Synthetic Inertia Control of Grid-connected Inverter Considering the Synchronization Dynamics

Abstract

The increasing penetration of renewable energy resources facilitates the carbon footprint reduction process yet reduces the power system inertia. As a result, the grid frequency and the rate of change of frequency (RoCoF) might probably go beyond the normal range, resulting in unexpected load shedding, generator tripping, and even frequency instability. To address this problem, grid-connected inverters are designed to participate in frequency regulation and provide the equivalent inertial support. Nevertheless, the inertia emulation effect is affected by the inverter synchronization dynamic and high RoCoF events may occur as the result of poor synchronization dynamics. In view of this limitation, a synthetic inertia control is developed in this article considering the synchronization dynamics. The synthetic inertia principles and control design guideline are explicitly provided. Finally, hardware experimental results of a scaled-down power system prototype are provided to validate the effectiveness of the proposed approach.