ZVS PWM昇圧チョッパ・ZVSフルブリッジDC-DCコンバータ構成の2ステージ電力変換システム

抄録

The high-frequency isolated power supply with low-voltage large-current output and widely fluctuating input voltage is discussed in this paper. It is described that it is difficult to achieve high efficiency of the power supply with ZVS phase-shift PWM controlled DC-DC power converter mainly due to high conduction power losses in the rectifier stage. The 2-stage DC-DC converter system configuration, which consists of boost ZVS-PWM DC-DC chopper and ZVS full-bridge high-frequency isolated DC-DC converter operating with maximum duty cycle, is presented. An ability to improve efficiency of the power conversion by using 2 stages DC-DC circuit configuration is discussed. 900W-100kHz DC-DC conversion system prototypes were built and tested. An efficiency comparison between full-bridge ZVS phase-shift PWM DC-DC power converter and 2-stage soft-switching DC-DC converter has been made. It is proved that using 2-stage DC-DC converter can improve efficiency under full load.