Calculation of stable and unstable periodic orbits in a chopper-fed DC drive

Abstract

It is well known that electric drives demonstrate various nonlinear phenomena. In particular, a chopper-fed analog DC drive system is characterized by the route to chaotic behavior though period-doubling cascade. Besides, the considered system demonstrates coexistence of several stable periodic modes within the stability boundaries of the main period-1 orbit. We discover the evolution of several periodic orbits utilizing the semi-analytical method based on the Filippov theory for the stability analysis of periodic orbits. We analyze, in particular, stable and unstable period-1, 2, 3 and 4 orbits, as well as independent on stability they are significant for the organization of phase space. We demonstrate, in particular, that the unstable periodic orbits undergo border collision bifurcations; those occur according to several scenarios related to the interaction of different orbits of the same period, including persistence border collision, when a periodic orbit is changed by a different orbit of the same period, and birth or disappearance of a couple of orbits of the same period characterized by different topology.