Grid-forming converters. A critical review of pilot projects and demonstrators

Grid-forming control can be a useful solution for all dynamic issues in weak grids and for providing ancillary services. It represents the new frontier in modern power electronics, responding to the needs of power systems more and more rich in renewables and, for this reason, with lower inertia. Today, the research on grid-forming is mainly oriented to propose new and more effective control schemes and to evaluate their performances with simulation tools, but few works in the literature focus on the results of on-field experimentation. Therefore, this paper aims to provide a comprehensive review of grid-forming pilot projects and demonstrators developed worldwide. The work describes the main pilots providing an accurate analysis of the technical features of each demonstrator, and it proposes a critical discussion on the motivations that have driven each installation and on the results which have been obtained or are expected. The demonstrators are finally compared remarking their analogies and differences, trying to chart the development trajectory of this new technology and suggesting some future developments for experimental tests on pilot systems.