Flexible System Architecture of Stand-alone PV Connected System with Energy Storage

This article proposed a flexible system architecture of a stand-alone photovoltaic connected system (SPVS) with energy storage. An SPVS with energy storage requires power management architecture to account for various operating modes. A co-ordinate controller is often required to manage the change in control architecture depending on the operating mode. This architecture contains a boost converter (BC), and a bidirectional switched quasi-Z-source DC-DC converter (BSQZSDC). The BC is used for two purposes. The first is to extract the maximum power from the PV by using the MPPT technique. The second is to control the DC link voltage when the SPVS is not in MPPT mode. This BSQZSDC is used for energy management and regulates DC link voltage when SPVS is operating in MPPT mode. To regulate the DC bus voltage and battery current in different modes of operation, BSQZSDC makes use of an effective control approach, the Integral Sliding Mode Control discussed in this paper. To prove that the controller is effective in fulfilling the control objectives, simulations were run.