New Control Schemes of Output Power Decoupling Based on Synchronverter

Synchronverters are grid-friendly inverters that mimic the behavior of the synchronous generator (SG). However, the output real power and reactive power of the synchronverter is coupled because of the resistance-inductance line impedance. In this paper, two control schemes of output power decoupling are proposed. The first scheme is to introduce a voltage tracker, consisting of a voltage outer loop and a current inner loop. By choosing suitable controller parameters, equivalent output impedance of the inverter presents inductive in fundamental frequency. The other scheme is an improved virtual impedance method (VIM) based on reference reactive power correction. In order to resolve the problem of inaccurate output reactive power, a correction term is added to the reference reactive power. Simulation results are given to validate the effectiveness of the proposed decoupling schemes.