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 (FC) thermal exhaust, and a cold-air (CA) valve which bypasses airflow rate from the FC cathode. The robust PID controller results for the upper and lower boundary of uncertain gains are presented first, followed by a design for the upper and lower boundary of uncertain time delays process for both, FV and CA bypass valves. The final design incorporates the combined uncertain gain and the time delay modeling for the upper and lower boundary of both actuators. This multiple-input multiple-output technique is beneficial to plants having a wide range of operation and a strong parameter interaction. The practical implementation of the PID controllers and the set point responses are presented through simulation in the matlab/simulink environment.