Dynamic Improvement of DC Microgrids Using a Dual Approach Based on Virtual Inertia

In this paper, inspired by the concept of virtual inertia in alternating current (AC) systems, a virtual impedance controller is proposed for the dynamic improvement of direct current microgrids (DCMGs). A simple and inexpensive method for injecting inertia into the system is used to adjust the output power of each distributed generation unit without using additional equipment. The proposed controller consists of two components: a virtual capacitor and a virtual inductor. These virtual components can change the rate of change of the DC bus voltage and also improve the transient response. A small-signal analysis is carried out to verify the impact of the proposed control strategy. Numerical simulation studies validate the effectiveness of the proposed solution for increasing the inertia of DC-MGs.