Power oscillation damping with grid-forming converters: a simulative and system-theoretical analysis

Grid-forming control concepts are often based on the dynamic behavior of synchronous generators. While this approach offers beneficial properties from a power system stability perspective, such as inertia provision, it also introduces negative aspects associated with synchronous generator-dominated grids, such as a tendency to participate in power system oscillations. However, converter-based power oscillation damping countermeasures are often structurally inspired by countermeasures originally developed for synchronous generators - although utilizing the fast controllability and additional capabilities of converter control. The effects of these countermeasures on the behavior of converter-based systems are not always immediately apparent but can significantly impact the converter’s performance if not properly addressed. This paper demonstrates these unintended effects through simulations and system theory analysis, with a particular focus on inertia provision. Additionally, modifications to these countermeasures are proposed to mitigate the identified and potentially undesirable effects while preserving the beneficial damping characteristics. The paper thus highlights limitations and possible constraints in the development and parameterization of grid-forming converter control and is of particular interest to both manufacturers and grid operators.