The paper presents a wide campaign of numerical simulations carried out subsequently to the formalization and the implementation in Matlab of a steady state-zero-dimensional numerical model. It describes the various processes of a global self sustained Indirect Internal CO2 Reforming Solid Oxide Fuel Cell System fed with biogas. The plant considered includes a thermo-electrochemical section in which the conversion of biogas into a hydrogen-rich stream occurs. It then feeds the electrochemical core where the generation of electrical and thermal energy take place. In addition, a heat exchanger to preheat fresh gases, a combustor to burn fuel traces in the fuel cell discharge gas and a system for partial recirculation of anode output gas are included. The simulations aim at describing the mapping of the system performance and the comprehension of its behaviour at the several operating and feeding conditions to which it can be subjected. Simulations are conducted as a function of the real possible feeding CO2/CH4 ratio for the biogas. Moreover, several simulations according to the fuel utilization factor, oxidant utilization factor, anode exhaust gas recirculation factor and the pressure are effected to equip an analysis kit for performance prediction. A check analysis on carbon formation is also considered to verify safe functioning. (C) 2017 Elsevier Ltd. All rights reserved.