Abstract – This paper presents a new three-phase step-up DCDC
converter with a three-phase high frequency isolation
transformer in an average current-mode controlled closed loop.
This converter was developed for industrial applications where
the dc input voltage is lower than the output voltage, for instance
in, installations fed by battery units, photovoltaic arrays or fuel
cell systems. The converter’s main characteristics are: reduced
input ripple current, step-up voltage, high frequency isolating
transformer, reduced output voltage ripple due to three pulsed
output current and the presence of only three actives switches
connected at the same reference, this being a main advantage of
this converter. By means of a specific switch modulation, the
converter allows two operational regions. An average currentmode
control strategy is applied to input-current and outputvoltage
regulation. Theoretical expressions and experimental
results are presented for a 6.8 kW prototype, operating in region
R2 and for a 3.4 kW prototype operating in region R3, both in
continuous conduction mode.