Distributed generation (DG) and microgrid will play an essential role in the modern power system. They could improve energy efficiency, reduce losses, minimize environmental impacts and enhance power system reliability and stability. Most of the renewable energy applications would require two or three power conversions before power reaches the loads. If the power from DG could be utilized in DC form, the loss could be minimized and system efficiency is improved. Fuel cell, energy storage battery, photovoltaic and power electronic building block (PEBB) are used in this research to set up a DC microgrid. Simulation and hardware implementation are conducted. Techniques studied in this thesis include different power sources interconnection and DC bus voltage and microgrid power controls. Based on the studied results, DC mircogrid integration and system operation schemes are recommended.