Article: A study on compensation for voltage unbalance in distribution transformer areas considering three-phase load imbalance using hybrid PV-ESS inverters Journal: International Journal of Information and Communication Technology (IJICT) 2026 Vol.27 No.45 pp.1 - 22 Abstract: To address voltage unbalance induced by three-phase load discrepancies in rural areas, this paper proposes a voltage compensation technology utilising hybrid photovoltaic-energy storage (PV-ESS) inverters. Data analysis from 12 typical distribution stations indicates an average three-phase load unbalance of 18.7% and a maximum phase-voltage deviation of 7.2%, contributing to a 35% rise in user-side equipment failure rates. The study employs a collaborative PV-ESS control strategy that dynamically modulates inverter output by monitoring three-phase currents alongside real-time active and reactive power. A three-month pilot verification involving 500 households in a distribution area demonstrated that voltage unbalance dropped from 15.3% to 2.1%, the power factor improved from 0.82 to 0.96, line losses decreased by 12.8%, and the user-side voltage compliance rate rose from 92.1% to 98.7%. Through optimised charge-discharge strategies, the technology achieves a PV self-consumption rate exceeding 85%, effectively mitigating heavy loads on distribution transformers. This study provides a quantifiable technical solution for rural grid voltage regulation, with empirical data validating its significant compensation efficacy. Inderscience Publishers - linking academia, business and industry through research

Title: A study on compensation for voltage unbalance in distribution transformer areas considering three-phase load imbalance using hybrid PV-ESS inverters

Authors: Jianfang Chen; Jianming Su; Wenguang Zhao; Xiaoming Wang; Nan Yang; Yunliang Quan

Addresses: Tongling Electric Power Supply Company, State Grid Corporation of China, Tongling Anhui 244000, China ' Tongling Electric Power Supply Company, State Grid Corporation of China, Tongling Anhui 244000, China ' Anhui Electric Power Research Institute, State Grid Corporation of China, Hefei Anhui 230601, China ' Anhui Electric Power Research Institute, State Grid Corporation of China, Hefei Anhui 230601, China ' Tongling Electric Power Supply Company, State Grid Corporation of China, Tongling Anhui 244000, China ' Tongling Electric Power Supply Company, State Grid Corporation of China, Tongling Anhui 244000, China

Abstract: To address voltage unbalance induced by three-phase load discrepancies in rural areas, this paper proposes a voltage compensation technology utilising hybrid photovoltaic-energy storage (PV-ESS) inverters. Data analysis from 12 typical distribution stations indicates an average three-phase load unbalance of 18.7% and a maximum phase-voltage deviation of 7.2%, contributing to a 35% rise in user-side equipment failure rates. The study employs a collaborative PV-ESS control strategy that dynamically modulates inverter output by monitoring three-phase currents alongside real-time active and reactive power. A three-month pilot verification involving 500 households in a distribution area demonstrated that voltage unbalance dropped from 15.3% to 2.1%, the power factor improved from 0.82 to 0.96, line losses decreased by 12.8%, and the user-side voltage compliance rate rose from 92.1% to 98.7%. Through optimised charge-discharge strategies, the technology achieves a PV self-consumption rate exceeding 85%, effectively mitigating heavy loads on distribution transformers. This study provides a quantifiable technical solution for rural grid voltage regulation, with empirical data validating its significant compensation efficacy.

Keywords: three-phase load imbalance; PV-ESS inverter; voltage unbalance compensation; data analysis; distribution network optimisation.

DOI: 10.1504/IJICT.2026.153517

International Journal of Information and Communication Technology, 2026 Vol.27 No.45, pp.1 - 22

Received: 10 Dec 2025
Accepted: 14 Jan 2026
Published online: 12 May 2026 *

Title: A study on compensation for voltage unbalance in distribution transformer areas considering three-phase load imbalance using hybrid PV-ESS inverters

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