Zita Vale

Prof. Zita Vale

GECAD-Research Group on Intelligent Engineering and Computing for Advanced Innovation and Development, Polytechnic of Porto (P.PORTO), P-4200-465 Porto, Portugal
orcid

Research Focus & Metrics

Academic Career Length

35Years (1992-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2010 in Renewable Energy
Verified
Journal Article
Closed access
Hugo MoraisHugo Morais
Hugo Morais
PKPéter Kádár
Péter Kádár
Pedro FariaPedro Faria
Pedro Faria
Zita ValeZita Vale
Zita Vale
HKH.M. Khodr
H.M. Khodr

2 May 2005 in IEEE Transactions on Power Systems
Verified
Journal Article
Closed access
VFV. Figueiredo
V. Figueiredo
FRFátima Rodrigues
Fátima Rodrigues
Zita ValeZita Vale
Zita Vale
JGJ.B. Gouveia
J.B. Gouveia
This paper presents an electricity consumer characterization framework based on a knowledge discovery in databases (KDD) procedure, supported by data mining (DM) techniques, applied on the different stages of the process. The core of this framework is a data mining model based on a combination of unsupervised and supervised learning techniques. Two main modules compose this framework: the load profiling module and the classification module. The load profiling module creates a set of consumer classes using a clustering operation and the representative load profiles for each class. The classification module uses this knowledge to build a classification model able to assign different consumers to the existing classes. The quality of this framework is illustrated with a case study concerning a real database of LV consumers from the Portuguese distribution company.

16 July 2018 in IEEE Transactions on Power Systems
Verified
Journal Article
Open access
FLFernando Lezama
Fernando Lezama
Joao SoaresJoao Soares
Joao Soares
PHPablo Hernandez-Leal
Pablo Hernandez-Leal
MKMichael Kaisers
Michael Kaisers
Tiago PintoTiago Pinto
Tiago Pinto
Zita ValeZita Vale
Zita Vale
Triggered by the increased fluctuations of renewable energy sources, the European Commission stated the need for integrated short-term energy markets (e.g., intraday), and recognized the facilitating role that local energy communities could play. In particular, microgrids and energy communities are expected to play a crucial part in guaranteeing the balance between generation and consumption on a local level. Local energy markets empower small players and provide a stepping stone toward fully transactive energy systems. In this paper, we evaluate such a fully integrated transactive system by, first, modeling the energy resource management problem of a microgrid under uncertainty considering flexible loads and market participation (solved via two-stage stochastic programming), second, modeling a wholesale market and a local market, and, third, coupling these elements into an integrated transactive energy simulation. Results under a realistic case study (varying prices and competitiveness of local markets) show the effectiveness of the transactive system resulting in a reduction of up to 75% of the expected costs when local markets and flexibility are considered. This illustrates that how local markets can facilitate the trade of energy, thereby increasing the tolerable penetration of renewable resources and facilitating the energy transition.


1 November 2019 in Energy Strategy Reviews
Verified
Journal Article
Open access
Omid AbrishambafOmid Abrishambaf
Omid Abrishambaf
FLFernando Lezama
Fernando Lezama
Pedro FariaPedro Faria
Pedro Faria
Zita ValeZita Vale
Zita Vale

7 December 2011 in IEEE Transactions on Smart Grid
Verified
Journal Article
Closed access
TSTiago Sousa
Tiago Sousa
Hugo MoraisHugo Morais
Hugo Morais
Zita ValeZita Vale
Zita Vale
Pedro FariaPedro Faria
Pedro Faria
Joao SoaresJoao Soares
Joao Soares
This paper proposes a simulated annealing (SA) approach to address energy resources management from the point of view of a virtual power player (VPP) operating in a smart grid. Distributed generation, demand response, and gridable vehicles are intelligently managed on a multiperiod basis according to V2G users' profiles and requirements. Apart from using the aggregated resources, the VPP can also purchase additional energy from a set of external suppliers. The paper includes a case study for a 33 bus distribution network with 66 generators, 32 loads, and 1000 gridable vehicles. The results of the SA approach are compared with a methodology based on mixed-integer nonlinear programming. A variation of this method, using ac load flow, is also used and the results are compared with the SA solution using network simulation. The proposed SA approach proved to be able to obtain good solutions in low execution times, providing VPPs with suitable decision support for the management of a large number of distributed resources.