Voltage Compensation Control and Parameter Adaptive Design of Virtual DC Machine for Microgrid Energy Storage Converters

To enhance the stability of a DC microgrid, a promising approach is to control the energy storage converter via the virtual DC machine control (VDMC), which can improve inertia and damping of the system. However, the conventional VDMC suffers from poor dynamic performance during large disturbances, partially due to its fixed control parameters. To track such problem, this paper proposes a voltage compensation control and parameter adaptive method for the VDMC of microgrid energy storage converters. Firstly, the dynamic process of microgrid bus voltage under disturbance is analyzed, and an armature voltage compensation control loop is then constructed. Subsequently, the influences of inertia, damping and compensation coefficients on the system dynamic characteristics are evaluated, and a parameter adaptive control method for the improved VDMC is proposed. Simulation and experimental results demonstrate that the proposed control strategy can effectively mitigate the DC bus voltage fluctuations, with faster response and smaller overshoot than the conventional VDMC strategy.