Fractional‐order modeling and nonlinear dynamics analysis of flyback converter

Abstract

AbstractTo accurately investigate the nonlinear dynamic characteristics of a flyback converter, a fractional‐order state‐space averaged model of a flyback converter in continuous conduction mode (CCM) is established based on fractional calculus theory. And nonlinear dynamical bifurcation maps which use reference current as bifurcation parameters are obtained. The period‐doubling bifurcation is analyzed and compared with that of an integral‐order flyback converter. The results show that under certain operating conditions, the fractional‐order flyback converter exhibits period‐doubling bifurcation as certain circuit and control parameters change. Under the same circuit conditions, there is a difference in the stable parameter region between the fractional‐ and integral‐order models of the flyback converter. The stable zone of the fractional‐order flyback converter is larger than that of the integral‐order one. Therefore, the circuit is more difficult to enter the state of the period‐doubling bifurcation and chaos. The stability domain of period‐doubling bifurcation can be accurately predicted by using the predictive correction model of the fractional‐order flyback converter. Finally, by performing circuit simulations and hardware‐in‐the‐loop experiments, the rationality and correctness of the theoretical analysis are verified.