Chaos through Sliding Bifurcations in a Boost Converter under a SMC Strategy*

Chaos in a hybrid model of a DC-DC boost converter operating in Discontinuous Conduction Mode (DCM), when controlled by Sliding Mode Control (SMC), is detected. The chaotic regime coexists with the stable operating point. It is rigorously shown that there is an unstable limit cycle in the sliding dynamics due to a subcritical Hopf bifurcation. The existence of this limit cycle and its evolution with parameters turn out to be of great importance for the stability and robustness control of this type of power converter.