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Reinforcement Learning of Heuristic EV Fleet Charging in a Day-Ahead Electricity Market ; ; Ernst, Damien et al in IEEE Transactions on Smart Grid (2015), 6(4), 1795-1805 This paper addresses the problem of defining a day-ahead consumption plan for charging a fleet of electric vehicles (EVs), and following this plan during operation. A challenge herein is the beforehand ... [more ▼] This paper addresses the problem of defining a day-ahead consumption plan for charging a fleet of electric vehicles (EVs), and following this plan during operation. A challenge herein is the beforehand unknown charging flexibility of EVs, which depends on numerous details about each EV (e.g., plug-in times, power limitations, battery size, power curve, etc.). To cope with this challenge, EV charging is controlled during opertion by a heuristic scheme, and the resulting charging behavior of the EV fleet is learned by using batch mode reinforcement learning. Based on this learned behavior, a cost-effective day-ahead consumption plan can be defined. In simulation experiments, our approach is benchmarked against a multistage stochastic programming solution, which uses an exact model of each EVs charging flexibility. Results show that our approach is able to find a day-ahead consumption plan with comparable quality to the benchmark solution, without requiring an exact day-ahead model of each EVs charging flexibility. [less ▲] Detailed reference viewed: 68 (9 ULg)An economic case for transnational and international transmission Ernst, Damien Speech/Talk (2015) Detailed reference viewed: 79 (11 ULg)Graph matching for reconciling SCADA and GIS of a distribution network Cornélusse, Bertrand ; ; Glavic, Mevludin et al in Proceedings of the International Conference on Electricity Distribution, CIRED 2015 (2015, June) This article deals with the problem of automatically es- tablishing a correspondence between two databases popu- lated independently over the years by a distribution com- pany, for instance a SCADA system ... [more ▼] This article deals with the problem of automatically es- tablishing a correspondence between two databases popu- lated independently over the years by a distribution com- pany, for instance a SCADA system and a geographical information system. This problem is abstracted as a graph matching problem, well known in the combinatorial op- timisation community. It is then casted as an integer quadratic program. An idea of achievable results on a real system is provided, and needs for approximation or decom- position algorithms are discussed. [less ▲] Detailed reference viewed: 250 (15 ULg)A process to address electricity distribution sector challenges: the GREDOR project approach Cornélusse, Bertrand ; ; Glavic, Mevludin et al in Proceedings of the International Conference on Electricity Distribution, CIRED 2015 (2015, June) This paper presents a general process set in the GREDOR (French acronym for “Gestion des Réseaux Electriques de Distribution Ouverts aux Renouvelables”) project to address the challenges in distribution ... [more ▼] This paper presents a general process set in the GREDOR (French acronym for “Gestion des Réseaux Electriques de Distribution Ouverts aux Renouvelables”) project to address the challenges in distribution systems posed by the integration of renewable generation, changing load patterns, and the changes in the electricity market sector. A use case describing interactions among different players that fits the process is also presented. A pseudo-dynamic approach to Global Capacity Announcement as a way to increase penetration of Renewable Energy Sources in a distribution system is elaborated in more details. [less ▲] Detailed reference viewed: 184 (13 ULg)Macroscopic analysis of interaction models for the provision of flexibility in distribution systems Mathieu, Sébastien ; Ernst, Damien ; Cornélusse, Bertrand in Proceedings of the International Conference on Electricity Distribution, CIRED 2015 (2015, June) To ease the transition towards the future of distribution grid management, regulators must revise the current interaction model, that is, the set of rules guiding the interactions between all the parties ... [more ▼] To ease the transition towards the future of distribution grid management, regulators must revise the current interaction model, that is, the set of rules guiding the interactions between all the parties of the system. Five interaction models are proposed, three of them considering active network management. This paper evaluates the economic efficiency of each model using macroscopic representation of the system, by opposition to more techniques requiring a complete picture of the system. The interaction models are simulated on the horizon 2015-2030. Results show that for the first five years all the models provide similar economic efficiency. For the remaining ten years, interaction models implementing active network management provide up to a 10% higher economic efficiency. [less ▲] Detailed reference viewed: 155 (23 ULg)The global grid for empowering renewable energy Ernst, Damien Speech/Talk (2015) Detailed reference viewed: 67 (1 ULg)Artificial Intelligence in Video Games: Towards a Unified Framework Safadi, Firas ; Fonteneau, Raphaël ; Ernst, Damien in International Journal of Computer Games Technology (2015), 2015 With modern video games frequently featuring sophisticated and realistic environments, the need for smart and comprehensive agents that understand the various aspects of complex environments is pressing ... [more ▼] With modern video games frequently featuring sophisticated and realistic environments, the need for smart and comprehensive agents that understand the various aspects of complex environments is pressing. Since video game AI is often specifically designed for each game, video game AI tools currently focus on allowing video game developers to quickly and efficiently create specific AI. One issue with this approach is that it does not efficiently exploit the numerous similarities that exist between video games not only of the same genre, but of different genres too, resulting in a difficulty to handle the many aspects of a complex environment independently for each video game. Inspired by the human ability to detect analogies between games and apply similar behavior on a conceptual level, this paper suggests an approach based on the use of a unified conceptual framework to enable the development of conceptual AI which relies on conceptual views and actions to define basic yet reasonable and robust behavior. The approach is illustrated using two video games, Raven and StarCraft: Brood War. [less ▲] Detailed reference viewed: 454 (37 ULg)The inevitable downfall of the Belgian electrical power industry? Ernst, Damien Speech/Talk (2015) Detailed reference viewed: 177 (15 ULg)L'arme de la transition énergétique pour combattre les djihadistes Ernst, Damien ; Hermans, Michel Article for general public (2015) Detailed reference viewed: 367 (29 ULg)Electricity storage with liquid fuels in a zone powered by 100% variable renewables Léonard, Grégoire ; François-Lavet, Vincent ; Ernst, Damien et al in Proceedings of the 12th International Conference on the European Energy Market - EEM15 (2015) In this work, an electricity zone with 100% renewables is simulated to determine the optimal sizing of generation and storage capacities in such a zone. Using actual wind output data, the model evaluates ... [more ▼] In this work, an electricity zone with 100% renewables is simulated to determine the optimal sizing of generation and storage capacities in such a zone. Using actual wind output data, the model evaluates the economic viability of a power-to-fuel storage technology that combines water electrolysis, CO2 capture and methanol synthesis. The main advantage of using methanol as an energy carrier is that liquid fuels are suitable for (long-term) energy storage thanks to their high energy density. The levelized electricity cost projection by 2050 equals 83.4 €/MWh in the base case configuration. The effects of storage round-trip efficiency and the storage unit lifetime are quantified and their impacts on the electricity cost discussed. Additional benefits of using methanol as a fuel substitute may be taken into account in further work. [less ▲] Detailed reference viewed: 483 (41 ULg)Electricity storage with liquid fuels in a zone powered by 100% variable renewables Léonard, Grégoire ; François-Lavet, Vincent ; Ernst, Damien et al Conference (2015) Detailed reference viewed: 24 (4 ULg)Le sabotage sophistiqué de Doel 4 et l’intrigant survol de centrales nucléaires par des drones: l’hypothèse pas folle d’un intérêt d’Etat ? Ernst, Damien ; Hermans, Michel Article for general public (2014) Detailed reference viewed: 232 (10 ULg)Using approximate dynamic programming for estimating the revenues of a hydrogen-based high-capacity storage device François-Lavet, Vincent ; Fonteneau, Raphaël ; Ernst, Damien in IEEE Symposium Series on Computational Intelligence (2014) This paper proposes a methodology to estimate the maximum revenue that can be generated by a company that operates a high-capacity storage device to buy or sell electricity on the day-ahead electricity ... [more ▼] This paper proposes a methodology to estimate the maximum revenue that can be generated by a company that operates a high-capacity storage device to buy or sell electricity on the day-ahead electricity market. The methodology exploits the Dynamic Programming (DP) principle and is specified for hydrogen-based storage devices that use electrolysis to produce hydrogen and fuel cells to generate electricity from hydrogen. Experimental results are generated using historical data of energy prices on the Belgian market. They show how the storage capacity and other parameters of the storage device influence the optimal revenue. The main conclusion drawn from the experiments is that it may be advisable to invest in large storage tanks to exploit the inter-seasonal price fluctuations of electricity. [less ▲] Detailed reference viewed: 75 (22 ULg)Blackouts: des vérités qui dérangent Ernst, Damien Speech/Talk (2014) Detailed reference viewed: 1184 (162 ULg)Mathematical Modeling of HIV Dynamics After Antiretroviral Therapy Initiation: A Review ; ; et al in BioResearch Open Acces (2014), 3(5), 233-241 This review shows the potential ground-breaking impact that mathematical tools may have in the analysis and the understanding of the HIV dynamics. In the first part, early diagnosis of immunological ... [more ▼] This review shows the potential ground-breaking impact that mathematical tools may have in the analysis and the understanding of the HIV dynamics. In the first part, early diagnosis of immunological failure is inferred from the estimation of certain parameters of a mathematical model of the HIV infection dynamics. This method is supported by clinical research results from an original clinical trial: data just after 1 month following therapy initiation are used to carry out the model identification. The diagnosis is shown to be consistent with results from monitoring of the patients after 6 months. In the second part of this review, prospective research results are given for the design of individual anti-HIV treatments optimizing the recovery of the immune system and minimizing side effects. In this respect, two methods are discussed. The first one combines HIV population dynamics with pharmacokinetics and pharmacodynamics models to generate drug treatments using impulsive control systems. The second one is based on optimal control theory and uses a recently published differential equation to model the side effects produced by highly active antiretroviral therapy therapies. The main advantage of these revisited methods is that the drug treatment is computed directly in amounts of drugs, which is easier to interpret by physicians and patients. [less ▲] Detailed reference viewed: 107 (9 ULg)Optimal Assignment of Off-Peak Hours to Lower Curtailments in the Distribution Network Merciadri, Luca ; Mathieu, Sébastien ; Ernst, Damien et al in Proceedings of the 5th European Innovative Smart Grid Technologies (ISGT) (2014, October) We consider a price signal with two settings: off-peak tariff and on-peak tariff. Some loads are connected to specific electricity meters which allow the consumption of power only in off-peak periods ... [more ▼] We consider a price signal with two settings: off-peak tariff and on-peak tariff. Some loads are connected to specific electricity meters which allow the consumption of power only in off-peak periods. Historically, off-peak periods were located during the night and on-peak periods during the day. Changing the assignment of off-peak periods is an easy method for distribution system operators to access to the flexibility of small consumers. This solution can be implemented quickly as the infrastructure needed already exists in some countries. We propose a mixed-integer linear model to assign optimally the off-peak hours so as to minimize a societal cost. This cost gathers together the cost of electricity, the financial losses due to energy curtailments of photovoltaic installations and the loads' wellbeing. Our model considers automatic tripping of inverters and constraints of the electrical distribution networks. Simulation results show that the new disposition of off-peak hours could reduce significantly the photovoltaic energy curtailed in the summer. [less ▲] Detailed reference viewed: 118 (26 ULg)Mathematical modeling of HIV dynamics after antiretroviral therapy initiation: A clinical research study ; ; et al in AIDS Research and Human Retroviruses (2014), 30(9), 831-834 Immunological failure is identified from the estimation of certain parameters of a mathematical model of the HIV infection dynamics. This identification is supported by clinical research results from an ... [more ▼] Immunological failure is identified from the estimation of certain parameters of a mathematical model of the HIV infection dynamics. This identification is supported by clinical research results from an original clinical trial. Standard clinical data were collected from infected patients starting Highly Active Anti-Retroviral Therapy (HAART), just after one month following therapy initiation and were used to carry out the model identification. The early diagnosis is shown to be consistent with the patients monitoring after six months. [less ▲] Detailed reference viewed: 97 (5 ULg)Global power grids for harnessing world renewable energy ; Ernst, Damien ; in Jones, Lawrence (Ed.) Renewable Energy Integration: Practical Management of Variability, Uncertainty and Flexibility in Power Grids (2014) The Global Grid advocates the connection of all regional power systems into one electricity transmission system spanning the whole globe. Power systems are currently forming larger and larger ... [more ▼] The Global Grid advocates the connection of all regional power systems into one electricity transmission system spanning the whole globe. Power systems are currently forming larger and larger interconnections. Environmental awareness and increased electricity consumption leads more investments towards renewable energy sources, abundant in remote locations (oﬀ-shore or in deserts). The Global Grid will facilitate the transmission of this “green” electricity to load centers, serving as backbone. This chapter elaborates on the concept presenting four stages that could gradually lead to the development of a globally interconnected power network. Quantitative analyses are carried out for all stages, demonstrating that a Global Grid is both technically feasible and economically competitive. Real price data from Europe and the USA are used to identify the potential of intercontinental electricity trade, showing that substantial proﬁts can be generated through such interconnections. [less ▲] Detailed reference viewed: 199 (16 ULg)A quantitative analysis of the effect of flexible loads on reserve markets Mathieu, Sébastien ; Louveaux, Quentin ; Ernst, Damien et al in Proceedings of the 18th Power Systems Computation Conference (PSCC) (2014, August) We propose and analyze a day-ahead reserve market model that handles bids from flexible loads. This pool market model takes into account the fact that a load modulation in one direction must usually be ... [more ▼] We propose and analyze a day-ahead reserve market model that handles bids from flexible loads. This pool market model takes into account the fact that a load modulation in one direction must usually be compensated later by a modulation of the same magnitude in the opposite direction. Our analysis takes into account the gaming possibilities of producers and retailers, controlling load flexibility, in the day-ahead energy and reserve markets, and in imbalance settlement. This analysis is carried out by an agent-based approach where, for every round, each actor uses linear programs to maximize its profit according to forecasts of the prices. The procurement of a reserve is assumed to be determined, for each period, as a fixed percentage of the total consumption cleared in the energy market for the same period. The results show that the provision of reserves by flexible loads has a negligible impact on the energy market prices but markedly decreases the cost of reserve procurement. However, as the rate of flexible loads increases, the system operator has to rely more and more on non-contracted reserves, which may cancel out the benefits made in the procurement of reserves. [less ▲] Detailed reference viewed: 250 (39 ULg)Relaxations for multi-period optimal power flow problems with discrete decision variables Gemine, Quentin ; Ernst, Damien ; Louveaux, Quentin et al in Proceedings of the 18th Power Systems Computation Conference (PSCC'14) (2014, August) We consider a class of optimal power flow (OPF) applications where some loads offer a modulation service in exchange for an activation fee. These applications can be modeled as multi-period formulations ... [more ▼] We consider a class of optimal power flow (OPF) applications where some loads offer a modulation service in exchange for an activation fee. These applications can be modeled as multi-period formulations of the OPF with discrete variables that define mixed-integer non-convex mathematical programs. We propose two types of relaxations to tackle these problems. One is based on a Lagrangian relaxation and the other is based on a network flow relaxation. Both relaxations are tested on several benchmarks and, although they provide a comparable dual bound, it appears that the constraints in the solutions derived from the network flow relaxation are significantly less violated. [less ▲] Detailed reference viewed: 194 (39 ULg) |
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