Due to their advantages in ensuring low harmonic distortion and high power factors, single-phase Pulse-Width Modulated (PWM) rectifiers are widely employed in several industrial applications. Generally, the conventional control loop of a single-phase PWM rectifier uses both voltage and current sensors. Hence, in case of sensor fault, the performance and the availability of the converter can be seriously compromised. Therefore, diagnosis approaches and fault-tolerant control (FTC) strategies are mandatory to monitor these systems. Accordingly, this paper introduces a novel multiple-sensor FTC scheme for a single-phase PWM rectifier. The proposed fault diagnosis approach relies on joining several Generalized Proportional Integral (GPI) and Model Reference Adaptive System (MRAS) observers with a residual generation technique to detect and isolate sensor faults in a simple and reliable manner. While conventional sensor FTC methods dedicated to PWM rectifiers can only deal with single faults, the suggested approach guarantees a very good effectiveness level of sensor fault detection, isolation (FDI) and FTC of multiple-sensor fault occurrence scenarios. Consequently, the single-phase PWM rectifier can work with only the survivable single sensor with the guarantee of very good performance as in healthy operation mode. The effectiveness of the proposed sensor FDI approach and its control reconfiguration performance are demonstrated through both extensive simulation and experimental results.

Grid-connected converters (GCC) commonly rely on proportional–integral (PI) controllers for DC-link voltage regulation. However, their performance can significantly degrade in the presence of parameter variations and external disturbances, resulting in overshoot, undershoot, and slow transient response. To address these limitations, this paper proposes a generalized proportional–integral observer (GPIO)-based control strategy for single-phase GCC. The proposed method improves disturbance estimation and rejection, thereby enhancing robustness against system uncertainties while ensuring fast and accurate DC-link voltage regulation. The main contribution of this work lies in the development of a GPIO-based controller that combines improved dynamic performance with strong disturbance rejection capability, without increasing control complexity. The proposed approach is validated through both simulation and experimental results, which demonstrate its effectiveness and superiority over conventional PI-based control in terms of transient response, stability, and robustness.