Output Waveform Improvement of Double-Connected 3-Phase Voltage Source Inverter by Single-Phase Inverter

단상 인버터의 동작에 의한 이중접속 3상 전압원 인버터의 출력파형 개선

This paper proposes a new double-connected 3-phase voltage source inverter with improved output voltage waveform. An auxiliary single-phase inverter injects a ripple voltage into the double- connected inverter to convert 12-step operation to 36-step operation. The KVA rating of the output phase-shifting transformer is reduced by employing a harmonic canceling reactor. The whole rectifier-inverter system including the proposed technique is introduced and the experimental results are provided.