DC micro-grid is beneficial to the access of such renewable energy as photovoltaic system

is convenient to provide electricity for DC load and can save the cost. However

DC micro-grid is easily affected by the output of new energy and load fluctuation and therefore has such weak points as unstable operation and weak power quality. In this paper

a sliding mode structure control method for bidirectional DC/DC circuit is proposed

which can be used in both island operation and grid-connection operation. The DC micro-grid simulation method for island power supply system and grid connection photovoltaic system is set up on the Matlab/Simulink platform respectively. The simulation results show that this method can improve quality of power supply and voltage DC micro-grid

and verify the robustness and effectiveness of the control method.