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  3. Volume 7, Number 1, 2025
  4. Propagation of Voltage Fluctuations in Distribution Grids Containing Renewable Energy Sources

Propagation of Voltage Fluctuations in Distribution Grids Containing Renewable Energy Sources

SEPES.
2025;
Volume 7, Number 1
: pp. 1 - 14
https://doi.org/10.23939/sepes2025.01.001
Authors:
  1. Yuriy Varetsky
  2. Andriy Kozovyj
  3. A. Fedun
1
Lviv Polytechnic National University, Department of Power Engineering and Control Systems
2
Lviv Polytechnic National University, Department of Power Engineering and Control Systems
3
Lviv Polytechnic National University, Department of Power Engineering and Control Systems

The increasing penetration of renewable energy sources (RESs), such as photovoltaic and wind power plants, into the medium-voltage distribution grid creates significant concerns regarding voltage control at local substations. Understanding the specifics of the RES operation impact on the phenomenon and propagation of voltage fluctuations in the distribution grid is important for engineering solutions in the practice of RES design and operation. The presented article describes an algorithm for estimating the impact of RES on voltage fluctuations in the medium-voltage grid. The algorithm utilises a RES fixed-power-factor control mode and is implemented in a grid model developed using software for power flow calculations. The study shows the impact of various RES power factor types on the nature of voltage fluctuations in the distribution grid. The RES operation with lagging reactive power factors, as a method of reducing voltage fluctuation magnitudes, results in a more complex pattern of voltage fluctuation propagation than with a leading power factor. Based on simulations of a true medium-voltage grid, the feasibility of optimally mitigating voltage fluctuations by selecting the required RES reactive power factor has been demonstrated. However, when choosing an appropriate level of RES reactive power for a selected distribution grid, certain contradictions must be considered: reducing voltage fluctuations by controlling RES reactive power causes increasing energy losses in the grid. The presented model also allows for calculating changes in distribution grid energy losses as a function of the RES reactive power factors, ensuring a practical solution of the optimal control strategy.

distribution grid
photovoltaic plant
reactive power
renewable energy source
voltage fluctuations
  1. Report on the Promotion and Use of Energy from Renewable Sources in Ukraine in 2019–2020. Державне агентство з енергоефективності та енергозбереження України. https://saee.gov.ua/en/activity/renewable- energy/current-state.
  2. Кулик М.М., Нечаєва Т.П., О.В. Згуровець О.В. Перспективи та проблеми розвиту об’єднаної енергосистеми україни в умовах її приєднання до енергосистеми євросоюзу і гіпертрофованого використання у її складі вітрових та сонячних електростанцій. Probl. Gen. Energy 2019, 4, 4–12. https://systemre.org/index.php/journal/article/view/730
  3. Ziadi, Z.; Taira, S.; Oshiro, M.; Funabashi, T. Optimal power scheduling for smart grids considering controllable loads and high penetration of photovoltaic generation. IEEE Trans. Smart Grid 2014, 5, 2350–2359. https://doi.org/10.1109/TSG.2014.2323969.
  4. Varetsky, Y.; Hanzelka, Z. Stochastic modelling of a hybrid renewable energy system. Tech. Electrodyn. 2016, 2, 58–62.    https://doi.org/10.15407/techned2016.02.058.
  5. Gómez, J.C.L.; Aldaco, S.E.L.; Aguayo Alquicira, J.A. Review of hybrid renewable energy systems architectures, battery sys-tems, and optimization techniques. Energies 2023, 4, 1446–1467. https://doi.org/10.3390/eng4020084.
  6. Weckx, S.; Gonzalez, C.; Driesen, J. Combined central and local active and reactive power control of PV inverters. IEEE Trans. Sustain. Energy 2014, 5, 776–784. https://doi.org/10.1109/TSTE.2014.2300934.
  7. Todorovski, M. Transformer voltage regulation-compact expression dependent on tap position and primary/secondary        voltage.        IEEE        Trans.        Power        Del.        2014,        29,        1516–1517.https://doi.org/10.1109/TPWRD.2014.2311959.
  8. Verma, A.; Krishan, R.; Mishra, S. A novel PV inverter control for maximization of wind power penetration. IEEE Trans. Ind. Appl. 2018, 54, 6364–6373. https://doi.org/10.1109/TIA.2018.2854875.
  9. Farag, H.E.Z.; El-Saadany, E.F. A novel cooperative protocol for distributed voltage control in active distribution systems. IEEE Trans. Power Syst. 2013, 28, 1645–1656. https://doi.org/10.1109/TPWRS.2012.2221146.
  10. IEEE Std 1547-2020; IEEE Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces. IEEE Standards Association: Piscataway, NJ, USA, 2020. https://doi.org/10.1109/IEEESTD.2020.9069495.
  11. Real-Time Power System Management Tool for Modeling, Analysis, Planning, and Optimization of Modern Electrical Net-works. Available online: https://dakar.eleks.com (accessed on).
  12. Varetsky, Y.; Konoval, V.; Hanzelka, Z. A method of evaluating FACTS device impact on voltage flicker in the EAF supply system. In Proceedings of the 2020 12th International Conference and Exhibition on Electrical Power Quality and Utilisation- (EPQU), Krakow, Poland, 14–15 September 2020; pp. 1–6. https://doi.org/10.1109/EPQU50182.2020.9220317.
  13. Varetsky, Y.; Konoval, V.; Seheda, M. Modeling power flow within a microgrid for energy storage sizing. In Proceedings of the 2020 IEEE 7th International Conference on Energy Smart Systems (ESS), Kyiv, Ukraine, 12– 14 May 2020, pp. 1–4. https://doi.org/10.1109/ESS50319.2020.9160148.