Optimal Bipolar MVDC Power Cable Designs for Future Wide-Body All Electric Aircraft

To reach the net-zero greenhouse gas (GHG) emissions goal, the electrification of transportation, as one of the main sources of GHG emissions, plays a crucial role. Transportation electrification includes the aviation industry as well. As one of the prospective initiatives to achieve net-zero emission aviation, the concept of all-electric aircraft (AEA) emerged recently. Future wide-body AEA requires high-power-density and low-system-mass electric power systems (EPS). As one of the main components of the aircraft EPS, power cables must be designed to increase the overall power density of the EPS. Due to the limited heat transfer by convection at the cruising altitudes of wide-body AEA, the design of power cables faces significant thermal challenges. These challenges are exacerbated by using bipolar MVDC EPSs, which are traditionally constituted of two power cables, negative and positive poles, next to one another. The surface area of the cable influences both radiative and convective heat transfers. Changing the shape of the cable is one technique to improve radiative heat transfer and compensate for the reduction in convective heat transfer caused by the low air pressure. For a given cross-sectional area, the cable’s surface area with the environment is improved by using a cuboid (square) geometry design and coaxial geometry with a hollow inner conductor. In this paper, the cuboid bipolar cables and coaxial cables are designed and analyzed along with conventional cylindrical bipolar cables to find out the optimal bipolar MVDC cable system for the future wide-body AEA. For comparing these designs, a parameter
J
is introduced, which quantifies the multiplication of the overall mass per unit length of the cables and their cross-sectional area. The findings indicate that among the designed cables, the cuboid bipolar cable system has shown better performance in terms of
J
than other bipolar cable systems, and if only the weight per unit length is considered then coaxial cable systems with a hollow inner conductor would be a solution for future wide-body AEA.