Power Quality Enhancement in Microgrids Using Distributed Energy Storage Systems

Abstract

Increasingly, microgrids are using renewable energy resources and distributed energy storage systems (ESS) to enable reliable operation within the changing generation and load environment. This work proposes a coordinated framework for enhancing the power quality of a microgrid using ESS, emphasizing the support for voltage sag and voltage swell, State of Charge (SoC) management, active-reactive power support and distributed power sharing. The proposed architecture is based on the integration of several ESSs via bidirectional converters and the coordination of their charging and discharging based on their SoC levels, power limits and system operating conditions. The quality of the power quality is evaluated in terms of voltage deviation, Total Harmonic Distortion (THD), frequency variation, active-reactive power response and SoC imbalance for both grid-connected and islanded operations. The control strategy will be developed to minimise voltage disturbances, minimise power imbalance, stabilise bus voltage and avoid excessive utilisation of the individual storage units. The framework also takes into account intermittency of renewables, variability of load, converter limitations and battery degradation. The overall proposed approach is a consolidated methodology that integrates power quality support and energy management in distributed storage-based microgrids. The study shows the potential of coordinated ESS control to enhance voltage regulation, operational stability, integration with renewables and storage utilization, and reliably operate future microgrids resiliently and efficiently.