Design of low-profile nanocrystalline transformer in high-current phase-shifted DC-DC converter

In the high-current phase-shifted DC-DC converter, the high-frequency transformer is a key component. Its conduction loss needs to be reduced and the leakage inductance needs to be specifically tuned. This paper investigates the design of low-profile nanocrystalline transformer for high-current phase-shifted DC-DC converters. The core dimension optimization to minimize the transformer loss is proposed. A lossless method of tuning the leakage inductance of the transformer, suitable for low-profile nanocrystalline transformer, is discussed. Designed for a dual active bridge (DAB) converter with high current transients, the planar transformers with both ferrite (3C90) and nanocrystalline (FT-3M) materials are compared. From these comparisons, the benefits and drawbacks of the low-profile nanocrystalline cores are identified.