Reliability-focused analysis of the performance and characteristics according to the secondary circuit structure of the transformer in the isolated DC-DC full-bridge converter

Abstract

This paper analyzes the characteristics and performance of an isolated DC-DC full-bridge converter’s transformer secondary circuit structure, focusing on reliability. The circuit structure of the primary of transformer of the isolated DC-DC full-bridge converter is the same, and the rectifier stage of the secondary of transformer compares the full-bridge, current-doubler, and center-tap methods. We supplement the validity of reliability analysis by applying the most straightforward failure rate analyses PCA (Part Count Failure Analysis), PSA (Parts Stress Analysis), which analyzes by adding environmental factors, and FTA (Fault Tree Analysis), which considers the risk of converter operation. For comparison, the input-output specifications and power capacity are set the same, the voltage margin of the component is selected to be 1.5 times the rated voltage, and the comparison is made under 65[°C] operating conditions. We also analyze the relationship between price and efficiency according to the voltage margin of components that affect reliability. This paper provides converter designers with essential guidelines for designing high-reliability converters by considering and analyzing all circuit components and structures that can affect reliability. Authors