Intrinsic Feedback Model for Coupled-Damped Self-Balancing of General Multiphase Hybrid Converters

This work develops a generalized analytical framework to demystify the current and voltage self-balancing in multiphase hybrid converters. Firstly, generalized mathematical criteria are explored to identify the self-balancing characteristics in steady-state. Moreover, the normalized oscillation equation of the balancing errors is derived, which reveals the coupled damping effect among phases. Finally, by performing the Laplace transform on the differential equations of the balancing errors, an intrinsic feedback model is established, which reveals the convergence speed and stability of the self-balancing process. The model indicates that small inductors, large equivalent parasitic resistors, and large flying capacitors are beneficial for fast and stable self-balancing. With the proposed framework, a new topology with self-balancing characteristics is predicted. The validity and generality of the developed theory are verified with experiments.