Control of Nonlinear Instabilities in a System of Coupled Interleaved Buck Converters

Novel controllers to improve the stability of coupled interleaved buck converters operating under current-mode control are proposed in this paper. The controllers are employed to force the eigenvalues of the monodromy matrix of the system (the state transition matrix over one full cycle) inside the unit circle, thus avoiding the Neimark bifurcation which has been known to occur in this system. The indirect coupling between the two inductors employed in the circuit is shown to improve the system's stability. Simulations and numerical analysis are presented to provide the basic theoretical evidence for the proposed control methods.