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 >

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 presents a Taguchi-tuned Particle Swarm Optimization (PSO) approach for the optimal placement and sizing of shunt capacitor banks (CBs) in unbalanced distribution systems. The optimization aims to minimize the total operational cost by reducing power losses and improving voltage profile. A systematic parameter tuning was carried out using the Taguchi method based on an L25 orthogonal array, with five PSO parameters evaluated through Signal-to-Noise (SN) ratios and Analysis of Variance (ANOVA). The IEEE 13-bus test feeder was used as a benchmark. The results show that the installation of four optimally placed CBs reduces active power losses by 29.6% (from 133.16 kW to 93.71 kW),... More >