Robust Sensor Fault Detection for a Single-Phase Pulse Width Modulation Rectifier

Abstract

Maintaining safe and efficient operation in a single-phase pulse width modulation (PWM) rectifier that employs current sensors relies heavily on accurate sensor readings. However, several factors such as environmental conditions, aging, or damage can lead to sensor faults. Therefore, it is imperative to implement robust fault detection methods to ensure reliable system operation. The use of unknown input observer techniques is one such method that involves analyzing the differences between actual and estimated states to detect and identify faults in the system. This paper presents the development of a fault detection method that employs an unknown input observer with high sensitivity to faults and disturbance rejection to achieve robust fault detection. The method involves modeling the system as a state-space model and designing an observer to estimate the system’s state variables based on input and output measurements. The deviations between the actual and estimated states are then analyzed to detect and identify sensor faults, without the need for additional hardware, making it a cost-effective solution. Hardware-in-the-loop tests confirm the effectiveness of the proposed method.

A Multiple-Sensor Fault-Tolerant Control of a Single-Phase Pulse-Width Modulated Rectifier Based on MRAS and GPI Observers

“…Regarding sensor FDI and FTC issues in single-phase grid-connected converters, several studies have been conducted. State observers have been investigated for a robust sensor fault-tolerant control of single-phase PWM rectifiers [15][16][17][18][19]. In [15], a Luenberger observer (LO)-based FDI is presented to allow DC-link and grid current sensors fault tolerance.…”

“…However, the proposed approach may be sensitive to the system's parameters' mismatch. Unknown input observers for sensor fault detection and localization are presented in [18]. A reducedorder observer-based resilient control for single-or multiple-sensor faults for cascaded H-bridge multilevel converters is provided in [19].…”

Voltage and Current Sensor Fault Diagnosis Method for Traction Rectifier in High-Speed Trains

“…Because of the destructiveness and high rate of rectifier failure, it has been paid much attention recently. Nevertheless, most of the research published in the past few years has been about transistor faults [7]. The accuracy of the feedback signals collected and provided by sensors deeply influences the control unit of the system [8].…”