Limit-cycle-oscillation in DC bus system and its death through heterogeneous coupling

摘要

Stability of a complex DC bus system (DBS) is a significant design consideration because of its constant power load (CPL) characteristics of the tightly-regulated load converter. In this paper, the dynamic properties of a stand-alone buck-type DBS are investigated based upon the closed-form large-signal-averaged model. The stability-analysis-in-large around the operation point shows that CPLs create a destabilizing effect on the system that can lead to severe voltage oscillation caused by discontinuity-induced Hopf bifurcations, which are qualitatively different from the bifurcations we know for smooth dynamical systems. Instead, this paper also explores the application of "amplitude death (AD) technique" to stabilize the coupled oscillatory DBSs and show that how this technique with its necessary modifications, for example, the heterogeneity-induced AD technique characterized by two or more coupled DBSs with mismatched frequency of oscillations can provide an efficient open-loop control solution for stabilizing the coupled DBSs. Finally, simulations and experimental results are provided to validate all these concepts.