A GENERAL REVIEW AND PERFORMANCE EVALUATION OF MULTI-LEVEL CONVERTERS FOR EFFICIENT POWER GENERATION AND APPLICATIONS

This paper comparatively assessed the performance status of seven different multi-level converters with respect to their output voltages, output currents and corresponding percentage total harmonic distortion under the same RL-load condition. The spectral distributions of these various multi-level converters’ waveforms obtained under normal modulation index of 0.8 are presented in this work. The significance of this paper is basically centered on the need to have an improved multi-level converter that has a better flexibility in control, which can ensure continuity in operation and can as well generate a reduced percentage harmonic distortion value under a varied modulation index. This converter will also be able to generate three level or five level output voltages depending on the point of load connection. The analysis and results obtained from this work thus showed that a five-level voltage source inverter formed by a cascade between a three-level flying capacitor and H-bridge produced a given percentage reduction in the value of harmonic distortion under the same loading condition and therefore ensures optimum performance with regard to other power converters of the same rating. http://dx.doi.org/10.4314/njt.v35i1.2