Distribution voltage control for DC microgrid with fuzzy control and gain-scheduling control

DC microgrid is an appropriate system to interconnect kinds of dc output sources and to supply high quality power. In this presentation, we show a novel dc distribution voltage control by several dc/dc converters for energy storages considering the stored energies. In an assumed system, electric double layer capacitors (EDLC) are connected to a dc grid by dc/dc converters, and each EDLC converter controls the dc distribution voltage when the system is operated under intentional islanding mode. In the past research, several papers already proposed dc distribution voltage controls, and most of them adopted droop controls. We proposed a new voltage control that combines fuzzy control to gain-scheduling control in order to manage the stored energies. The simulation and experimental results show that the dc distribution voltages were within 340 V ± 5 %, and the ratio of stored energy is approximated equal. It means that dc voltage regulation control and stored energy balancing control can be realized simultaneously by the proposed control.