Auxillary Power Unit

The primary challenge for hybrid vehicle designers is the auxillary power unit, or A.P.U. In order to avoid adding too much weight to the vehicle platform, the A.P.U. must be as compact and powerful as possible.

In the case of the Triton, a power level of at least 24 kilowatts is called for. Conventional, off the shelf generation units in this power range generally weigh in at over 300 pounds and take up at least 4 cubic feet of space. These parameters are not workable within the confines of
the Triton’s platform, and so it becomes neccesary to design and construct a special application auxillary power plant, with small size, ( less than 2 cubic feet ) low weight, ( below 150 pounds ) and high power to weight ratio. A carefull review of all the available options, optimized for availability, reliability, conventional fuel use, economical cost, smooth, low vibration operation, and high power to weight ratio, yields only one choice; rotary power plants.

Wankel Rotary of Germany has designed and made available one of the finest motors of this type for specialized aviation use, with aluminum construction, fuel injection, and electronic engine management. Although currently priced at a level that is impractical for anything other than prototype research and development, there is reason to hope that future trends in vehicle design will utilize rotary power plants on a scale that will allow substantial cost reductions from greater production volumes.
The generation end of the Triton A.P.U. is also sourced from aircraft application equipment; A 27 kilowatt 3-phase self-exciting alternator, capable of delivering over 100 amps into a 200 volt load, is coupled to the Wankel motor. This U.S. Navy surplus unit weighs in at under 50 pounds, and has a minor diam. of just 7 inches.

The 400 cycle output of the alternator is rectified to 200 volt d.c. and the current is fed directly to the main electrical buss of the vehicle’s propulsion system. The complete and totally self-contained A.P.U. module weighs just 125 pounds, and measures 12x10x30 inches long. Future A.P.U. modules that will be constructed for testing will include fuel cells, advanced battery/super-capacitor combinations, and micro-turbines.

The basic Wankel motor option has much to recommend it, and Wankel Rotary is currently developing alternate-fuel versions that will operate on kerosene, alcohol, and heavy-base hydrocarbons such as cooking oil and diesel, which will greatly enhance their utility and effectiveness.

Trident H.E.V., Ltd., is committed to developing the lowest polluting, highest efficiency A.P.U.possible within the envelope of cost-effective design.