Typical Fault Mechanism Analysis And Diagnostic Strategy Research Of Power Converter

In recent years, with the rapid development of the SCR, research and development ofpower converter device control system has also been improved by leaps and bounds, withfull-controlled and high-speed switching devices——IGBT as switches in power converters,represented widely used in various fields of industrial manufacturing and national production.Meanwhile, along with the rising power converter device pillar position, people pay moreattention to its secure, reliable and efficient operation of the process. However, powerconverter failure is inevitable, so it is necessary to carry out real-time fault detection, toachieve rapid and efficient diagnostic purposes, will help improve system reliability, improveutilization of system devices.This paper focuses on the important part of power converter system-PWM rectifier faultdiagnosis. PWM rectifier faults concentrates in the rectifying bridge mainly conclude openand short circuit faults of IGBT power device, in particular open-circuit fault, due to its faultcharacteristic fine but large harm, and difficult to detect made its become mainly study objectof PWM rectifier. Therefore, this feature based gate signals of switches and voltage of bridgein the rectifier bridge arm, to achieve the purpose of the fault PWM rectifier fault diagnosisfor single tube open fault.In this paper, select three-phase voltage PWM rectifier as the main study object. Firstly，under its normal circumstances, detailedly analysis the single-phase, two-phase, three-phaseof rectifier bridge arm work mode，and carried out a number of performance indicators of itsnormal operation; Secondly, built two simulation models under two different controlalgorithms in Matlab for PWM rectifier-hysteresis current and space vector (SVPWM)control algorithms，and when occurred single-tube open-circuit fault in rectifier bridge, studythe fault information by extracting establish fault feature vectors presented to the gate signalas a reference point for the two fault diagnosis method: Based on the gate signal and emittervoltage in single-phase fault diagnosis method and based on the gate signal and line voltage intwo-phase fault diagnosis method. Finally, a large number of simulations fully verify thesetwo methods in different control algorithms can achieve the purpose of accurate diagnosis,the results of the theory is consistent.