A Generalised Power Synchronisation Loop Design for Performance Enhancement of Grid-Forming Converter

Abstract

The dynamic characteristics of a grid-forming converter (GFM) directly affect the stable operation of converter-based power systems, where the power synchronisation loop plays a critical role in the shaping of the dynamic characteristics of the GFM converter. Currently, the power synchronisation loop is generally designed by emulating the synchronous machine models and can only provide the inertia and damping characteristics. The stiffness, one of the most important dynamic features, is lacking in the dynamic design of the GFM converter. In this paper, we propose a generalised power synchronisation loop (GPSL) to enable the GFM converter with the inertia, the damping and the stiffness simultaneously. By properly choosing the loop parameters, the dynamic performance and flexibility of the GFM converter can be enhanced. The dynamic property of the GFM converter system and the multiple GFM converter system under the proposed GPSL is both analysed. Moreover, a parameter tunning procedure is given to facilitate the usage of the GPLS. Finally, simulation and experimental results verify the feasibility and effectiveness of the proposed method.