Power sharing control of fuel cell/gas-turbine hybrid power systems

The solid oxide fuel cell/gas turbine (SOFC/GT) hybrid power systems can utilize exhaust fuel and waste heat from fuel cells in gas turbines to increase system efficiency. The control system plays a critical role in achieving the synergistic operation of various subsystems, improving the reliability of operation, and reducing the maintenance frequency and costs. This paper aims to investigate different control strategies for the power sharing between the subsystems. An internally-reforming SOFC/MT hybrid power system is considered for development of advanced control algorithms, where the anode exhaust, which contains the remainder of the fuel, is mixed with the cathode exhaust in a catalytic oxidizer in which oxidation of fuel is completed. The hot oxidizer exhaust is expanded through the turbine, driving an electric generator. The power electronics interfaces and controls for the hybrid power system are discussed. Two different power sharing strategies are studied and compared. Simulation results are presented and analyzed.