Dynamic Impact of Voltage-Dependent Current Injection on Fault-Ride-Through of Grid-Following Converters

This article analyzes transient stability of grid-following voltage source converters (GFL-VSCs) considering the voltage-dependent current injection (VDCI) dynamics during fault-ride-through (FRT). The dynamic interaction between the VDCI and the phase-locked loop (PLL) under the weak grid is revealed to provide insight for their impact on system transient stability. The critical values of K-factor used in VDCI are further quantified to guarantee GFL-VSCs with equilibrium points during FRT. Finally, case studies based on electromagnetic transient (EMT) simulations and numerical method are given to verify the correctness of the theoretical findings.