Cover
Vol. 26 No. 1 (2026)

Published: July 28, 2026

Pages: 9-16

Research Article

Time-Dependent Voltage Unbalance Assessment in Low Voltage Residential Distribution Networks

Amir Abdulwahab Abdulzahrah 1
1 Department of Electrical Engineering, MoE Ministry of Electricity, Basrah, Iraq
History
  • Received: February 24, 2026
  • Revised: April 6, 2026
  • Accepted: April 17, 2026
  • Available Online: July 28, 2026
DOI

https://doi.org/10.33971/bjes.26.1.2

Abstract

Low-voltage (LV) residential distribution networks are highly susceptible to voltage unbalance due to the stochastic and time-varying nature of residential single-phase loads. The assessment methodologies based on snapshots have a difficulty in allowing the spatial and temporal characteristics of the unbalance events. Based on 10-minute resolution time-series unbalanced power flow simulation in OpenDSS, this paper introduces a time-dependent evaluation framework. While the time-varying load profiles and Monte Carlo analysis represent the variance in daily load and uncertainty in phase allocation, respectively. The parameters include both voltage unbalance assessment indexes (i.e., Voltage Unbalance Factor (VUF), Phase Voltage Unbalance Rate (PVUR)), as well as temporal risk indicators (i.e., Time-at-Risk (TAR) and a TimeDependent Unbalance Risk Index (TD-URI)). The analysis produced shows voltage unbalance behaves transitory and locational, being most threatening during peak demand and faraway buses. The quantity and duration of unbalance events are reduced significantly with the help of phase balancing. The framework has been reconciled with the EN 50160 and it aims to buttress a tangible foundation for planning-oriented voltage unbalance evaluation and remediation in low-voltage residential networks.

Keywords

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