Magnetic coupling is a very promising concept to be applied in interleaved power converter in a context of power electronics integration. However, several possible architectures using parallel and/or series intercell transformers can be chosen. It must be found which architectures have to be used when the number of phases increases. In the first part of the paper, a model of magnetic coupler is proposed. This model is used to analyze and compare different magnetic coupling configurations used in interleaved Buck converters in order to find the best configurations (efficiency and complexity). It is based on a harmonic analysis of a multi-phase balanced system. In the second part, an optimal modified sequence of phase order is proposed to enhance performances of configurations in order to find the best. Finally, an experiment validation is presented.