Characteristics of Parallel Inverters Applying Virtual Synchronous Generator Control

The virtual synchronous generator (VSG) is a promising way to deal with the lack of physical inertia and damping introduced by the power-electronic-based power supply system. However, the inertia and damping characteristics may be complicated in a paralleled VSG system due to the lack of a stiff power grid and the interactions between the control system of the inverters. In this paper, the dynamics of parallel inverters with VSGs is studied. The equivalent inertia and damping characteristics are derived and analyzed in detail considering both changing of set-points and load disturbance, where the transient load sharing is also investigated. Furthermore, a better dynamics is achieved by an inertia switching strategy. Experimental results verify the effectiveness of the analysis and the proposed strategy.