Sensor fault tolerant control method for electric traction PWM rectifier using sliding mode observer

The single-phase PWM rectifier is the main component of the AC-DC-AC converters in high-speed railway electric traction system. This paper presents a fast and robust fault diagnosis and fault tolerant control method for the catenary current and DC-link voltage sensor faults in the single-phase PWM rectifier control system. The sliding mode observer (SMO) including inserted linear correction term is designed. The residuals are generated between measurements and observed values. The fault diagnosis unit locates the faulty sensors in few sampling periods by comparing residuals with thresholds. The analytical redundancy is employed in the control reconfiguration. Simulation results are presented to verify the effectiveness and reliability of the proposed strategy.