Generalized Automated Tool for Analysis and Design of Multiphase Coupled Inductor Buck Converters

This paper presents the implementation and validation of a tool for analyzing multi-phase coupled inductor buck converters. In this type of converter, the equivalent inductance seen by each phase changes significantly within one switching cycle and the number of equivalent inductances increases significantly as the number of phases increase. The manual analysis of these converters is prone to errors and using available simulation tools does not result in a symbolic closed-form solution for the equivalent inductance versus the number of phases. The proposed tool not only considers the coupled inductor design with symmetric inductances and coupling coefficients but also the asymmetric design parameters. Moreover, the possibility of specifying the winding directions of the coupled inductor makes it more suitable for practical applications. The tool is benchmarked against simulation and experimental setup by designing three winding symmetric and asymmetric coupled inductors for three phase buck converters. The tool has an error ranging from 0.0288% to 4.661%.