1200U hydrogen fuel-cell power system

The Honeywell Aerospace 1200U is a hydrogen fuel-cell power system for unmanned aircraft, rated at 1200 W continuous net output. It is a complete, hybridised unit: the fuel cell, control electronics, heat exchanger and a battery with charger are supplied together, and the stack runs on gaseous hydrogen with liquid cooling.

The system is intended for multirotor and fixed-wing UAS that need longer endurance than a battery alone provides, with the fuel cell supplying cruise power and the battery covering peaks. Net output power from the fuel cell alone is 0 to 1200 W. The maximum output current with the battery is 60 A continuous and 100 A peak for one second, and the output voltage range is 18 to 84 VDC. The recommended hybrid battery is a 6S to 20S lithium polymer pack.

Efficiency is expressed as hydrogen consumption: 53 g/kWh at 400 W net and 63 g/kWh at 1300 W net, with a brake specific fuel consumption plot on the datasheet. Hydrogen must meet J2719 purity or better and be supplied at 12 to 18 psi, so the airframe needs a regulated tank and supply line sized for the mission.

Physical and environmental data guide payload planning. The system weighs 4.0 kg including heat exchanger and control and power-management electronics, but excluding the battery. Dimensions are 17.0 in x 10.5 in x 6.5 in, mounted with 8 x 8-32 UNF fasteners. Ambient temperature is 5 to 45 degrees C, humidity 0 to 100 %, and standard operating altitude 0 to 15,000 ft, with power de-rating starting at 5,000 ft and reaching a maximum of 10 % at 15,000 ft.

For integration, power leaves through non-sparking XT-90 connectors and the communication interface is RS-422, with CAN bus as an option. The controller is therefore addressed from the flight controller or ground software over a serial link, and the power bus connects directly to the aircraft battery bus.

Durability figures are 3,000 hours before stack replacement and an overhaul interval of 1,000 hours for balance-of-plant inspection and maintenance. Typical applications are long-endurance inspection, mapping, surveillance and cargo UAS in the sub-kilowatt power class.