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Browsing by Author "Pinheiro, Raul"

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  • Knowledge extraction from medium voltage load diagrams to support the definition of electrical tariffs
    Publication . Ramos, Sérgio; Figueiredo, Vera; Rodrigues, Fátima; Pinheiro, Raul; Vale, Zita
    With the electricity market liberalization, distribution and retail companies are looking for better market strategies based on adequate information upon the consumption patterns of its electricity customers. In this environment all consumers are free to choose their electricity supplier. A fair insight on the customer´s behaviour will permit the definition of specific contract aspects based on the different consumption patterns. In this paper Data Mining (DM) techniques are applied to electricity consumption data from a utility client’s database. To form the different customer´s classes, and find a set of representative consumption patterns, we have used the Two-Step algorithm which is a hierarchical clustering algorithm. Each consumer class will be represented by its load profile resulting from the clustering operation. Next, to characterize each consumer class a classification model will be constructed with the C5.0 classification algorithm.
    2007Journal article Open access Show more
  • Scheduling maintenance activities of electric power transmission networks using an hybrid constraint method
    Publication . Gomes, Nuno; Pinheiro, Raul; Vale, Zita; Ramos, Carlos
    In this paper we present a Constraint Logic Programming (CLP) based model, and hybrid solving method for the Scheduling of Maintenance Activities in the Power Transmission Network. The model distinguishes from others not only because of its completeness but also by the way it models and solves the Electric Constraints. Specifically we present a efficient filtering algorithm for the Electrical Constraints. Furthermore, the solving method improves the pure CLP methods efficiency by integrating a type of Local Search technique with CLP. To test the approach we compare the method results with another method using a 24 bus network, which considerers 42 tasks and 24 maintenance periods.
    2007Journal article Restricted access Show more