Distributed DC voltage based grid forming control of interlinking converters in DC local grids

Abstract

This paper proposes a distributed DC-voltage-based grid-forming control strategy for bidirectional interlinking converters in DC local grids. The proposed method establishes GFM (grid-forming) capability through DC-voltage synchronization among converters and enables sensorless droop operation using AC active power feedback. Small-signal analysis reveals the synchronous oscillation mechanism, which is mitigated using a notch-filterbased stabilization method. Simulation results demonstrate that the proposed control effectively suppresses synchronous oscillation and improves dynamic performance compared with conventional droop-GFM and DVSCGFM methods under various scenarios including weak-grid and increased renewable penetration conditions.