Performance evaluation of a simple and general space vector pulse-width modulation-based M-level inverter including over-modulation operation

This study presents a simple and a generalised space vector pulse-width modulation scheme for a neutral point clamped multi-level inverter as well as cascaded inverter of any level. This modulation algorithm implements the online generation of desired switching states and their sequences through generalised expressions without any predetermined stored data in a memory look-up table. The proposed algorithm also incorporates the concept of reference vector and on-time modification combined during the over-modulation region for any level of inverter. Performance of the proposed modulation algorithm is tested experimentally through a digital signal processor-based controller for a five-level cascaded inverter with very low execution time that does not depend much on the level of inverter. The simulation waveform and the harmonic analysis of the voltage at different modulation index are presented and these are verified with the experimental results.