Implementation of a grid-forming converter based on modified synchronous reference frame

Abstract

Renewable resources power generation systems are mainly constituted by power converters. These converters can be controlled in several ways to execute different functions inside microgrids. Some of the converters cannot operate on isolated grids, that is, without connection to the electrical grid. Therefore, there are converters whose purpose is to provide a voltage reference so that other converters continue to deliver power independent of grid presence. These devices are called grid-forming converters and are usually constituted by a converter associated to an energy storage system. This paper presents the practical implementation of a grid-forming converter using the Modified Synchronous Reference Frame as base structure for the converter control. The developed control strategies are described along with experimental results of a single-phase 5 kVA prototype.