Online Inertia Estimation of Droop Control-Based Grid-Forming Inverters in Islanded Microgrid
Saeid Pashazadeh, Zahra Dehghani Arani, Amir Khorsandi, Hamed Nafisi, Gevork B. Gharehpetian
Department of Electrical Engineering, Amirkabir University of Technology, Tehran. Iran

Abstract

Inertia estimation of the droop control-based grid-forming (GFM) inverters has not been performed in an islanded microgrid by using an online method with low computational cost. This paper deals with this issue by considering the relationship between the active power-angular frequency droop equation and the conventional swing equation. As a solution, a first-order differential equation in the time domain is extracted from the active power-angular frequency droop equation in the Laplace domain to estimate the inertia constant of the GFM inverter... READ MORE

Hybrid Renewable Microgrid Design for a Public University Building: Technical, Economic, Environmental and Educational Assessment
M. González-Pérez(1),F. J. Asensio(1), A. Ordoño(1), J. Rodriguez-Gongora(1), G. Saldaña(2), O. Oñederra(2)
1. Department of Electrical Engineering. G.I.E. Eibar, University of the Basque Country (EHU). Eibar. Spain
2. Department of Electrical Engineering. B.I.E., University of the Basque Country (EHU). Bilbao. Spain

Abstract

This paper presents the design and assessment of a hybrid electrical and thermal microgrid for a public university building. The project aims to reduce the building’s energy expenditure while simultaneously creating a full-scale learning infrastructure for students enrolled in the Renewable Energy Engineering degree. Several microgrid configurations are evaluated, combining photovoltaic generation (PV), micro‑wind power (WT), gas microturbine cogeneration (GM-CHP), battery storage (BES), and hydrogen storage technologies (HES).... READ MORE

Controllability of Magnetic Flux Linkages in Variable-Speed Electrically-Excited Synchronous Generators
B. Polajžer(1), A. Muetze(2), S. A. Seyed-Bouzari(2), J. Ritonja(1)
1. Faculty of Electrical Engineering and Computer Science. University of Maribor. Slovenia
2. Electric Drives and Power Electronic Systems Institute. Graz University ofTechnology Graz. Austria

Abstract

Synchronous generators (SGs) are the primary technology for large-scale electricity generation, with stator windings connected directly to the grid. This setup limits controllability, as control action is exerted only through rotor voltage. Variable-speed SGs, which integrate a power electronic converter between the stator and grid, enhance controllability. This paper analyzes the controllability of an electrically excited SG using a d-q-axis model of the electromagnetic subsystem, assuming that both the rotor and stator voltages are controlled..... READ MORE

Impact of Retail Tariff Choice and Virtual Wallet on Forecast-Based PV Sharing in Residential Energy Communities
J. Serrano González, J.T. Villalonga Palou, J.M. Riquelme Santos, J.M Roldán Fernández<
Department of Electrical Engineering. University of Seville. Spain

Abstract

Collective self-consumption schemes typically require dynamic sharing coefficients—hourly allocation ratios per customer—to be submitted during the month preceding settlement, making reliable month-ahead, hour-by-hour demand forecasts essential. This paper presents a practical framework that generates these forecasts from historical consumption data and derives compliant allocation coefficients, while explicitly assessing how the economic value of forecasting depends on the retail tariff and compensation rules..... READ MORE

AI Poses New Challenges in Energy Education: On the Example of Robotics
V. Vodovozov, Z. Raud
Department of Electrical Power Engineering and Mechatronics. Tallinn University of Technology. Tallinn. Estonia

Abstract

The arrival of artificial intelligence (AI) rapidlytransforms technological, economic and social life, leading to a rethinking of the role of an engineer and changing requirements for engineering education. This paper presents some results obtained at Tallinn University of Technology in the field of energy education using AI. The research is based on explicit data collection from staff experiences, student communications and feedback, as well as descriptive statistics of learning management systems while the participants studied energy features of robots in two disciplines, namely “Robotics” at the Bachelor's level and “Advanced Robotics” at the Master's level. ... READ MORE

A Risk-Aware Market Selection Framework for Prosumers in Multi-Market Energy Environments
R. Estudillo(1), G. Fernández(1), R. Rocca(1,2), M. Gallego(1), M. García(1), D. Ferreira(3)
1. CIRCE Technology Centre.   Zaragoza. Spain
2. ENERGAIA Mixed Research Institute (University of Zaragoza and CIRCE Technology Centre). Zaragoza. Spain
3. URBENER S-L. — Sistemas Urbanos de Energías Renovables, Zaragoza. Spain

Abstract

With the ongoing transition towards Smart Grids, power systems are increasingly characterized by the integration of distributed energy assets, the electrification of loads, and the deployment of advanced monitoring and control infrastructures. While these developments enable more efficient operation, they also introduce new operational challenges, particularly at distribution level, such as congestion and voltage issues. As a result, the use of flexibility and the emergence of new energy markets have gained relevance, enabling distributed resources to actively support system operation. In this context, the prosumer becomes a key actor..... READ MORE

Development and Validation of a LabVIEW-Based Software for Power Quality Analysis in Microgrids
E. G. L. Maniçoba(1,2), E. A. Vieira(1), R. F. Pinheiro(2)
1. Department of Environmental Sustainability. UTEC – Technological University, South Central Technological Institute – Durazno. Uruguay
2. Postgraduate Programme in Electrical Energy. UFRN – Federal University of Rio Grande do Norte. Brazil

Abstract

The increasing integration of Distributed Energy Resources in microgrids demands efficient Power Quality  monitoring. However, the high cost of commercial analyzers and the complexity of interpreting data from Smart Meters often hinder effective diagnosis. This paper presents a hardware-agnostic, LabVIEW-based software designed for post-processing and automatic PQ diagnosis. The tool processes CSV datasets and translates complex regulatory standards—specifically PRODIST and URSEA—into intuitive compliance indicators, making analysis accessible to non-experts..... READ MORE

Design and Experimental Validation of an Active Cell-Balancing Battery Management System for Lithium-Ion Energy Storage Applications
F.J. Asensio(1), E. Vázquez(1), M. González-Pérez(1), J. Rodríguez-Góngora(1), A. Ordoño(1), G. García-Ramos(2)
1. Department of Electrical Engineering. Engineering School of Gipuzkoa – University of the Basque Country - UPV/EHU. Eibar. Spain
2. MC3 Mondragon Components Competence Center. Spain

Abstract

Lithium-ion battery–based energy storage systems are a key enabler for renewable energy integration, electric mobility, and portable electronic applications. Their performance and lifetime critically depend on the proper management of individual cells within the battery pack. Battery Management Systems (BMS) are therefore essential to ensure reliable operation and mitigate cell imbalance effects. ... READ MORE

Real-Time Multi-Objective Optimization for Reactive Power Dispatch in Islanded Power System
Carolina M. Martín, Francisco Arredondo, Santiago Arnaltes, Jaime Alonso-Martínez, José Luis Rodríguez-Amenedo
Departamento de Ingeniería Eléctrica. Universidad Carlos III de Madrid. Spain

Abstract

This paper proposes a real-time (RT) optimization strategy for managing reactive power reserves in islanded power systems, explicitly maintaining safe margins from voltage limits. Existing formulations, dominated by objective functions aimed at minimizing losses, are shown to systematically drive bus voltages close to their upper admissible limits, potentially reducing operational margins and increasing the risk of overvoltage tripping... READ MORE

Methodology for Sizing Regional Energy Storage for Large-Scale PV Deployment
M. Pintarič(1), N. Lukač(1), P. Rijavec Simonič(1), P. Sukič(1), M. Božič(2), G. Dolanc(3), S. Gerkšič(3), G. Štumberger(1)
1. Faculty of Electrical Engineering and Computer Science. University of Maribor. Slovenia
2. Dravske elektrarne Maribor. Slovenia
3. Jožef Stefan Institute, Ljubljana. Slovenia

Abstract

When national plans for the deployment of photovoltaic (PV) systems significantly exceed the installed capacity of existing generation sources, the integration of energy storage systems becomes necessary. This paper presents a methodology for determining the required power rating and energy capacity of energy storage systems at the national level. The methodology is based on hourly electricity consumption and PV generation profiles from previous years, combined with data on the total installed PV capacity by month and projections of electricity demand growth and PV deployment over the next decade and beyond. .... READ MORE

Operating Envelopes Assessment Using Temporally Power Sensitivities Derived from a Data-Driven Approach
L.D. Andagoya-Alba, E. Torres  
Department of Electrical Engineering. School of Engineering in Bilbao, University of the Basque Country. Bilbao. Spain

Abstract

The increasing penetration of distributed energy resources poses several challenges in compliance with low-voltage distribution network operating limits. Operating Envelopes describe time-varying export/import limits for distributed energy resources determined to not violate network limits. This paper presents a methodology for estimating dynamic operating envelopes using data from smart meters. .... READ MORE

Impact of PV Inverter Reactive Power Control on Local Voltage and Real Power Generation
Sampson A. Bendor, Yahia Baghzouz
Department of Electrical Engineering. University of Nevada, Las Vegas. USA

Abstract

Behind-the-meter smart photovoltaic inverters areknown to have the ability to generate or absorb reactive power for local voltage regulation/support, in addition to their main task of converting DC to AC power. This paper presents field tests on the impact of inverter reactive power on the local voltage at two customer sites with rooftop PV systems. Two inverter control approaches were tested: Volt-VAR control, and direct reactive power dispatch. .... READ MORE

AI-Driven Energy Management for Interconnected Microgrid: A Comparative Performance Analysis
P. Motevakel, C. Roldán-Blay, C. Roldán-Porta
Institute for Energy Engineering. Universitat Politècnica de València. Spain

Abstract

This paper proposes a lightweight AI-based energy management framework for the coordinated operation of interconnected microgrids and evaluates its performance relative to conventional non-cooperative operation. The study examines two microgrids with photovoltaic generation and battery storage operating in parallel with the main grid. The proposed coordination strategy is based on key system variables, including battery state-of-charge and local power imbalance, enabling real-time decision-making without reliance on complex optimization or large-scale data-intensive training, while requiring only a lightweight offline training phase..... READ MORE

Real-Time Estimation of Polarization Dynamics and Stress Regimes in Lithium-Ion Batteries Based on Thevenin Equivalent Model and Extended Kalman Filter
Mauricio Mendes da Silva(1), Mario Lucio da Silva Martins(1), Conrado Fleck dos Santos(2), Éder Bridi(2), Sergio Pires(2)
1. UFSM — Universidade Federal de Santa Maria, Santa Maria–RS, Brasil
2. UTEC — Universidad Tecnológica, Rivera. Uruguay

Abstract

This paper presents an online method for estimating the internal polarization level of lithium-ion batteries based on a Thevenin equivalent circuit model. The proposed approach focuses on the dynamic polarization branch, which reflects transient electrochemical effects associated with diffusion and relaxation phenomena. An energy-based formulation is introduced to characterize the behaviour of the polarization branch in terms of stored and dissipated energy, providing a physically meaningful indicator of internal battery stress. .... READ MORE

Stability Control of a SG–PV Integrated Distribution Network Basrah City Case Study
Salam B. Abood(1), Ali Jafer Mahdi(2,3), Ali K. Abdulabbas(1)
1. Electrical Engineering Department, Basrah University. Iraq
2. Electrical and Electronics Engineering Department, University of Kerbala, Iraq.
3. College of Information Technology Engineering, Al-Zahraa University for Women. Karbala. Iraq

Abstract

The main challenges facing the Iraqi electrical network are insufficient infrastructure and the fast growth in demand. Advances in renewable energy technologies have made them one of the most actual techniques to address these issues. Because renewable energy systems have a largely static structure and lack significant inertia, they are more susceptible to frequency and voltage fluctuations, which makes the development of advanced control strategies necessary. .... READ MORE

Probabilistic and Time-Series Analysis of the Combined Impact of Electric Vehicles and Photovoltaic Systems on Voltage Profiles in a Real Low-Voltage Distribution Network
E. Simonič(1), K. Sredenšek(1,2), J. Počivalnik(1), D. Kuhar(1), B. Stergar(1), K. Zupanc(3), S. Seme(1,2)
1. Faculty of Energy Technology, University of Maribor. Slovenia
2. Faculty of Electrical Engineering and Computer Science, University of Maribor. Slovenia
3. Elektro Gorenjska, d. d.  Kranj. Slovenia

Abstract

The increasing integration of electric vehicles and photovoltaic systems significantly affects voltage conditions in low-voltage distribution networks. This paper presents a probabilistic assessment of their impact on voltage profiles in a real low-voltage feeder. A Monte Carlo-based framework is employed to progressively allocate electric vehicle chargers and photovoltaic systems across network nodes and to quantify the probability of voltage violations under critical operating conditions, including peak load and maximum solar radiation. .... READ MORE

Enabling Effective Consumer Adoption of Local Renewable Energy Systems through Integrating Societal-Readiness Thinking
W.G. Früh
Institute of Mechanical, Process and Energy Engineering, School of Engineering & Physical Sciences. Heriot-Watt University. Riccarton. Edinburgh. UK

Abstract

To overcome the multi-faceted barriers faced in significant upscaling of embedded renewable energy generation, a design process complementing the necessary engineering and economic development activities it proposed here which centres around a fully inclusive co-creation process in designing energy and information layers to the immediate benefit to individuals, communities and grid operators..... READ MORE

MILP-Based Optimal Sizing of a Hybrid Battery-Hydrogen Energy Storage in a Grid-Connected Photovoltaic System
Zakaria A. Souleymane(1), A. Mpanda Mabwe(1), H. Augendre(2), J. Fortin(1)
1. UniLaSalle, GeNumEr, Amiens. France
2. BELLOVA, Aéroport Paris-Beauvais, Tillé. France

Abstract

This study is part of a large-scale decarbonization initiative for Paris-Beauvais Airport (PBA). The focus is the integration of renewable energy sources (RES) with the aim of decreasing grid dependency by enhancing local energy autonomy. The system under scrutiny comprises a photovoltaic (PV) generator, a Battery Energy Storage System (BESS), and a hydrogen energy storage subsystem consisting of an electrolyzer (ELZ), a hydrogen tank, and a fuel cell (FC). The global system supplies electrical loads and is connected to the utility grid. .... READ MORE

Integration of High-Frequency and Harmonic Measurements from Open-Source Meters into NILMTK Datasets
C. Rodriguez-Navarro(1), F. Portillo(1), I. Robalo(1), L. Castro-Santos(2), A. Filgueira-Vizoso(3), F. G. Montoya(1), A. Alcayde(1)
1. Departamento de Ingeniería.Escuela Superior de Ingeniería, Universidad de Almería. Spain 
2. Departamento de Enxeñaría Naval e Industrial. Centro de Investigación en Tecnoloxías Navais e Industriais (CITENI), Escola Politécnica de Enxeñaría de Ferrol, Universidade da Coruña. Spain
3. Departamento de Química. Centro de Investigación en Tecnoloxías Navais e Industriais (CITENI), Escola Politécnica de Enxeñaría de Ferrol, Universidade da Coruña. Spain

Abstract

This work presents a methodology for generating datasets compatible with the Non-Intrusive Load Monitoring Toolkit (NILMTK) using measurements from open-source smart meters: OpenZmeter (oZm) and Open Multi Power Meter (OMPM). The purpose is to advance research on Non-Intrusive Load Monitoring by enabling detailed analysis of energy disaggregation and power quality. The main challenge is integrating data sources with extended timestamps and high-frequency electrical harmonics into the standardised NILMTK format. .... READ MORE

Implementation of 132 kV for inner-array systems in offshore wind farms
Iñaqui Arrambide
Department of Electrical Engineering. Escuela de Ingeniería de Guipúzcoa, University of the Basque Country. Donostia-San Sebastián. Spain

Abstract

Since offshore wind energy production is taking part in different countries´ energy mixes, significant cost reductions have been developed during last years. Together with offshore wind turbine power size one of the key improvements is stepping up inner-array system rated voltage from 33 kV to 66 kV or even to 132 kV expected for the beginning of the next decade..... READ MORE

Comparative analysis of inner-array systems in offshore wind farms mixing copper and aluminium raw materials
Iñaqui Arrambide
Department of Electrical Engineering. Escuela de Ingeniería de Guipúzcoa, University of the Basque Country. Donostia-San Sebastián. Spain

Abstract

This work presents an evaluation methodology ofelectrical losses in the cables of collector systems for two common options considered nowadays in large offshore wind parks, copper and aluminium raw materials. Furthermore, two additional options of study are evaluated mixing copper and aluminium cables in the same strings. Taking into account the current situation of the offshore collector systems, a summary about schemes employed in commissioned wind farms is presented..... READ MORE

Activated Carbon Production from Biomass and its Use in Industrial Effluent Treatment
Rafael Pochmann Ferreira, Felipe de Aguiar Linhares, Pedro Juarez Melo, Dirléia dos Santos Lima Bortoletti, Nilson Romeu Marcilio
Department of Chemical Engineering. Federal University of Rio Grande do Sul. Brazil

Abstract

This study evaluates the feasibility of converting black wattle (acacia mearsii) bark residue - a byproduct of tannin extraction - into activated carbon (AC) for wastewater treatment. In southern Brazil, the industrial sector generates approximately 250 t/day of this residue, which is typically landfilled or composted. To add value to this waste, AC was produced via pyrolysis and chemical activation with H3PO4. .... READ MORE