An Adaptive Virtual Impedance Control for Reactive Power Sharing in Microgrids

Abstract

In multi-inverter parallel connected islanded micro-grids, reactive power sharing is challenged by the differences in feeder impedance and various controller parameters. In order to address this issue, a virtual impedance reshaping strategy based on the consensus algorithm is proposed in this paper. The proposed method facilitates adaptive modulation of virtual impedance to ensure that it is consistent with the desired value. Notably, the method has the advantage of accurate reactive power sharing even in the presence of communication delays and interruptions. Furthermore, the proposed strategy exhibits resistance to malicious cyber-attacks by integrating an auxiliary controller that reconstructs the propagated information in the face of cyber threats that challenge the integrity of the original signal. Furthermore, this paper introduces an exit strategy that enables data exchange during the system construction phase and subsequently fixes the virtual impedance proportionally. This feature significantly reduces the communication burden. The effectiveness of the proposed control strategy is evaluated through several experimental cases, including accurate reactive power sharing and plug-and-play capability.