Scientific publications
SCIENTIFIC PUBLICATIONS AND CONFERENCE PAPERS
Find all the scientific publications produced by WeForming partners, presenting the latest scientific findings of the project.
SCIENTIFIC PUBLICATION
Authors
Tomislav Antić, Andrew Keane, Tomislav Capuder
Abstract
Hosting capacity (HC) and dynamic operating envelopes (DOEs), defined as dynamic, time-varying HC, are calculated using three-phase optimal power flow (OPF) formulations. Due to the computational complexity of such optimisation problems, HC and DOE are often calculated by introducing certain assumptions and approximations, including the linearised OPF formulation, which we implement in the Python-based tool ppOPF. Furthermore, we investigate how assumptions of the distributed energy resource (DER) connection phase impact the objective function value and computational time in calculating HC and DOE in distribution networks of different sizes. The results are not unambiguous and show that it is not possible to determine the optimal connection phase without introducing binary variables since, no matter the case study, the highest objective function values are calculated with mixed integer OPF formulations. The difference is especially visible in a real-world low-voltage network in which the difference between different scenarios is up to 14 MW in a single day. However, binary variables make the problem computationally complex and increase computational time to several hours in the DOE calculation, even when the optimality gap different from zero is set.
Published in Sustainable Energy, Grids and Networks journal
Authors
Nikolina Čović, Jochen L. Cremer, Hrvoje Pandžić
Abstract
Accelerated development of demand response service provision by the residential sector is crucial for reducing carbon-emissions in the power sector. Along with the infrastructure advancement, encouraging the end users to participate is crucial. End users highly value their privacy and control, and want to be included in the service design and decision-making process when creating the daily appliance operation schedules. Furthermore, unless they are financially or environmentally motivated, they are generally not prepared to sacrifice their comfort to help balance the power system. In this paper, we present an inverse-reinforcement-learning-based model that helps create the end users’ daily appliance schedules without asking them to explicitly state their needs and wishes. By using their past consumption data, the end consumers will implicitly participate in the creation of those decisions and will thus be motivated to continue participating in the provision of demand response services.
Published in Electric Power Systems Research journal
Authors
Angel Paredes, Jean-Francois Toubeau, Jose A. Aguado, Francois Vallee
Abstract
Battery Energy Storage Systems (BESSs) are particularly well-suited to deepen the decarbonisation of reserve markets, traditionally dominated by non-renewable generators. BESSs operators often rely on Predict-Then-Optimise (PTO) methods to participate in these markets, which focus on forecasting market conditions without directly considering the impact of subsequent decisions while training. Recently, learning models have evolved to incorporate decision outcomes during training, known as Decision Focused Learning (DFL) methodologies, which have the potential to increase market benefits. This paper introduces a DFL approach that integrates the decision-making process of BESSs when participating in reserve markets into the training of their predictive models. By expressing the optimization problem as a primal-dual mapping using the Karush–Kuhn–Tucker (KKT) conditions, the proposed DFL method enables the regressor to learn from the BESS’s decisions, refining its predictions based on observed outcomes, improving decision accuracy and market performance. Results show that the proposed DFL approach outperforms traditional PTO methods, with up to a 9.5% increase in profits for a case study based on the Belgian secondary reserve market, highlighting its effectiveness in managing the complexities of dynamic market conditions.
Authors
Johannes Galenzowski, Simon Waczowicz, Hüseyin Çakmak, Erfan Tajalli-Ardekani, Sebastian Beichter, Ömer Ekin, Ralf Mikut, Veit Hagenmeyer
Abstract
Recently, there has been a surge of interest in novel concepts for jointly operating devices in urban areas in clusters, motivated by their potential to support decarbonization, enhance power system flexibility, and promote energy justice. Such clusters encompass multiple devices or buildings but operate on a smaller scale than cities. Examples include Renewable Energy Communities and Positive Energy Districts. These Novel District Concepts (NDCs) integrate interdisciplinary urban planning and social sciences terminology into the energy domain. However, these concept’s precise definitions and practical implementation lack consistency, leading to conceptual ambiguities in the literature.
CONFERENCE PAPERS
Authors
Tomislav Antić, Tomislav Capuder
Abstract
Installing distributed energy resources (DERs) in low voltage networks is limited by distribution grid codes, often defining a conservative connection power threshold, especially in the case of a single-phase connection or by the network’s technical constraints. Calculating the maximum installed power in that way is called hosting capacity (HC). Traditional HC calculation presents an assessment of static connection limits, determined by the lowest or highest electricity demand, depending on whether export or import limits are calculated. In this paper, we calculate the available range of aggregated active power of DERs based on worst-case and base-case demand scenarios. The results suggest the potential grid code redefinition since the analysed network can accommodate additional DERs in the range of 300 and 500 kW, compared to the current grid code limits. When observing only the grid code limitations in the import limits analysis, the results show an unrealistically high integration of more than 750 kW DERs, which is even higher than the best-case scenario. In the worst-case scenario, no additional DERs can be installed due to the initial violation of the network’s constraints. Dynamic export and import limits are in the theoretical range of values, showing the benefit of the concept.
Presented at CIRED 2024 Vienna Workshop
Authors
Tomislav Antić, Tomislav Capuder
Abstract
In this paper, we analyse the potential of demand-side flexibility and the importance of considering higher-order harmonics in calculating distributed energy resources (DERs) hosting capacity in low voltage (LV) distribution networks. We step aside from traditional calculations, in which hosting capacity (HC) is assessed based on the worst-case scenario and calculate dynamic export and import limits, based on near real-time electricity consumption estimates. In the scenario without modelling higher-order harmonics, the results show that upward flexibility contributes to the increase of installed distributed generators since aggregated active power increases between 0.05 and 38%, depending on the case study. When import limits are calculated, dynamic HC (DHC) also increases due to the demand-side flexibility potential, with the impact even more significant than in the case of export. Introducing higher-order harmonics in the model leads to decreased DHC in the scenario in which export limits are calculated. The decrease happens not only because of the total harmonic distortion (THD) constraint but also due to the contribution of the higher-order harmonics to the root-mean-square (RMS) voltage value. When calculating dynamic import limits, harmonic voltages increase the RMS voltage magnitude and, that way, free up additional space for the DERs installation.
Presented at CIRED 2024 Vienna Workshop
Authors
Aitor Cendoya, Frederic Ransy, Vincent Lemort, Andres Hernandez, Pierre Dewallef, Pierre-Henri Gresse, Jacques Windeshausen
Abstract
Nowadays, most countries are striving to transition their energy matrices towards renewable sources. To achieve this goal, energy storage systems play a crucial role in compensating for the inherent intermittency ofrenewable sources. Buildings are among the largest consumers of primary energy, due to their heating demands. Consequently, integrating renewable energies into buildings is essential. This paper presents a pioneering approach that integrates renewable energy sources with a multi-energy system. This system powers a Heat Pump (HP) responsible for heating an abandoned mine flooded with water, producing electricity via a Carnot Battery (CB), and distributing heating and cooling through a district heating network (DHN).This study is conducted in a real case of an abandoned slate mine in Martelange, Belgium, where three different size caverns are employed to store energy: 800, 6840, and 80000 m cubed for hot (90 C) medium (50 C) and cold (5 C) water temperature, respectively. The system combines photovoltaic panels, an electrical battery, heat pumps, electrical resistance, and an Organic Rankine Cycle. This study highlights the potential of reusing abandoned mines as energy storage systems, which can benefit adjacent communities by integrating diverse energy demands within a single system. This generates new perspectives for investors and residents, enabling the possibility of connecting the system to the grid for energy arbitrage and balancing services.
Published in Purdue
Authors
Aitor Cendoya F. University of Liège
