Mathematical model of new bi-directional DC-AC-DC converter for supercapacitor energy storage system in photovoltaic generation

Energy storage system is an all-important part in photovoltaic. A new bi-directional DC-AC-DC converter for supercapacitor energy storage system in photovoltaic generation is put forward. In the beginning, some experiments on super capacitor have been performed, which shows super capacitor has good performance in quick charge and discharge. And mathematical model of the dual full-bridge bi-directional DC-AC-DC converter circuits with a transformer and its simplified model are derived. In the end, A phase current in the transformer primary side (ia) can be investigated with mathematical calculation simulation and detailed circuit simulation. The comparative result shows the mathematical model rationality. Through deduction, unified model of SESS also can be gotten.