Almost Globally Stable GFL Inverter Control Scheme Based on Current Control Synchronization

Various control strategies have been proposed to enhance the transient stability of grid-following (GFL) inverters. However, most existing approaches are tailored to specific operating conditions and often lack theoretical guarantees, limiting their adaptability. Furthermore, these methods tend to complicate the controller design and parameter tuning. To address these limitations, this paper introduces a novel current control synchronization (CCS)-based control strategy for GFL inverters. The stability of the CCS-based control scheme is rigorously verified using the qualitative theory of differential equations and phase portrait analysis, establishing almost global asymptotic stability. Moreover, the controller parameters can be tuned with exceptional simplicity, greatly streamlining the design process. The performance of the CCS-based approach is validated through electromagnetic transient (EMT) simulations and controller hardware-in-the-loop (CHIL) experiments. The results show that the proposed method matches phase-locked loop-based schemes in power tracking and frequency synchronization, while significantly outperforming them in transient stability. These findings further underscore the enhanced adaptability and practical feasibility of the proposed method.