Extended time-delay autosynchronization for the buck converter
  Time-delay autosynchronization (TDAS) can be used to stabilize unstable periodic orbits in dynamical systems. The technique involves continuous feedback of signals delayed by the orbit's period. One variant, ETDAS, uses information further in the past. In both cases, the feedback signal vanishes on the target periodic orbit and hence the stabilized periodic orbit is one of the original dynamical system. Furthermore, this control method only requires the knowledge of the period of the unstable orbit. The amount of feedback gain needed to achieve stabilization varies with the bifurcation parameter(s) of the system, resulting in a domain of control.   In this paper we compute the domain of control of the unstable periodic orbits of the \textit{buck} converter. We obtain a closed analytical expression for the curve $g:S^1 \rightarrow\C$ whose index determines the stability, and this index is then numerically computed. We run several simulations of the controlled system and discuss the results. 
C. Batlle, E. Fossas, G. Olivar (Department of Applied Mathematics and   Telematics, Polytechnical University of Catalonia, ...