Improvement of a PV-FC hybrid source operation in a microgrid

A microgrid system has multiple distributed generators (DGs) which participate in sharing the local load. The considered microgrid system includes a hybrid source connected to a feeder in parallel with other distributed generators. The hybrid source comprises of a Photovoltaic (PV) array and a Proton exchange membrane fuel cell (PEMFC). The PV array normally uses a maximum power point tracking (MPPT) technique to continuously deliver the highest power to the load when variations in irradiation and temperature occur, which make it becomes an uncontrollable source. In coordination with PEMFC, the hybrid system output power becomes controllable. On the other hand, the microgrid has two control modes, Unit-power control (UPC) mode and Feeder-flow control (FFC) mode. Therefore, the operation of PV and FC must be coordinated when the control mode is either UPC or FFC. The paper presents a method to operate the hybrid source so that the PV can always work with MPPT and the PEMFC can work in a high efficiency performance band regardless the UPC mode or the FFC mode. Such a proposed method can improve the performance of the system operation, enhance the system stability, and decreases the number of mode change.