Modeling and Controlling an Off-Grid Hybrid PV-Battery system

Hybrid energy systems can be formed by combining fuel cells, PV cells, wind turbines, diesel generators, gas generators, microturbines, and battery storages. A common hybrid system adopted for distant loads is PV cells and wind turbines. PV cells have a maximum power point, at which the generated power reaches its maximum value, based on atmospheric conditions, irradiation, etc. Thus, a control method is required to always achieve the maximum power and thus maximum utilization. Here, first a suitable battery is chosen for the hybrid system. Then, an accurate PV cell and a control model are presented. Finally, a simulation of a PV-battery hybrid system is performed. The results show of stable a PV-battery system power output. Depending on the circumstances in which solar cells are like weather, radiation, etc. have a Maximum Power Point (MPP). So a method is required to steadily keep solar cell in its Maximum Power Point to get maximize power and efficiency of solar cells. Solar energy absorbed by the solar cells should become transferable to local charges and network, and this can be done using power converters. Using converters with high efficiency and low and constant initial cost seems necessary.

Keywords:

PV system , fuel cells , MPPT , hybrid system