Efficient Megawatt-Scale Cable for Electric Aircraft Propulsion
Propulsion
Efficient Megawatt-Scale Cable for Electric Aircraft Propulsion (LEW-TOPS-185)
High Power Density Enabled by Integrated Active Cooling
Overview
The electrification of aircraft is constrained by the limitations of conventional cabling. Transmitting megawatt-scale power requires cables that are not only lightweight but also capable of maintaining efficiency and insulation integrity at high altitudes. Standard high-voltage cables add excessive mass and suffer from reduced dielectric performance in low-pressure environments, making them unsuitable for large-scale electrified aviation.
To overcome these challenges, innovators at NASA’s Glenn Research Center have developed a new class of lightweight, cooled high-voltage cable designed specifically for aircraft electrification. This cable is a single system that can both power and cool the motors, generators, and other power electronics of an electrified aircraft. By combining electrical and thermal functionality in one integrated solution, the technology addresses critical barriers to scaling electric propulsion in aviation.
The Technology
Distilled to its core components, the cable is composed of either a flexible or rigid transmission line with integrated oil-based cooling. Instead of solid wire, current flows through small conductive tubes made of aluminum or copper, which are actively cooled by pump-driven oil flowing through them. Although these smaller conductors have higher resistance and generate more heat, the active cooling offsets this heat generation. This integrated design results in a cable with up to a tenfold improvement in weight per megawatt of power delivered compared to existing solutions.
The use of smaller conductive cables with active cooling reduces the temperature requirements for insulation because more current can be run through the cable. As such, voltage can be reduced, mitigating partial discharge issues, and making insulation an easier engineering challenge. Due to significant weight reductions, specialized duct work is no longer needed. A collection of junction, splicing, and termination components allow the cable to be built into a power and thermal bus to service multiple electrical components.
Initial tests demonstrated the ability to conduct 1,000 amps through actively cooled cables at lower mass than state-of-the-art alternatives, confirming feasibility for next-generation aircraft electrification. However, the cable has broad applications across all vehicle electrification where weight and thermal management are high priorities and is now available for patent licensing.
Benefits
- Power-to-Weight Ratio: Delivers up to a tenfold improvement in weight per megawatt of power transmitted compared to conventional cables.
- Active Thermal Management: Enables continuous high-current operation without overheating, eliminating the need for oversized conductors or bulky passive cooling systems.
- Lower Source Voltage: Supports higher current at reduced voltage, reducing insulation requirements.
- Integrated Electric and Thermal Bus: Combines power transmission and thermal management in a single system, streamlining integration and reducing system complexity.
- Modular and Scalable Architecture: Compatible with a range of junctions, splices, and terminations, enabling flexible system design and simpler integration into distributed power architectures.
Applications
- Electric Airplanes: Powers hybrid and fully electric aircraft by delivering lightweight, cooled cabling that sustains high-current loads efficiently.
- Large Unmanned Aerial Vehicles: Supports high-endurance cargo and surveillance UAVs by minimizing weight and maintaining reliable power delivery under heavy electrical loads.
- Advanced Air Mobility: Reduces mass and heat buildup in eVTOL power systems, extending range and improving efficiency for short-range air mobility.
- Maritime: Supports compact, high-capacity power systems for ferries and naval platforms where weight and cooling are critical.
- Rail and High-Speed Trains: Provides efficient, lightweight power distribution for next-generation electrified trains with reduced losses and improved reliability.
- Electric Buses: Enables lighter, thermally managed cabling for bus fleets, improving efficiency and extending range in high-duty urban transit.
Technology Details
Propulsion
LEW-TOPS-185
LEW-20225-1
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