특정 고조파 제거를 위한 Cascaded H-bridge 7레벨 인버터의 특성해석 및 시뮬레이션

Analysis and simulation of Cascaded H-bridge 7 level inverter for eliminating typical harmonic waveforms

  This paper is presented the analysis results and simulation results of cascaded H-bridge 7 level inverter with various modulation index. Stepped waveform having N number of switching was used to eliminate N-1 harmonic components. Switching angles according to modulation index are calculated numerically. Therefore, 3 times of switching - General in 7 level topology - in QWS(Quarter Wave Symmetry) could eliminate 5th and 7th harmonics. The Harmonic characteristics are compared to those of space vector modulation method which known as common modulation method in industrial field. Stepped waveform method showed higher ability to reduce, especially lower order of harmonics.