Analysis on the loss of hybrid transformer winding for multi-output high frequency (300W) LLC resonance converters

With a growing concern over environmental issues, smaller and more energy efficient electronic devices continue to draw attention. Usually, high frequency has more advantages in making switching power smaller. A number of suppliers have already launched single-output power (single or double-digit W) which can be operated in high frequency (higher than 500kHz.) Despite increasing demand for multi-output high-capacity power, it is not easy to operate this power in high frequency. Reducing the loss of both switching components and transformer winding holds great significance in high frequency operation. This abstract is written to suggest a new transformer structure for multi-output (300W) high-frequency (500kHz) operation as well as present mathematical analysis and test results on the loss of transformer winding operated in high frequency. This suggestion can lead to approximately 40% of transformer size reduction compared to the existing one operated in 100kHz.