BlueSky Mobile Power 6kW Hybrid Generator System

The BlueSky Mobile Power 6 kW Hybrid Auxiliary Power Unit, or HAPU, is a compact hybrid power system designed for demanding Defence, vehicle and field operations. Combining the BMP 478 tactical diesel engine with an axial flux motor and variable speed hybrid technology, the system provides efficient DC power in a mobile configuration built for modern operational environments.

The HAPU delivers 5 kW of rated continuous output with up to 6.5 kW available in Battle Mode. With a standard 28 VDC output, maximum current of 250 A and compatibility with a range of battery systems and inverters, it provides a flexible power platform for mobile and integrated applications.

Key benefits

• Hybrid power technology: Combines a tactical diesel engine with an axial flux motor and variable speed operation.
• High power output: Provides 5 kW rated continuous output with up to 6.5 kW peak output in Battle Mode.
• High current capability: Delivers up to 250 A at 28 VDC.
• Flexible voltage configuration: Standard 24 and 28 VDC configuration with a programmable 12 to 150 VDC range and custom 48 V and higher configurations available.
• Reduced fuel consumption: Variable speed operation can provide up to 50% fuel savings at part load compared with fixed speed generators.
• Low acoustic signature: Published aural signature of 65 dB at 40% load from 8 metres.
• Battery compatibility: Supports lead acid and lithium ion battery chemistries.
• Inverter compatibility: Compatible with various commercial off the shelf and MIL STD inverter systems.
• Multi fuel operation: Approved for Diesel #1, Diesel #2, JP8 and F24.
• Variable speed operation: Eliminates wet stacking associated with conventional fixed speed diesel operation.

Typical applications

• Defence vehicle auxiliary power requirements.
• Mobile and expeditionary power generation.
• Field systems requiring high current 28 VDC power.
• Hybrid power and battery charging configurations.
• Applications using commercial or MIL STD inverter systems.
• Operational environments where fuel efficiency, mobility and reduced acoustic output are important.

Hybrid power technology

The BlueSky HAPU combines the BMP 478 diesel engine with a co developed axial flux motor and variable speed hybrid technology. Unlike a conventional fixed speed generator, the engine can operate according to power demand rather than remaining at a constant operating speed.

This variable speed approach supports improved efficiency during part load operation, with published fuel savings of up to 50% compared with fixed speed generators. It also eliminates wet stacking while allowing the system to support both direct electrical loads and compatible energy storage systems.

Power output

• Rated continuous output: 5 kW
• Peak output: 6.5 kW in Battle Mode
• Standard DC voltage: 28 VDC
• Programmable voltage range: 12 to 150 VDC
• Maximum output current: 250 A
• Standard configuration: 24 and 28 VDC, 12 to 32 V
• Custom configurations: 48 V and higher available
• AC compatibility: Various commercial off the shelf and MIL STD inverters
• Energy storage compatibility: Lead acid and lithium ion battery chemistries
• Power limiting: Standard voltage droop method

BMP 478 tactical diesel engine

At the centre of the HAPU is the BlueSky BMP 478, a compact two cylinder naturally aspirated diesel engine designed to support mobile power generation applications.

The engine uses electronic common rail direct injection with multi shot combustion to reduce noise and vibration. Liquid cooling, pressurised lubrication and hydraulic lifters support operation in demanding mobile environments while reducing routine adjustment requirements.

• Engine model: BMP 478
• Configuration: 2 cylinder, naturally aspirated
• Displacement: 478 cc
• Bore × stroke: 69 × 64 mm
• Compression ratio: 20:1
• Maximum engine power: 8.5 kW
• Peak torque: 28.5 Nm
• Fuel injection: Electronic common rail direct injection
• Maximum speed: 3,600 rpm standard and 4,000 rpm over run
• Cooling system: Liquid cooled
• Lubrication: Pressurised oil system supporting operation at up to 15° inclination in any direction
• Valve train: Hydraulic lifters with no adjustment required
• Minimum BSFC: 245 g/kWh

Fuel performance

The variable speed powertrain allows the engine to adapt its operating speed to demand, helping reduce fuel use when the system is operating below maximum output.

• Approved fuels: Diesel #1, Diesel #2, JP8 and F24
• Fuel consumption at idle: 0.33 L/h
• Fuel consumption at 1.5 kW: 0.69 L/h
• Fuel consumption at 3.0 kW: 1.14 L/h
• Fuel consumption at 4.5 kW: 1.71 L/h
• Fuel consumption at 6.0 kW: 2.35 L/h
• Part load fuel savings: Up to 50% compared with fixed speed generators
• Wet stacking: Eliminated through variable speed operation

Published fuel consumption figures are rated using JP8.

System performance

• System weight: 165.6 kg wet
• Peak DC output: 6.5 kW
• Maximum current: 250 A at 28 VDC
• Aural signature: 65 dB at 40% load from 8 m
• Elevation derating: 1% for every 100 m elevation
• Temperature derating: 2% for every 5 °C above 25 °C

Technical highlights

• Product: BlueSky Mobile Power Hybrid Auxiliary Power Unit
• Technology: Variable speed diesel hybrid power
• Engine: BMP 478 tactical diesel engine
• Rated continuous output: 5 kW
• Peak output: 6.5 kW
• Standard voltage: 28 VDC
• Maximum current: 250 A
• System weight: 165.6 kg wet
• Fuel compatibility: Diesel #1, Diesel #2, JP8 and F24
• Battery compatibility: Lead acid and lithium ion
• Voltage capability: Programmable from 12 to 150 VDC
• Part load fuel savings: Up to 50% compared with fixed speed generators
• Aural signature: 65 dB at 40% load from 8 m

Why choose the BlueSky HAPU

• Power for mobile operations: Compact hybrid generation supports vehicle mounted and field power requirements.
• Flexible electrical integration: Wide voltage capability, high current output and compatibility with batteries and inverter systems allow the HAPU to support different power architectures.
• Improved part load efficiency: Variable speed operation reduces unnecessary engine speed when full output is not required.
• Operational fuel flexibility: Compatibility with Diesel #1, Diesel #2, JP8 and F24 supports a range of operational fuel arrangements.
• Hybrid system compatibility: Support for lead acid and lithium ion batteries allows integration with energy storage systems.
• Built for demanding environments: The BMP 478 combines liquid cooling, pressurised lubrication and a compact tactical diesel configuration for mobile applications.

The BlueSky Mobile Power HAPU provides compact, flexible hybrid power for demanding Defence and field operations. Talk to J3Seven about integrating the BlueSky HAPU into your mobile power requirements.