Design of a Cable System for a High-Power Density MVDC Aircraft Electric Power System

Electric power systems (EPS) for the future generation of electrified aircraft such as more electric aircraft (MEA) and all electric aircraft (AEA) are required to be high power delivery and low system mass. Due to the limited heat transfer by convection at the cruising altitude of a wide-body aircraft, designing cables for high power delivery and low system mass electric power systems (EPSs) based on typical standards e.g., IEC 60502 faces challenges such as thermal limits of the typical insulation systems. To design a low system mass cable system, aluminum should be used as the conductor and the overall diameter of the cable should be decreased. The former increases the joule losses of the cable, and the latter reduces heat transfer by radiation and convection, both resulting in exceeding the cable's maximum permissible temperature. In this paper, a multi-layer insulation system for a +/- 5 kV cable is designed for aircraft applications. The designed multi-layer insulation system experiences higher thermal conductivity and contains hightemperature materials such as AlN, PI, and PFA to compensate for the overall heat transfer reduction caused by decreasing the cable's overall diameter. The designed multi-layer cable has a smaller thickness and a lower mass compared to insulation systems designed based on IEC 60502 standard. To determine the electric field and temperature field distributions across the designed insulation system a coupled study in COMSOL Multiphysics has been conducted. The main purpose of this study is to compare the designed multi-layer cable system's overall diameter and mass to the cables designed based on IEC 60502 standard. Moreover, the obtained electric field distribution across the designed insulation shows that the designed insulation system is electrically safe.