Impact of load and transmission line parameters on power quality

Voltage deviations from nominal values significantly degrade the performance and operational reliability of electrical equipment in agricultural power systems. Current voltage deviation calculations, often relying solely on the approximate longitudinal component of voltage drop, are frequently imprecise. This research aimed to precisely assess the influence of power line wire and variable load parameters on system operation, and to establish a robust method for determining permissible voltage deviation (or voltage loss) by integrating the characteristics of the power source, the transmission line, and the load. The study employed fundamental AC linear circuit calculations on a simulated system: a 10/0.4 kV transformer supplying a symmetrical load via a three-phase line with a solidly grounded neutral. The authors established that load and power line parameters directly influence total system impedance. This impedance, inversely proportional to the system current, subsequently dictates critical operational parameters such as voltage loss and supply voltage deviation. Consequently, they propose a method to determine supply voltage deviation based on the normative voltage loss in the power line wires. This approach utilizes the voltampere characteristic of a low-voltage AC source, integrating the total impedance and power factor of both the power line and the load, specifically when the power factor of the load matches that of the power line (cosφ_н = cosφ_л).

1. Isaeva O.A. Review of the influence of voltage level on the operation of electrical equipment and electrical receivers. Science Bulletin. 2025;4(2):662-665. (In Russ.)

2. Turduev I.E. The quality of electricity and the effect of electricity on the operation of electric receivers. Bulletin of Science and Practice. 2024;10(2):359-364. (In Russ.)

3. Efremenko V.M., Savinkina O.A., Naumkin R.B. Analysis of voltage losses in power distribution networks. Bulletin of the Kuzbass State Technical University. 2010;3:69-72. (In Russ.)

4. Naumov A.A. The required quality of electrical energy provision. Power engineering: research, equipment, technology. 2020;22(1):85-92. (In Russ.) https://doi.org/10.30724/1998-9903-2020-22-1-85-92

5. Lestayev O.V., Stushkina N.A., Zaginaylov V.I. Analysis of power quality indicators in power supply systems with grid-connected solar power plants of small capacity. International Technical and Economic Journal. 2021;5:48-53. (In Russ.)

6. Zaginaylov V.I., Mamedov T.A., Leshtayev O.V., Manko V.E. Identification of quality and energy efficiency of low-voltage power transmission. Agricultural Engineering (Moscow). 2024;26(1):80-88. (In Russ.) https://doi.org/10.26897/2687-1149-2024-1-80-88