Control of MW-Scale High-Frequency “SiC+Si” Multilevel ANPC Inverter in Pump-Back Test for Aircraft Hybrid-Electric Propulsion Applications

High-power-density high-speed electric motors for aircraft hybrid-electric propulsion (HEP) applications require high fundamental output frequency from power inverters. Conventional silicon (Si)-based megawatt (MW)-scale power inverters typically have low switching frequency that is not sufficient to meet the dynamic and harmonic requirements for such applications. An MW-scale medium-voltage three-level active neutral-point-clamped (ANPC) inverter based on a hybrid utilization of silicon carbide (SiC) and Si power devices (i.e., “SiC+Si”) has been developed for high-speed HEP drive applications, which has a rated output frequency of 1.4 kHz at 1-MW active power. To evaluate the power capability and efficiency of this ANPC inverter in the laboratory, power pump-back tests need to be carried out. In this article, control methods for single- and three-phase inverter pump-back tests have been developed to evaluate the performance of such high-frequency propulsion drives. The implementation and experimental results are presented to verify the efficacy of the control methods and the performance of the MW-scale “SiC+Si” ANPC inverters.