EFFECTS OF THE DIGITAL MODULATOR DELAY ON THE BIFURCATION BEHAVIOR OF A TWO-CELL DC-DC BUCK CONVERTER

Recent findings on nonlinear analysis of a two-cell DC-DC buck converter under an ideal Digital Pulse Width Modulation (DPWM) control reveal that the system undergoes a non smooth period doubling bifurcation and border collision route to chaos. Here we give a more complete dynamic model that take into account some imperfections in the feedback loop like delays in the DPWM controller. The analysis of this new model shows that the system undergoes discontinuous Neimark-Sacker bifurcation and quasiperiodic route to chaos rather than a period doubling phenomenon. Morever the critical values of the parameters where bifurcations take place are modified by the delay effect. Numerical simulations confirm the theoretical predictions.