Operation and efficiency analysis of a five-level single-phase hybrid Si/SiC active neutral point clamped converter

The ability to improve both the size and efficiency of multilevel single-phase converters is a key to uplift them as an attractive solution for industries, while the high number of switches and complex modulation techniques understandably make them unattractive. Five-level active neutral point clamped (ANPC) converter, due to its inherent advantages such as employing different switching frequencies and using different switch technologies, presents an ideal candidate for study. This article performs a comprehensive analysis of the converter to highlight the advantages of it. This analysis results in a modified hybrid modulation that effectively regulates the neutral point (NP) of the dc link. Consequently, the combination of the topology and the modified modulation make the converter ideal to utilize two different switch technologies - in this article, silicon carbide (SiC) and Si MOSFET. To evaluate the analysis and the effectiveness of modulation, a 2-kW hybrid five-level ANPC is built. The converter current behavior is analyzed to determine the power loss in the filter and switches. The efficiency measurement is performed and compared with the calculated efficiency. There is a close coherency between the measurement and the calculated results and a peak efficiency of 98.4% is achieved.