Author(s): G S Thakur and Prabodh Khampriya

The growing diversity of applications together with commercial, telecommunications, transports, aerospace, navy, and the non-stop demand for smaller, lighter, and extra high power supplies have forc ed to draw attention towards high frequency isolated, three-phase DC–DC converter. Power applications are found mostly with low output voltage around 9V to 10V .and power level found to be 750W.A power conditioning system for such applications generally consists of a dc-dc converter and a dc-ac inverter, and the dc-dc converter for low-voltage, high-power must deal with a high voltage step-up conversion ratio and high input currents. Although many dc-dc converters have been proposed, most deal with high input voltage systems that focus on step-down applications, and such dc-dc converters are not suitable for low-voltage, high-power applications. Multiphase isolated dc-dc converters offer several advantages that are very desirable in low-voltage, high-power applications. First, a multiphase is constructed with paralleled phases, which increase power rating and current handling capability for high input current. Second, an interleaving control scheme produces a high operating frequency with a low switching frequency, and the high operating frequency reduces size of passive components. Thirdly, use of a transformer provides electrical isolation and a high conversion ratio. Lastly, several multiphase converters are capable of soft-switching operation, which increases converter efficiency. Keywords: Three phase inverter rectifier high frequency transformer isolated dc-dc converter Pulse with modulation and symmetrical and asymmetrical technique.