Integrated Policy-Driven Adaptive Control Framework for Grid-Tied Inverters per Frequency Decomposition Based Optimization

This paper presents a unique control architecture for grid-connected inverters. By adding vendor-provided static controllers to an identification-based adaptive control strategy, the proposed method expands the controller’s operating range for dynamic grid conditions. The optimal control policy, based on the nonlinear system dynamics per energy signals at the inverter terminals, determines each controller’s contribution, respectively. These dynamic energy signals are transformed into a physically meaningful signal that represents the dynamics that influence the inverter output power quality via a frequency mode decomposition algorithm per a discrete transform. To enhance the grid’s power quality and overall stability over a wide range of operating conditions, the proposed integrated control architecture eliminates the undesirable high-frequency content via the decomposed energy signals. The proposed method is validated based on experimental results, which showcase the effectiveness of the proposed control over conventional static proportional–integral control (e.g., settling time reduced >56%).