In course of the ongoing energy transition the demand of grid-forming converters increases rapidly due to the loss of large synchronous machines providing inertia and grid-forming voltage behaviour. Therefore, a thorough analysis and comparison of potential grid-forming control approaches is needed to evaluate and validate not only their grid-forming behaviour but also their impact on the overall grid stability.

This contribution aims to compare the Virtual Synchronous Machine approach and the Synchronverter as a grid-forming converter control by means of an impedance-based stability analysis. For this, both approaches are implemented for a two-level converter-based grid booster and a MMC-based ES-STATCOM as an EMT simulation model. In the following, their frequency-dependent impedance is determined by scanning with an online impedance scan tool in EMT simulation environment. The resulting impedances are analysed and compared in terms of their passivity-based stability evaluating their potential impact on the stability of the connected grid.

The contribution is prepared in course of a PhD research project.