A Concept of Multi-Level Converter Building Modules to Realize Higher Number of Output Levels

Multi-level converters can essentially reduce the harmonics and EMI. To realize extremely high quality output and low EMI, the number of output levels should be high. However, as the number of levels increases, the number of components also increases and implementation will be difficult significantly. Thus, flexible building platform of the multi-level converters suitable for the higher number of the output levels should be developed. In this paper, a concept of Multi-Level converter Building Modules (MLBM) is proposed to realize the multi-level converters with a higher number of output levels systematically. A prototype of the MLBM is constructed as a 5-level flying capacitor converter with extendable configuration. It is verified experimentally that single-phase and three-phase converters with 5-17 output levels are realized by various combinations of the six MLBMs. From these results, possibility of implementation of multi-level converters with further number of output levels with proposed MLBM is shown.