Wide Bandgap devices allow building more compact power converters. To study these new devices (SiC and GaN), static and dynamic tests are performed to models validating. A simulation for each target device is developed considering the main parasitic elements and the measurement instrument models. Thus, the switching losses are calculated and compared to experimental results. Since the whole system is validated, in order to compare the SiC and GaN devices for automotive applications, a DC-DC converter simulation is used for comparing each device under different operation points. Measurement results are presented to validate the simulation approach.