Virtual Impedance Control for Load Sharing and Bus Voltage Quality Improvement in Low Voltage AC Microgrid

Abstract

Due to the mismatched feeder impedances in a resistive feeder AC microgrid, it's challenging to accurately share harmonic and active power while promising a low bus voltage distortion rate. To address this issue, this paper proposes a distributed philosophy-based virtual impedance modulation strategy. The proposed method regulates the fundamental and harmonic impedance at the desired value by exchanging information with its adjacent inverters. Notably, the proposed method benefits from resilience against communication delay, failure, and cyber-attacks. Moreover, it significantly reduces the communication burden. The proposed method's effectiveness is validated through experiments conducted in various cases, including different communication scenarios and plug-and-play operations.