Evaluation of Voltage Unbalance Metrics in Distribution Networks with High DER Penetration

TL;DR

This paper investigates how high levels of distributed energy resources affect voltage unbalance in distribution networks and evaluates the effectiveness of various unbalance metrics under these conditions.

Contribution

It provides a comparative analysis of voltage unbalance metrics in the context of high DER penetration, highlighting their strengths and limitations.

Findings

DER can both mitigate and exacerbate voltage unbalance.

Different unbalance indices vary in accuracy depending on DER configurations.

Effective assessment strategies are essential for modern distribution systems.

Abstract

Voltage unbalance, caused by variations in voltage magnitude and phase angle, is a significant power quality issue in three-phase systems, leading to equipment inefficiencies and increased system losses. The integration of distributed energy resources (DER) into the grid adds complexity, as DER can either reduce or worsen voltage unbalance, depending on factors such as grid configuration and the distribution of loads and DER themselves. This study explores the effects of DER penetration on voltage unbalance levels and the accuracy of the different indices most commonly used to quantify this unbalance. The results highlight the varying impacts of DER on unbalance and index performance, emphasizing the need for effective strategies to assess voltage unbalance in modern distribution systems.