Heat-Pipe-Integrated Shielding for High-Frequency Transformers in Isolated DC-DC Converters: An Electromagnetic-Thermal Holistic Design

High-frequency transformers (HFTs) are key components in isolated DC-DC converters. During HFT construction, minimizing leakage flux to mitigate electromagnetic interference (EMI) is crucial. Yet, external magnetic shields, commonly used for this purpose, may obstruct cooling airflow. Therefore, identifying effective shielding solutions with optimal thermal performance is essential. This study proposes a shielding setup: a cage structure utilizing heat pipes as electromagnetic shielding bars and coated with silicon steel sheets on their outer surfaces to enhance the shielding effectiveness due to magnetic inductance effects. During operations, external airflow can freely traverse the spaces between the heat pipes. Furthermore, the heat pipes' superior heat transfer capabilities ensure efficient heat transfer from evaporators to condensers. Cooling fins attached to the condensers aid in effective heat dissipation. To balance and optimize thermal and electromagnetic impacts, the Taguchi method identifies the optimal parameters for the shielding structure. The optimized design, after being applied to an HFT prototype, has been experimentally verified to enhance performance and reduce energy consumption.