Browsing by Author "214"
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    The challenges of estimating the impact of distributed energy resources flexibility on the TSO/DSO boundary node operating points
    ( 2018) Luís Seca ; Vladimiro Miranda ; Manuel Matos ; João Vieira Silva ; Jean Sumaili ; Ricardo Jorge Bessa ; 4417 ; 208 ; 214 ; 4882 ; 6299 ; 5164
    The increasing penetration of renewable energy sources characterized by a high degree of variability and uncertainty is a complex challenge for network operators that are obligated to ensure their connection while keeping the quality and security of supply. In order to deal with this variable behavior and forecast uncertainty, the distribution networks are equipped with flexible distributed energy resources capable of adjusting their operating point to avoid technical issues (voltage problems, congestion, etc.). Within this paradigm, the flexibility that, in fact, can be provided by such resources, needs to be estimated/forecasted up to the transmission network node (primary substation) and requires new tools for TSO/DSO coordination. This paper addresses this topic by developing a methodology capable of finding the flexibility area while taking into account the technical grid constraints. The proposed approach is based on the formulation of a single optimization problem which is run several times, according with the expected precision for the flexibility area estimation. To each optimization problem run, a different objective function belonging to a family of straight lines is assigned. This allows exploring the active and reactive power flow limits at the TSO/DSO boundary nodes - which define the flexibility area. The effectiveness of the proposed model has been evaluated on two test networks and the results suggest a step forward in the TSO/DSO coordination field. Nevertheless, further investigations to study the effect of assets with discrete control nature (e.g., on load tap changers - OLTC, capacitor banks) on the occurrence of disjoint flexibility areas should be carried. © 2017 Elsevier Ltd.
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    Consumer-centric electricity markets: A comprehensive review on user preferences and key performance indicators
    ( 2022) Oliveira,C ; Botelho,DF ; Tiago André Soares ; António Sérgio Faria ; Dias,BH ; Manuel Matos ; De Oliveira,LW ; 214 ; 6611 ; 7694
    The power system is facing a transition from its traditional centralized model to a more decentralized one, through the emergence of proactive consumers on the network, known as prosumers. This paradigm shift favors the emergence of new electricity market designs. Peer-to-Peer (P2P) based structures have been gaining prominence worldwide. In the P2P market, the prosumer assumes a more active role in the system, being able to directly trade its energy without the need for intermediaries. This paper contributes with a comprehensive overview of consumer-centric electricity markets, providing background on different aspects of P2P sharing, in particular the inclusion of peer preferences in the electricity trading process through product differentiation. A performance assessment of the different modeled preferences was carried out using key performance indicators (KPIs). Different user preferences under the product differentiation mechanism were simulated. The results demonstrate that consumer-centric markets increase the penetration of renewable energy sources into the network and tend to affect loads flexibility according to the renewable generation.
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    Design of an Energy Policy for the Decarbonisation of Residential and Service Buildings in Northern Portugal
    ( 2023) Capelo,S ; Tiago André Soares ; Azevedo,I ; Fonseca,W ; Manuel Matos ; 214 ; 6611
    The decarbonisation of the building sector is crucial for Portugal’s goal of achieving economy-wide carbon neutrality by 2050. To mobilize communities towards energy efficiency measures, it is important to understand the primary drivers and barriers that must be overcome through policymaking. This paper aims to review existing Energy Policies and Actions (EPA) in Portugal and assess their effectiveness in improving Energy Efficiency (EE) and reducing CO2 emissions in the building sector. The Local Energy Planning Assistant (LEPA) tool was used to model, test, validate and compare the implementation of current and alternative EPAs in the North of Portugal, including the national EE plan. The results indicate that electrification of heating and cooling, EE measures, and the proliferation of Renewable Energy Sources (RES) are crucial for achieving climate neutrality. The study found that the modelling of alternative EPAs can be improved to reduce investment costs and increase Greenhouse Gas (GHG) emissions reduction. Among the alternatives assessed, the proposed one (Alternative 4) presents the best returns on investment in terms of cost savings and emissions reduction. It allows for 52% investment cost savings in the residential sector and 13% in the service sector when compared to the current national roadmap to carbon neutrality (Alternative 2). The estimated emission reduction in 2050 for Alternative 4 is 0.64% for the residential sector and 3.2% for the service sector when compared to Alternative 2.
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    Dimensioning Studies for Reversible Hydro Power Plants in Portuguese Islands
    ( 2018) Manuel Matos ; Nuno Soares Fonseca ; André Guimarães Madureira ; João Peças Lopes ; 1103 ; 214 ; 5517 ; 4560
    This work is within the scope of set of consultancy studies made for Portuguese islands. It focuses on the integration of Pumped Storage Power in isolated islands. The paper starts to address several power systems circumstances about two Portuguese islands on the energetic level. For each of these islands, an independent examination of the conditions to install a reversible hydro power plant is accomplished. Therefore, the energy volume to be stored due to excess of renewable generation and the ideal power and number of the pumps and turbines to be installed were identified and evaluated for the sake of using the produced energy surplus as to be pumped and later generated. The paper enhances the importance of storing energy in the operation of isolated and small systems with considerable amount of intermittent power resources as well as the conditions for the viability of installing new exploitations of this kind.
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    Distributed Network-Constrained P2P Community-Based Market for Distribution Networks
    ( 2023) Oliveira,C ; Simoes,M ; Bitencourt,L ; Tiago André Soares ; Manuel Matos ; 214 ; 6611
    Energy communities have been designed to empower consumers while maximizing the self-consumption of local renewable energy sources (RESs). Their presence in distribution systems can result in strong modifications in the operation and management of such systems, moving from a centralized operation to a distributed one. In this scope, this work proposes a distributed community-based local energy market that aims at minimizing the costs of each community member, accounting for the technical network constraints. The alternating direction method of multipliers (ADMM) is adopted to distribute the market, and preserve, as much as possible, the privacy of the prosumers’ assets, production, and demand. The proposed method is tested on a 10-bus medium voltage radial distribution network, in which each node contains a large prosumer, and the relaxed branch flow model is adopted to model the optimization problem. The market framework is proposed and modeled in a centralized and distributed fashion. Market clearing on a day-ahead basis is carried out taking into account actual energy exchanges, as generation from renewable sources is uncertain. The comparison between the centralized and distributed ADMM approach shows an 0.098% error for the nodes’ voltages. The integrated OPF in the community-based market is a computational burden that increases the resolution of the market dispatch problem by about eight times the computation time, from 200.7 s (without OPF) to 1670.2 s. An important conclusion is that the proposed market structure guarantees that P2P exchanges avoid the violation of the network constraints, and ensures that community agents’ can still benefit from the community-based architecture advantages. © 2023 by the authors.
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    Estimating the Active and Reactive Power Flexibility Area at the TSO-DSO Interface
    ( 2018) João Vieira Silva ; Sebastian Viana,M ; Goncer,B ; Caujolle,M ; Vladimiro Miranda ; Manuel Matos ; Seca,L ; Ricardo Jorge Bessa ; Sumaili,J ; 6299 ; 4882 ; 208 ; 214
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    Optimal bidding strategy for an aggregator of prosumers in energy and secondary reserve markets
    ( 2019) Manuel Matos ; José Pedro Iria ; Filipe Joel Soares ; 5485 ; 4999 ; 214
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    Participation of an EV Aggregator in the Reserve Market through Chance-Constrained Optimization
    ( 2020) António Sérgio Faria ; Tiago André Soares ; Sousa,T ; Manuel Matos ; 214 ; 6611 ; 7694
    The adoption of Electric Vehicles (EVs) will revolutionize the storage capacity in the power system and, therefore, will contribute to mitigate the uncertainty of renewable generation. In addition, EVs have fast response capabilities and are suitable for frequency regulation, which is essential for the proliferation of intermittent renewable sources. To this end, EV aggregators will arise as a market representative party on behalf of EVs. Thus, this player will be responsible for supplying the power needed to charge EVs, as well as offering their flexibility to support the system. The main goal of EV aggregators is to manage the potential participation of EVs in the reserve market, accounting for their charging and travel needs. This work follows this trend by conceiving a chance-constrained model able to optimize EVs participation in the reserve market, taking into account the uncertain behavior of EVs and their charging needs. The proposed model, includes penalties in the event of a failure in the provision of upward or downward reserve. Therefore, stochastic and chance-constrained programming are used to handle the uncertainty of a small fleet of EVs and the risk profile of the EV aggregator. Two different relaxation approaches, i.e., Big-M and McCormick, of the chance-constrained model are tested and validated for different number of scenarios and risk levels, based on an actual test case in Denmark with actual driving patterns. As a final remark, the McCormick relaxation presents better performance when the uncertainty budget increases, which is appropriated for large-scale problems.
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    Unit Commitment Including Economic Dispatch with Network Constraints
    ( 2007) Jorge Correia Pereira ; Ana Viana ; Manuel Matos ; 214 ; 1809 ; 3708
    In this paper it is presented the development of an algorithm to solve two complex power systems problems at once. The algorithm carry out two steps: solve the Unit Commitment problem using a meta-heuristic with Constraint Oriented Neighborhoods and promote the base to the Economic Dispatch problem, which consists on the optimization of operating costs under the general constraints to the power system, which is solved through the use of linear programming. The algorithm was applied with success to the Mozambique electric power system, achieving good results and less execution timing consuming.
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    Unit Commitment Including Economic Dispatch with Network Constraints
    ( 2007) Jorge Correia Pereira ; Ana Viana ; Manuel Matos ; 214 ; 1809 ; 3708
    In this paper it is presented the development of an algorithm to solve two complex power systems problems at once. The algorithm carry out two steps: solve the Unit Commitment problem using a meta-heuristic with Constraint Oriented Neighborhoods and promote the base to the Economic Dispatch problem, which consists on the optimization of operating costs under the general constraints to the power system, which is solved through the use of linear programming. The algorithm was applied with success to the Mozambique electric power system, achieving good results and less execution timing consuming.