In this article, ePropelled explains what a hybrid UAV is, how it works, and the benefits it can offer for manufacturers and end users.
A variety of options among UAV power systems allows for more choices based on different mission parameters. UAVs can be either fully electric, powered by Internal Combustion Engines (ICEs), or operate in hybrid mode, where the UAV power system works with the ICE to provide electrical power to the aircraft when necessary.
The hybrid mode offers UAV designers the option of optimizing engine size while using the battery for range extension, emergency landing, or power assist on takeoff. As a result, a smaller engine will work in situations that demand high power and the range of the aircraft can be extended thanks to the option of using battery power.
This mode relies on electric support and, as a side note, it’s important to remember that batteries need to be versatile to offer reliable power in fully electric or hybrid applications. They shouldn’t simply store energy, but also release it efficiently, enable onboard charging, and be dependable in hybrid mode. Batteries need to enable all types of missions and fulfill multiple parameters.
What Can a Hybrid Offer?
A starter generator in an ICE machine can be changed from power-generation mode to power-assist mode, enabling it to draw power from the battery and use it for propulsion, thereby supplementing the engine. Starter generators can act like range extenders, powering the propulsion motors during maneuvers. They can also switch to generator mode, extracting power from the ICE to charge batteries and flight instruments. The quality of such range extension depends on the power conversion rate (the energy from fuel converted to electric power with minimum losses).
Hybrids use propulsion motors that rely on battery power during maneuvers and forward flight, utilizing the pusher propeller that is fitted to the main ICE which, in turn, uses oil to power it. Using range extenders eliminates the need to carry an additional power source, since they can extract power from ICE directly.
A mode of operation that combines an internal combustion engine with electric propulsion and onboard power generation fulfills differing power requirements for takeoff and steady flight. Usually, such differing requirements cause the engine not to be very fuel efficient.
Is It Worth It?
Hybrid mode operations of a UAV power system work with internal combustion engines to provide electrical power to the aircraft. It allows for a smaller engine in situations that demand high power (such as takeoff) or to extend the range of the aircraft using battery power.
The right hybrid solutions can keep weight and cost down while extending flight time and allowing the aircraft to be self-contained when starting the engine.
For example, an ePropelled hybrid mode combines:
- An existing combustion engine
- Our combined stater generator and propulsion motor
- Our intelligent air motor controller with a built-in electronic engine starter
- Our intelligent power system (PMU)
These modular components can be mixed and matched to supply from 500 watts to 12 kW of power.