Detection of a Two-Level Inverter Open-Circuit Fault Using the Discrete Wavelet Transforms Technique

Three-phase static converters with voltage structure are widely used in many industrial systems. In order to prevent the propagation of the fault to other components of the system and ensure continuity of service in the event of a failure of the converter, efficient and fast methods of detection and localization must be implemented. This paper work addresses a diagnostic technique based on the discrete wavelet transforms (DWT) for the detection of an inverter IGBT open-circuit switch fault. The study focuses on the investigation of the harmonics (related to the obtained details) which may appear in the spectrum due to the faults. To illustrate the merits of the technique and validate the results, experimental tests are conducted using a built voltage inverter fed induction motor. The inverter is controlled by the SVM control strategy.