Virtual Synchronous Generator Control with Double Decoupled Synchronous Reference Frame for Single-Phase Inverter

Abstract

Several virtual synchronous generator (VSG) controls for three-phase inverters have been proposed in order to extend the advantages of synchronous generators to inverters. The VSG controls facilitate smooth transitions between the grid-connected mode and the island mode. The governor and the automatic voltage regulator (AVR) realized in the VSG stabilize the frequency and the voltage respectively in the island mode. In addition, they can control the active and reactive power of the inverter in the grid-connected mode. The objective of this paper is to extend these useful properties of VSG to single-phase inverters. The proposed single-phase inverter with a VSG is based on two synchronous d-q reference frames, i.e., the positive and negative sequences. The double decoupled synchronous reference frame (DDSRF) theory is applied to generate these two reference frames. The simulation and experimental results indicate that the properties of a three-phase inverter with a VSG can be extended to a single-phase inverter effectively.