IGBT Open-Circuit Fault Diagnosis Based on the Voltage Estimation in the Line-Side AC/DC Converter

In this paper the transistor open-circuit fault diagnosis strategy based on the converter voltage estimation error in the voltage oriented controlled three-phase two-level AC/DC lineside converter was presented. In accordance with the developed method, for the converter voltage estimation, the signals of the duty cycles of the voltage modulator as well as simple calculations, that use the line-to-line grid voltage measurements, are utilized. The technique allows to find the single IGBT faults under the rectifying and regenerating converter mode faster than in the one current fundamental period. The method effectiveness has been experimentally validated using the rapid prototyping system.