3-PHASE SELF-EXCITING POWER CONVERTER AND 3-PHASE SELF- EXCITING DC INTERLOCKING APPARATUS

摘要

PROBLEM TO BE SOLVED: To eliminate the need for a transformer and a reactor in multiplexing a converter to improve reliability and reduce conversion loss and cost. SOLUTION: This power converter connects in series (cascade-connects) a plurality of 3-level single phase bridge circuits (51, 52, 53), (54, 55, 56), (57, 58, 59) for each phase in the AC side, while supplies in the DC side the power from the independent DC power supply for each 3-level single phase bridge circuit as indicated with a capacitor. Ignition control is conducted to obtain equal output of each 3-level single phase bridge circuit of each phase and this ignition control is also performed so that the combined waveform of each phase becomes the approximated sine wave. As a result, an output of the 3-level single phase bridge circuit does not become unbalance and a multiplex transformer and reactor are no longer required.