International Journal of Electrical and Computer Engineering Research

Web Application in Python for Voltage Regulation Calculation in Short Transmission Lines: Development and Validation

2025-12-11T10:55:24+03:00

The analysis of electric power systems requires tools that facilitate understanding of the phenomena associated with transmission lines. Among the most relevant parameters, voltage regulation stands out as a key indicator for evaluating the operational performance of a network. This paper presents the development of a didactic web application implemented in Python, designed to calculate the voltage regulation of short transmission lines through an interactive environment that supports teaching in electromechanical engineering. The tool incorporates a database of ACSR conductors and displays both intermediate and final calculations, promoting active and visual learning. Validation was carried out through complementary academic and reference-based approaches, including educational examples and classical textbook problems. The results show a high level of agreement with traditional analytical methods, confirming the technical accuracy and pedagogical value of the proposed tool. The study concludes that the application represents an open, replicable, and accessible resource for strengthening practical learning in transmission line analysis.

Equivalent Circuit Synthesis of Plant Cell Vacuole by Fitting on 2-3 GHz Resonant Frequencies

2025-08-27T20:17:42+03:00

The reflective S-parameters S11 of pure water and five plants of pear, tomato, carrot, ginger, and potato, representing fruits, vegetables, and root vegetables, were measured using a highly sensitive five-pin SMA probe, five times higher than an open-end SMA probe, and the admittance curves were plotted on a Smith chart. The cell vacuole was extracted by grinding and filtering through a 20-micron filter. A specific circle feature and resonant frequencies were observed at high frequencies above 2 GHz in the admittance curve over a frequency range of 1 to 4000 MHz. Equivalent circuits were synthesized using curve fitting on strict values of serial and parallel resonant frequencies when the susceptance, jB, equals zero, and the circuit element values of C, R, and L were determined. The values of the elements were related to the polar molecule H₂O, K ions, and SMA probe configuration. The simulated and calculated values of admittance, circuit elements, and resonant frequencies, determined using synthesized equivalent circuits and derived equations, are consistent with the measured values. Since the cell vacuole substantially consists of polar molecule H₂O and K ion, and the NaCl solution consists of H₂O and Na and Cl ions, the strict value of the NaCl solution can be used as a reference for the admittance value of the cell vacuole.

Comparative SOH Diagnosis and Forecasting of LFP and NMC Lithium-Ion Batteries in Electric Vehicles under Realistic Operating Conditions

2025-11-14T10:42:45+03:00

Accurate State of Health (SOH) diagnosis and forecasting are critical for ensuring the safety, efficiency, and longevity of batteries in electric vehicles (EVs). This novel research provides a comprehensive simulation-based comparative analysis of two Lithium Iron Phosphate (LFP) and Nickel Manganese Cobalt Oxide (NMC) batteries' degradation under realistic EV cycling conditions across an extended temperature range (25°C to 65°C). The design model used in this research, rigorously parameterized using published experimental data, tracks capacity fade and internal resistance growth, as well as coulombic efficiency decline, as key SOH indicators. Results of this novel and useful study demonstrate that both chemistries degrade faster with rising temperature, but NMC exhibits significantly accelerated aging above 50°C, reaching 80% SOH in fewer than half the cycles of LFP at 65°C. LFP maintains superior thermal resilience in a perfect manner, retaining higher SOH and lower resistance, including more stable coulombic efficiency across all temperatures. Achieved results also confirm and show greater degradation variability in NMC under thermal stress as well as increasing failure risk. This useful research quantifies critical temperature thresholds of batteries for end-of-life (SOH = 80%) and provides clear, data-driven guidance for battery selection and thermal management in EVs, particularly in hot climates or high-duty applications. By establishing a validated, multi-temperature simulation benchmark, this novel research work fills a major gap in chemistry-specific degradation forecasting and supports the design of adaptive battery management systems tailored to regional operating environments.