IV. SINGLE AND THREE-PHASE TRANSFORMER COMPARISON
One case study has been carried out at 20 kHz, 250 kW,
5000 V as an example. The operating points of DAB1 and
DAB3 are as shown in TABLE II.
By using J-B Method, the maximum current density is
selected from 100 A/cm2 to 500 A/cm2, and maximum flux
density from 0.3 T to 0.7 T. Optimization calculations have
been carried out at each point of (Bmax, Jmax) and the volume
comparison results of single and three-phase transformers
are shown in Fig. 8. And for further analysis, the
temperature rise of each design has been calculated and
compared in Fig. 9, based on the thermal model discussed in
Section III. A. From Fig. 8, it is apparent that at that range of
Bmax and Jmax, three-phase transformer has a smaller volume
than single-phase one.