A Novel Voltage-Sensorless Grid Voltage Full Feedforward Estimator-Based Current Control Strategy for a Grid-Connected Inverter

This brief presents a novel voltage-sensorless grid voltage full feedforward estimator (GVFFE)-based current control strategy for a grid-connected inverter with an LCL filter. The grid voltage full feedforward (GVFF) signal can be directly estimated by the GVFFE using a closed-loop structure based on a repetitive controller. Furthermore, the grid voltage can be reconstructed from the estimated GVFF signal without relying on a voltage sensor. Compared with traditional GVFF methods, the GVFFE eliminates the noise amplification caused by derivative operations and compensates for computational delay. As a result, the disturbance rejection performance for grid voltage is significantly improved. The stability and harmonic suppression capabilities of the proposed strategy are comprehensively analyzed. Experimental results validate the effectiveness of the proposed control strategy, demonstrating its potential for practical applications in grid-connected inverter systems.