Circuit theoretic classification and performance comparison of parallel-connected switching converters

This paper studies the various paralleling styles for dc/dc switching converters from a circuit theoretic viewpoint. The purpose is to examine all possible paralleling 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 described 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, comparison is made for all the schemes in terms of their performances in current sharing and voltage regulation. Finally, an experiment prototype is built to validate the analysis.