Comprehensive review and a novel technique on voltage unbalance compensation

Voltage unbalance has gained more attention due to a rapid increase in single-phase distributed energy resources (DERs) penetration compound with existing unbalance characteristics of low voltage distribution network. The purposes of this article are to summarise various techniques on voltage unbalance compensation from three different strategies: (1) techniques based on passive approach and advanced power electronics; (2) Techniques based on three-phase DERs; (3) techniques based on single-phase DERs. In addition, a novel voltage unbalance compensation technique that applies a voltage sensitivity analysis along with a symmetrical component concept to meet a desired voltage unbalance factor (VUF) is introduced in this article. Coordination among single-phase DERs that contributes in the voltage unbalance compensation is also considered. In order to evaluate the effectiveness of this proposed technique, its results are compared with the results that are obtained using a current unbalance compensation strategy. The results indicate that the novel technique proposed in this study provides more stable voltage unbalance compensation while successfully achieving the specified VUF thresholds.