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Publications

Publications by CPES

2018

Bottom-Up approach to compute der flexibility in the transmissiondistribution networks boundary

Authors
Fonseca, N; Neyestani, N; Soares, F; Iria, J; Lopes, M; Antunes, CH; Pinto, D; Jorge, H;

Publication
IET Conference Publications

Abstract
The integration of Renewable Energy Sources, mainly in distribution grids, has been changing the paradigm of power systems operation. This constitutes an opportunity to make use of flexible energy resources to support DSOs and TSOs on network operation activities. The amount of total flexibility available in the system can be quantified starting from lower voltage levels considering the implementation of demand response schemes. This work is focused on the development of an expeditious methodology to assess the total flexibility of low voltage consumers and aggregate it by means of a bottom-up approach until reaching the transmission network nodes.

2018

Data Mining for Prosumers Aggregation considering the Self-Generation

Authors
Ribeiro, C; Pinto, T; Vale, Z; Baptista, J;

Publication
DISTRIBUTED COMPUTING AND ARTIFICIAL INTELLIGENCE

Abstract
Several challenges arrive with electrical power restructuring, liberalized electricity markets emerge, aiming to improve the system's efficiency while offering new economic solutions. Privatization and liberalization of previously nationally owned systems are examples of the transformations that have been applied. Microgrids and smart grids emerge and new business models able to cope with new opportunities start being developed. New types of players appear, allowing aggregating a diversity of entities, e. g. generation, storage, electric vehicles, and consumers, Virtual Power Players (VPPs) are a new type of player that allows aggregating a diversity of players to facilitate their participation in the electricity markets. A major task of VPPs is the remuneration of generation and services (maintenance, market operation costs and energy reserves), as well as charging energy consumption. The paper proposes a normalization method that supports a clustering methodology for the remuneration and tariffs definition. This model uses a clustering algorithm, applied on normalized load values, the value of the micro production, generated in the bus associated to the same load, was subtracted from the value of the consumption of that load. This calculation is performed in a real smart grid on buses with associated micro production. This allows the creation of sub-groups of data according to their correlations. The clustering process is evaluated so that the number of data sub-groups that brings the most added value for the decision making process is found, according to players characteristics.

2018

Customized normalization clustering methodology for consumers with heterogeneous characteristics

Authors
Ribeiro, C; Pinto, T; Vale, Z; Baptista, J;

Publication
ADCAIJ-ADVANCES IN DISTRIBUTED COMPUTING AND ARTIFICIAL INTELLIGENCE JOURNAL

Abstract
The increasing use and development of renewable energy sources and distributed generation, brought several changes to the power system operation. Electricity markets worldwide are complex and dynamic environments with very particular characteristics, resulting from their restructuring and evolution into regional and continental scales, along with the constant changes brought by the increasing necessity for an adequate integration of renewable energy sources. With the eminent implementation of micro grids and smart grids, new business models able to cope with the new opportunities are being developed. Virtual Power Players are a new type of player, which allows aggregating a diversity of entities, e.g. generation, storage, electric vehicles, and consumers, to facilitate their participation in the electricity markets and to provide a set of new services promoting generation and consumption efficiency, while improving players' benefits. This paper proposes a clustering methodology regarding the remuneration and tariff of VPP. It proposes a model to implement fair and strategic remuneration and tariff methodologies, using a clustering algorithm, applied to load values, submitted to different types of normalization process, which creates sub-groups of data according to their correlations. The clustering process is evaluated so that the number of data sub-groups that brings the most added value for the decision making process is found, according to the players characteristics. The proposed clustering methodology has been tested in a real distribution network with 30 bus, including residential and commercial consumers, photovoltaic generation and storage units.

2018

Dynamic electricity tariff definition based on market price, consumption and renewable generation patterns

Authors
Ribeiro, C; Pinto, T; Faria, P; Ramos, S; Vale, Z; Baptista, J; Soares, J; Navarro Caceres, M; Manuel Corchado, JM;

Publication
2018 CLEMSON UNIVERSITY POWER SYSTEMS CONFERENCE (PSC)

Abstract
The increasing use of renewable energy sources and distributed generation brought deep changes in power systems, namely with the operation of competitive electricity markets. With the eminent implementation of micro grids and smart grids, new business models able to cope with the new opportunities are being developed. Virtual Power Players are a new type of player, which allows aggregating a diversity of entities, e.g. generation, storage, electric vehicles, and consumers, to facilitate their participation in the electricity markets and to provide a set of new services promoting generation and consumption efficiency, while improving players' benefits. In order to achieve this objective, it is necessary to define tariff structures that benefit or penalize agents according to their behavior. In this paper a method for determining the tariff structures has been proposed, optimized for different load regimes. Daily dynamic tariff structures were defined and proposed, on an hourly basis, 24 hours day-ahead from the characterization of the typical load profile, the value of the electricity market price and considering the renewable energy production.

2018

ECIR 2018: Text2Story Workshop - Narrative Extraction from Texts

Authors
Jorge, A; Campos, R; Jatowt, A; Nunes, S; Rocha, C; Cordeiro, JP; Pasquali, A; Mangaravite, V;

Publication
SIGIR Forum

Abstract

2018

A Fokker-Planck approach to joint state-parameter estimation

Authors
Lemos, JM; Costa, BA; Rocha, C;

Publication
IFAC PAPERSONLINE

Abstract
The problem of joint estimation of parameters and state of continuous time systems using discrete time observations is addressed. The plant parameters are assumed to be modeled by a Wiener process. The a priori probability density function (pdf) of an extended state that comprises the plant state variables and the parameters is propagated in time using an approximate solution of the Fokker-Planck equation that relies on Trotter's formula for semigroup decomposition. The a posteriori (i. e., given the observations) pdf is then computed at the observation instants using Bayes law.

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