LCL Filter Design of a 50-kW 60-kHz SiC Inverter with Size and Thermal Considerations for Aerospace Applications

Abstract

To achieve high power density, increasing the switching frequency of the power converter has become a trend. The LCL filter is a major contributor of the overall weight of a high-power-density converter (HPDC), especially the inverter-side inductor, which requires to suppress higher frequency harmonic contents at the inverter side. This paper describes a comprehensive design flow of the LCL filter for a 50-kW, 60-kHz two-level silicon carbide (SiC) inverter for high-power aerospace applications with space constraint and harsh ambient temperature environment. To meet the space constraint requirement and reduce the inductor size, specific design attention is made on a customized amorphous cored inductor with a comprehensive study on the relationships of inductor weight, core width, and total surface area with respect to air gap length. To overcome the harsh ambient temperature environment, a liquid cooling system of the amorphous cored inductor is also described.