Harmonic comparison of two existing modulation strategies applicable to a multi-level cascaded H-bridge converter

This paper outlines a comparison between two traditional modulation strategies according to some indicators and figures of merit. The paper highlights the harmonic performance benefits of Average Value Modulation (AVM), which is a scheme that produces the same output voltage waveforms as level shifted modulation. The comparison was carried out using a well-established model and an ABB/FACTS simulation Tool. Experimental verifications will be the subject of a later paper. The comparative analysis shows that “AVM” improves the harmonic content in the range of low frequencies by a small increase of the harmonic content in the high frequency range. The high-frequency electromagnetic interference can be reduced by filtering high frequencies at a lower cost.