The three-phase dual-active bridge (DAB3) converter has drawn great attention due to the substantial demand for renewable energy. Because of the lack of natural zero-crossing points, short-circuit faults are the most severe faults in dc grids, and more attention must be given to the protection of dc grids. The space-vector-based asymmetrical duty-cycle control (SV-ADCC) method and FRT-Buck modulation, which do not require DC circuit breakers or additional semiconductor devices, are proposed for the fault ride-through (FRT) operation. This paper analyzes the power losses of IGBT modules in FRT-Buck modulation. The conduction and switching losses are calculated based on the parameter values provided in the manufacturer’s datasheet. Additionally, the comparison between FRT-Buck modulation and SPS modulation under various conditions is made to estimate the thermal design for different conditions.