Weak-Grid Stability Analysis of Quasi-PR Controlled LCL-Type Grid-Connected Inverters with Capacitor-Current Active Damping
Three-phase grid-tied inverters built around an LCL filter exhibit two intertwined difficulties under weak-grid conditions: resonance-driven instability and inadequate harmonic rejection. This paper develops a joint tuning procedure in which a quasi-proportional-resonant (Q-PR) current regulator is paired with capacito...