Designing and Experimenting an Auto-Adaptive Controller for a Stand-Alone Photovoltaic System with Hybrid Storage

An auto-adaptive controller has been successfully designed and implemented in a stand-alone PV system with a hybrid storage that combines batteries and ultracapacitors. Our controller, based on a Perturb and Observe (P&O) algorithm, gives better results and enhances considerably the efficiency, by making Maximum Power Point Tracking (MPPT) more stable and faster. Moreover, it is demonstrated that ultracapacitors are useful to face peak power demand and allow batteries to operate under better conditions because deep discharges are strongly reduced. The algorithm has been successfully implemented via a digital controller based on a dSPACE card. Results are validated experimentally on a benchmark prototype under real climatic conditions, particularly for low irradiation. Finally, performances and advantages of the global system are discussed in the paper. Copyright (C) 2012 Praise Worthy Prize S.r.l. - All rights reserved.