VSC Control Strategy for Systems with high penetration of Power Electronic Converters

Abstract

This paper presents a Voltage Source Converter (VSC) with an implemented Virtual Synchronous Machine (VSM) control strategy, which is able to work in both grid-tied and islanded mode, providing inertia to the grid and regulating the frequency and the voltage of the system. Those capabilities are necessary to make possible a high penetration of power electronic converters in the power grid. Converters work in parallel with the conventional generators while being able to deal with islanding or some other critical grid events. The proposed control strategy has been tested in a test bench with a synchronous generator (SG). When islanding the VSC, the converter demonstrates its grid forming capabilities controlling the frequency and voltage of the microgrid. The VSM control has proved its grid forming and grid supporting capabilities, without switching between control modes, making it ideal to react to different grid events and showing a soft transition between grid-tied and islanded operation modes.