Subject: Re: Alternative Fuels?

From: Jordan Wilkerson <[email-masked]>
Date: Thu, 13 Apr 1995 20:39:08 GMT

>       My biggest question is about the actual advantage of a hybrid
> powered vehicle.  It seems that each power system reduces the advantages
> of the other.  For example, each system has to haul around the weight of
> the one that is not being used.  Is the idea that people would use electric
> only most of the time and use the ICE only for occasional long trips?
>
>                               Kevin Riley
There are two configurations of hybrid vehicles:  Series and Parallel

A Series system is basically an electric vehicle with a motor/generator
set used as a range extension.  The simplest is very inefficient...

the liquid fuel must be converted into mechanical energy, then
electrical, then Chemical for battery storage.  Furthermore, it must be
converted back to electrical and mechanical to the drive wheels.

Our System is a Parallel Hybrid.  The best description of our application
of the hybrid drivetrain is a "Power Assist" Hybrid.  By literal
definition, this means one of the hybrid drive components will assist the
power of the other.  The previously described series system is an energy
assist, if you will, since the motor/generator supplies the extra energy
to extend the range of the vehicle.

The Series hybrid is an electric vehicle, foremost.  The electric motor
must propel the vehicle at all times.  Our parallel system has the
electric motor and the ICE mechanically in parallel, and either could
drive the transmission.

So here is how the drivetrain interacts

        Our Geo metro ICE is configured to drive the transmission at all
times, but is certainly under-powered for the over-all vehicle
requirements.  Any time that little engine can't perform the way the
driver wants (hill climbing and fast accelerations) the electric motor
kicks in and provides the extra requested power (power assist).  Any time
the driver is not requesting this extra power, the motor is used as a
generator to recharge the batteries.

        The electric motor and ICE are coupled upstream of the
transmission, Subaru ECVT.  The ECVT allows the engine to run at an
optimum RPM.   This helps reduce the number of transients which produce
the most emissions and usually consume the largest fuel rate.

        This allows us to "Load level" the ICE to optimize its overall
performance.  Since it is the most inefficient part of the drivetrain,
any time you can double its overall efficiency, the entire drivetrain
efficiency is nearly doubled.  By allowing the engine to operate most of
the time at its optimum RPM under a set load, (lowest bsfc point) we
maximize the fuel economy.

        The ECVT maintains the RPMs of the ICE, but the electric motor
maintains the load.  If the engine has too much load to be efficient,
the electric motor will add power to the drivetrain which reduces the
load on the ICE.  Likewise, if the ICE doesn't have have enough load
to be efficient, the electric motor will act as a generator to increase
the load on the ICE while storing that energy in the batteries.

        The individual systems can power the vehicle by themselves;
however, neither will give the performance or the efficiency that is
desired.  A parallel hybrid is designed to run in a hybrid mode all of the
time.  The components work together to optimize the entire system as a whole.

Last year's results:
59 mpg highway
30 mpg city
1994 Emission levels

These mpg values are twice that of the original vehicle and the emissions
were achieved without much effort.

expected this year (June):
80+ mpg highway
50+ mpg city
ULEV emission levels

Any other questions??

Jordan Wilkerson

University of Maryland
Hybrid Electric Vehicle Research
Project Manager
[email-masked]

"Ignorance Breeds Fear"

Re: Alternative Fuels?                                                       R

---

From: Jordan Wilkerson <[email-masked]>
Date: Thu, 13 Apr 1995 19:31:23 GMT

> I am also looking for practical ways to run my motorcycle safely on
> renewable methane, hydrogen, ethanol or methanol. I need a supplier of
> safety pressure tanks and gas carburation conversions. Any offers?
>
>  -- ++ +M.+ ++$

We are using methanol (M85) in our hybrid vehicle, as well as several other
vehicles.

The characteristics of methanol and ethanol are very similar, though I
have never worked with the latter.  M85 is a saver liquid than gasoline
so there really is very little safety required for its use of over the
conventional Gasoline system.  The only concern is the engineering to
optimize the combustion and energy conversion.  We are running a Geo
Metro, 3-cylinder, one liter engine at about 12:1 compression with very
good results.  Our emission level should approach ULEVs and we expect to
achieve 80 mpg gasoline equivalent this year.

        Our fuel delivery system includes a Bosch M85 fuel pump
supplying a 55psi fuel rail and multi-port injectors (designed by Seimens).
We purchased a Haltech fuel management controller which allows dynamic
and real-time adjustment of several parameters for tuning.  The controller
also allows for open or closed loop.  A Jacobs spark ignition allows for
the right spark energy on every ignition.

We have not ever tried a carberated system with M85, so I can't give any
info.  You might try EPA.  Try Matt Dorson :

        [email-masked]

Jordan Wilkerson

University of Maryland

"Ignorance Breeds Fear"

Re: Alternative Fuels?                                                       R