Bifurcation analysis and experimental study of a multi-operating-mode photovoltaic-battery hybrid power system

Abstract

Stand-alone hybrid renewable power generation systems have gained popularity in recent years. However, due to the intermittent nature of the renewable resources, hybrid renew- able power generation systems are often designed to operate with multiple structures and multiple operating modes. The design for stable operation of such systems requires consideration of the sta- bility conditions for all possible structures and operating modes. A stand-alone photovoltaic-battery hybrid power system is studied for illustrating the possible complex behavior in this paper. We reveal smooth bifurcation, including slow-scale Neimark–Sacker bifurcation, fast-scale period-doubling bifurcation as well as coexisting bifurcation. Under certain conditions, when the system switches its operating mode, a nonsmooth bifurcation, manifested as a jump between stable and unstable behavior, can also be observed. Moreover, a detailed analysis based on a discrete-time mapping model is performed to evaluate the stability boundaries of the system. Extensive experiments verify the analysis and simulated results