Coordinate control and energy management strategies for a grid-connected hybrid system

Abstract

This paper explains how to operate a networked hybrid system. A Proton Exchange Membrane Fuel Cell (PEMFC) and a hybrid photovoltaic (PV) array system are taken into account. The hybrid system can run in Feeder Flow Control (FFC) or Unit Capacity Control (UPC) mode. Changes in load demand are adjusted by the main grid because the hybrid source's output is controlled by reference power in UPC mode. Renewable energy is widely used. When light and temperature fluctuate, a PV battery uses Maximum Power Point Tracking (MPPT) to give maximum power to a load. Photovoltaic electricity is uncontrollable because its output varies with the outside and cell temperature. PEMFC should be added to the hybrid system to overcome its limitations. The output of the hybrid source can be controlled by adjusting the output power of the frequency converter. As a result, it is necessary to set a reference value for the output of the hybrid source. In Feeder-Flow Control (FFC) mode, the feeder flow is controlled to remain constant, the hybrid source takes on additional load, and as a result, the feeder reference power needs to be understood. This method reduces load shedding and boosts electricity under high loads. Under light load, the hybrid power supply switches to UPC mode. When the load requirement is near the border of the mode change, UPC or FFC mode is used. Hysteresis eliminates power reference fluctuations. The proposed operation strategy increases system performance, system stability, and mode transitions by consistently operating the PV array at maximum output power and the Photovoltaic–Fuel Cell (PVFC) within its highefficiency range.