Fuzzy controlled power management strategies for a grid connected hybrid energy system

Abstract

This paper describes a fuzzy controlled power management strategies for a grid connected hybrid energy system. The hybrid energy system consists of a Photovoltaic (PV) array model and a Solid Oxide fuel cell (SOFC). As the solar energy is intermittent in nature the system becomes uncontrollable. To make the system controllable and deliver maximum power to the load a fuzzy controlled Solid Oxide Fuel Cell (SOFC) is used with Fuzzy maximum power point tracking (MPPT) controlled Photovoltaic array to make the output power of the hybrid energy system controllable. The two power management strategies unit power control and feeder flow control strategies are used to operate a grid connected Photovoltaic (PV) array and a Solid Oxide Fuel Cell (SOFC) hybrid energy system. The proposed operating strategy coordinates the two control modes, Unit Power Control (UPC) and feeder-flow control (FFC) mode and make the hybrid system output controllable. The proposed fuzzy controlled hybrid system eliminates the perturbations in the PV output power and transients in the fuel cell voltage and always operates the hybrid energy system at maximum output power with reduced number of mode changes.