NWUAV designs custom all-electric propulsion systems & hybrid ICE/Electric propulsion systems for variety of Unmanned Aircraft and Ground Robotic Systems.
- NWUAV designs Electric Propulsion Systems utilizing significant expertise gained designing and manufacturing UAV Power Generation Systems.
- NWUAV is currently developing a Variable Pitch Propeller System for an Army all-electric aircraft. This system is part of the Hybrid Propulsion System developed for Air Force Research Labs.
- NWUAV develops complete Electric Propulsion Systems from Design & Development, and transitioning to High-Volume Production.
Electric Motor selection includes:
- industry research into the current state of the art
- a vetting process based upon those findings and pragmatic analysis
- lab testing when appropriate to provide efficiency
- durability metrics as a final guide.
After an electric motor design is selected, development proceeds for a Generator Control Unit (GCU).
The AC output of the alternator shall may be rectified by the AC-DC rectifier module. The output of this module shall may be unregulated DC; the DC voltage can increase and decrease as a function of the alternator RPM. The circuitry for this module is designed by NWUAV.
The unregulated DC output of the AC-DC rectifier may be regulated by the DC-DC converter to produce a stable DC voltage. The regulated DC voltage can be used to drive a DC-to-AC inverter that produces AC voltage at 60Hz. And can also charge a battery or super-capacitor (super-cap) for a generator application. DC-DC converter is likely be a COTS module or a number of COTS modules in parallel.
The DC-to-AC inverter takes in regulated DC and produce a clean sine-wave AC voltage with minimal harmonic distortion. The suitability of various COTS inverters are investigated; if none are found that meet the requirements of power, voltage, and the MIL-STD environmental specifications, NWUAV will design in-house. An EMI filter shall likely be required to meet MIL-STDs for EMI conducted emissions.
Battery or Super-Cap
The battery or super-cap shall provide sufficient short-term capacity to meet sudden increases in electrical load. Batteries have been the traditional method of reserve power in this type of application but tend to be heavy and require periodic maintenance and replacement. Due to demands from the automotive industry for use in electric vehicle drivetrains, advancements in super-cap technology have occurred that make them viable for some applications. A super-cap can be substantially lighter than a battery with comparable storage capacity but shock-resistance and endurance to MIL-STD temperature extremes is a consideration.
The Controller/EMU is microprocessor-based and has the ability to sense the electrical load and vary the engine RPM to meet the load. It will monitor engine temperature, alternator temperature, and engine oil level to ensure that they are within safe limits. It shall also interface to the control panel. The circuitry and software for the Controller/EMU is designed by NWUAV.
Current Control Board for 1.5kW Genset for Unmanned Ground Robot Range Extender
The interface controls are designed in-house and all cable wiring harnesses are designed & built in the NWUAV Cable Harness assembly facility. For a Power Generator or Hybrid Propulsion System, the Control Panel is designed with switches and indicators that the operator shall use to control the generator and receive operational status.