Small-signal modeling and stability analysis of autonomous direct current microgrid with distributed energy storage system

This paper presents the small-signal modeling and stability analysis of a novel control method for a distributed energy storage system (DESS) to maintain DC bus voltage in an autonomous direct current microgrid (DCMG). In this proposed control method, a fuel cell (FC) storage system is applied to address the slow-frequency power surges; meanwhile, supercapacitors (SCs) storage system has been adopted to achieve the fast-frequency power surges. The proposed method improves the FC efficiency by diverting unwaged FC currents to SCs for quick compensations. The proposed control method efficacy is examined by simulations, including comparing peak deviations in dc bus voltage with a conventional control method. The test scenarios have been tested in MATLAB/SIMULINK. Experimental validation of the findings is performed using a real-time hardware-in-the-loop (HIL) simulator based on a field-programmable gate array (FPGA).