Operation and Efficiency Analysis of a 5-level Single-Phase Hybrid Si/SiC Active Neutral Point Clamped Converter

Abstract

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. 5-level active neutral point clamped converter, due to its inherent advantages such as employing different switching frequencies and using different switch technologies, presents an ideal candidate for study. This paper 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 paper Silicon Carbide (SiC) and Si MOSFET. To evaluate the analysis and the effectiveness of modulation, a 2kW hybrid 5-level ANPC is built. Analyzing of the behavior of the converter current, power loss in the filter and switches are, therefore, calculated. 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.