Interleave-Modes on a DC-DC Converter Using Three-Phase Transformer with Zero-Phase Current

In this paper, interleave operation modes of a high frequency isolation circuit using zero-phase current of a three-phase transformer is studied. In the proposed circuit scheme, the amount of power transmission between the primary and secondary bus bars is controlled by the phase difference between the voltages output by the primary and secondary circuits. The proposed circuit system also controls the voltage ratio between the primary power supply and the primary bus bar voltage by the duty ratio output by the primary side. By adjusting the primary bus bar voltage, the proposed circuit method can regulate the amount of current flowing through the three-phase transformer, and can both superimpose the current to achieve soft switching and suppress the conduction loss. In this paper, the interleave operation modes of the proposed circuit system is analyzed to clarify the conditions for achieving soft switching. In this paper, the conditions for achieving soft-switching in the interleave operation modes are investigated and the operation is verified by simulation. The proposed circuit has a wide soft-switching area especially in the low power range, and it can be effectively used in the demand and supply adjustment applications where small charge and discharge operations are frequently required.