A Virtual DC Machine Control Strategy with Nonlinear Behavior to Enhance Power Sharing and Voltage Regulation in DC Microgrids

For a smooth and safe operation and management of a DC microgrid, it is necessary to develop control strategies capable of operating the system functions automatically and guaranteeing its stability. The use of mathematical models of electric machines as a control method for power converters is indicated since they have these characteristics in power systems. This article proposes a control strategy based on virtual DC machine (VDCM) to promote virtual inertia to the common bus of a DC microgrid as well as mitigate the trade-off between voltage regulation and power-sharing among the converters since these are the major issues of DC microgrids. These features are achieved by adding non-linear droop behavior in the VDCM model, like the armature reaction in a rotational DC machine. Simulation results validate the performance and the benefits of the control method based on virtual DC machine in DC systems.