The techniques of interleaving phases and magnetic coupling in power converters are effective downsizing the capacitive components as well as the inductive components in certain configurations. These techniques help tackle the problem of large mass and volume in autonomous electric vehicles as the use of the transformer-linked method in interleaved converters facilitates the miniaturization of the inductor, the output capacitor and the cooling system. Consequently, the analysis of all the characteristics of each component in the converter should be taken into account. This study presents the analysis of the output capacitor voltage ripple in the three-phase interleaved boost converter with coupled inductor (Transformer-linked). In this paper, the operating principle of the three-phase interleaved boost converter with coupled inductor is presented, then the output voltage ripple analysis is conducted for each mode of the operating principle, and finally the voltage ripple analysis is validated by experimental tests of a 1kW prototype.