C. Experimental Results
The performance of the proposed two-inductor boost
converter was verified on a 1-kW prototype circuit that was
designed to operate from a 40–70-V battery input and deliver
up to 2.9 A at a 380-V output. The simplified schematic
diagram is shown in Fig. 8. This converter was operated at
40 kHz switching frequency. However, the ripple of the input
current and the ripple of the output voltage are 80 kHz, since
the switching periods of the two switches are interleaved as
shown in Fig. 6. The efficiency measurements for the prototype
converter at 40 V and 70 V input are summarized in Fig. 9. As
can be seen from the figure, the measured full-load efficiency
was around 92% at the minimum line voltage. The peaking
of efficiency at for and at
for indicates the saturation of the
ferrite toroidal core in boost inductors and .
Figs. 10 and 11 show the measured waveforms of the proposed
two-inductor boost converter at 40 V and 70 V input voltages
under the full load and 1.5% load conditions, respectively.
As can be seen in the figures, the boost inductor current increases
during the period when both switches and are
JANG AND JOVANOVIC´ : NEW TWO-INDUCTOR BOOST CONVERTER 175
on. During the period when one of the switches is off, the boost
inductor current decreases. There is a good agreement between
the experimental and theoretical waveforms. It should be noted
that the blocking voltage of the switch is approximately 190 V
which is half of the output voltage. Moreover, inductor current
is also half of the input current, since two inductors and
share the current equally.
IV. CONCLUSION
A new two-inductor, two-switch boost converter topology
and its variations that can regulate the output voltage in a wide
range of load current and input voltage with a constant-frequency
control are introduced. The constant-frequency control
is achieved with the employment of a unity-turns-ratio auxiliary
transformer that couples the current paths of the two inductors
and forces them to be virtually identical. Since in this topology
no energy can be stored in the inductors when the conduction
times of the switches do not overlap , the output
voltage can be regulated from full load down to practically no
load.
The described two-inductor topologies with the auxiliary
transformer are suitable for applications that require a high
input-to-output voltage conversion ratio. Specifically, a nonisolated
implementation with a voltage-doubler rectifier exhibits a
voltage gain that is four times of the corresponding gain of the
conventional nonisolated boost converter
The performance of the proposed two-inductor boost converter
was verified on a 1-kW prototype circuit that was designed
to operate from a 40–70-V battery voltage input and deliver
up to 2.9 A at a 380-V output