Ali Shamsnia, Hossein Hosseini, Saeed Danyali,
Volume 1, Issue 2 (2-2013)
Abstract
In this paper a hybrid inverter with input energy sources of sun light and wind is proposed in which use of single inverter for both of the input sources, has reduced the cost and simplify the power circuit. Since P-V characteristics of PV cell and wind turbine are almost identical, MPPT algorithm has been employed for them both to absorb maximum power from these energy sources in different weather conditions. In addition, use of a new, combined MPPT algorithm for PV cells has solved problem of tracking MPP under low light conditions. DC-DC converters placed between the sources and a common DC link, make realization of the MPPT algorithms possible. In addition to presented parts, this system includes a backup hydrogen fuel cell. The hydrogen needed for this part is produced by a catalyzer when there is extra produced electrical energy than needed by load and at the case of fewer production than load demand, the stored hydrogen drives fuel cell to compensate shortage. Inverter of this system is a full bridge single-phase one driven by SPWM switching algorithm to regulate the output voltage under small load variations. Regulation of output voltage against larger load variations is obtained using fuel cell.
Also, a new model for PV cell is proposed in this paper which imitates PV cell behavior much more closely than common current source model.