A Fault-Estimation-Based Tolerant Control Method for Single-Phase PWM Rectifiers with Sensor Faults

In this article, a fault-tolerant control (FTC) method based on fault estimation (FE) is proposed to address the problem of sensor faults for single-phase pulse width modulation (PWM) rectifiers. The desired effect of FTC is achieved in three critical steps: 1) an augmented system is constructed with rectifier states and sensor faults as new state vectors; 2) a state observer is devised for the augmented system to simultaneously estimate the original system states and sensor faults; and 3) the estimated fault is borrowed to compensate for the impact of the fault on the system. The main innovation of the proposed strategy is that it provides a more generalized method and can be adopted to more types of all faults which are norm-bounded and differentiable. It is totally different from the conventional approaches based on fault detection and isolation (FDI), the superior FTC performance can be obtained by the proposed FE-based FTC strategy without the complex design process. Simulation and Hardware-in-the-loop (HIL) experimental tests are conducted to verify the effectiveness of the proposed method.