Cycle Skipping-Induced Bifurcation Analysis of Single-Inductor Bipolar-Output DC–DC Converters With One-Cycle Control

Abstract

Due to strong nonlinear coupling effect amongst input/output ports and special cycle skipping effect, single-inductor bipolar-output (SIBO) DC-DC converters with one-cycle control may exhibit various bifurcation phenomena with complex border collision. This brief aims to investigate the cycle skipping effect and explore the occurrence mechanism of these nonlinear behaviors for stability improvement. On account of the cycle skipping effect, a set of the discrete-time mathematical expressions are derived to describe the dynamic characteristics of the one-cycle controlled (OCC) SIBO converter in discontinuous state space. Then, bifurcation analysis is performed by numerical simulation and eigenvalue trajectories. It is shown that cycle skipping effect activates more multi-cycle modes except single-cycle modes. Interestingly, the same slow-scale bifurcations in different operation region present various oscillatory form, which leads to hybrid-scale instability. Especially, the stability boundaries are presented in multi-mode space to guide optimal design. Finally, some experiment results are provided to verify the theoretical analysis.