An active life extension strategy for power switches in interleaved converters

The research on non-invasive incipient fault diagnosis of power converters is very critical to avoid strenuous periodic check-ups and costly interruptions. In many of the research studies, on-state resistance of power MOSFETs is identified as the fault precursor, and suggested to be monitored online for prognosis. In this paper, a condition monitoring algorithm is proposed for power MOSFETs of interleaved converters and integrated with the conventional current loops. The proposed technique utilizes on-state resistance information of the switches to adjust the current reference of each interleaving leg. Thus, the thermal stress on the aged device can be reduced and the overall lifetime of the converter can be extended. The proposed approach is verified on two-leg interleaved dc/dc and ac/dc converters.