A Simple Power Loss Evaluation Method for High-Frequency Transformers Based on Surface Temperature Measurement Within Wide Operation Range

Power loss measurement and evaluation form the foundation of loss modeling and optimization. This paper proposes a method for evaluating power loss in high-frequency (HF) transformers operating under forced air-cooling conditions, simply based on surface temperature measurement with a thermal camera. A direct correlation is established between power loss and surface temperature, utilizing a simplified thermal network. This method enables the measurement of both total loss and individual core loss and winding loss directly for HF transformers operating within the whole range of normal working conditions. Simulations are conducted to validate the practicality and accuracy of the proposed method. Experiments are carried out on a HF transformer prototype, following the proposed loss evaluation process, validating the accuracy of the evaluated power loss within wide operation range in loaded tests.