DC DIPS: Direct Current in Distributed Power Systems

Abstract

With the significant presence of DC generation methods and devices that utilize DC in the current global technological landscape, it is a rational course of action to seek to integrate DC generation and utilization in an efficient manner. This is particularly pertinent in distributed power systems were electricity is generated at or close to the location at which it is consumed. Currently, buildings are typically electrically configured to circulate AC within it, meaning that any electricity generated by a DC source would need to be converted by an inverter to AC, and DC devices require adapters to convert AC to DC for their operation. Assuming that the DC sources of a building are solar panels and batteries connected via a solar charge controller, the efficiency of this DC to AC to DC conversion in a power system varies between 60.45% to 73.63%. Based on our experiments, skipping the inverter and dealing entirely with DC while using multiple independent DC-DC converters gave a minimum efficiency of about 86% and a maximum efficiency of about 97%. However, using a Multi-Active Bridge DC-DC converter instead of multiple independent converters, the power system model can achieve efficiency values between 89.28% and 98.5% - saving 12.65% to 38.05% of electric power from the solar panel. However, the current iteration of the MAB converter we used has a maximum power rating of 300 W. This restricts the range devices and appliances it can be connected to, and by extension, narrows the scope of its applicability to low power residential buildings such as those present in rural Sub-Saharan African nations. Because of these limitations, any improvements in the MAB converter architecture that enable it to handle higher power would significantly increase the viability of a purely DC building.