Active power oscillation (APO) issues may arise during the deployment of multiple parallel converters with Virtual Synchronous Generator (VSG) control in Microgrids. To that end, the equivalent circuit models of a converter with VSG control are proposed, which intuitively reveals the root cause of APOs. Accordingly, a graph-theory-based virtual impedance is introduced to harmonize parameters among involved VSGs, effectively eliminating APOs. Simulation and experimental results verify the improvements of the proposed control.
