Systematic Design of Active Power Control Parameters for Multi-VSG Systems Based on Active Power Separation

According to emerging guidelines, system operators are increasingly emphasizing three critical performance aspects from grid-forming (GFM) plants: active power-frequency (P-f) droop, low-frequency oscillation (LFO) damping, and active power setpoint tracking (APST) bandwidth. In GFM plants implemented by multiple virtual synchronous generators (VSGs), these performance aspects are dominated by VSGs’ active power control (APC) parameters, i.e., the inertia constant H and damping coefficient D. However, an APC parameter design with these performance aspects comprehensively considered remains unexplored, potentially leading to inappropriate P-f droop, underdamped LFOs, or excessive APST bandwidth. To address this issue, first, by separating the multi-VSG system’s active power responses into a common part and a differential part, the analytical expressions for its LFO damping ratio and APST bandwidth are derived. Second, by aligning these performance aspects with the requirements outlined in representative GFM plant guidelines, a systematic APC parameter design method is proposed. This method explicitly formulates the feasible region for the APC parameters that ensures appropriate P-f droop, LFO damping, and APST bandwidth. Finally, real-time simulations and experiments are conducted in various multi-VSG systems to validate the theoretical analysis and the proposed APC parameter design method.