Load Imbalance Analysis on Low-Voltage Distribution Network: A Case Study on SM3 Feeder, Tomohon Main Substation
Main Article Content
Load imbalance on low-voltage distribution networks arises from the uneven distribution of single-phase loads across a three-phase system, resulting in elevated neutral currents, increased power losses, and degraded voltage quality. This research systematically analyzes the degree of load imbalance on the low-voltage distribution network of SM3 Feeder, Tomohon Main Substation, PT PLN (Persero) UP3 Manado, using phase current measurements, neutral current readings, and customer load data collected from field surveys. The methodology employed phase current measurements, neutral current readings, and customer load data collected from field surveys at five measurement points representing diverse loading conditions and network topologies. The percentage load imbalance (PLI) was calculated and benchmarked against SPLN D3.002-1:2007 and IEEE Std 1159 standards, with measurements conducted during morning, afternoon, and evening peak periods. Findings reveal significant imbalance in four of five assessed feeder segments, with the most critical level reaching 31.7% at MP-5. Elevated neutral currents produced measurable additional power losses in the neutral conductor, and customer terminal voltage violations were confirmed at MP-3 and MP-5, with the most severe deviation reaching ?9.7% below the nominal 220 V. The study concludes that systematic load redistribution at MP-5, MP-3, and MP-1, combined with mandatory phase allocation for new connections and quarterly monitoring protocols, is required to restore standard compliance and improve network efficiency, power quality, and reliability on the SM3 Feeder distribution system.
Acharya, S., El Moursi, M. S., Al-Hinai, A., Al-Sumaiti, A. S., & Lotfy, M. E. (2020). An overview of unbalance compensation techniques using power electronic converters for active distribution systems with renewable generation. Renewable and Sustainable Energy Reviews, 125, 109835. https://doi.org/10.1016/j.rser.2020.109835
Arrillaga, J., & Watson, N. R. (2003). Power system harmonics (2nd ed.). Wiley.
Baggini, A. (Ed.). (2008). Handbook of power quality. Wiley.
De La Rosa, F. C. (2006). Harmonics and power systems. CRC Press.
Dugan, R. C., McGranaghan, M. F., Santoso, S., & Beaty, H. W. (2012). Electrical power systems quality (3rd ed.). McGraw-Hill.
Golmohamadi, H. (2022). Demand-side flexibility in power systems: A survey of residential, industrial, commercial, and agricultural sectors. Sustainability, 14(13), 7916.
IEC. (2009). IEC 60038: IEC standard voltages. International Electrotechnical Commission.
IEEE. (2014). IEEE Std 519-2014: IEEE recommended practice for harmonic control in electric power systems. IEEE.
IEEE. (2019). IEEE Std 1159-2019: IEEE recommended practice for monitoring electric power quality. IEEE.
Kharrazi, A., Sreeram, V., & Mishra, Y. (2020). A control scheme for voltage unbalance mitigation in distribution network with rooftop PV systems based on distributed batteries. Electric Power Systems Research, 186, 106400. https://doi.org/10.1016/j.epsr.2020.106400
Rzayeva, S. V., Piriyeva, N. M., & Guseynova, I. A. (2024). Analysis of reliability of typical power supply circuits. Reliability: Theory & Applications, 19(3(79)), 173–178.
Sakar, S., Balci, M. E., Abdel Aleem, S. H. E., & Zobaa, A. F. (2021). On the impact of different voltage unbalance metrics in distribution system optimization. Electric Power Systems Research, 196, 107260. https://doi.org/10.1016/j.epsr.2021.107260
Sepasi, S., Talichet, C., & Pramanik, A. S. (2023). Power quality in microgrids: A critical review of fundamentals, standards, and case studies. IEEE Access, 11, 108493–108531.
Short, T. A. (2014). Electric power distribution handbook (2nd ed.). CRC Press.
Tenti, P., Mattavelli, P., & Paredes, H. K. M. (2022). Load unbalance mitigation and neutral current compensation in distributed microgrids with active power filters. Electric Power Systems Research, 204, 107693. https://doi.org/10.1016/j.epsr.2021.107693
Willis, H. L. (2004). Power distribution planning reference book (2nd ed.). Marcel Dekker.
Zabihi, A., Badesa, L., & Hernández, A. (2026). On the impact of voltage unbalance on distribution locational marginal prices. International Journal of Electrical Power & Energy Systems, 163, 110342. https://doi.org/10.1016/j.ijepes.2026.110342
Zimann, F. J., Batschauer, A. L., Neves, F. A. S., & Todeschini, G. (2021). Energy storage system for power quality improvement and peak demand reduction. Electric Power Systems Research, 196, 107224. https://doi.org/10.1016/j.epsr.2021.107224
Zulkifli, S. A., Saad, N., Mokhtar, A. S., & Khalid, N. S. A. (2024). Techniques for compensation of unbalanced conditions in LV distribution networks with integrated renewable generation: An overview. Renewable and Sustainable Energy Reviews, 189, 113966. https://doi.org/10.1016/j.rser.2022.112830
