DC micro grid system

The invention aims to provide a DC micro grid system. The DC micro grid system comprises a DC bus, a power generation system which generates DC electricity and loads the DC electricity to the DC bus, an electrical utilization system which is connected with the DC bus and comprises an energy storage unit and a load, and a bidirectional AC/DC converter through which the DC bus is connected with an AC main grid. Compared with the prior art, the DC micro grid system provides an effective researching method for a DC distribution application mode and is an effective supplement for an AC micro grid application mode. According to the DC micro grid system, grid connected self-balance control strategy takes consuming and absorbing renewable energy resources at a maximum degree as a control target, a DC micro grid is enabled to realize local balance to a maximum degree, power exchange of a main grid is reduced, so stable and high-efficiency operation of the DC micro grid can be realized.