An appropriations bill passed by Congress before the holidays and now awaiting the President’s signature contains a $2.1-million provision for the development of Hybrid-Electric Military Vehicles, including Integrated Starter Alternator research and development according to Raser Technologies, a developer of advanced electric motors and a founding member of the Plug-In Hybrid Development Consortium (earlier post).
(This bill—the Support Our Scouts Act H.R. 2863—is a different bill than the large defense appropriations bill H.R. 1815 (earlier post), and also contains an agglomeration of various projects seemingly unrelated to direct military spending.)
Although the language of the bill does not specify the HEV program, Raser, which was active in developing integrated starter alternator designs for the US Military for potential use in Future Combat System vehicles including a hybrid Humvee, says that the funding for the HEV program, which comes out of a R & D appropriations section, will be administered by the Department of Defense.
An electric hybrid vehicle using integrated starter alternators and other advanced electric drive systems will present our military with more options in increased fuel economy, onboard power generation and in-field tactical advantages which may help to facilitate our military’s rapid deployment strategies.
Congress acknowledged the need and the potential for incorporating new hybrid vehicle technologies in their truck fleet to help the military in terms of economy of operation, rapid deployment, stealth tactics on the ground and promoting the safety of our troops.—Brent Cook, Raser CEO
Raser, founded in 2003, is an R&D company developing advanced electric motors based on its proprietary Symetron technology; Raser’s business plan calls for it then to license its technology to manufacturers.
Symetron is an umbrella label for several Raser innovations in motors and controllers that increase power, torque and efficiency. The company recently received its third Notice of Allowance from the Patent Office, a milestone prior to the actual issuing of a patent.
Put another way, the Symetron technology, which can be applied in a range of packages, AC or DC, can deliver the high torque of a permanent magnet motor without the use of permanent magnets—in essence, enabling the production of smaller, more powerful and less expensive motors.
There are two major design attributes of the Symetron motors contributing to their capability: full flux density at high rpm, and a 90º torque angle.
The Raser motor differs from a brushless DC motor in one major way: the usual permanent magnet rotor is replaced with an electromagnetic wound rotor. According to Raser, even with the most advanced permanent magnet neodymium super magnet materials, the flux density within the brushless DC motor is only half the flux capacity of iron. By contrast, Raser claims that its motor delivers near saturation flux capacity, effectively doubling iron utilization.
Maximizing flux density in the motor allows doubling of torque per unit of heat generation relative to a brushless DC motor. In other words, torque may be produced with less than a fourth of the energy losses. Power density is over twice as great for a given heat dissipation with a corresponding increase in motor efficiency.
The Symetron motor always operates efficiently at the ideal 90º torque angle yielding a three-fold boost in torque density (torque per pound of motor weight) over AC induction motors operating at a torque angle of 160º to 170º degrees, according to the company.
Raser sees four major benefits to its system:
Downsizing. For a comparable power output, drive systems can be smaller in size and lighter in weight.
High torque for vehicle launch assist. This makes Symetron motors good candidates for hybrid vehicle applications.
Production cost. Standard components and simplicity of design should result in costs equal to or less than current motors and controllers for a given output.
Energy savings and range extension.
|Raser Symetron vs. Toshiba Prius Motor|
|Parameter||Toshiba PM||Raser P-180|
|Peak torque||400 Nm||590 Nm|
|Continuous torque||186 Nm||188 Nm|
|Peak power||50kW @1250 rpm||77kW @1250 rpm|
|Efficiency||87.5% @1250 rpm||88% @1250 rpm|
|Torque density||24.3 Nm/liter||35.8 Nm/liter|
As a demonstration, Raser earlier this year dropped a small 147-pound pancake AC induction motor into a Formula Lightning race car. The motor was about the same dimensions as the electric motor in the Toyota Prius. The Raser motor, however, powered the race car on its own, delivering 569 Nm of torque.
In June, Raser and Prestolite Electric, a global manufacturer of alternators and starters for heavy-duty vehicles, signed a non-binding Letter of Intent to work together on Integrated Starter Alternators for military equipment. Under the terms of the agreement, Raser will design and develop the Integrated Starter Alternators and Prestolite manufacture them.
The ISAs are to provide acceleration support and mobile power generation. The ISAs are pancake-shaped, in-line motors, which will be sized appropriately for existing and/or future military wheeled vehicles. In addition, under the agreement, Raser and Prestolite will collaborate in a commercial truck ISA development program. Prestolite intends to market commercial ISAs to the medium- and heavy- truck markets under license from Raser.
In October, Raser signed a Cooperative Research and Development Agreement (CRADA) with the U.S. Army’s National Automotive Center (TAC) and their Tank Automotive Research Development and Engineering Center (TARDEC) to explore common interests in ground vehicle applications of the components, designs, and technology associated with high performance electro-magnetic equipment, especially in hybrid electric vehicle uses.
As part of the CRADA, TARDEC and Raser will investigate the possibility of using an ISA in military vehicles, using Raser’s motor technology as an ISA in the Humvee, and using Raser’s motor and controller technology in non-ISA applications in military vehicles. Under the Agreement, the parties will share engine/vehicle design specifications for multiple vehicles, and document testing/performance parameters of the motors, controllers and ISAs.
|Prototype Symetron Integrated Starter Alternators (ISA)|
|Parameter||AC ISA—Humvee||AC ISA—Future Tactical Truck|
|Modeling and simulation, assumes engine supports ISA|
|Size||35.6 cm x 12.7 cm||50.8 cm x 20.3 cm|
|Weight||50.8 kg||160 kg|
|Peak Torque||512 Nm @1000 rpm (431 @3000 rpm)||1,020 Nm @1000 rpm (796 @3000 rpm)|
|Peak Power||136 kW @3000 rpm||250 kW @3000 rpm|
|Continuous Power||32 kW @1000 rpm (generating)||77 kW @1000 rpm (generating)|
|Efficiency||93.5% @3000 rpm||94.9% @3000 rpm|
|Power Density||10.8 kW/liter @3000 rpm (peak)||6.1 kW/liter @3000 rpm (peak)|
|Torque Density||40.5 Nm/liter @1000 rpm (peak)||24.8 Nm/liter @1000 rpm (peak)|
H.R. 2863 Support Our Scouts Bill
US Patent Application 20050073281, Electromagnetic motor