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 >

U.S. Treasury Department’s Office of Foreign Assets Control (OFAC) placed sanctions on Russian petroleum companies in January 2025, but for the petroleum industry of Serbia (NIS JSC Novi Sad), they were postponed repeatedly before finally took effect on October 9, 2025. In particular, PJSC Gazprom Neft owns 44.85% of NIS JSC Novi Sad, followed by Serbian government with 29.87%, JSC Intelligence with 11.3%, and small shareholders with 13.98%. Because of this, Pančevo Oil Refinery ran out of crude oil and stopped its operation on December 2, 2025. However, NIS JSC Novi Sad produces not only petroleum derivatives but also significant amounts of electricity. Part of this electricity is used b... More >

The increasing integration of digital technologies into electric power networks has transformed traditional grids into complex cyber-physical systems. Yet, the level of digital maturity across operators remains uneven, lacking a unified assessment framework. This paper proposes a structured model for evaluating the degree of digitalization in power grids, integrating technological, organizational, and analytical dimensions. The model introduces six core domains, technological infrastructure, data and analytics, operational processes, cybersecurity, organizational culture, and distributed energy integration, each evaluated across four maturity levels. A weighted scoring system is used to comp... More >

This paper presents a procedure for calculating switching overvoltage on the main circuit breaker of a medium-voltage (MV) cable feeder, to which induction and/or synchronous generators are connected, during a three-phase short circuit. When a fault occurs, the feeder is disconnected by the circuit breaker located at its beginning. After the set operating time of the relay protection, since islanded operation is not permitted, the connected distributed generators will also be disconnected. It is shown that, during the period when the network is disconnected while the generators remain connected, the overvoltage factor reaches values between 2.2 and 2.5, depending on the types of generators a... More >

This paper proposes a Taguchi-based optimization framework for short-term load forecasting (STLF) using single-layer feedforward neural networks (SLFNs). Although SLFNs are computationally efficient, their accuracy strongly depends on proper hyperparameter configuration, which is often selected through inefficient trial-and-error procedures. The proposed approach applies orthogonal arrays and signal-to-noise analysis to identify robust and reproducible SLFN settings. A MATLAB-based load forecasting interface is developed to support data preprocessing, model selection, parameter tuning, forecasting, and performance evaluation. The methodology is validated using real historical load and meteor... More >

This paper presents a power quality analysis of a 50 MW photovoltaic (PV) power plant connected to a 220 kV overhead transmission line in a Southeast European country. The analysis covers a seven-day measurement period. Voltage quality is assessed in accordance with the requirements of the grid codes of three transmission system operators (TSOs) in Southeast Europe. In contrast, current quality was evaluated following the IEEE Std. 2800. The results show that PV power plants, as nonlinear sources of electrical energy, slightly influence power quality parameters, particularly through the generation of harmonics. Continuous monitoring of power quality parameters is important to ensure complian... More >

This paper provides a comprehensive analysis of the economic implications of implementing advanced loss-reduction measures in electrical distribution networks, as observed across developed economies. The study evaluates a set of technical and infrastructural interventions that have demonstrated significant potential in enhancing network efficiency and reducing operational losses. These measures encompass the large-scale deployment of smart electricity meters, the replacement of conventional distribution transformers with units employing amorphous metal cores, and the mitigation of transformer overloading through the installation of higher-rated capacity units. Additional strategies include i... More >