Comparative Analysis of Reliability for Single-Phase and Three-Phase Dual Active Bridge Converters

In most electrified vehicles, there is a high-voltage system to feed the powertrain and a low-voltage system for auxiliary loads. Single-phase and three-phase dual active bridge converters (1P-DAB and 3P-DAB) are two potential isolated bidirectional topologies that can be used to connect the two systems. While prior research has extensively compared the volume and efficiency aspects of these converters, their reliability has received limited scholarly attention. To fill this research gap, this paper presents a comprehensive analysis comparing the reliability of 1p-DAB and 3p-DAB converters over a wide range of power levels in two distinct temperature conditions. The reliability evaluation is based on a failure rate model developed from widely utilized handbooks and incorporates the Markov model to account for the fault-tolerant capabilities of each converter. The results show that, for the conditions considered, the 3p-DAB has a 3.24% to 44.92% higher reliability than the 1p-DAB considering the fault-tolerant capabilities, with the improvement increasing over time.