Comparison of configurations for parallel dc/dc converters

This paper studies the characteristics of various parallel connected DC/DC converters from a circuit theoretic viewpoint. The purpose is to examine all possible parallel structures and control configurations, allowing simple and direct comparison of the characteristics and limitations of different paralleling schemes. In the paper, a circuit theoretic classification of parallel connected converters is proposed firstly. Converters are modeled as current sources or voltage sources in the classification, and their connection possibilities are categorized systematically into three basic types. Then, control arrangements are classified according to the presence of current-sharing and voltage- regulation loops. Moreover, comparisons are made for all the schemes in terms of current sharing and voltage regulation. Finally, an experiment prototype is built to validate the analysis. The results clearly show the properties of various paralleling schemes.