The availability of reliable simulation models can reduce the time required for commissioning test rigs as well as preventing components from suffering serious damage during testing. The aim of this study is to set up and validate, against experimental data, a real-time model referring to the Rolls-Royce Fuel Cell System Limited (RRFCS) based on hybrid system concept, composed by SOFCs. The dynamic model of the SOFC “block” has been developed, run in real-time, and successfully validated against experiments.Initially, the dynamic evolution of the model is considered under constant inputs at steady-state and is compared against experimental data; in the second step, transient analysis is also considered. Step variations of the main air flow, main fuel flow, syngas flow and electrical current were performed.The model can now be employed to carry out the following: performance analysis, design verification, development of control strategies, on-line analysis and integration with Human Machine Interface.