Experimental Test of Temperature and Power Control for a SOFC Hybrid System Emulator

This work concerns the implementation of a new control system for hybrids with solid oxide fuel cell and micro gas turbines. It is based on a complete hybrid system emulator test rig developed at the University of Genoa (Savona laboratory) by the Thermochemical Power Group (TPG). The plant is mainly composed of a 100 kW recuperated micro gas turbine coupled with both anodic and cathode vessels for high temperature fuel cell emulation and a complete real time model which purpose is to simulate the fuel cell and its electrochemical behavior. The model and the connected physical plant represent a full hardware-in-the-loop (HIL) facility. Temperature, pressure and air mass flow rate at the recuperator outlet (downstream of the compressor) and rotational speed of the machine are inputs from the plant to the model. The turbine outlet temperature (TOT) calculated by the model is fed into the machine control system and the turbine electric load is moved to match the model TOT values. A new revised stack inlet temperature controller has been extensively tested and showed to be very stable and robust. It is capable to contain temperature deviation against a fixed set point within a band of 3 \ub0C when a fuel cell load ramp occurs. The controller is a standard PID (proportional-integral-derivative) plus a feed forward contribution. The PID is protected against wind up