Tethered drones for unlimited flight time

Technological developments in tethered UAVs have opened up new possibilities for border patrols, live streaming events, temporary communication towers, low-altitude satellite surveillance, and much more. Many more applications are on their way, where there is a need for unlimited flight time and reliability, with the flexibility to detach the tether for range when needed. This article shows how power delivery networks (PDNs) using Vicor high-performance, high-density power modules enable greater performance and functionality of tethered drones.

One of the major challenges for a tethered drone is the physical design of the tether cable. It must be capable of delivering power to the rotor drive motors, control electronics, and on-board battery, while also being strong enough to secure the drone and light enough to avoid being a safety concern when the tether is detached for free flight. A light cable also reduces the load on the drone, resulting in greater efficiency and longer flight times.

The proper design of a power delivery network overcomes the opposing requirements of a thinner, lighter cable for safety, and a thicker, heavier cable for transmitting power. Architecting a PDN to deliver a high voltage (e.g., 800V_DC) over the cable significantly reduces transmission losses, enabling the use of a thinner cable, as well as allowing for longer cables to increase UAV performance. High-density Vicor power modules on the drone itself convert the high voltage to lower voltages used by the drone’s motors and electronics. The light weight and small size of Vicor modules allow that conserved payload space to be used to increase drone functionality.

The combination of a lighter tether cable and lighter, space efficient power electronics are enabling UAVs to have unlimited flight time.