Application of virtual synchronous generator technology in microgrid

Abstract

This paper presents the modeling and simulation of the application of virtual synchronous generator(VSG) technology in a bidirectional DC/AC converter and a PV/battery system in a hybrid AC/DC microgrid. The battery unit in the DC sub-microgrid maintains DC bus voltage stable and the DC bus is equivalent to a storage system. The voltage-controlled type of VSG control strategy is applied to the bidirectional DC/AC converter being as the support node in hybrid AC/DC microgrid. And the DC/AC inverter of the PV/battery system adopts the current-controlled type of VSG control strategy to assist the bidirectional DC/AC converter with frequency and voltage regulation. Then the mathematical models of two types of VSG control strategy are introduced. Based on Matlab/Simulink, the simulation model of a hybrid AC/DC microgrid with two types of VSG control strategy is established. The simulation results show that the VSG control technology can effectively improve the operation stability of hybrid AC/DC and realize the smooth switching between the island mode and grid-connected mode.