Adaptive Virtual Inertia to Improve Transient Response of Frequency and Output Active Power When Virtual Synchronous Generator Connected with SMES Coil in DC Side

Virtual inertia in Virtual Synchronous Generators (VSGs) plays a crucial role in enhancing the frequency dynamic response during disturbances, especially in low-inertia power system. However, when using VSGs as gridforming converter in distributed energy resources (DERs), there is a fundamental trade-off between maintaining frequency stability and suppressing output power dynamics of DER, posing a significant challenge in balancing these two critical aspects. A possible oscillation issue is the conflict between power reference tracking, such as during energy storage systems' charging and discharging operations or while maximum power point tracking of PV system, and the large power needed for inertia provision. To address these challenges, this paper introduces a novel method designed to harmonize frequency control with the suppression of VSG output power oscillations. The proposed solution is modeled and simulated in Matlab/Simulink, leveraging an significantly low-inertia grid as the test environment. Simulation results demonstrate the effectiveness of this strategy, achieving improved frequency control performance while mitigating output power oscillations in VSGs.