New Control Seheme for AC-DC-AC Converters without DC Link Electrolytic Capacitor

직류링크 전해커패시터 없는 AC-DC-AC 컨버터 재어에 관한 연구

In this paper, a novel concept for a static three-phase to three-phase power converter for an AC drive with a unity power factor and reduced harmonics on the utility line is presented. The power circuit consists of two back-to-back connected six-pulse bridges having only a $\mu$F ceramic capacitor in the DC link. By controlling the active kpower balance between two bridges, the DC link voltage can be maintained within 20V deviation from the nominal value with the small ceramic capacitors regardless of the load variation even in the unbalanced source condition.