Virtual motor control can improve the power quality problems caused by power fluctuations in DC microgrids

but it cannot take into account the dynamic performance of DC voltage. Aiming at solving this problem

a DC-DC converter of battery energy storage unit in the DC microgrid is taken as a research object. Based on the analogous virtual synchronous generator control technology for DC microgrid

a flexible analogous virtual synchronous generator control

utilizing the coupling of DC voltage change rate with inertia parameters

is proposed to regulate DC voltage dynamically. Additionally

a small-signal model is established. Based on the analysis of DC-DC converter port response and root trajectory

the influences of the main parameter changes on the system inertia and stability are revealed

and the corresponding setting methods are given. Then

the bidirectional characteristics of the battery are combined with the system stability margin index

so that a stable value range for the inertia parameters is established to achieve flexible adjustment of the inertia control within a reasonable range. In addition

according to the influence of the state of charge（SOC） on the ability of battery to provide inertial power

the droop coefficient of the control is constrained in real time based on the SOC. The results show that this control can prove flexible and adjustable inertial support to the system

thus the DC voltage has better dynamic performance and stability. Finally

Matlab/Simulink simulation results validate the proposed control and operating boundary.