The rapid integration of battery energy storage systems (BESS) into modern power grids necessitates robust safety architectures to prevent catastrophic failures such as thermal runaway. Current diagnostic frameworks are often reliant on isolated, single-parameter thresholds and lack direct linkage to hardware-level execution. This work proposes a comprehensive, multi-parameter early warning and hierarchical protection methodology that bridges the gap between software-based fault detection and practical electromechanical response. The proposed algorithm calculates a dynamic, weighted safety score in real-time by structurally integrating internal battery management system (BMS) metrics, such a... More >

This paper presents an experimental comparative analysis of electromechanical, static, and microprocessor-based protective relays using the secondary injection testing method. The study evaluates key performance indicators, including pickup current, dropout current, and operating time, under controlled laboratory conditions. The results show that electromechanical relays exhibit pickup current deviations below 5\%, accompanied by relatively high variability in operating time (up to 0.2 s), mainly due to inherent mechanical limitations. Static relays demonstrate improved performance, with enhanced stability, reduced deviations, and limited time variation within ±0.1 s. Microprocessor-based r... More >

The GoToTwin project (INTERREG IPA ADRION PROGRAMME) deals with integration of renewable energy sources thus strengthening the innovation capacities in the region that is presented by partners from North Macedonia, Slovenia, Croatia, Bosnia and Herzegovina, Serbia and Greece. The mentioned integration will go through a digital platform and will represent digital twins for each renewable energy source (sun, wind and water). Besides technical goals, this project will promote cross-sector collaboration, enable capacity building, create policies and establish cooperation networks across the region. This paper presents an overview of the project objectives together with a partial progress report... More >

Microgrids and nanogrids are increasingly deployed to support decentralized generation, local resilience, and renewable integration. However, their growing reliance on digital control, communication networks, cloud services, and IT–OT integration exposes them to diverse cybersecurity threats. Unlike traditional utility-scale systems, microgrids and nanogrids often operate under resource constraints, heterogeneous architectures, and limited cybersecurity expertise, making direct application of large-scale security frameworks impractical. This paper proposes a structured cybersecurity assessment framework for small- and medium-scale energy systems, supporting systematic risk identification,... More >

In large-scale 2D finite element steady-state thermal models for underground cable ampacity calculations, where the lateral and lower boundaries are adiabatic, the ground surface may be represented by isothermal Dirichlet, convective Robin, or coupled convection–radiation conditions. In such cases, the soil temperature at depths significantly below the cables tends to be equal or to exceed the temperature of reference soil or air. This paper proposes a novel approach addressing this issue by dividing the native soil into two layers, introducing an effective thermal conductivity for the upper layer, and assuming distinct reference soil temperatures at the cable depth and at the lower bounda... More >

This paper proposes the two-step approach for improving the voltage profile of the distribution network (DN) using the optimal integration of photovoltaic-battery energy storage (PV-BES) system. In the first step of the approach the optimal location of the PV-BES system in the DN and its optimal powers are determined, considering the topology and the load of the DN. This is done to improve the voltage profile of the DN using the meta-heuristic wild horse optimization method (WHO) and genetic algorithm (GA). The second step of the approach determines the optimal sizing of the PV-BES system, by taking into account the optimal powers obtained in the first step, the solar irradiance diagram and... More >

This paper analyzes the lightning protection of a 110 kV underground cable line connecting two overhead transmission lines with a 110 kV substation. The transition from two overhead lines to two underground cable lines is implemented at a special double-circuit overhead line tower located approximately 2.4 km from the 110 kV substation. Lightning transients are calculated at: (i) both cable terminations, first at the transition tower and second at the substation, (ii) at the first (more critical) cable joint, (iii) at the cable sheath to the surrounding soil and objects. The latter analysis is performed to assess the risk of outer cable insulation breakdown between the sheath and the transi... More >

The accumulation of atmospheric and industrial pollution of high-voltage insulators is one of the frequent problems and a pattern of failures in transmission systems. In this paper, a two-phase approach based on deep learning is proposed for the detection of pollution of high-voltage insulators. The proposed approach automatically detects three types of pollution (salt, soot and excrement) based on UAV images. In addition to detection, the classification of pollution is automatically done into three levels (low, medium and high pollution). In the first phase, the You Only Look Once (YOLO) detector is used for precise detection and isolation of insulators, where an average accuracy of [email protected]... More >