Percorrer por autor "Cordeiro, Manuel"
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- Decision support for power system control centers – a model based reasoning componentPublication . Malheiro, Nuno; Vale, Zita; Ramos, Carlos; Cordeiro, Manuel; Marques, Albino; Couto, Vieira; Ramos, Carlos; Vale, ZitaThe increasing demand on Power System Control Centers (PSCC) for optimization of the use of the Electrical Network implies, as one of its key focuses, the fastest possible restoration of service. Human PSCC operators (PSCCO) control the Electrical Network aided by a distributed system of sensors and actuators, which produce temporal information about the networks’ state. These distributed systems are known as Supervisory Control and Data acquisition or SCADA systems. In incident situations, in which SCADA systems can produce huge amounts of information, PSCCOs can become very stressed and loose the necessary focus to perform an accurate diagnosis and hence proper power restoration. Several approaches have been made to develop systems which can cope with the particularly hard features of this problem in real-time. This paper presents a model based teasoning component which is integrated in a multicomponent system with the task of Electrical Network diagnosis and restoration. This particular component adds adaptability to the system ensuring correct behaviour on any topological variation of the part of the electrical network in service or its protection schemes. The whole system is fully functional and operating in the Portuguese Electrical Network Dispatch Center.
- Hybrid methods for the maintenance scheduling of generating units problemPublication . Gomes, Nuno; Cordeiro, Manuel; Vale, Zita; Ramos, Carlos; Ramos, Carlos; Vale, ZitaReal world search and optimization problems are usually characterized by having large search spaces, being difficult to model and being constantly changing. Constraint Logic Programming (CLP) has proved to be a good tool to model and solve this type of problems despite some efficiency problems. It seams that the problem is related to some lack of a “global perspective” of the constraints in the search process, One way of overcoming this problem is to hybridize Constraint Logic Programming with Linear Programming (LP) in order to enhance the solving process by finding feasible solutions early in the search by “global reasoning”. In this work we propose 4 hybrid methods for solving a Maintenance Scheduling of Generating Units problem. The main idea is to take the advantages of both CLP and LP avoiding their problems. Some initial tests show that for some conditions all the hybrid methods can perform better than CLP alone.
- MASCEM: A Multiagent System That Simulates Competitive Electricity MarketsPublication . Praça, Isabel; Ramos, Carlos; Vale, Zita; Cordeiro, ManuelAround the world, the electricity industry, which has long been dominated by vertically integrated utilities, is experiencing major changes in the structure of its markets and regulations. Owing to new regulations, it's evolving into a distributed industry in which market forces drive electricity's price. The industry is becoming competitive; a market environment is replacing the traditional centralized-operation approach. This transformation is often called the deregulation of the electricity market. MASCEM, a multiagent simulator system, is a valuable framework for evaluating new rules, new behavior, and new participants in the numerous electricity markets that are moving toward liberalization and competition.
- A multi-agent system to support decision making in electricity marketsPublication . Praça, Isabel; Ramos, Carlos; Vale, Zita; Cordeiro, Manuel; Ramos, Carlos; Vale, ZitaThroughout the world, the electricity industry is undergoing enormous changes in the structure of its markets and their regulations. The electricity industry is evolving into a distributed and competitive industry in which market forces drive the price of electricity. Changes are towards a competitive framework and a market environment is replacing the traditional centralized operation approach. As electricity markets evolve there is a need for new modelling approaches that simulate how electric power markets could evolve over time and how participants in these markets may act and react to the changing economic, financial and regulatory environment in which they operate. In this paper we present a Multi-Agent simulator to give decision support in Competitive Electricity Markets combining bilateral trading with power exchange mechanisms. This Multi-Agent environment includes several heterogeneous and autonomous intelligent agents, which are endowed with historical information about the market and have strategic behaviour to negotiate. This paper focuses on the different negotiation mechanisms supported by the simulator, and on agents’ strategic behaviour to face them. A special attention is devoted to the structure of market players, Seller and Buyer agents, particularly in what concerns their decision analysis process to face the challenging market.