2010
Authors
Fidalgo, JN; Matos, MA; Jorge, H;
Publication
IET Conference Publications
Abstract
This paper describes the methodology and results obtained in the studies developed for deriving loss profiles for the Portuguese electricity market. For each voltage level (LV, MV, HV and VHV) the losses were distributed by the corresponding global load diagram, proportionally to the square of the hourly consumption. Transformer losses are assigned to the consumers of voltage levels equal or smaller to the secondary voltage. Loss profiles (like load profiles) were developed for each specific year, with its calendar particularities, and the global energy balance expected for that year. A subsequent product of the adopted methodology is the set of loss factors, which are directly driven from these profiles. The methodology was developed in a project with EDP (the Portuguese distribution system operator) and the result was approved by the regulatory authority that adopted the proposed loss profiles for market use.
2012
Authors
Fidalgo, JN; Matos, MA; Ribeiro, L;
Publication
ELECTRIC POWER SYSTEMS RESEARCH
Abstract
In open energy markets, the settlement process between distribution operators and traders is made on an hourly (or 15 min) basis, while LV consumers' billing data continues to result from monthly energy bills. In order to reconcile these two different realities, load profiling is used as a means to redistribute the consumed energy of each trader's portfolio by hourly intervals, according to recorded consumption patterns. This paper presents a new clustering approach to derive typical load diagrams that can be used in the process. The algorithm uses real load diagrams obtained in measurement campaigns to define classes (in the billing information space) that maximize the compactness of the diagrams in each class. The methodology was developed in a project with EDP Distribution (the Portuguese distribution system operator) and the result was approved by the Regulatory Authority that adopted the proposed profiles for market use.
1995
Authors
MIRANDA, V; FIDALGO, JN; LOPES, JAP; ALMEIDA, LB;
Publication
IEEE TRANSACTIONS ON POWER SYSTEMS
Abstract
This paper reports a new approach in defining preventive control measures to assure transient stability relatively to one or several contingencies that may occur separately in a power system. Generation dispatch is driven not only by economic functions but also with the derivatives of the transient energy margin value; these derivatives are obtained directly from a trained Artificial Neural Network (ANN), using ri:al time monitorable system values. Results obtained from computer simulations, for several contingencies in the CIGRE test system, confirm the validity of the developed approach.
1996
Authors
Fidalgo, JN; Lopes, JAP; Miranda, V;
Publication
IEEE TRANSACTIONS ON POWER SYSTEMS
Abstract
This paper presents an artificial neural network (ANN) based approach for the definition of preventive control strategies of autonomous power systems with a large renewable power penetration. For a given operating point, a fast dynamic security evaluation for a specified wind perturbation is performed using an ANN. If insecurity is detected, new alternative stable operating points are suggested, using a hybrid ANN-optimization approach that checks several feasible possibilities, resulting from changes in power produced by diesel and wind generators, and other combinations of diesel units in operation, Results obtained from computer simulations of the real power system of Lemnos (Greece) support the validity of the developed approach.
2004
Authors
Matos, MA; de Leao, MTP; Saraiva, JT; Fidalgo, JN; Miranda, V; Lopes, JP; Ferreira, JR; Pereira, JMC; Proenca, LM; Pinto, JL;
Publication
METAHEURISTICS: COMPUTER DECISION-MAKING
Abstract
Most optimization and decision problems in power systems include integer or binary variables, leading to combinatorial problems. In this paper, several approaches using metaheuristics and genetic algorithms are presented that deal with real problems of the power industry Most of these methodologies are now implemented in distribution management systems (DMS) used by several utilities.
2000
Authors
Miranda, V; Matos, M; Lopes, JP; Saraiva, JT; Fidalgo, JN; de Leao, MTP;
Publication
2000 IEEE POWER ENGINEERING SOCIETY SUMMER MEETING, CONFERENCE PROCEEDINGS, VOLS 1-4
Abstract
This text describes a real-world DMS environment in which intelligent tools and techniques such as neural networks, fuzzy sets and meta-heuristics (like evolutionary computing and simulated annealing) have given a strong positive contribution.
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