17 research outputs found
efantnu/drep-2021-collab-MINESParisTech-NTNU: Pre-print version IEEE Access
No full textThis repository contains the data sets of the paper "Allocation of spinning reserves in autonomous grids considering frequency stability constraints and short-term solar power variations" authored by Erick F. Alves, Louis Polleux, Gilles Guerassimoff, Magnus Korpås, Elisabetta Tedeschi. With these files, it is possible to reproduce most simulations and results obtained in the paper.
Folder organization
Results: final results and values of intermediate steps of the optimization model implemented in Gurobi 9.1 and described in section III-A and III-B of the paper.
Validation: test system implemented in OpenModelica for validation of the results and described in section III-C of paper.
Solar convex hulls: hourly convex hulls obtained using the procedure detailed in Appendix A.
Solar irradiance profiles: high-resolution irradiance timeseries from NREL used to identify the worst-case solar PV ramp scenarios
Intégration de la variabilité de l'ensoleillement dans les méthodes de simulation et de dimensionnement des micro-réseaux industriels
No full textThe integration of a large-scale solar power plant in off-grid industrial power systems brings new challenges related to the short-term variability. The long-term planning and management of industrial microgrids must now consider the relationship between renewable penetration, short-term variability, and power quality. This thesis aims to integrate the short-term solar photovoltaic variability in the optimization process of off-grid industrial microgrids. To ensure the resiliency of the grid against renewable variation, a procedure for the variability analysis of irradiance time series is proposed. Then, the performance of optimal management strategies is evaluated thanks to a multi-layer simulation framework that reproduces scheduling decisions and power quality control. Finally, optimal and robust sizing of the power plant is performed and ensures both resiliency to cloud passage and to fossil generators contingencies.L'intégration de centrales photovoltaïques dans les réseaux électriques industriels hors réseau pose de nouveaux défis liés à la variabilité de l'ensoleillement. La planification des micro-réseaux industriels doit désormais tenir compte de la relation entre la pénétration des énergies renouvelables, la variabilité court terme et la qualité de la fourniture électrique. Cette thèse vise à intégrer la variabilité court-terme de l'ensoleillement dans le processus d'optimisation des micro-réseaux industriels. Dans un premier temps, une procédure d'analyse de la variabilité des séries temporelles d'ensoleillement est proposée. Ensuite, la performance des stratégies de gestion optimale est évaluée grâce à un cadre de simulation composé d'une couche d'optimisation couplée à un modèle électrique dynamique. Enfin, un problème de dimensionnement optimal et robuste est formulé. Il assure à la fois la résilience face au passage nuageux et aux pannes des générateurs fossiles
efantnu/drep-2021-collab-MINESParisTech-NTNU: v0.1
No full textData repository of the paper "Allocation of spinning reserves for autonomous grids subject to frequency stability constraints and short-term renewable power variations".
Pre-print release, before first submission to APEN.This research was funded by the Research Council of Norway under the program PETROMAKS2, grant number 281986, project "Innovative Hybrid Energy System for Stable Power and Heat Supply in Offshore Oil \& Gas Installation (HES-OFF)
IMPACTS OF THERMAL GENERATION FLEXIBILITY ON POWER QUALITY AND LCOE OF INDUSTRIAL OFF-GRID POWER PLANTS
No full textInternational audienceThis study proposes a power quality analysis based on the frequency response of an isolated industrial hybrid power plant. The power system and its control strategy are modelled using MATLAB/SIMULINK and simulated using high resolution irradiance data. The results are used to validate a power quality criterion designed to size a hybrid PV-genset power plant. Finally, an economic analysis shows that neglecting the power quality issues at the sizing stage, it may lead to misjudging the plant's performance
Optimal and robust sizing of industrial solar powered microgrids with cloud passage resiliency constraints
No full textInternational audienceIntermittency of renewable resources brings new challenges for the optimal investment planning of industrial power systems. Reliability, availability, and power quality constraints force to strictly ensure the system's power balance during the operation. The risk of power quality degradation is increased with the integration of large-scale photovoltaic plants that face power variation due to cloud passage. If fossil generators cannot quickly compensate for the solar power drops, a fast-responding storage system must take over to guarantee electrical stability. Therefore, the sizing of industrial microgrid must integrate this storage system and consider cloud passage which modifies the techno-economic optimization paradigm. In this paper, sub-minute solar variability is anticipated thanks to robust scenarios and integrated within the optimization formulation. A linear power quality constraint is formulated to evaluate the storage needs for cloud passage resiliency. A case study is detailed and reports that short-term variability impacts the optimal solution due to additional storage costs
Neurogenin2 specifies the connectivity of thalamic neurons by controlling axon responsiveness to intermediate target cues.
No full textMany lines of evidence indicate that important traits of neuronal phenotype, such as cell body position and neurotransmitter expression, are specified through complex interactions between extrinsic and intrinsic genetic determinants. However, the molecular mechanisms specifying neuronal connectivity are less well understood at the transcriptional level. Here we demonstrate that the bHLH transcription factor Neurogenin2 cell autonomously specifies the projection of thalamic neurons to frontal cortical areas. Unexpectedly, Ngn2 determines the projection of thalamic neurons to specific cortical domains by specifying the responsiveness of their axons to cues encountered in an intermediate target, the ventral telencephalon. Our results thus demonstrate that in parallel to their well-documented proneural function, bHLH transcription factors also contribute to the specification of neuronal connectivity in the mammalian brain.Comparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe
Increasing the accuracy of PV plants and power system dynamic models: a comparison of benefits for battery capacity sizing
No full textInternational audienc
On the relationship between battery power capacity sizing and solar variability scenarios for industrial off-grid power plants
No full textInternational audienceDue to its high short-term variability, solar-photovoltaic power in isolated industrial grids faces a challenge of grid reliability. Storage systems can provide grid support but come at a high cost that requires carefully evaluating power capacity needs. Battery sizing methodologies are now the focus of many studies, with a global upward trend in detailed modelling and complex optimization. However, although solar variability can be the source of uncertainties and battery oversizing, it rarely features as an input in scenarios. This study proposes several solar variability scenarios thanks to the wavelet-variability model and two variability metrics. These scenarios are employed as inputs in two sizing methodologies to compare the resulting battery capacity and draw conclusions on the role of modelling complexity and scenario identification. Results show that neglecting the photovoltaic power plant smoothing effect leads to an overestimation of the battery power support of 51%. In the other hand, complex dynamic modelling may reduce the battery power capacity by 25%. The economic analysis shows that a proper combination of variability scenario and battery sizing methodology may reduce the levelized costs of electricity by 3%
An overview of the challenges of solar power integration in isolated industrial microgrids with reliability constraints
No full textInternational audienceReducing carbon emissions and electricity costs in industry is a major challenge to ensure competitiveness and compliance with new climate policies. Photovoltaic power offers a promising solution but also brings considerable uncertainties and risks that may endanger the continuity and quality of supply. From an operational point of view, large-scale integration of solar power could result in unmet demand, electrical instabilities and equipment damage. The performance and lifetime of conventional fossil equipment are likely to be altered by repeated transient operations, making it necessary to adopt specific modeling tools. Control strategies and sizing methodologies must be adapted to account for the strong reliability constraint while dealing with significant production uncertainties. In addition, conventional mitigation technologies, such as storage and load flexibility, have limited potential in these applications and may result in high investments or penalties if they are not properly assessed. This study provides an overview of these challenges by providing a transversal analysis of the scientific literature from fossil engine thermodynamics to control system theory applied to industrial systems. The main characteristics of reliability-constrained microgrids are identified and a conceptual definition is proposed by analyzing state-of-the art studies of various industrial applications and taking oil-and gas microgrids as an enlightening example. Then follows a review of the challenges of accounting for dynamical behavior of fossil equipment, PV and storage systems, ending with the identification of several research gaps. Finally, applicable control strategies and sizing techniques are presented
Allocation of Spinning Reserves in Autonomous Grids Considering Frequency Stability Constraints and Short-Term Solar Power Variations
No full textInternational audienceLow-inertia, isolated power systems face the problem of resiliency to active power variations. The integration of variable renewable energy sources, such as wind and solar photovoltaic, pushes the boundaries of this issue further. Higher shares of renewables requires better evaluations of electrical system stability, to avoid severe safety and economic consequences. Accounting for frequency stability requirements and allocating proper spinning reserves, therefore becomes a topic of pivotal importance in the planning and operational management of power systems. In this paper, dynamic frequency constraints are proposed to ensure resiliency during short-term power variations due to, for example, wind gusts or cloud passage. The use of the proposed constraints is exemplified in a case study, the constraints being integrated into a mixedinteger linear programming algorithm for sizing the optimal capacities of solar photovoltaic and battery energy storage resources in an isolated industrial plant. Outcomes of this case study show that reductions in the levelized cost of energy and carbon emissions can be overestimated by 8.0% and 10.8% respectively, where frequency constraints are neglected. The proposed optimal sizing is validated using time-domain simulations of the case study. The results indicate that this optimal system is frequency stable under the worst-case contingency
