摘要 |
<p>A harmonic blocking converter system (12) for converting power between an AC source (13) and a DC source (14) includes a harmonic blocking transformer (30) and a converter (15) which generates undesirable harmonic currents including fifth and seventh harmonic components. The harmonic blocking transformer (30) includes a polyphase main transformer (32) and a harmonic blocker (80) coupled with wye and delta secondary windings (52, 54) of the main transformer (32), so as to substantially block passage of the fifth and seventh harmonic currents to the AC source (13). A waveform enhancer (100), having plural center-tapped interphase transformers (110), or having plural interphase transformers (152, 154, 156) arranged in multiple parallel phase legs (150), may couple the harmonic blocking transformer with the converter. The converter may be constructed for 2-level operation, or, with the addition of auxiliary diodes (230, 232), for 3-level operation. Such a harmonic blocking transformer (30) and a method of blocking undesirable harmonic currents are also provided.</p> |