A Megawatt-Range Electric Converter for Advanced Hybrid Aircraft

In the field of "green" aviation, various concepts of the electrical part of hybrid propulsion systems for aircraft are currently developed in order to achieve their maximum possible specific parameters. The article analyzes modern approaches to the development of high-capacity (over 1 MW) electric power converters as part of a hybrid aircraft propulsion system. The topologies used in high-capacity converters and electronic components available in the market are reviewed. In order to achieve maximum specific parameters, the choice is made in favor of the converter structure comprising several parallel-operating modules with a two-level topology based on silicon carbide field-effect transistor assemblies. A methodology for calculating losses in the assemblies of power transistors and determining their temperature operating conditions is proposed. The approaches to the selection of capacitor capacitance and the converter pulse-width modulation frequency were compared. The criterion for selecting the components and converter operation mode was the optimum combination of the efficiency, transistor temperature operating conditions and converter specific power. Based on the numerical analysis results, the optimum design versions have been elaborated for a 1500 kW converter consisting of three and four modules operating in parallel and fed from separate generator windings.