DC/DC POWER CONVERTING APPARATUS

摘要

Three or more circuits (A1-A4), in which series-connected low-voltage and high-voltage side switches made of MOSFETs having parasitic diodes are connected across positive and negative terminals of each of smoothing capacitors (Cs1-Cs4), are connected in series. One of elementary series circuits, each including a capacitor (Cr) and an inductor (Lr), is disposed between any adjacent two of the circuits with the elementary series circuits set to have the same period of resonance. The MOSFETs of rectifier circuits (A2-A4) are brought into an ON state simultaneously with the MOSFETs of a driving inverter circuit (A1) and brought into an OFF state earlier than the MOSFETs of the driving inverter circuit (A1) by a period of time not exceeding a time period (t) equal to (period of resonance)/2. With this arrangement, a resonance phenomenon of the capacitor (Cr) and the inductor (Lr) is used and conduction loss in the rectifier circuits (A2-A4) is reduced in DC/DC power conversion performed through charging and discharging operation of the capacitor (Cr).