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Publications

Publications by CPES

2022

A decision-making experiment under wind power forecast uncertainty

Authors
Mohrlen, C; Bessa, RJ; Fleischhut, N;

Publication
METEOROLOGICAL APPLICATIONS

Abstract
As the penetration levels of renewable energy sources increase and climatic changes produce more and more extreme weather conditions, the uncertainty of weather and power production forecasts can no longer be ignored for grid operation and electricity market bidding. In order to support the energy industry in the integration of uncertainty forecasts into their business practices, this work describes an experiment conducted with 105 participants from the energy industry. In the framework of an IEA Wind Task 36 workshop, the experiment aimed to investigate existing psychological barriers in the industry to adopt probabilistic forecasts and to better understand human decision processes. We designed and ran a 'decision game' to demonstrate the potential benefits of uncertainty forecasts in a realistic-although simplified-problem, where an energy trader had to decide whether to trade 100% or 50% of the energy of an offshore wind park on a given day based on deterministic and probabilistic uncertainty day-ahead forecasts. The focus thus was on a decision-making process dealing with extremes that can cause high costs in the form of security issues in the electric grid for system operators, or high monetary losses for traders, who have bid a power production into the market that failed to be produced due to high-speed shutdown of the wind turbines. This paper presents the obtained results, extracts behavioural conclusions and identifies how to overcome psychological barriers to the adoption of uncertainty forecasts in the energy industry.

2022

Data-Driven Anomaly Detection and Event Log Profiling of SCADA Alarms

Authors
Andrade, JR; Rocha, C; Silva, R; Viana, JP; Bessa, RJ; Gouveia, C; Almeida, B; Santos, RJ; Louro, M; Santos, PM; Ribeiro, AF;

Publication
IEEE ACCESS

Abstract
Network human operators' decision-making during grid outages requires significant attention and the ability to perceive real-time feedback from multiple information sources to minimize the number of control actions required to restore service, while maintaining the system and people safety. Data-driven event and alarm management have the potential to reduce human operator cognitive burden. However, the high complexity of events, the data semantics, and the large variety of equipment and technologies are key barriers for the application of Artificial Intelligence (AI) to raw SCADA data. In this context, this paper proposes a methodology to convert a large volume of alarm events into data mining terminology, creating the conditions for the application of modern AI techniques to alarm data. Moreover, this work also proposes two novel data-driven applications based on SCADA data: (i) identification of anomalous behaviors regarding the performance of the protection relays of primary substations, during circuit breaker tripping alarms in High Voltage (HV) and Medium Voltage (MV) lines; (ii) unsupervised learning to cluster similar events in HV line panels, classify new event logs based on the obtained clusters and membership grade with a control parameter that helps to identify rare events. Important aspects associated with data handling and pre-processing are also covered. The results for real data from a Distribution System Operator (DSO) showed: (i) that the proposed method can detect unexpected relay pickup events, e.g., one substation with nearly 41% of the circuit breaker alarms had an 'atypical' event in their context (revealed an overlooked problem on the electrification of a protection relay); (ii) capability to automatically detect and group issues into specific clusters, e.g., SF6 low-pressure alarms and blocks with abnormal profiles caused by event time-delay problems.

2022

Conditional parametric model for sensitivity factors in LV grids: A privacy-preserving approach

Authors
Sampaio, G; Bessa, RJ; Goncalves, C; Gouveia, C;

Publication
ELECTRIC POWER SYSTEMS RESEARCH

Abstract
The deployment of smart metering technologies in the low voltage (LV) grid created conditions for the application of data-driven monitoring and control functions. However, data privacy regulation and consumers' aversion to data sharing may compromise data exchange between utility and customers. This work presents a data-driven method, based on smart meter data, to estimate linear sensitivity factors for three-phase unbalanced LV grids, which combines a privacy-preserving protocol and varying coefficients linear regression. The proposed method enables centralized and peer-to-peer learning of the sensitivity factors. Potential applications for the sensitivity factors are demonstrated by solving voltage violations or computing operating envelopes in a LV grid without resorting to its network topology or electrical parameters.

2022

Forecasting: theory and practice

Authors
Petropoulos, F; Apiletti, D; Assimakopoulos, V; Babai, MZ; Barrow, DK; Ben Taieb, S; Bergmeir, C; Bessa, RJ; Bijak, J; Boylan, JE; Browell, J; Carnevale, C; Castle, JL; Cirillo, P; Clements, MP; Cordeiro, C; Oliveira, FLC; De Baets, S; Dokumentov, A; Ellison, J; Fiszeder, P; Franses, PH; Frazier, DT; Gilliland, M; Gonul, MS; Goodwin, P; Grossi, L; Grushka Cockayne, Y; Guidolin, M; Guidolin, M; Gunter, U; Guo, XJ; Guseo, R; Harvey, N; Hendry, DF; Hollyman, R; Januschowski, T; Jeon, J; Jose, VRR; Kang, YF; Koehler, AB; Kolassa, S; Kourentzes, N; Leva, S; Li, F; Litsiou, K; Makridakis, S; Martin, GM; Martinez, AB; Meeran, S; Modis, T; Nikolopoulos, K; Onkal, D; Paccagnini, A; Panagiotelis, A; Panapakidis, I; Pavia, JM; Pedio, M; Pedregal, DJ; Pinson, P; Ramos, P; Rapach, DE; Reade, JJ; Rostami Tabar, B; Rubaszek, M; Sermpinis, G; Shang, HL; Spiliotis, E; Syntetos, AA; Talagala, PD; Talagala, TS; Tashman, L; Thomakos, D; Thorarinsdottir, T; Todini, E; Arenas, JRT; Wang, XQ; Winkler, RL; Yusupova, A; Ziel, F;

Publication
INTERNATIONAL JOURNAL OF FORECASTING

Abstract
Forecasting has always been at the forefront of decision making and planning. The uncertainty that surrounds the future is both exciting and challenging, with individuals and organisations seeking to minimise risks and maximise utilities. The large number of forecasting applications calls for a diverse set of forecasting methods to tackle real-life challenges. This article provides a non-systematic review of the theory and the practice of forecasting. We provide an overview of a wide range of theoretical, state-of-the-art models, methods, principles, and approaches to prepare, produce, organise, and evaluate forecasts. We then demonstrate how such theoretical concepts are applied in a variety of real-life contexts. We do not claim that this review is an exhaustive list of methods and applications. However, we wish that our encyclopedic presentation will offer a point of reference for the rich work that has been undertaken over the last decades, with some key insights for the future of forecasting theory and practice. Given its encyclopedic nature, the intended mode of reading is non-linear. We offer cross-references to allow the readers to navigate through the various topics. We complement the theoretical concepts and applications covered by large lists of free or open-source software implementations and publicly-available databases. (C) 2021 The Author( s). Published by Elsevier B.V. on behalf of International Institute of Forecasters.

2022

A Blockchain-based Data Market for Renewable Energy Forecasts

Authors
Coelho, F; Silva, F; Goncalves, C; Bessa, R; Alonso, A;

Publication
2022 FOURTH INTERNATIONAL CONFERENCE ON BLOCKCHAIN COMPUTING AND APPLICATIONS (BCCA)

Abstract
This paper presents a data market aimed at trading energy forecasts data. The system architecture is built using blockchain as a service, allowing access to data streams and establishing a distributed settlement between stakeholders. Energy Forecasts data is presented as the commodity traded in the market, whose settlement is provided through the blockchain on the basis of the extracted value provided by market stakeholders. Our proposal allows market stakeholders to acquire energy forecasts and pay according to the data accuracy, solving the confidentiality problem of freely sharing data. A data quality reward is introduced, steering the compensation sent to market participants. The data market design is presented and an evaluation campaign is performed, showing that the data market produced functionally valid results in comparison with the results achieved with a central simulated approach. Moreover, results show that the data market architecture is able to scale.

2022

Local flexibility need estimation based on distribution grid segmentation

Authors
Retorta, F; Gouveia, C; Sampaio, G; Bessa, R; Villar, J;

Publication
International Conference on the European Energy Market, EEM

Abstract
This work presents a methodology to segment the MV electric grid into grid zones for which the active power flexibility needs that solve the forecasted voltage and current issues are computed. This methodology enables the Distribution System Operator (DSO) to publish flexibility needs per zones, allowing aggregators to offer flexibility by optimizing their portfolio of resources in each grid zone. A case study is used to support the methodology results and its performance, showing the feasibility of solving grid issues by activating flexibility per grid zones according to the proposed methodology. © 2022 IEEE.

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