Stability Analysis of the Interleaved Buck Converter With Coupled Inductor

To avoid oscillation phenomena of the interleaved buck converter with coupled inductors (IBCCIs) under continuous conduction mode (CCM), the stability of IBCCI is analyzed in this article. First, a bilinear discrete-time model of the IBCCI is established, and the effect of converter and controller parameters on stability can be revealed based on bifurcation diagrams, Jacobian matrix, and eigenvalue locus. The established model can accurately predict the dynamic performance. Besides, the stable boundary of the system is derived, considering system parameters such as self-inductance, mutual inductance, and the proportional integral (PI) controller parameters. The boundary can guide the design of converter and controller parameters. What is more, the effect of coupled inductors on stability has been clearly exhibited by comparing the IBCCI and interleaved buck converter without coupled inductor. Finally, the simulation and experimental results are conducted to verify the effectiveness and feasibility of the analysis.