Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to diesel electric loco-
motives and more particularly to a booster unit for
boosting the locomotive power output.
The diesel electric locomotive has long been
regarded as a relatively powerful and energy efficient
source of motive power for many rail transport applica-
tion~. However, it has been recognized that more power-
ful internally powered locomotive than is currently
available namely, the diesel power locomotive would be an
asset to many railways. This is because the more power
the locomotive embodies, the more productive it is pro-
viding that this power can be successfully transferred to
the driving wheelq of the locomotive and the rail it
rides on.
It has been found that a more powerful locomo-
tive can be provided by "adding to" or "boosting" the
power of the widely used diesel electric locomotive with
an onboard electric power-producing booster unit. The
booster unit is an engine and an electric generator that
would assi~t the e~fort when needed of the locomotive
diesel engine and traction generator by parallelling the
electrical output from both generators for supplying the
extra electrical power to the traction motors.
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Because of the minimal space available on the
diesel electric locomotive itself, the required booster
unit (engine and generator) must be compact and must have
a high power density (relatively high power output for
its volume).
It has been found that the high power density
gas turbine is very well suited to the limited space
requirement required by a booster unit. Also, it has
been found that a high speed alternator is equally well
suited in physical size for its relative power conversion
capacity ~ince the high speed alternator is able to run
directly from the gas turbine without a gearbox which is
space consuming and energy robbing.
In addition to the power density aspect of the
gas turbine and complimentary high speed alternator, a
number of attributes have been found to make thi~ power
producing equipment attractive in rail transport for the
application being consldered. First it is the ability of
gaq turbines to run intermittently, second i8 the long
service life wlth a relatively minimal maintenanoe
requirements and thirdly the gas turbine simplicity.
It has been found that even with the relative
inferior thermal efficiency of the gas turbine as com-
pared with the diesel engine the Locomotive Booster Unit
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(gas turnbine and high ~peed alternator) can improve the
operating economy for railways with a certain operational
characteristic. This characteristic is the need to meet
peak motive power demands for relatively short period~ of
time. Typical of a railway with this characteristic is
one with ~teep grade~ and heavy tonnage moving in one
direction. This can describe railways operating in moun-
tainous terrain hauling re30urce products. Under these
conditions the dieqel motive power operating economy can
be improved with the implementation of the locomotive
booster unit by providing additional power on a limited
duty cycle. If the locomotive's traction motor can
accept the additional power and if there is adequate
wheel and rail adhesion the Locomotive Boo~ter Unit
effectively replace~ the additional die~el electric loco-
motives that are in the consist for meeting the peak
motive power demands. With this concept of operations,
the Locomotive Booster Unit i5 used only when it i8
needed to raise the peak power output of the diesel
electri¢ locomotive to meet peak motive power demand.
The Locomotive Boo~ter would not be uqed for operating
segment~ where power provided by the die~el engine is
sufficient, thereby retaining the ~uperior economy of
straight diesel locomotive operation.
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Accordingly a booster unit would increase the
horsepower provided per locomotive unit and a
corresponding reduction in the number of units needed to
handle a train or to operate a railroad. With this
reduction in the number of units there are substantial
capital and operating cost savings.
The limited high fuel consumption for the
energy that i~ produced while power boosting is fully
offset by reduced capital, maintenance and possible
energy cost providing the described conditions create
peak motive power demand of short duration and the loco-
motive booster operates on a sufficiently limited duty
cycle. There is the possibility with locomotive power
boosting to substantially or fully offset the additional
fuel that is used during the boost period by not taxing
the train movements total energy requirement with the
extra energy that is needed to haul additional diesel
eleotric locomotive that are needed for a limited period
of time.
Accordingly, the present invention provides a
booster unit for diesel electric locomotives having a
frame mounted diesel engine, a main traction generator
and a series of traction motors connected to said genera-
tor, comprising: a gas turbine mounted on said frame
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adjacent to said diesel engine; a high speed alternator
connected directly with said turbine; a series of rec-
tifiers at the output of said high speed alternator, said
alternator and rectifiers forming a high speed traction
generator; load control means connected at the output of
said alternator for controlling the output power thereof,
wherein ~aid high speed electric generator is connected
in parallel with said main traction generator such that
said traction motors can be supplied with extra electri-
cal power when required.
Particular embodiments of the invention will be
understood in con~unction with the accompanying drawings
in which:
Figure 1 is a schematic of the locomotive
booster unit as used according to the present invention.
The qchematic of Figure 1 shows the intercon-
nection of the diesel electric locomotive booster 11
which is basically used as a second power qource and is
mounted on the frame and under the hood of the conven-
tional diesel electric locomotive. The locomotive
booster 11 is comprised of a gas turbine 12 which is used
as the prime mover. The gas turbine is directly con-
nected to a high qpeed traction generator 13 which is
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basically comprised of a high speed alternator connected
to a series of rectifiers. The booster's output 14 and
control line 15 is integrated into the electrical system
which is run by microprocessor controller 17. The gas
turbine 12 is fueled from the locomotive's fuel tanks
with die~el fuel.
The governor or load controller 18 is used in
conjunction with a power controller 19 to regulate the
loading of the generator 13 (and therefore, the
resistance it offers to the turning of gas turbine 12)
just matches the horsepower the turbine can develop, and
permit the system to remain stable at the governed speed.
The basic electric diesel locomotive is pro-
vided with a diesel engine 20 used as a prime mover, con-
nected to a main traction generator 21 which is further
connected to a series of traction motors 22 ~upported on
each axle. Similarly, a governor or load controller 24
is being used along with excitation system 23 to regulate
the field of generator 21 so that the electrical power
produced by the generator matches the horsepower the
diesel can develop permitting the system to stay stable
at the governed speed.
Gas turbine 12 has to meet a certain number of
physical requirements such as a small physical size,
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require~ power output, rug~edness, simpllclty, avallabl-
lity and CoQt. Such a 8as turblne i~ currently commer-
cially avallable as a ~awa~aki*Gas Turbine Model M1A-01
which can develop 1600 horsepower and able to rotate the
high speed alternator at 22,000 revolutions per minute.
The high speed alternator used for generator
13, iQ a permanent maBnet synchronou~ alternator pro-
viding superior power density, efficiency and overall
ruggedness.
An auxiliary gearbox (not shown) iQ mounted on
the end bell of the alternator. The gearbox allow
accesQories, such aQ the fuel pump and the governor for
the gas turbine, to be mounted. The output voltage Or
the alternator will be constant at approximately 1,300
volts when rectified. The governor load controller 18
can either regulate by phase control with thyristors or
by use of a chopper circuit operating at 1,300 volt~.
The Qystem could be mounted on a 6 axle locomo
tive capable of utilizlng 6,000 horsepower at the input
to the electric transmiQsion. Newer traction motors like
to EMD's D87 are capable of developing 875 horsepower per
motor and would be Quitable for this type of locomotive
and power output Such a locomotive is made available by
General Motors*of Canada, Diesel Division under Model
*Trade Marks
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SD60 which is rated at 3,800 horsepower and with power
boosted would be rated at 5,400 horsepower at the alter-
nator inputs. Other similar locomotive units could also
be adapted to use a booster unit. The type of locomotive
will, of course, be dependent upon the operation and
terrain the locomotive is used for because minimum speeds
effect traction capacities and wheels and rail adhesion.
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