Tuning of grid-forming converters with a settings-free optimization algorithm to improve frequency response of low-inertia systems

The substantial integration of non-synchronous energy resources into power systems is leading to different challenges in frequency dynamics. Although grid-forming (GFM) converters with particular control structures can potentially deal with that, the appropriate selection of GFM control parameters to achieve a given frequency response is still an issue that needs further research. Therefore, an approach for the determination of the inertia and damping factors in a Virtual Synchronous Machine (VSM) based GFM control scheme is presented in this paper. The tuning of these parameters is formulated here as a constrained optimization problem, which is solved through an iterative strategy using the Jaya optimization algorithm (JOA). Since JOA does not depend on any algorithm-specific settings, its application can be more direct and flexible (as compared to popular alternatives where the value of these settings may significantly affect overall algorithm performance). The effectiveness of the proposed approach is illustrated through a sample system under several penetration levels of converter-interfaced generation, where frequency support is provided by optimized GFM control. Simulations results show that the JOA based tuning strategy can provide a systematic selection of VSM parameters to appropriately shape the system frequency response after a given power imbalance.