Adaptive Inertia and Damping Control of Parallel System with Multi-VSGs in Microgrids

Abstract

With the rapid development of new energy, the wide application of microgrids has become the main trend of energy structure reform in the world. Virtual synchronous generator (VSG) control technology makes the microgrids inverter have the operation characteristics of synchronous generator, provides the necessary inertia and damping support for the system, and realizes the friendly grid connection of lots of new energy. In order to better realize the coordination of multi-VSGs units in the microgrids when providing inertial damping support, a small signal model of steady-state working point is established to analyze the influence of key control parameters on the stability of the system. Combined with the dynamic and stability characteristics of VSG, the comprehensive value area of virtual moment of inertia and damping coefficient of VSG is determined. According to the frequency variation, the adaptive control strategy of moment of inertia and damping can be adopted to improve the transient stability and dynamic frequency response of the system. Finally, simulation result shows that the presented strategy can suppress the system frequency and active power oscillation under different working conditions, and can well meet the operation requirements of microgrids.