A review of power loss measurement method for high-frequency transformer

Solid-state transformer (SST) is a potential equipment in future energy system. High-frequency transformer (HFT), which serves as a vital component in SSTs, is exposed to complex electromagnetic and thermal stresses in real-world operations. High-precision power loss measurement is essential for efficiency evaluation and hotspot temperature prediction of HFT, which is particularly difficult for high-frequency and high-power applications. This article reviews the core loss, winding loss, and total power loss measurement methods for HFT. The electrical methods and calorimetric methods for power loss measurement are summarized, discussed, and compared. The electrical method is suitable for rapid loss measurement, but its measurement accuracy decreases at high frequencies, and complex calibration or compensation is required to improve it. The calorimetric method enables high-accuracy loss measurement, but the complicated procedure limits its application to laboratory validation and makes it impractical for real-world or online use. High-frequency high-power test power supply, advanced high-accuracy loss measurement method, power loss equivalent test method, and online power loss measurement technology are future trends for power loss evaluation of HFT.