Robust PID Controller Design of a Solid Oxide Fuel Cell Gas Turbine

The performance of a 300 kW Solid Oxide Fuel Cell Gas Turbine (SOFC-GT) pilot power plant simulator is evaluated by applying a set of robust Proportional Integral Derivative (PID) controllers that satisfy time delay and gain uncertainties of the SOFC-GT system. The actuators are a fuel valve (FV) that models the fuel cell thermal exhaust, and a cold-air (CA) valve which bypasses airflow rate from the fuel cell cathode. The robust PID controller results for the uncertain gains are presented first, followed by a design for uncertain time delays for both, FV and CA bypass valves. The final design incorporates the combined uncertain gain parameters with the time delay modeling of both actuators. This Multiple-Input Multiple-Output (MIMO) technique is beneficial to plants having a wide range of operation and a strong parameter interaction. The practical implementation is presented through simulation in the Matlab/Simulink environment.