2024
Authors
Campos, V; Klyagina, O; Andrade, JR; Bessa, RJ; Gouveia, C;
Publication
ELECTRIC POWER SYSTEMS RESEARCH
Abstract
Nowadays, human operators at control centers analyze a large volume of alarm information during outage events and must act fast to restore the service. To assist operator decisions this work proposes novel machine learning-based functions aiming to: (a) classify the complexity of a fault occurrence (Occurrences Classifier) and its cause (Fault Cause Classifier) based on its alarm events; (b) provide fast insights to the operator on how to solve it (Data2Actions). The Occurrences Classifier takes alarm information of an occurrence and classifies it as a simpleor complexoccurrence, while the Fault Cause Classifier predicts the cause class of MV lines faults. The Data2Actions takes a sequence of alarm information from the occurrence and suggests a more adequate sequence of switching actions to isolate the fault section. These algorithms were tested on real data from a Distribution System Operator and showed: (a) an accuracy of 86% for the Data2Actions, (b) an accuracy of 68% for the Occurrences Classifier, and (c) an accuracy of 74% for the Fault Cause Classifier. It also proposes a new representation for SCADA event log data using graphs, which can help human operators identify infrequent alarm events or create new features to improve model performance.
2024
Authors
Reiz, C; Alves, E; Melim, A; Gouveia, C; Carrapatoso, A;
Publication
2024 IEEE 22ND MEDITERRANEAN ELECTROTECHNICAL CONFERENCE, MELECON 2024
Abstract
The integration of inverter-based distributed generation challenges the implementation of an reliable protection This work proposes an adaptive protection method for coordinating protection systems using directional overcurrent relays, where the settings depend on the distribution network operating conditions. The coordination problem is addressed through a specialized genetic algorithm, aiming to minimize the total operating times of relays with time-delayed operation. The pickup current is also optimized. Coordination diagrams from diverse fault scenarios illustrate the method's adaptability to different operational conditions, emphasizing the importance of employing multiple setting groups for optimal protection system performance. The proposed technique provides high-quality solutions, enhancing reliability compared to traditional protection schemes.
2024
Authors
Alves, E; Reiz, C; Melim, A; Gouveia, C;
Publication
IET Conference Proceedings
Abstract
The integration of Distributed Energy Resources (DER) imposes challenges to the operation of distribution networks. This paper conducts a systematic assessment of the impact of DER on distribution network overcurrent protection, considering the behavior of Inverter Based Resources (IBR) during faults in the coordination of medium voltage (MV) feeders' overcurrent protection. Through a detailed analysis of various scenarios, we propose adaptive protection solutions that enhance the reliability and resilience of distribution networks in the face of growing renewable energy integration. Results highlight the advantages of using adaptive protection over traditional methods and topology changes, and delve into current protection strategies, identifying limitations and proposing mitigation strategies. © The Institution of Engineering & Technology 2024.
2025
Authors
Retorta, F; Mello, J; Gouveia, C; Silva, B; Villar, J; Troncia, M; Chaves Avila, JP;
Publication
UTILITIES POLICY
Abstract
Local flexibility markets are a promising solution to aid system operators in managing the network as it faces the growth of distributed resources and the resulting impacts on voltage control, among other factors. This paper presents and simulates a proposal for an intra-day local flexibility market based on grid segmentation. The design provides a market-based solution for distribution system operators (DSOs) to address near-real-time grid issues. The grid segmentation computes the virtual buses that represent each zone and the sensitivity indices that approximate the impact of activating active power flexibility in the buses within the zone. This approach allows DSOs to manage and publish their flexibility needs per zone and enables aggregators to offer flexibility by optimizing their resource portfolios per zone. The simulation outcomes allow for the assessment of market performance according to the number of zones computed and show that addressing overloading and voltage control through zonal approaches can be cost-effective and counterbalance minor errors compared to node-based approaches.
2025
Authors
Reiz, C; Gouveia, C; Bessa, RJ; Lopes, JP; Kezunovic, M;
Publication
SUSTAINABLE ENERGY GRIDS & NETWORKS
Abstract
Increased electrification of various critical infrastructures has been recognized as a key to achieving decarbonization targets worldwide. This creates a need to better understand the risks associated with future power systems and how such risks can be defined, assessed, and mitigated. This paper surveys prior work on power system risk assessment and management and explores the various approaches to risk definition, assessment, and mitigation. As a result, the paper proposes how future grid developments should be assessed in terms of risk causes, what methodology may be used to reduce the risk impacts, and how such approaches can increase grid resilience. While we attempt to generalize and classify various approaches to solving the problem of risk assessment and mitigation, we also provide examples of how specific approaches undertaken by the authors in the past may be expanded in the future to address the design and operation of the future electricity system to manage the risk more effectively. The importance of the metrics for risk assessment and methodology for quantification of risk reduction are illustrated through the examples. The paper ends with recommendations on addressing the risk and resilience of the electricity system in the future resilient implementation while achieving decarbonization goals through massive electrification.
2025
Authors
Habib H.U.R.; Reiz C.; Alves E.; Gouveia C.S.;
Publication
2025 IEEE Kiel Powertech Powertech 2025
Abstract
This paper presents an adaptive protection strategy for multi-microgrid (MMG) systems with inverter-based resources (IBRs) in medium voltage (MV) networks, using the IEEE 33-bus test system. The approach combines overcurrent (OC) and undervoltage (UV) protections through an offline-optimized, clustering-based scheme and real-time selection of setting groups. A metaheuristic algorithm determines optimal relay settings for representative scenarios, ensuring responsive and coordinated protection. Hardware-in-the-loop validation on OPAL-RT confirms the method's effectiveness across varying loads, DER outputs, and fault conditions. Results demonstrate reliable fault isolation, smooth mode transitions, and uninterrupted supply to healthy segments. Identified limitations in high-impedance fault handling suggest future improvements.
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