Control for Bipolar DC Microgrid and DC/DC Bidirectional Converter in Energy Access Context

MSc defense of Xiaochuan Zhou

Rural electrification challenges due to geography and infrastructure are potentially addressed by Solar Home Systems (SHS) and Direct Current (DC) microgrids. A bidirectional DC/DC converter connects a SHS to a grid, necessitating a control method for smooth exchange of power in both directions. Moreover, the system-level control should coordinate photovoltaic (PV), battery storage, and grid power supply priorities within the SHS. This thesis proposes a novel control approach for converter based on mathematical modeling. Simulation and testing demonstrate its effectiveness. Analysis of energy exchange between the DC microgrid and SHS employs a bipolar DC microgrid model, utilizing droop control for converters. System-level control strategies are developed to prioritize PV, battery, and grid power supply. Simulation results validate the order of supply priority and the impact of transitions between scenarios on the load.