Bifurcation in standalone photovoltaic-battery hybrid power systems

Standalone photovoltaic-battery hybrid power systems are attractive renewable power generation systems, a particular form of which is based on a photovoltaic system and a battery connected to an output dc bus via a buck converter and a bidirectional buck-boost converter, respectively. To operate this system, a specific control strategy is required. In this paper we consider one such system and control strategy, and study the effects of variations of the load current and sunlight intensity on the stability of the system. A Neimark-Sacker bifurcation is identified in this system. Moreover, a detailed analysis based on discrete-time mapping is performed to evaluate the effect of variations in sunlight intensity and load current on the stability boundary of the system.