DC Microgrid Voltage Stability through Inertia Enhancement Using a Bidirectional DC-DC Converter

Abstract

The cascaded buck-boost converter (CBBC) with high power density, 98% efficiency and higher operating temperature can be considered as a suitable alternative to buck-boost converter in energy storage systems (ESSs). DC bus voltage stability in DC microgrid (DCMG) is the main factor studied in the event of an error. In this paper, a proposed virtual DC machine (VDCM) control strategy is presented. Therefore, charging and discharging ESS to enhance the virtual inertia of the system is done through the converter. The proposed inertia control has a first-order inertia loop that is implemented in the interface converter between ESS and DCMG. The study plan is simulated on a conventional islanded microgrid in Matlab/Simulink. Also, the stability of the system has been analyzed according to the small signal model of VDCM control units and CBBC. The simulation results and small signal analysis confirm the stability of the proposed idea under different scenarios.