| Abstract |
Active-clamp forward converters are typically not applied for converters with power ratings larger than 500 W as power as the power transfer between primary and secondary is discontinuous leading to large magnetic components. This paper, however, proves that silicon carbide (SiC) devices enable this topology as a well-suitable topology for a wide voltage-transfer ratio due to the low switching losses allowing high switching frequencies reducing the size of the magnetic components. A laboratory prototype is designed using a very precise model. It employs SiC MOSFETs of 900 V for the primary and Si synchronous rectifiers of 100 V. The semiconductors are cooled with cost-efficient copper inlays, which effectiveness is demonstrated through a thermal FEM simulation. The developed prototype achieves a maximum efficiency of 95 \% while maintaining an efficiency above 92 \% for almost the entire operating region. The high efficiency and the power density of approximately 2 kW/l confirm the proposed concept. Finally, the converter is benchmarked to two LLC resonant converters (Si, SiC) and the prototype is used to verify a highly accurate steady-state model showing errors below 1 \%. |
