Enhanced overload current suppression strategy based on adaptive voltage reference and hybrid feed-forward

Purpose This study is conducted to address overcurrent protection and transient voltage recovery in three-phase three-wire inverters. The primary objective of this study is to enhance the response speed of overload current suppression and prevent integrator saturation, thereby ensuring the operational reliability and rapid voltage restoration of stand-alone systems under extreme load conditions. Design/methodology/approach An adaptive voltage reference adjustment strategy is proposed based on real-time load impedance identification. The voltage reference is dynamically modulated through impedance estimation. Additionally, a hybrid feed-forward compensation mechanism is investigated to enhance the response speed during reference transitions and provide stability against abrupt load variations. Findings Simulation and experimental results demonstrate that the overload current is restricted within 0.5 fundamental cycles, with overshoot suppressed by over 50%. Furthermore, the voltage recovery time after overload clearance is notably reduced, and PI integrator windup is effectively eliminated, ensuring superior transient performance. Originality/value This work synergistically integrates impedance-based adaptive modulation with hybrid feed-forward compensation. Unlike conventional hard-clamping methods, the proposed strategy maintains control loop integrity and enhances the transient stability of off-grid inverters, providing a robust solution for systems subjected to extreme load transients.