A GaN-based modular multilevel DC-DC converter for high-density anode discharge power modules

This paper proposes a DC-DC Modular Multilevel Converter (MMC) as an alternative to traditional isolated and non-isolated converter topologies for the purpose of achieving high voltage and power density in Anode Discharge Power Modules (ADPMs) for Solar Electric Propulsion (SEP) systems. The paper presents the background for the use of GaN HFETs in multilevel topologies at high frequency and makes the case for GaN HFETs in spacecraft power systems. It then presents an analytical model, simulation results, and initial hardware evaluation of the proposed topology. The result is a 2 kW converter system operating at 600 V output at a power density of 110 W/in
³
, achieving 83% full load efficiency at 1 MHz. The proposed topology is scalable to higher voltage and power ratings.