New multiple DC-DC converter topology with a high frequency zig-zag transformer

In this paper, new multiple dc-dc converter topologies such as boost and buck types are proposed. Basically, multiple converters are interleaved together along with an integrated high frequency multiphase magnetic called zig-zag transformer. The balanced multiphase winding voltages of the transformer are generated by three pulse width modulation (PWM) signals appropriately phase-shifted. The transformer automatically makes all the multi-phase currents identical so that current control can be simply achieved by sensing only a single current even for multiple converters without current sharing technique. Switching frequency of each phase is slightly lower since today's semiconductor technology limits the level. But with the proposed topology, overall input/output ripples are appeared at the number of phases times the switching frequency. First of all, three-interleaved converters are introduced for simplification of the analysis. It is noted that no current ripple is appeared at the boundary conditions where converter operating point needs to be placed. The proposed topology also improves transient response since all identical phase currents flow through the magnetic. Experimental results are shown to confirm the validity of possible use of the proposed approach in practice.