Multi-port converters are used widely in satellite electrical systems to provide power management between different power sources. Three-port converters are popular ones that can be employed in satellite electrical systems. Thus, the evaluation performance of this converter in different operation modes is of great importance. Sudden power switches failures may lead the main parts of the electric satellite system to be damaged significantly. Thus, the effect of the power switches failures on the overall operation of the electrical systems and presenting a solution to reduce the risk of out of reaching the main part of the electric systems of the satellite. In this paper, a popular TPC is selected as a case study to be investigated in different aspect performance indexes point id view; such a failure rate analyses, the situation of the electric system after power switch failures and fault-tolerant feature of the studied converter. Simulation results are used to demonstrate the performance of the studied converter for post-fault conditions.