Dynamic performance improvement of DC microgrids using virtual inductive impedance loop

This paper presents a new control strategy for the autonomous operation of a multi-source DC microgrid (MG). The main objective is to effectively improve the dynamic response of DC MGs under various load changes. The proposed control system of each DC source consists of a multi-loop voltage control unit to regulate the MG voltage, and a virtual impedance loop for its power management. The virtual impedance loop is equipped with inductive impedance to improve the dynamic performance of the power sharing control unit. The inductive gain for each DC source is determined based on small signal analysis. The proposed strategy minimizes the low-frequency power oscillation in the DC MG. The performance of the proposed control scheme is verified by using digital time-domain simulation studies in the PSCAD/EMTDC software environment.