Reliability consideration for a high power zero-voltage-switching flyback power supply

In this study, a high power zero-voltages-witching flyback power supply is presented. An appropriate efficiency is achieved by designing an auxiliary circuit for reduction of dynamic losses in the power switch. Due to the importance of reliability in the switch mode power supplies, reliability assessment is discussed for this zero-voltage-switching flyback converter in details. This paper illustrates that flyback topology has suitable reliability in the high power applications. Although by implementing auxiliary circuit in this topology, softer switching for the main switch is achieved, simplicity of the flyback converter is reduced. As a result, the control and power stages are more complicated. Also, reliability calculations demonstrate that due to soft switching and, consequently, reduction of power switch stresses, zero-voltage-switching flyback has a proper failure rate.