A 2kW, High Power-Density (100W/in(3)), GaN-Based, Modular Multilevel Converter for Variable Speed Drive Applications in DC Systems

Achieving higher power-density for shipboard power conversion systems is extremely important for reduction of space requirements for electrical systems. This paper presents a single-phase, high power density inverter (450VDC, 2kW, 25in(3)) for variable frequency drive applications. High-power density is achieved through the application of the modular multilevel converter (M2C) topology in a low voltage inverter system, which is enabled through the use of millimeter scale, GaN HEMT devices. This work presents the fundamental design, Simulink/PLECS and finite element simulations, and initial hardware development for the high-density inverter system. The design and manufacturing challenges associated with this high-density inverter design, including motor control, low frequency voltage oscillation are discussed. The design is modular with the capability of achieving higher power ratings for varying naval ship applications.