Design of a power management system for an active PV station including various storage technologies

A hybrid power system with a PV energy conversion system is proposed with lead-acid batteries based long-term storage units and ultracapacitors based fast-dynamic storage units in a DC-coupled structure. It is necessary and important to manage the powers among those different power sources. A power management algorithm is proposed for this hybrid power system by taking into account the characteristics of each power source. It carries out the calculation and the power distribution of an adjustable power margin for the power sources. As results, the lead-acid batteries can smooth the generated fluctuating photovoltaic power in a long time range (from minutes to hours), and the ultracapacitors can smooth the photovoltaic power in a short time range (from seconds to minutes).