In order to meet the demands of different DC voltage levels of DC loads

we put forward a coordination control strategy of DC microgrid with two DC buses. The proposed system contains two DC microgrids with different voltage levels

and the two microgrids are connected with a bidirectional converter which is used to keep balance of the power in both sides and improve the operational reliability of the entire system. Based on the droop characteristics of bidirectional converter

the droop control of Buck/Boost converter is proposed to achieve a power balance in the whole system. Besides

according to the high power density of super capacitor and the high energy density of battery

hybrid energy storage system（HESS） is adopted to optimize the system operation and prolong the service life of the battery. Finally

the availability of the control strategy is verified by d SPACE. The experimental results show that the power flow between the high and low voltage DC bus can be achieved through the control of the bidirectional converter

ensuring the stable operation of the system.