Current Sensor Fault Reconstruction and Compensation of an AC-Voltage Sensorless Controlled Single Phase Grid Connected Converter using PI-Observers

Ensuring reliability and availability while reducing cost are the main desirable characteristics of single-phase grid connected converters. With a view to guarantee the aforementioned characteristics, this work presents a grid current sensor fault tolerant control (FTC) of an AC voltage sensorless controlled single-phase grid connected converter. Contrary to classical sensor FTC methods based on residual generation, the proposed approach aims to reconstruct the current sensor fault. Hence, a bank of proportional-Integral (PI) observers is proposed to first, insure accurate estimation of the grid voltage and second to achieve a robust grid current sensor fault estimation. Finally, the current sensor fault tolerant control process consists on fault compensation in the converter's control loop as well as in the grid voltage estimation stages. The effectiveness of the proposed FTC algorithm is demonstrated through simulation under Matlab/Simulation Software and experimental results.