DESIGN CONSIDERATIONS FOR HIGH-FREQUENCY COAXIAL WINDING POWER TRANSFORMERS

The use of coaxial windings to create low loss, low leakage reactance, power transformers for use in high frequency soft switched dc/dc and resonant converters has been demonstrated in [1]. This paper examines some of the important loss aspects of the design of coaxial winding tr ansformers such as the influence of skin effect on winding resistance, the variation of core loss caused by nonuniform core flux density, an d the choice of the principle dimensions and aspect ratios for maximum efficiency. Experimental measurements on a 50 kVA 50 kHz unit, are in cluded to confirm portions of the analytical results and suggested des ign procedures.