulations will provide data for some climate (data) analysis, and supply data for numerical integration of different models: (a) Regime of the extreme events for temperature and precipitation fields: statistical analysis will be applied on the BRAMS data, (b) CCATT-BRAMS (Coupled Chemistry Aerosol Tracer Transport - BRAMS) is an environmental prediction system that will be used to evaluate if the new standards of temperature, rain regime, and wind field have a significant impact on the pollutant dispersion in the analyzed regions, (c) MGB-IPH (Portuguese acronym for the Large Basin Model (MGB), developed by the Hydraulic Research Institute, (IPH) from the Federal University of Rio Grande do Sul (UFRGS), Brazil) will be employed to simulate the alteration of the river flux under new climate patterns. Important meteorological input variables for the MGB-IPH are the precipitation (most relevant

Vertical grid of retrieved atmospheric profiles

International Nuclear Information System (INIS)

Ceccherini, Simone; Carli, Bruno; Raspollini, Piera

2016-01-01

The choice of the vertical grid of atmospheric profiles retrieved from remote sensing observations is discussed considering the two cases of profiles used to represent the results of individual measurements and of profiles used for subsequent data fusion applications. An ozone measurement of the MIPAS instrument is used to assess, for different vertical grids, the quality of the retrieved profiles in terms of profile values, retrieval errors, vertical resolutions and number of degrees of freedom. In the case of individual retrievals no evident advantage is obtained with the use of a grid finer than the one with a reduced number of grid points, which are optimized according to the information content of the observations. Nevertheless, this instrument dependent vertical grid, which seems to extract all the available information, provides very poor results when used for data fusion applications. A loss of about a quarter of the degrees of freedom is observed when the data fusion is made using the instrument dependent vertical grid relative to the data fusion made using a vertical grid optimized for the data fusion product. This result is explained by the analysis of the eigenvalues of the Fisher information matrix and leads to the conclusion that different vertical grids must be adopted when data fusion is the expected application. - Highlights: • Data fusion application is taken into account for the choice of the vertical grid. • The study is performed using ozone profiles retrieved from MIPAS measurements. • A very fine vertical grid is not needed for the analysis of a single instrument. • The instrument dependent vertical grid is not the best choice for data fusion. • A data fusion dependent vertical grid must be used for profiles that will be fused.

Nuclear reactor spring strip grid spacer

International Nuclear Information System (INIS)

Patterson, J.F.; Flora, B.S.

1978-01-01

A bimetallic grid spacer is described comprising a grid structure of zircaloy formed by intersecting striplike members which define fuel element openings for receiving fuel elements and spring strips made of Inconel positioned within the grid structure for cooperating with the fuel elements to maintain them in their desired position. A plurality of these spring strips extend longitudinally between sides of the grid structure, being locked in position by the grid retaining strips. The fuel rods, which are disposed in the fuel openings formed in the grid structure, are positioned by means of the springs associated with the spring strips and a plurality of dimples which extend from the zircaloy grid structure into the openings. In one embodiment the strips are disposed in a plurality of arrays with those spring strip arrays situated in opposing diagonal quadrants of the grid structure extending in the same direction and adjacent spring strip arrays in each half of the spacer extending in relatively perpendicular directions. Other variations of the spring strip arrangements for a particular fuel design are disclosed herein

Power Grid:Connecting the world

Institute of Scientific and Technical Information of China (English)

Liu Liang; Zhu Li

2012-01-01

With the acceleration of global economic integration,the trend has been towards opening up markets.Large enterprises in countries around the world,the developed countries in particular,attach great importance to going abroad,with the aim to optimally allocate energy resources in a wider range.Actively responding to the "going out" strategy of the State,the two giant power grid enterprises in China,State Grid Corporation of China (SGCC) and China Southern Power Grid (CSG),have made plans for grid development in line with the State's energy strategy and global resources allocation.

Wind and Solar on the Power Grid: Myths and Misperceptions, Greening the Grid (Spanish Version)

Energy Technology Data Exchange (ETDEWEB)

Authors: Denholm, Paul; Cochran, Jaquelin; Brancucci Martinez-Anido, Carlo

2016-04-01

This is the Spanish version of the 'Greening the Grid - Wind and Solar on the Power Grid: Myths and Misperceptions'. Wind and solar are inherently more variable and uncertain than the traditional dispatchable thermal and hydro generators that have historically provided a majority of grid-supplied electricity. The unique characteristics of variable renewable energy (VRE) resources have resulted in many misperceptions regarding their contribution to a low-cost and reliable power grid. Common areas of concern include: 1) The potential need for increased operating reserves, 2) The impact of variability and uncertainty on operating costs and pollutant emissions of thermal plants, and 3) The technical limits of VRE penetration rates to maintain grid stability and reliability. This fact sheet corrects misperceptions in these areas.

Spacer grid corner gusset

International Nuclear Information System (INIS)

Larson, J.G.

1984-01-01

There is provided a spacer grid for a bundle of longitudinally extending rods in spaced generally parallel relationship comprising spacing means for holding the rods in spaced generally parallel relationship; the spacing means includes at least one exterior grid strip circumscribing the bundle of rods along the periphery thereof; with at least one exterior grid strip having a first edge defining the boundary of the strip in one longitudinal direction and a second edge defining the boundary of the strip in the other longitudinal direction; with at least one exterior grid strip having at least one band formed therein parallel to the longitudinal direction; a plurality of corner gussets truncating each of a plurality of corners formed by at least one band and the first edge and the second edge

Parallel Sn Sweeps on Unstructured Grids: Algorithms for Prioritization, Grid Partitioning, and Cycle Detection

International Nuclear Information System (INIS)

Plimpton, Steven J.; Hendrickson, Bruce; Burns, Shawn P.; McLendon, William III; Rauchwerger, Lawrence

2005-01-01

The method of discrete ordinates is commonly used to solve the Boltzmann transport equation. The solution in each ordinate direction is most efficiently computed by sweeping the radiation flux across the computational grid. For unstructured grids this poses many challenges, particularly when implemented on distributed-memory parallel machines where the grid geometry is spread across processors. We present several algorithms relevant to this approach: (a) an asynchronous message-passing algorithm that performs sweeps simultaneously in multiple ordinate directions, (b) a simple geometric heuristic to prioritize the computational tasks that a processor works on, (c) a partitioning algorithm that creates columnar-style decompositions for unstructured grids, and (d) an algorithm for detecting and eliminating cycles that sometimes exist in unstructured grids and can prevent sweeps from successfully completing. Algorithms (a) and (d) are fully parallel; algorithms (b) and (c) can be used in conjunction with (a) to achieve higher parallel efficiencies. We describe our message-passing implementations of these algorithms within a radiation transport package. Performance and scalability results are given for unstructured grids with up to 3 million elements (500 million unknowns) running on thousands of processors of Sandia National Laboratories' Intel Tflops machine and DEC-Alpha CPlant cluster

Grid-Tied Photovoltaic Power System

Science.gov (United States)

Eichenberg, Dennis J.

2011-01-01

A grid-tied photovoltaic (PV) power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. Operating costs of a PV power system are low compared to conventional power technologies. This method can displace the highest-cost electricity during times of peak demand in most climatic regions, and thus reduce grid loading. Net metering is often used, in which independent power producers such as PV power systems are connected to the utility grid via the customers main service panels and meters. When the PV power system is generating more power than required at that location, the excess power is provided to the utility grid. The customer pays the net of the power purchased when the on-site power demand is greater than the onsite power production, and the excess power is returned to the utility grid. Power generated by the PV system reduces utility demand, and the surplus power aids the community. Modern PV panels are readily available, reliable, efficient, and economical, with a life expectancy of at least 25 years. Modern electronics have been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy equal to the modern PV panels. The grid-tied PV power system was successfully designed and developed, and this served to validate the basic principles developed, and the theoretical work that was performed. Grid-tied PV power systems are reliable, maintenance- free, long-life power systems, and are of significant value to NASA and the community. Of particular value are the analytical tools and capabilities that have been successfully developed. Performance predictions can be made confidently for grid-tied PV systems of various scales. The work was done under the NASA Hybrid Power Management (HPM

Advanced KSNP fuel, plus7 : grid-to-rod fretting wear resistance of the plus7 spacer grids

International Nuclear Information System (INIS)

Kim, Kyu Tae; Kim, Yong Hwan; Jang, Young Ki; Choi, Joon Hyung

2003-01-01

Vibration-induced grid-to-rod fretting wear initiates at a certain critical gap correlated with a critical work rate. A critical gap between grid and rod forms due to in-reactor performance of fuel, thermal relaxation of grid spring and irradiation growth of grid strap, etc. A critical work rate may be generated by three vibration mechanisms proposed in this paper. Three vibration mechanisms have been derived with various fretting wear experience in commercial reactors as well as various out-of-pile hydraulic test results. The first active vibration mechanism is high turbulence-induced excessive fuel rod vibration with the combination of excessive grid-to-rod gap. The second active vibration mechanism is self-excited fuel assembly vibration in a low frequency range caused by hydraulically unbalanced mixing vanes of the spacer grid assembly. The third active vibration mechanism is self-excited spacer grid strap vibration in quite a high frequency range caused by some spacer grid designs. In this study, each vibration mechanism on the grid-to-rod fretting wear damage is discussed. On the other hand, the effects of various grid designs on the fretting wear damage in the commercial reactors are predicted using the long-term fretting wear test results. It is found that the larger grid-to-rod initial contact area generates the less fretting wear damage. Consequently the conformal spring of PLUS7 is superior to typical convex shaped spring with regard to fretting wear resistance since the former generates relatively larger contact area than the latter

DanGrid. Report from working group 24. Roadmap for Smart Grid in Denmark with emphasis on the transmission companies' role; DanGrid. Delrapport. Arbejdsgruppe 24. Roadmap for Smart Grid i Danmark med saerlig vaegt pae netselskabernes rolle

Energy Technology Data Exchange (ETDEWEB)

Lomholt Finnemann, K. [DONG Energy, Virum (Denmark); Soerensen, Per [TRE-FOR, Kolding (Denmark); Larsen, Jim [EnergiMidt, Silkeborg (Denmark); Balasiu, A. [Siemens, Ballerup (Denmark); Holmberg Rasmussen, L. [Nordjysk Elhandel, Aalborg (Denmark); Moeller Joergensen, J. [Energinet.dk, Fredericia (Denmark); Norsk Jensen, A.; Nejsum, T.; Andersen, Kim [Dansk Energi, Frederiksberg (Denmark)

2012-09-15

The present report identifies a number of recommendations where specifically grid companies, but also authorities, customers and market players must initiate actions and activities to realize Smart Grid in Denmark by 2020. The report forms the basis for each network operator to implement Smart Grid, and is divided such that: 1 the management can create an overview of the steps to be taken in connection with the implementation, and 2. the technical department can develop a series of concrete actions to be implemented in the Smart Grid. The measures are divided into four groups: 1 - Establishment of business case and strategy: Efforts that support that each network operator prepares a business case and define a strategy for the creation of a Smart Grid. 2 - New technology in the grid: Measures relating to the importation of new technology in the grid, for example establishment of technology solutions for automating and monitoring the load on the network, and installing additional measurements at strategic points in the distribution network. 3 - Enabling customers' demand response: Initiatives that support that the grid company actively involves end users through price signals or by entering into agreements to regulate or move power consumption to a time of free capacity in the grid. 4 - Other activities: Measures which are horizontal and support that network companies develop a Smart Grid. New economic regulation of network companies is required to support the introduction of new technology in the grid, and at the same time crucial to enable customers' demand response. IT and data security must be established and customer engagement as active consumers of electricity should be strengthened. (LN)

The Internet of things and Smart Grid

Science.gov (United States)

Li, Biao; Lv, Sen; Pan, Qing

2018-02-01

The Internet of things and smart grid are the frontier of information and Industry. The combination of Internet of things and smart grid will greatly enhance the ability of smart grid information and communication support. The key technologies of the Internet of things will be applied to the smart grid, and the grid operation and management information perception service centre will be built to support the commanding heights of the world’s smart grid.

Wind energy in offshore grids

DEFF Research Database (Denmark)

Schröder, Sascha Thorsten

special characteristics of offshore grids. With an operational real options approach, it is furthermore illustrated how different support schemes and connections to additional countries affect the investment case of an offshore wind farm and the income of the transmission system operator. The investment...... and investment implications under different regulatory frameworks are a hitherto underrepresented research field. They are addressed by this thesis. Offshore grids between several countries combine the absorption of wind energy with international power trading. However, the inclusion into an offshore grid......This cumulative PhD thesis deals with wind integration in offshore grids from an economic point of view. It is composed of a generic part and eight papers. As the topic has mostly been analysed with a focus on topology and technical issues until now, market-operational questions in offshore grids...

Distribution Grid Integration of Photovoltaic Systems in Germany – Implications on Grid Planning and Grid Operation

International Nuclear Information System (INIS)

Stetz, Thomas

2017-01-01

Photovoltaic is the most dispersed renewable energy source in Germany, typically interconnected to low and medium voltage systems. In recent years, cost-intensive grid reinforcements had to be undertaken all across Germany’s distribution grids in order to increase their hosting capacity for these photovoltaic installations. This paper presents an overview on research results which show that photovoltaic itself can provide ancillary services to reduce its cost of interconnection. Especially the provision of reactive power turned out to be a technically effective and economically efficient method to increase a grid’s hosting capacity for photovoltaic capacity. Different reactive power control methods were investigated, revealing significant differences with regards to their grid operation implications. Business cases for residential-scale photovoltaic applications have shifted from feed-in-tariff based active power feed-in to self-consumption. However, increasing the photovoltaic self-consumption by additional battery-storage systems is still not economically reliable in Germany. (author)

Security and privacy in smart grids

CERN Document Server

Xiao, Yang

2013-01-01

Presenting the work of prominent researchers working on smart grids and related fields around the world, Security and Privacy in Smart Grids identifies state-of-the-art approaches and novel technologies for smart grid communication and security. It investigates the fundamental aspects and applications of smart grid security and privacy and reports on the latest advances in the range of related areas-making it an ideal reference for students, researchers, and engineers in these fields. The book explains grid security development and deployment and introduces novel approaches for securing today'

Research on the comparison of extension mechanism of cellular automaton based on hexagon grid and rectangular grid

Science.gov (United States)

Zhai, Xiaofang; Zhu, Xinyan; Xiao, Zhifeng; Weng, Jie

2009-10-01

Historically, cellular automata (CA) is a discrete dynamical mathematical structure defined on spatial grid. Research on cellular automata system (CAS) has focused on rule sets and initial condition and has not discussed its adjacency. Thus, the main focus of our study is the effect of adjacency on CA behavior. This paper is to compare rectangular grids with hexagonal grids on their characteristics, strengths and weaknesses. They have great influence on modeling effects and other applications including the role of nearest neighborhood in experimental design. Our researches present that rectangular and hexagonal grids have different characteristics. They are adapted to distinct aspects, and the regular rectangular or square grid is used more often than the hexagonal grid. But their relative merits have not been widely discussed. The rectangular grid is generally preferred because of its symmetry, especially in orthogonal co-ordinate system and the frequent use of raster from Geographic Information System (GIS). However, in terms of complex terrain, uncertain and multidirectional region, we have preferred hexagonal grids and methods to facilitate and simplify the problem. Hexagonal grids can overcome directional warp and have some unique characteristics. For example, hexagonal grids have a simpler and more symmetric nearest neighborhood, which avoids the ambiguities of the rectangular grids. Movement paths or connectivity, the most compact arrangement of pixels, make hexagonal appear great dominance in the process of modeling and analysis. The selection of an appropriate grid should be based on the requirements and objectives of the application. We use rectangular and hexagonal grids respectively for developing city model. At the same time we make use of remote sensing images and acquire 2002 and 2005 land state of Wuhan. On the base of city land state in 2002, we make use of CA to simulate reasonable form of city in 2005. Hereby, these results provide a proof of

A Review on Current Reference Calculation of Three-Phase Grid-Connected PV Converters under Grid Faults

DEFF Research Database (Denmark)

Afshari, Ehsan; Moradi, Gholam Reza; Yang, Yongheng

2017-01-01

Unbalanced grid voltage dips may lead to unbalanced non-sinusoidal current injections, dc-link voltage oscillations, and active and/or reactive power oscillations with twice the grid fundamental frequency in three-phase grid-connected Photovoltaic (PV) systems. Double grid frequency oscillations...... of the most important issues that should be coped with for a reliable operation of grid-connected converters under unbalanced grid faults. Accordingly, this paper reviews the existing CRC methods and presents a current reference generation method, which can have 16 unique modes. Issues are also investigated...... at the dc-link of the conventional two-stage PV inverters can further deteriorate the dc-link capacitor, which is one of the most life-limiting components in the system. Proper controls of these converters may efficiently address this problem. In those solutions, Current Reference Calculation (CRC) is one...

Challenges to Grid Synchronization of Single-Phase Grid-Connected Inverters in Zero-Voltage Ride-Through Operation

DEFF Research Database (Denmark)

Zhang, Zhen; Yang, Yongheng; Blaabjerg, Frede

2016-01-01

With the fast development in Photovoltaic (PV) technology, the relevant grid-connection requirements/standards are continuously being updated, and more challenges have been imposed on both single-phase and three-phase grid-connected PV systems. For instance, PV systems are currently required...... to remain connected under grid voltage sags (even zero voltage condition). In this case, much attention should be paid to the grid synchronization in such a way to properly ride-through grid faults. Thus, in this paper, the most commonly-used and recently-developed Phase Locked Loop (PLL) synchronization...... methods have been evaluated for single-phase grid-connected PV systems in the case of Zero-Voltage Ride-Through (ZVRT) operation. The performances of the prior-art PLL methods in response to zero voltage faults in terms of detection precision and dynamic response are assessed in this paper. Simulation...

Grid-Optimization Program for Photovoltaic Cells

Science.gov (United States)

Daniel, R. E.; Lee, T. S.

1986-01-01

CELLOPT program developed to assist in designing grid pattern of current-conducting material on photovoltaic cell. Analyzes parasitic resistance losses and shadow loss associated with metallized grid pattern on both round and rectangular solar cells. Though performs sensitivity studies, used primarily to optimize grid design in terms of bus bar and grid lines by minimizing power loss. CELLOPT written in APL.

Grid-connected photovoltaic (PV) systems with batteries storage as solution to electrical grid outages in Burkina Faso

International Nuclear Information System (INIS)

Abdoulaye, D; Koalaga, Z; Zougmore, F

2012-01-01

This paper deals with a key solution for power outages problem experienced by many African countries and this through grid-connected photovoltaic (PV) systems with batteries storage. African grids are characterized by an insufficient power supply and frequent interruptions. Due to this fact, users who especially use classical grid-connected photovoltaic systems are unable to profit from their installation even if there is sun. In this study, we suggest the using of a grid-connected photovoltaic system with batteries storage as a solution to these problems. This photovoltaic system works by injecting the surplus of electricity production into grid and can also deliver electricity as a stand-alone system with all security needed. To achieve our study objectives, firstly we conducted a survey of a real situation of one African electrical grid, the case of Burkina Faso (SONABEL: National Electricity Company of Burkina). Secondly, as study case, we undertake a sizing, a modeling and a simulation of a grid-connected PV system with batteries storage for the LAME laboratory at the University of Ouagadougou. The simulation shows that the proposed grid-connected system allows users to profit from their photovoltaic installation at any time even if the public electrical grid has some failures either during the day or at night.

Triple-layer smart grid business model

DEFF Research Database (Denmark)

Ma, Zheng; Lundgaard, Morten; Jørgensen, Bo Nørregaard

2016-01-01

Viewing the smart grid with the theory of business models may open opportunities in understanding and capturing values in new markets. This study tries to discover and map the smart grid ecosystem-based business model framework with two different environments (sub-Saharan Africa and Denmark......), and identifies the parameters for the smart grid solutions to the emerging markets. This study develops a triple-layer business model including the organizational (Niche), environmental (Intermediate), and global (Dominators) factors. The result uncovers an interface of market factors and stakeholders...... in a generic smart grid constellation. The findings contribute the transferability potential of the smart grid solutions between countries, and indicate the potential to export and import smart grid solutions based on the business modeling....

A Guidebook on Grid Interconnection and Islanded Operation of Mini-Grid Power Systems Up to 200 kW

Energy Technology Data Exchange (ETDEWEB)

Greacen, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Engel, Richard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Quetchenbach, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2013-04-01

A Guidebook on Grid Interconnection and Islanded Operation of Mini-Grid Power Systems Up to 200 kW is intended to help meet the widespread need for guidance, standards, and procedures for interconnecting mini-grids with the central electric grid as rural electrification advances in developing countries, bringing these once separate power systems together. The guidebook aims to help owners and operators of renewable energy mini-grids understand the technical options available, safety and reliability issues, and engineering and administrative costs of different choices for grid interconnection. The guidebook is intentionally brief but includes a number of appendices that point the reader to additional resources for indepth information. Not included in the scope of the guidebook are policy concerns about “who pays for what,” how tariffs should be set, or other financial issues that are also paramount when “the little grid connects to the big grid.”

Integrating GRID tools to build a computing resource broker: activities of DataGrid WP1

International Nuclear Information System (INIS)

Anglano, C.; Barale, S.; Gaido, L.; Guarise, A.; Lusso, S.; Werbrouck, A.

2001-01-01

Resources on a computational Grid are geographically distributed, heterogeneous in nature, owned by different individuals or organizations with their own scheduling policies, have different access cost models with dynamically varying loads and availability conditions. This makes traditional approaches to workload management, load balancing and scheduling inappropriate. The first work package (WP1) of the EU-funded DataGrid project is addressing the issue of optimizing the distribution of jobs onto Grid resources based on a knowledge of the status and characteristics of these resources that is necessarily out-of-date (collected in a finite amount of time at a very loosely coupled site). The authors describe the DataGrid approach in integrating existing software components (from Condor, Globus, etc.) to build a Grid Resource Broker, and the early efforts to define a workable scheduling strategy

Integration of Heat Pumps in Distribution Grids: Economic Motivation for Grid Control

NARCIS (Netherlands)

Nykamp, Stefan; Molderink, Albert; Bakker, Vincent; Toersche, Hermen; Hurink, Johann L.; Smit, Gerardus Johannes Maria

2012-01-01

Electric heat pumps combined with heat buffers are important elements in smart grids since they together allow to shift the consumption of electricity in time. In this paper the effects of different control algorithms for heat pumps on the investment costs for distribution grids are investigated.

Integration of heat pumps in distribution grids: economic motivation for grid control

NARCIS (Netherlands)

Nykamp, Stefan; Molderink, Albert; Bakker, Vincent; Toersche, Hermen; Hurink, Johann L.; Smit, Gerardus Johannes Maria

2012-01-01

Electric heat pumps combined with heat buffers are important elements in smart grids since they together allow to shift the consumption of electricity in time. In this paper the effects of different control algorithms for heat pumps on the investment costs for distribution grids are investigated.

Benchmarking of grid fault modes in single-phase grid-connected photovoltaic systems

DEFF Research Database (Denmark)

Yang, Yongheng; Blaabjerg, Frede; Zou, Zhixiang

2012-01-01

Pushed by the booming installations of single-phase photovoltaic (PV) systems, the grid demands regarding the integration of PV systems are expected to be modified. Hence, the future PV systems should become more active with functionalities of low voltage ride-through (LVRT) and the grid support...

The CrossGrid project

International Nuclear Information System (INIS)

Kunze, M.

2003-01-01

There are many large-scale problems that require new approaches to computing, such as earth observation, environmental management, biomedicine, industrial and scientific modeling. The CrossGrid project addresses realistic problems in medicine, environmental protection, flood prediction, and physics analysis and is oriented towards specific end-users: Medical doctors, who could obtain new tools to help them to obtain correct diagnoses and to guide them during operations; industries, that could be advised on the best timing for some critical operations involving risk of pollution; flood crisis teams, that could predict the risk of a flood on the basis of historical records and actual hydrological and meteorological data; physicists, who could optimize the analysis of massive volumes of data distributed across countries and continents. Corresponding applications will be based on Grid technology and could be complex and difficult to use: the CrossGrid project aims at developing several tools that will make the Grid more friendly for average users. Portals for specific applications will be designed, that should allow for easy connection to the Grid, create a customized work environment, and provide users with all necessary information to get their job done

Flexible Control Strategy for Grid-Connected Inverter under Unbalanced Grid Faults without PLL

DEFF Research Database (Denmark)

Guo, Xiaoqiang; Liu, W.; Zhang, X.

2015-01-01

Power oscillation and current quality are the important performance targets for the grid-connected inverter under unbalanced grid faults. Firstly, the inherent reason for the current harmonic and power oscillation of the inverter is discussed with a quantitative analysis. Secondly, a new control...... strategy is proposed to achieve the coordinate control of power and current quality without the need for a phase-locked loop or voltage/current positive/negative sequence extraction calculation. Finally, the experimental tests are conducted under unbalanced grid faults, and the results verify...

Smart Grid Status and Metrics Report

Energy Technology Data Exchange (ETDEWEB)

Balducci, Patrick J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weimar, Mark R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kirkham, Harold [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-07-01

To convey progress made in achieving the vision of a smart grid, this report uses a set of six characteristics derived from the National Energy Technology Laboratory Modern Grid Strategy. It measures 21 metrics to provide insight into the grid’s capacity to embody these characteristics. This report looks across a spectrum of smart grid concerns to measure the status of smart grid deployment and impacts.

Optimal sizing of a hybrid grid-connected photovoltaic and wind power system

International Nuclear Information System (INIS)

González, Arnau; Riba, Jordi-Roger; Rius, Antoni; Puig, Rita

2015-01-01

Highlights: • Hybrid renewable energy systems are efficient mechanisms to generate electrical power. • This work optimally sizes hybrid grid-connected photovoltaic–wind power systems. • It deals with hourly wind, solar irradiation and electricity demand data. • The system cost is minimized while matching the electricity supply with the demand. • A sensitivity analysis to detect the most critical design variables has been done. - Abstract: Hybrid renewable energy systems (HRES) have been widely identified as an efficient mechanism to generate electrical power based on renewable energy sources (RES). This kind of energy generation systems are based on the combination of one or more RES allowing to complement the weaknesses of one with strengths of another and, therefore, reducing installation costs with an optimized installation. To do so, optimization methodologies are a trendy mechanism because they allow attaining optimal solutions given a certain set of input parameters and variables. This work is focused on the optimal sizing of hybrid grid-connected photovoltaic–wind power systems from real hourly wind and solar irradiation data and electricity demand from a certain location. The proposed methodology is capable of finding the sizing that leads to a minimum life cycle cost of the system while matching the electricity supply with the local demand. In the present article, the methodology is tested by means of a case study in which the actual hourly electricity retail and market prices have been implemented to obtain realistic estimations of life cycle costs and benefits. A sensitivity analysis that allows detecting to which variables the system is more sensitive has also been performed. Results presented show that the model responds well to changes in the input parameters and variables while providing trustworthy sizing solutions. According to these results, a grid-connected HRES consisting of photovoltaic (PV) and wind power technologies would be

Incentive Mechanism of Micro-grid Project Development

Directory of Open Access Journals (Sweden)

Yong Long

2018-01-01

Full Text Available Due to the issue of cost and benefit, the investment demand and consumption demand of micro-grids are insufficient in the early stages, which makes all parties lack motivation to participate in the development of micro-grid projects and leads to the slow development of micro-grids. In order to promote the development of micro-grids, the corresponding incentive mechanism should be designed to motivate the development of micro-grid projects. Therefore, this paper builds a multi-stage incentive model of micro-grid project development involving government, grid corporation, energy supplier, equipment supplier, and the user in order to study the incentive problems of micro-grid project development. Through the solution and analysis of the model, this paper deduces the optimal subsidy of government and the optimal cooperation incentive of the energy supplier, and calculates the optimal pricing strategy of grid corporation and the energy supplier, and analyzes the influence of relevant factors on optimal subsidy and incentive. The study reveals that the cost and social benefit of micro-grid development have a positive impact on micro-grid subsidy, technical level and equipment quality of equipment supplier as well as the fact that government subsidies positively adjust the level of cooperation incentives and price incentives. In the end, the validity of the model is verified by numerical analysis, and the incentive strategy of each participant is analyzed. The research of this paper is of great significance to encourage project development of micro-grids and to promote the sustainable development of micro-grids.

Smart Grid facets in the world; Les visages de Smart Grid dans le monde

Energy Technology Data Exchange (ETDEWEB)

Marcoux, Benoit; Bauchot, Frederic

2010-09-15

There is a certain consensus on what is the Smart Grid, but priorities vary from one world region to the next. These differences bring business strategies and objectives that vary from one electrical company to the next. However: Smart Grid programs of electrical companies are based on the same elements. -Smart Grid benefits are mainly gained by a greater integration at all levels. -Implementation priorities vary from one region to the next; the regions studied in this paper are the United States, Quebec, France, Denmark and China. [French] Un certain consensus se forme sur ce que constitue le Smart Grid, mais les priorites varient d'une region du monde a l'autre. Ces differences amenent des strategies et des objectifs d'affaires qui varient d'une entreprise d'electricite a l'autre. Cependant : -Les programmes de Smart Grid des entreprises d'electricite se basent sur les memes elements. -Les benefices du Smart Grid passe avant tout par une plus grande integration a tous les niveaux. -Les priorites d'implantation varient d'une region a l'autre; les regions etudiees dans ce papier sont les etats-Unis, le Quebec, la France, le Danemark et la Chine.

Using a grid platform for solving large sparse linear systems over GF(2)

OpenAIRE

Kleinjung , Thorsten; Nussbaum , Lucas; Thomé , Emmanuel

2010-01-01

International audience; In Fall 2009, the final step of the factorization of rsa768 was carried out on several clusters of the Grid'5000 platform, leading to a new record in integer factorization. This step involves solving a huge sparse linear system defined over the binary field GF(2). This article aims at describing the algorithm used, the difficulties encountered, and the methodology which led to success. In particular, we illustrate how our use of the block Wiedemann algorithm led to a m...

Security for grids

Energy Technology Data Exchange (ETDEWEB)

Humphrey, Marty; Thompson, Mary R.; Jackson, Keith R.

2005-08-14

Securing a Grid environment presents a distinctive set of challenges. This paper groups the activities that need to be secured into four categories: naming and authentication; secure communication; trust, policy, and authorization; and enforcement of access control. It examines the current state of the art in securing these processes and introduces new technologies that promise to meet the security requirements of Grids more completely.

SoilGrids1km--global soil information based on automated mapping.

Directory of Open Access Journals (Sweden)

Tomislav Hengl

Full Text Available BACKGROUND: Soils are widely recognized as a non-renewable natural resource and as biophysical carbon sinks. As such, there is a growing requirement for global soil information. Although several global soil information systems already exist, these tend to suffer from inconsistencies and limited spatial detail. METHODOLOGY/PRINCIPAL FINDINGS: We present SoilGrids1km--a global 3D soil information system at 1 km resolution--containing spatial predictions for a selection of soil properties (at six standard depths: soil organic carbon (g kg-1, soil pH, sand, silt and clay fractions (%, bulk density (kg m-3, cation-exchange capacity (cmol+/kg, coarse fragments (%, soil organic carbon stock (t ha-1, depth to bedrock (cm, World Reference Base soil groups, and USDA Soil Taxonomy suborders. Our predictions are based on global spatial prediction models which we fitted, per soil variable, using a compilation of major international soil profile databases (ca. 110,000 soil profiles, and a selection of ca. 75 global environmental covariates representing soil forming factors. Results of regression modeling indicate that the most useful covariates for modeling soils at the global scale are climatic and biomass indices (based on MODIS images, lithology, and taxonomic mapping units derived from conventional soil survey (Harmonized World Soil Database. Prediction accuracies assessed using 5-fold cross-validation were between 23-51%. CONCLUSIONS/SIGNIFICANCE: SoilGrids1km provide an initial set of examples of soil spatial data for input into global models at a resolution and consistency not previously available. Some of the main limitations of the current version of SoilGrids1km are: (1 weak relationships between soil properties/classes and explanatory variables due to scale mismatches, (2 difficulty to obtain covariates that capture soil forming factors, (3 low sampling density and spatial clustering of soil profile locations. However, as the SoilGrids system is

Understanding consumer attitudes toward food technologies in Canada.

Science.gov (United States)

Henson, Spencer; Annou, Mamane; Cranfield, John; Ryks, Joanne

2008-12-01

This article reports a study on consumer attitudes to 21 food and nonfood technologies in Canada. The study involves repertory grid interviews with 36 food consumers, the data from which are analyzed using generalized Procrustes analysis. Results highlight the role of perceived risk and perceived benefit in determining the acceptability of the technologies, with individual technologies lying along a continuum between the two. For technology as a whole and the 21 specific technologies, the perceived risk and perceived benefit constructs were the dominant determinants of consumer acceptability. While perceptions of perceived risk and perceived benefit differed between individual respondents, there were very limited consistent relations with a range of sociodemographic variables.

A Grid Voltage Measurement Method for Wind Power Systems during Grid Fault Conditions

Directory of Open Access Journals (Sweden)

Cheol-Hee Yoo

2014-11-01

Full Text Available Grid codes in many countries require low-voltage ride-through (LVRT capability to maintain power system stability and reliability during grid fault conditions. To meet the LVRT requirement, wind power systems must stay connected to the grid and also supply reactive currents to the grid to support the recovery from fault voltages. This paper presents a new fault detection method and inverter control scheme to improve the LVRT capability for full-scale permanent magnet synchronous generator (PMSG wind power systems. Fast fault detection can help the wind power systems maintain the DC-link voltage in a safe region. The proposed fault detection method is based on on-line adaptive parameter estimation. The performance of the proposed method is verified in comparison to the conventional voltage measurement method defined in the IEC 61400-21 standard.

Power Quality of Grid-Connected Wind Turbines with DFIG and Their Interaction with the Grid

DEFF Research Database (Denmark)

Sun, Tao

quality issues of grid-connected wind turbines and the interaction between wind turbines and the grid. The specific goal of the research has been to investigate flicker emission and mitigation of grid-connected wind turbines with doubly fed induction generators (DFIG) during continuous operation...... measures are proposed to mitigate the flicker levels produced by grid-connected wind turbines with DFIG, respectively by wind turbine output reactive power control and using STATCOM. Simulation results demonstrate that these two measures are effective for flicker mitigation regardless of mean wind speed....... To evaluate the flicker levels produced by grid-connected wind turbines with DFIG, a flickermeter model is developed according to the IEC standard IEC 61000-4-15, which simulates the response of the lamp-eye-brain chain and provides on-line statistical analysis ofthe flicker signal and the final results...

Ecosystem Based Business Model of Smart Grid

DEFF Research Database (Denmark)

Lundgaard, Morten Raahauge; Ma, Zheng; Jørgensen, Bo Nørregaard

2015-01-01

This paper tries to investigate the ecosystem based business model in a smart grid infrastructure and the potential of value capture in the highly complex macro infrastructure such as smart grid. This paper proposes an alternative perspective to study the smart grid business ecosystem to support...... the infrastructural challenges, such as the interoperability of business components for smart grid. So far little research has explored the business ecosystem in the smart grid concept. The study on the smart grid with the theory of business ecosystem may open opportunities to understand market catalysts. This study...... contributes an understanding of business ecosystem applicable for smart grid. Smart grid infrastructure is an intricate business ecosystem, which have several intentions to deliver the value proposition and what it should be. The findings help to identify and capture value from markets....

Equivalent Simplification Method of Micro-Grid

OpenAIRE

Cai Changchun; Cao Xiangqin

2013-01-01

The paper concentrates on the equivalent simplification method for the micro-grid system connection into distributed network. The equivalent simplification method proposed for interaction study between micro-grid and distributed network. Micro-grid network, composite load, gas turbine synchronous generation, wind generation are equivalent simplification and parallel connect into the point of common coupling. A micro-grid system is built and three phase and single phase grounded faults are per...

Data privacy for the smart grid

CERN Document Server

Herold, Rebecca

2015-01-01

The Smart Grid and PrivacyWhat Is the Smart Grid? Changes from Traditional Energy Delivery Smart Grid Possibilities Business Model Transformations Emerging Privacy Risks The Need for Privacy PoliciesPrivacy Laws, Regulations, and Standards Privacy-Enhancing Technologies New Privacy Challenges IOT Big Data What Is the Smart Grid?Market and Regulatory OverviewTraditional Electricity Business SectorThe Electricity Open Market Classifications of Utilities Rate-Making ProcessesElectricity Consumer

Smart grid standards specifications, requirements, and technologies

CERN Document Server

Sato, Takuro; Duan, Bin; Macuha, Martin; Zhou, Zhenyu; Wu, Jun; Tariq, Muhammad; Asfaw, Solomon A

2015-01-01

With numerous existing Smart Grid standards, it is clear that governments and industrial organizations world-wide have understood and acknowledged the critical role they play. This timely book is a useful guide for Smart Grid professionals in easily classifying fundamental Smart Grid standards, and to quickly find the building blocks they need to analyse and implement a Smart Grid system. The standards are organized in a systematic manner that aids identification, according to grid requirements. It also covers broader Smart Grid areas including, but not limited to, the following: A fully c

Planning in Smart Grids

NARCIS (Netherlands)

Bosman, M.G.C.

2012-01-01

The electricity supply chain is changing, due to increasing awareness for sustainability and an improved energy efficiency. The traditional infrastructure where demand is supplied by centralized generation is subject to a transition towards a Smart Grid. In this Smart Grid, sustainable generation

Smart Grid in Denmark. Appendix report; Smart Grid i Danmark. Bilagsrapport

Energy Technology Data Exchange (ETDEWEB)

2010-07-01

Electricity consumption and electricity production in Denmark will change significantly in future years. Electricity customers will demand new services in line with that they replace oil furnaces with electric heat pumps and the traditional petrol car with an electric car. The electricity sector must be ready to deliver those services with the same high delivery reliability as before. This must happen in a situation where power generation is increasingly coming from renewable energy. The purpose of the present analysis was to describe and analyse the specific challenges facing the electricity system in the next 15 to 25 years. Energinet.dk and the Danish Energy Association has analysed the part of the Smart Grid that enables an efficient interaction between wind power production, heat pumps in residential buildings as well as electric and plug-in hybrid cars. The appendix report describes the following issues: Scenarios for the power system's future loads; Optimisation of the power distribution grid for the future; Electro technical challenges in the future power grid; Components for handling the future challenges; Value of power system deliveries through establishing a Smart Grid; Economic analyses. (ln)

Smart grid: hope or hype?

DEFF Research Database (Denmark)

Lunde, Morten; Røpke, Inge; Heiskanen, Eva

2016-01-01

how their (intentional or unintentional) choices serve to create or maintain certain boundaries in smart grid development: for example, an exclusive focus on electricity within the broader context of a sustainable energy system. As serious investment starts being made in the smart grid, concepts like......The smart grid is an important but ambiguous element in the future transition of the European energy system. The current paper unpacks one influential national vision of the smart grid to identify what kinds of expectations guide the work of smart grid innovators and how the boundaries of the smart...... research and development and to attract new players into the field. A scenario process such as that demonstrated in this article can serve to articulate some of these implicit assumptions and help actors to navigate the ongoing transition. On the basis of our analysis, European policy makers might consider...

Compilation and review of methodologies for estimating the comparative electric power system costs for renewable energy systems. Working material

International Nuclear Information System (INIS)

1993-01-01

This Working Material provides a review of methodologies for estimating the costs of renewable energy systems and the state of art knowledge on stochastic features and economic evaluation methodologies of renewable energy systems for electricity generation in a grid integrated system. It is expected that this material facilitates the wider access by interested persons to sources for relevant comparative assessment activities which are progressing in the IAEA. Refs, figs, tabs

Smart Grids and Distributed Generation

Directory of Open Access Journals (Sweden)

Dorin BICĂ

2018-06-01

Full Text Available This paper describes the main characteristics of Smart Grids and distributed generation. Smart Grids can be defined as a modernization of the power system so it monitors, protects and automatically optimizes the operation of its interconnected elements (power plants, transmission and distribution system, industrial and residential loads. Distributed generation (DG refers to the production of electricity near the consumption place using renewable energy sources. A load flow analysis is performed for the IEEE14 system in which a DG source (a 5MW wind turbine is added that is on-grid or off-grid. The power losses are determined for these two cases.

Helicopter Rotor Blade Computation in Unsteady Flows Using Moving Overset Grids

Science.gov (United States)

Ahmad, Jasim; Duque, Earl P. N.

1996-01-01

An overset grid thin-layer Navier-Stokes code has been extended to include dynamic motion of helicopter rotor blades through relative grid motion. The unsteady flowfield and airloads on an AH-IG rotor in forward flight were computed to verify the methodology and to demonstrate the method's potential usefulness towards comprehensive helicopter codes. In addition, the method uses the blade's first harmonics measured in the flight test to prescribe the blade motion. The solution was impulsively started and became periodic in less than three rotor revolutions. Detailed unsteady numerical flow visualization techniques were applied to the entire unsteady data set of five rotor revolutions and exhibited flowfield features such as blade vortex interaction and wake roll-up. The unsteady blade loads and surface pressures compare well against those from flight measurements. Details of the method, a discussion of the resulting predicted flowfield, and requirements for future work are presented. Overall, given the proper blade dynamics, this method can compute the unsteady flowfield of a general helicopter rotor in forward flight.

Wind power integration in island-based smart grid projects : A comparative study between Jeju Smart Grid Test-bed and Smart Grid Gotland

OpenAIRE

Piehl, Hampus

2014-01-01

Smart grids seem to be the solution to use energy from renewable and intermittent energy sources in an efficient manner. There are many research projects around the world and two of them are Jeju Smart Grid Test-bed and Smart Grid Gotland. They have in common that they are both island-based projects and connected to the Powergrid on the mainland by HVDC-link. The purpose of this thesis is to compare the two projects and find out what challenges and strategies they have related to wind power i...

Grid computing in high-energy physics

International Nuclear Information System (INIS)

Bischof, R.; Kuhn, D.; Kneringer, E.

2003-01-01

Full text: The future high energy physics experiments are characterized by an enormous amount of data delivered by the large detectors presently under construction e.g. at the Large Hadron Collider and by a large number of scientists (several thousands) requiring simultaneous access to the resulting experimental data. Since it seems unrealistic to provide the necessary computing and storage resources at one single place, (e.g. CERN), the concept of grid computing i.e. the use of distributed resources, will be chosen. The DataGrid project (under the leadership of CERN) develops, based on the Globus toolkit, the software necessary for computation and analysis of shared large-scale databases in a grid structure. The high energy physics group Innsbruck participates with several resources in the DataGrid test bed. In this presentation our experience as grid users and resource provider is summarized. In cooperation with the local IT-center (ZID) we installed a flexible grid system which uses PCs (at the moment 162) in student's labs during nights, weekends and holidays, which is especially used to compare different systems (local resource managers, other grid software e.g. from the Nordugrid project) and to supply a test bed for the future Austrian Grid (AGrid). (author)

A login shell interface for INFN-GRID

Energy Technology Data Exchange (ETDEWEB)

Pardi, S [INFN - Sezione di Napoli, Complesso di Monte S.Angelo - Via Cintia 80126 Napoli (Italy); Calloni, E; Rosa, R De; Garufi, F; Milano, L; Russo, G [Universita degli Studi di Napoli ' Federico M' , Dipartimento di Scienze Fisiche, Complesso di Monte S.Angelo - Via Cintia 80126 Napoli (Italy)], E-mail: silvio.pardi@na.infn.it

2008-12-15

The user interface is a crucial service to guarantee the Grid accessibility. The goal to achieve, is the implementation of an environment able to hide the grid complexity and offer a familiar interface to the final user. Currently many graphical interfaces have been proposed to simplify the grid access, but the GUI approach appears not very congenital to UNIX developers and users accustomed to work with command line interface. In 2004 the GridShell project proposed an extension of popular UNIX shells such as TCSH and BASH with features supporting Grid computing. Starting from the ideas included in GridShell, we propose IGSH (INFN-GRID SHELL) a new login shell for the INFN-GRID middleware, that interact with the Resource Broker services and integrates in a 'naturally way' the grid functionality with a familiar interface. The architecture of IGSH is very simple, it consist of a software layer on the top of the INFN-GRID middleware layer. When some operation is performed by the user, IGSH takes in charge to parse the syntax and translate it in the correspondents INFN-GRID commands according to some semantic rules specified in the next sections. The final user interacts with the underlying distributed infrastructure by using IGSH instead of his default login shell, with the sensation to work on a local machine.

A login shell interface for INFN-GRID

International Nuclear Information System (INIS)

Pardi, S; Calloni, E; Rosa, R De; Garufi, F; Milano, L; Russo, G

2008-01-01

The user interface is a crucial service to guarantee the Grid accessibility. The goal to achieve, is the implementation of an environment able to hide the grid complexity and offer a familiar interface to the final user. Currently many graphical interfaces have been proposed to simplify the grid access, but the GUI approach appears not very congenital to UNIX developers and users accustomed to work with command line interface. In 2004 the GridShell project proposed an extension of popular UNIX shells such as TCSH and BASH with features supporting Grid computing. Starting from the ideas included in GridShell, we propose IGSH (INFN-GRID SHELL) a new login shell for the INFN-GRID middleware, that interact with the Resource Broker services and integrates in a 'naturally way' the grid functionality with a familiar interface. The architecture of IGSH is very simple, it consist of a software layer on the top of the INFN-GRID middleware layer. When some operation is performed by the user, IGSH takes in charge to parse the syntax and translate it in the correspondents INFN-GRID commands according to some semantic rules specified in the next sections. The final user interacts with the underlying distributed infrastructure by using IGSH instead of his default login shell, with the sensation to work on a local machine.

Synchronous compensators for mini-grids and islanding: final report

Energy Technology Data Exchange (ETDEWEB)

Thornycroft, J.; Caisley, A.; Russell, T.; Willis, S.; Youssef, R.; Bawden, R.; Holden, G.; Williams, J.

2004-07-01

This report presents the findings of a project to develop equipment suitable for the operation of islanded induction generator wind turbines in remote areas with voltage control supplied by synchronous compensators and frequency control supplied by distributed intelligent load controllers. The development of a design methodology for stand-alone wind turbines systems is described, and details are given of its application to the construction of a 25kw Gazelle wind turbine in Sunderland and a 300kW Windmaster wind turbine in Northumberland. Both systems were islanded from the electric grid and fitted with synchronous compensators and distributed intelligent load controllers. The work carried out is listed, and design considerations, system simulation, and the data logging systems are discussed.

A novel multi-model neuro-fuzzy-based MPPT for three-phase grid-connected photovoltaic system

Energy Technology Data Exchange (ETDEWEB)

Chaouachi, Aymen; Kamel, Rashad M.; Nagasaka, Ken [Department of Electronic and Information Engineering, Tokyo University of Agriculture and Technology, Nakamachi (Japan)

2010-12-15

This paper presents a novel methodology for Maximum Power Point Tracking (MPPT) of a grid-connected 20 kW photovoltaic (PV) system using neuro-fuzzy network. The proposed method predicts the reference PV voltage guarantying optimal power transfer between the PV generator and the main utility grid. The neuro-fuzzy network is composed of a fuzzy rule-based classifier and three multi-layered feed forwarded Artificial Neural Networks (ANN). Inputs of the network (irradiance and temperature) are classified before they are fed into the appropriated ANN for either training or estimation process while the output is the reference voltage. The main advantage of the proposed methodology, comparing to a conventional single neural network-based approach, is the distinct generalization ability regarding to the nonlinear and dynamic behavior of a PV generator. In fact, the neuro-fuzzy network is a neural network based multi-model machine learning that defines a set of local models emulating the complex and nonlinear behavior of a PV generator under a wide range of operating conditions. Simulation results under several rapid irradiance variations proved that the proposed MPPT method fulfilled the highest efficiency comparing to a conventional single neural network and the Perturb and Observe (P and O) algorithm dispositive. (author)

GENIUS: a web portal for the grid

International Nuclear Information System (INIS)

Andronico, A.; Barbera, R.; Falzone, A.; Lo Re, G.; Pulvirenti, A.; Rodolico, A.

2003-01-01

The architecture and the current implementation of the grid portal GENIUS (Grid Enabled web environment for site Independent User job Submission), jointly developed by INFN and NICE within the context of the INFN Grid and DataGrid Project, is presented and discussed

Reliability evaluation of smart distribution grids

OpenAIRE

Kazemi, Shahram

2011-01-01

The term "Smart Grid" generally refers to a power grid equipped with the advanced technologies dedicated for purposes such as reliability improvement, ease of control and management, integrating of distributed energy resources and electricity market operations. Improving the reliability of electric power delivered to the end users is one of the main targets of employing smart grid technologies. The smart grid investments targeted for reliability improvement can be directed toward the generati...

STAMMEX high resolution gridded daily precipitation dataset over Germany: a new potential for regional precipitation climate research

Science.gov (United States)

Zolina, Olga; Simmer, Clemens; Kapala, Alice; Mächel, Hermann; Gulev, Sergey; Groisman, Pavel

2014-05-01

We present new high resolution precipitation daily grids developed at Meteorological Institute, University of Bonn and German Weather Service (DWD) under the STAMMEX project (Spatial and Temporal Scales and Mechanisms of Extreme Precipitation Events over Central Europe). Daily precipitation grids have been developed from the daily-observing precipitation network of DWD, which runs one of the World's densest rain gauge networks comprising more than 7500 stations. Several quality-controlled daily gridded products with homogenized sampling were developed covering the periods 1931-onwards (with 0.5 degree resolution), 1951-onwards (0.25 degree and 0.5 degree), and 1971-2000 (0.1 degree). Different methods were tested to select the best gridding methodology that minimizes errors of integral grid estimates over hilly terrain. Besides daily precipitation values with uncertainty estimates (which include standard estimates of the kriging uncertainty as well as error estimates derived by a bootstrapping algorithm), the STAMMEX data sets include a variety of statistics that characterize temporal and spatial dynamics of the precipitation distribution (quantiles, extremes, wet/dry spells, etc.). Comparisons with existing continental-scale daily precipitation grids (e.g., CRU, ECA E-OBS, GCOS) which include considerably less observations compared to those used in STAMMEX, demonstrate the added value of high-resolution grids for extreme rainfall analyses. These data exhibit spatial variability pattern and trends in precipitation extremes, which are missed or incorrectly reproduced over Central Europe from coarser resolution grids based on sparser networks. The STAMMEX dataset can be used for high-quality climate diagnostics of precipitation variability, as a reference for reanalyses and remotely-sensed precipitation products (including the upcoming Global Precipitation Mission products), and for input into regional climate and operational weather forecast models. We will present

Power reserve provision with wind farms. Grid integration of wind power

Energy Technology Data Exchange (ETDEWEB)

Gesino, Alejandro J.

2011-07-01

Wind power is, admittedly, different from other power technologies and integrating large amounts of it in the existing power systems is a challenge that requires innovative approaches to keep the sustainability of the power system operation. In the coming years its contribution to the system security will become mandatory as far as the trend goes towards more decentralized structures and an increase in complexity due to a higher number of market participants. This PhD addresses one of the fundamental ancillary services researching about a secure and flexible methodology for power reserve provision with wind farms. Based on the current needs and security standards of those highly developed European grid codes, a new model for power reserve provision with wind power is developed. This methodology, algorithms and variables are tested based on real scenarios from five German wind farm clusters. Finally, once the methodology for power reserve provision with wind power has been tested, real control capabilities from already installed wind farms in Germany and Portugal are analyzed. Their capabilities of following control commands as well as an error deviation analysis are also presented. (orig.)

For smart electric grids

International Nuclear Information System (INIS)

Tran Thiet, Jean-Paul; Leger, Sebastien; Bressand, Florian; Perez, Yannick; Bacha, Seddik; Laurent, Daniel; Perrin, Marion

2012-01-01

The authors identify and discuss the main challenges faced by the French electric grid: the management of electricity demand and the needed improvement of energy efficiency, the evolution of consumer's state of mind, and the integration of new production capacities. They notably outline that France have been living until recently with an electricity abundance, but now faces the highest consumption peaks in Europe, and is therefore facing higher risks of power cuts. They also notice that the French energy mix is slowly evolving, and outline the problems raised by the fact that renewable energies which are to be developed, are decentralised and intermittent. They propose an overview of present developments of smart grids, and outline their innovative characteristics, challenges raised by their development and compare international examples. They show that smart grids enable a better adapted supply and decentralisation. A set of proposals is formulated about how to finance and to organise the reconfiguration of electric grids, how to increase consumer's responsibility for peak management and demand management, how to create the conditions of emergence of a European market of smart grids, and how to support self-consumption and the building-up of an energy storage sector

GENECODIS-Grid: An online grid-based tool to predict functional information in gene lists

International Nuclear Information System (INIS)

Nogales, R.; Mejia, E.; Vicente, C.; Montes, E.; Delgado, A.; Perez Griffo, F. J.; Tirado, F.; Pascual-Montano, A.

2007-01-01

In this work we introduce GeneCodis-Grid, a grid-based alternative to a bioinformatics tool named Genecodis that integrates different sources of biological information to search for biological features (annotations) that frequently co-occur in a set of genes and rank them by statistical significance. GeneCodis-Grid is a web-based application that takes advantage of two independent grid networks and a computer cluster managed by a meta-scheduler and a web server that host the application. The mining of concurrent biological annotations provides significant information for the functional analysis of gene list obtained by high throughput experiments in biology. Due to the large popularity of this tool, that has registered more than 13000 visits since its publication in January 2007, there is a strong need to facilitate users from different sites to access the system simultaneously. In addition, the complexity of some of the statistical tests used in this approach has made this technique a good candidate for its implementation in a Grid opportunistic environment. (Author)

A performance study of grid workflow engines

NARCIS (Netherlands)

Stratan, C.; Iosup, A.; Epema, D.H.J.

2008-01-01

To benefit from grids, scientists require grid workflow engines that automatically manage the execution of inter-related jobs on the grid infrastructure. So far, the workflows community has focused on scheduling algorithms and on interface tools. Thus, while several grid workflow engines have been

Conference on grid integration of renewable energies

International Nuclear Information System (INIS)

Fontaine, Pierre; Goeke, Berthold; Mignon, Herve; Brakelmann, Heinrich; Huebner, Gundula; Tanja Schmedes; Remy Garaude Verdier; Pierre-Guy Therond; Werner Diwald

2012-01-01

The French-German office for Renewable energies (OFAEnR) organised a conference on grid integration of renewable energies. In the framework of this French-German exchange of experience, about a hundred of participants exchanged views on the similarities and differences between the French and German approaches of renewable energies integration to grids. This document brings together the available presentations (slides) made during this event: 1 - Power grid development - Policy and challenges (Pierre Fontaine); 2 - Grid Development: German Strategy (Berthold Goeke); 3 - Power grids development: situational analysis (Herve Mignon); 4 - Traditional Power Lines, Partial Underground Cabling and HVDC lines: Costs, Benefits and Acceptance (Heinrich Brakelmann); 5 - Transmission Lines - Local Acceptance (Gundula Huebner); 6 - eTelligence- energy meets Intelligence: experience feedback from the grid operator EWe on smart grids and the integration of renewable energies (Tanja Schmedes); 7 - Nice Grid, The French Smart Grid Project within Grid4eU (Remy Garaude Verdier); 8 - Economical Analysis Of energy Storage For Renewable energy Farms - experience of EDF en on the basis of 3 call for tender issued by the French Government in 01/2010, 11/2010, and 09/2011: what conditions for a real deployment (Pierre-Guy Therond); 9 - Hydrogen as a renewable energies storage mean (Werner Diwald)

MammoGrid: a mammography database

CERN Multimedia

2002-01-01

What would be the advantages if physicians around the world could gain access to a unique mammography database? The answer may come from MammoGrid, a three-year project under the Fifth Framework Programme of the EC. Led by CERN, MammoGrid involves the UK (the Universities of Oxford, Cambridge and the West of England, Bristol, plus the company Mirada Solutions of Oxford), and Italy (the Universities of Pisa and Sassari and the Hospitals in Udine and Torino). The aim of the project is, in light of emerging GRID technology, to develop a Europe-wide database of mammograms. The database will be used to investigate a set of important healthcare applications as well as the potential of the GRID to enable healthcare professionals throughout the EU to work together effectively. The contributions of the partners include building the GRID-database infrastructure, developing image processing and Computer Aided Detection techniques, and making the clinical evaluation. The first project meeting took place at CERN in Sept...

PV-hybrid and mini-grid

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

Within the 5th European PV-hybrid and mini-grid conference 29th and 30th April, 2010 in Tarragona (Spain) the following lectures were held: (1) Overview of IEA PVPS Task 11 PV-hybrid systems within mini grids; (2) Photovoltaic revolution for deployment in developing countries; (3) Legal and financial conditions for the sustainable operation of mini-grids; (4) EU instruments to promote renewable energies in developing countries; (5) PV hybridization of diesel electricity generators: Conditions of profitability and examples in differential power and storage size ranges; (6) Education suit of designing PV hybrid systems; (7) Sustainable renewable energy projects for intelligent rural electrification in Laos, Cambodia and Vietnam; (8) Techno-economic feasibility of energy supply of remote villages in Palestine by PV systems, diesel generators and electric grid (Case studies: Emnazeil and Atouf villages); (9) Technical, economical and sustainability considerations of a solar PV mini grid as a tool for rural electrification in Uganda; (10) Can we rate inverters for rural electrification on the basis of energy efficiency?; (11) Test procedures for MPPT charge controllers characterization; (12) Energy storage for mini-grid stabilization; (13) Redox flow batteries - Already an alternative storage solution for hybrid PV mini-grids?; (14) Control methods for PV hybrid mini-grids; (15) Partial AC-coupling in mini-grids; (15) Normative issues of small wind turbines in PV hybrid systems; (16) Communication solutions for PV hybrid systems; (17) Towards flexible control and communication of mini-grids; (18) PV/methanol fuel cell hybrid system for powering a highway security variable message board; (19) Polygeneration smartgrids: A solution for the supply of electricity, potable water and hydrogen as fuel for transportation in remote Areas; (20) Implementation of the Bronsbergen micro grid using FACDS; (21) A revisited approach for the design of PV wind hybrid systems; (22

Low-cost wireless voltage & current grid monitoring

Energy Technology Data Exchange (ETDEWEB)

Hines, Jacqueline [SenSanna Inc., Arnold, MD (United States)

2016-12-31

This report describes the development and demonstration of a novel low-cost wireless power distribution line monitoring system. This system measures voltage, current, and relative phase on power lines of up to 35 kV-class. The line units operate without any batteries, and without harvesting energy from the power line. Thus, data on grid condition is provided even in outage conditions, when line current is zero. This enhances worker safety by detecting the presence of voltage and current that may appear from stray sources on nominally isolated lines. Availability of low-cost power line monitoring systems will enable widespread monitoring of the distribution grid. Real-time data on local grid operating conditions will enable grid operators to optimize grid operation, implement grid automation, and understand the impact of solar and other distributed sources on grid stability. The latter will enable utilities to implement eneygy storage and control systems to enable greater penetration of solar into the grid.

Computing Flows Using Chimera and Unstructured Grids

Science.gov (United States)

Liou, Meng-Sing; Zheng, Yao

2006-01-01

DRAGONFLOW is a computer program that solves the Navier-Stokes equations of flows in complexly shaped three-dimensional regions discretized by use of a direct replacement of arbitrary grid overlapping by nonstructured (DRAGON) grid. A DRAGON grid (see figure) is a combination of a chimera grid (a composite of structured subgrids) and a collection of unstructured subgrids. DRAGONFLOW incorporates modified versions of two prior Navier-Stokes-equation-solving programs: OVERFLOW, which is designed to solve on chimera grids; and USM3D, which is used to solve on unstructured grids. A master module controls the invocation of individual modules in the libraries. At each time step of a simulated flow, DRAGONFLOW is invoked on the chimera portion of the DRAGON grid in alternation with USM3D, which is invoked on the unstructured subgrids of the DRAGON grid. The USM3D and OVERFLOW modules then immediately exchange their solutions and other data. As a result, USM3D and OVERFLOW are coupled seamlessly.

Evaluation of the Electric Vehicle Impact in the Power Demand Curve in a Smart Grid Environment

DEFF Research Database (Denmark)

Morais, Hugo; Sousa, Tiago; Vale, Zita

2014-01-01

be beneficially used to address this problem; the massive use of electric vehicles, particularly of vehicle-to-grid (usually referred as gridable vehicles or V2G), becomes a very relevant issue. This paper addresses the impact of Electric Vehicles (EVs) in system operation costs and in power demand curve...... for a distribution network with large penetration of Distributed Generation (DG) units. An efficient management methodology for EVs charging and discharging is proposed, considering a multi-objective optimization problem. The main goals of the proposed methodology are: to minimize the system operation costs...... and to minimize the difference between the minimum and maximum system demand (leveling the power demand curve). The proposed methodology perform the day-ahead scheduling of distributed energy resources in a distribution network with high penetration of DG and a large number of electric vehicles. It is used a 32...

Grid-code of Croatian power system

International Nuclear Information System (INIS)

Toljan, I.; Mesic, M.; Kalea, M.; Koscak, Z.

2003-01-01

Grid Rules by the Croatian Electricity Utility deal with the control and usage of the Croatian power system's transmission and distribution grid. Furthermore, these rules include obligations and permissions of power grid users and owners, with the aim of a reliable electricity supply.(author)

Replica consistency in a Data Grid

International Nuclear Information System (INIS)

Domenici, Andrea; Donno, Flavia; Pucciani, Gianni; Stockinger, Heinz; Stockinger, Kurt

2004-01-01

A Data Grid is a wide area computing infrastructure that employs Grid technologies to provide storage capacity and processing power to applications that handle very large quantities of data. Data Grids rely on data replication to achieve better performance and reliability by storing copies of data sets on different Grid nodes. When a data set can be modified by applications, the problem of maintaining consistency among existing copies arises. The consistency problem also concerns metadata, i.e., additional information about application data sets such as indices, directories, or catalogues. This kind of metadata is used both by the applications and by the Grid middleware to manage the data. For instance, the Replica Management Service (the Grid middleware component that controls data replication) uses catalogues to find the replicas of each data set. Such catalogues can also be replicated and their consistency is crucial to the correct operation of the Grid. Therefore, metadata consistency generally poses stricter requirements than data consistency. In this paper we report on the development of a Replica Consistency Service based on the middleware mainly developed by the European Data Grid Project. The paper summarises the main issues in the replica consistency problem, and lays out a high-level architectural design for a Replica Consistency Service. Finally, results from simulations of different consistency models are presented

PSG: Peer-to-Peer semantic grid framework architecture

Directory of Open Access Journals (Sweden)

Amira Soliman

2011-07-01

Full Text Available The grid vision, of sharing diverse resources in a flexible, coordinated and secure manner, strongly depends on metadata. Currently, grid metadata is generated and used in an ad-hoc fashion, much of it buried in the grid middleware code libraries and database schemas. This ad-hoc expression and use of metadata causes chronic dependency on human intervention during the operation of grid machinery. Therefore, the Semantic Grid is emerged as an extension of the grid in which rich resource metadata is exposed and handled explicitly, and shared and managed via grid protocols. The layering of an explicit semantic infrastructure over the grid infrastructure potentially leads to increase interoperability and flexibility. In this paper, we present PSG framework architecture that offers semantic-based grid services. PSG architecture allows the explicit use of semantics and defining the associated grid services. PSG architecture is originated from the integration of Peer-to-Peer (P2P computing with semantics and agents. Ontologies are used in annotating each grid component, developing users/nodes profiles and organizing framework agents. While, P2P is responsible for organizing and coordinating the grid nodes and resources.

Smart grid for comfort; Smart grid voor comfort

Energy Technology Data Exchange (ETDEWEB)

Zeiler, W.; Van der Velden, J.A.J. [Kropman, Rijswijk (Netherlands); Vissers, D.R.; Maaijen, H.N. [Faculteit Bouwkunde, Technische Universiteit Eindhoven TUE, Eindhoven (Netherlands); Kling, W.L. [Faculteit Electrical Engineering, Technische Universiteit Eindhoven TUE, Eindhoven (Netherlands); Larsen, J.P. [Sense Observation Systems, Rotterdam (Netherlands)

2012-04-15

A new control strategy was developed based on the application of wireless sensor network with the connection to a smart grid to investigate if it is possible to save energy on the level of the user under the condition of maintaining the same or even improved level of individual comfort. By using different scenarios, for individual comfort and energy consumption, agents provide the steering of the process control This forms the basis of a new approach to optimize the energy consumption, after which the effect of it can be used on the level of residential building to optimize the interaction with the electrical infrastructure, the smart grid. [Dutch] Er vindt onderzoek plaats naar een nieuwe regelstrategie gebaseerd op de toepassing van een draadloos sensor netwerk dat is gekoppeld aan het smart grid. Doel van deze regelstrategie is om op gebruikersniveau energie te kunnen besparen met behoud of zelfs verbetering van het individueel comfort. Er zijn verschillende scenario's voor individueel comfort en energiegebruik van apparatuur met behulp van agents die voor de aansturing kunnen zorgen. Zo wordt de kern van de energievraag geoptimaliseerd. De doorwerking hiervan tot op het niveau van woninggebouw en de koppeling met het externe elektriciteitsnet kan vervolgens worden geoptimaliseerd.

GEMSS: grid-infrastructure for medical service provision.

Science.gov (United States)

Benkner, S; Berti, G; Engelbrecht, G; Fingberg, J; Kohring, G; Middleton, S E; Schmidt, R

2005-01-01

The European GEMSS Project is concerned with the creation of medical Grid service prototypes and their evaluation in a secure service-oriented infrastructure for distributed on demand/supercomputing. Key aspects of the GEMSS Grid middleware include negotiable QoS support for time-critical service provision, flexible support for business models, and security at all levels in order to ensure privacy of patient data as well as compliance to EU law. The GEMSS Grid infrastructure is based on a service-oriented architecture and is being built on top of existing standard Grid and Web technologies. The GEMSS infrastructure offers a generic Grid service provision framework that hides the complexity of transforming existing applications into Grid services. For the development of client-side applications or portals, a pluggable component framework has been developed, providing developers with full control over business processes, service discovery, QoS negotiation, and workflow, while keeping their underlying implementation hidden from view. A first version of the GEMSS Grid infrastructure is operational and has been used for the set-up of a Grid test-bed deploying six medical Grid service prototypes including maxillo-facial surgery simulation, neuro-surgery support, radio-surgery planning, inhaled drug-delivery simulation, cardiovascular simulation and advanced image reconstruction. The GEMSS Grid infrastructure is based on standard Web Services technology with an anticipated future transition path towards the OGSA standard proposed by the Global Grid Forum. GEMSS demonstrates that the Grid can be used to provide medical practitioners and researchers with access to advanced simulation and image processing services for improved preoperative planning and near real-time surgical support.

Ecosystem Based Business Model of Smart Grid

OpenAIRE

Lundgaard, Morten Raahauge; Ma, Zheng; Jørgensen, Bo Nørregaard

2015-01-01

This paper tries to investigate the ecosystem based business model in a smart grid infrastructure and the potential of value capture in the highly complex macro infrastructure such as smart grid. This paper proposes an alternative perspective to study the smart grid business ecosystem to support the infrastructural challenges, such as the interoperability of business components for smart grid. So far little research has explored the business ecosystem in the smart grid concept. The study on t...

Exploring virtualisation tools with a new virtualisation provisioning method to test dynamic grid environments for ALICE grid jobs over ARC grid middleware

International Nuclear Information System (INIS)

Wagner, B; Kileng, B

2014-01-01

The Nordic Tier-1 centre for LHC is distributed over several computing centres. It uses ARC as the internal computing grid middleware. ALICE uses its own grid middleware AliEn to distribute jobs and the necessary software application stack. To make use of most of the AliEn infrastructure and software deployment methods for running ALICE grid jobs on ARC, we are investigating different possible virtualisation technologies. For this a testbed and possible framework for bridging different middleware systems is under development. It allows us to test a variety of virtualisation methods and software deployment technologies in the form of different virtual machines.

Mini Smart Grid @ Copenhagen Business School

DEFF Research Database (Denmark)

Pedersen, Rasmus U.; Furtak, Simon J.; Häuser, Ivan

2013-01-01

Project Smart Grid: The Intelligent Electrical System Is the Way Forward In 2012 Peter Møllgaard from Department of Economics and Rasmus Pedersen from Department of IT Management initiated a new project supported by CBS Sustainability Platform. The purpose of the project is to establish an unders......Project Smart Grid: The Intelligent Electrical System Is the Way Forward In 2012 Peter Møllgaard from Department of Economics and Rasmus Pedersen from Department of IT Management initiated a new project supported by CBS Sustainability Platform. The purpose of the project is to establish...... an understanding of micro-economic and IT challenges related to Smart Grid technology. The mini-smart-grid project at Copenhagen Business School (MSC@CBS) project seeks to investigate the business opportunities and issues that arise from this new technology. The project revolves around the concepts of Smart Grids......, Smart Meters and prosumers. Smart Grids are a new method of managing electricity and power supply. It has not reached its full potential yet, but it offers a more interactive platform for both the consumer and the main supplier e.g. Dong Energy. The Smart Grid will collect and control the behavior...

An Improved Current Controller to ensure the robust performance of grid-connected converters under weak grid conditions

DEFF Research Database (Denmark)

Khazraj, Hesam; Silva, Filipe Miguel Faria da; Bak, Claus Leth

2016-01-01

Voltage Source Converters (VSCs) operating in very weak grids with low Short Circuit Ratio (SCR) are known to meet stability challenges. This article investigates instability of a grid connected current-controlled converter under weak grid conditions, which is often attributed to the dynamic...

Grid technologies and applications: architecture and achievements

International Nuclear Information System (INIS)