SiC-Based Bidirectional Multilevel High-Voltage Gain Switched-Capacitor Resonant Converter with Improved Efficiency

This paper presents the research results of the bidirectional multilevel resonant switched capacitor converter (MRSCC). The converter can achieve a high voltage ratio in multilevel topology, which limits the voltage stress on switches and is able to operate with high power efficiency. The converter can be applied as an interconnector between DC voltage systems used for various applications. This paper presents a method that significantly improves the efficiency of the MSRCC through topology modification. Furthermore, the feasibility of the converter was demonstrated with the use of SiC and Si MOSFET switches, together with suitable passive components. It was demonstrated that the proposed modification of the topology makes the converter very efficient in SiC-based ones and can significantly improve the efficiency of Si MOSFET converters. The series of test results of the SiC-based converter is a novel aspect presented in this paper and shows promising achievements of efficiency. The results were obtained from the laboratory setup of 5 kW and 0.5/2 kV MRSCC. To demonstrate the bidirectional operation of the converter, a back-to-back setup (0.5/2/0.5 kV) was used. It also demonstrates that such a high-voltage gain converter can be accurately tested with the use of laboratory equipment with a typical voltage range.