Compared with AC micro-grid

DC micro-grid has fewer power conversion links

and it is more efficient and reliable to connect with distributed generation and DC load. But traditional droop control cannot solve the problems of small inertia and bus voltage being greatly affected by power fluctuation in DC micro-grid system. In order to improve the inertia of DC microgrid and solve the problem of DC bus voltage fluctuation

an improved virtual inertia control strategy of DC/DC converter in DC microgrid is proposed by analogizing the rotor characteristics and primary frequency modulation characteristics of synchronous generators. Firstly

according to the response characteristics of power fluctuation

the variation of the system control parameters needed to obtain the disturbance is analyzed. The response characteristics of DC/DC converter under the proposed virtual inertial damping coefficient self-adaption control strategy for DC micro-grid are analyzed by signal model

and the influences of key control parameters on system response characteristics and system stability are discussed. Finally

a DC microgrid model is built in PSCAD/EMTDC

and the simulation results verify the correctness and effectiveness of the proposed control strategy.