Effect of paralleling switches on reduction of reliability of fuel cell DC-DC converters

Reliability plays an important role in industrial systems, and if a system has a low reliability, it would not be suitable for high-reliability and high-availability systems. In this paper, reliability of three DC-DC converters compliant with fuel cell applications is calculated. In one of these applications switch-paralleling method for increasing the current rating, and where the number of switches is increased for the purposes of this study. It is shown in this study, based on comparison of results of reliability calculations for each converter type, that this paralleling has caused extreme decreased reliability proportional to incremental increase in number of used switches.