Hopf bifurcation and chaos in a free-running current-controlled Cuk switching regulator

An autonomous free-running Cuk converter is studied in this paper. Analysis of the describing nonlinear state equations shows that the system loses stability via a supercritical Hopf bifurcation. The boundary of stability is derived and local trajectories of motion studied. Cycle-by-cycle simulations of the actual system reveal the typical bifurcation from a stable equilibrium state to chaos, via limit cycles, and quasi-periodic orbits. Experimental measurements confirm the bifurcation scenarios. The occurrence of such kinds of bifurcation in autonomous dc/dc converters has been rarely known in power electronics.