Improvements in Systems of Electrical Distribution
Year: 1898

page_text: [-
Improvements in Systems of Electrical Distribution
I, BENJAMIN GARVER LAMME, c/o Westinghouse Electric & Manufacturing
Company; East Pittsburg, State of Pennsylvania, United States of America;
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
·
My invention relates to systems of electrical distribution, and particularly to
such systems as involve the transmission of energy to a considerable distance
for the operation of translating devices constituting a variable load upon the
system such for example, as railway motors.
The object of my invention. is to provide means for automatically varying the
electromotive force of a circuit in proportion to the load, without the employment
of apparatus specially designed or constructed for this specific purpose.
It is the usual practice to supply long feeders by means of generators, the field
magnets of which are over-compounded, that is to say, the electromotive force
increases with the load. In the case of suburban or inter-urban railways, how-
ever, it has been found necessary to employ an additional device which has
usually consisted of a series wound generator connected in the positive branch of
the-feeder circuit. The desired result. is thereby obtained. but such a machine
must be of necessity specially constructed and wound for the particular purpose
for which it is used.
According to my present invention, in place of a specially constructed machine
such as-above described, I employ an ordinary compound machine which I connect
in the circuit in the following manner:-
. The armature and series winding of the supplementary machine. are connected
in series with the main generator, and the shunt coil of the supplementary
machine is joined to the brushes of an exciter the field magnet of which is
separately excited, being connected in series with the main circuit. By this
means both the shunt and the series coil of the compound generator are utilized,.
the current through both of these coils depending upon the load in the main
circuit!
In place of a compound generator, I may sometimes employ as a supplementary
dynamo a shunt wound machine the field magnet coil of which is connected direct
to the brushes of an exciter, the field. magnet coil on said exciter being in the

page_text: main circuit, consequently the excitation of the field magnet of the shunt machine
will vary proportionately with the. load and the additional electromotive force
supplied will vary in the same degree.
Dated this 5th day of wil 1808
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.
I, BENJAMIN GARVER LAMME, c/o Westinghouse Electric & Manufacturing
Company, East Pittsburg, State of Pennsylvania, United States of America,
do hereby declare the nature of this invention and in what manner the same is
to be performed to be particularly described and ascertained in and by the
following statement:-
My invention relates to systems of electrical distribution which involve the
transmission of energy to a considerable distance and in which the load is variable,
such a system as an electric railway for example.
The object of my invention is to provide means for automatically varying the
electromotive force of a circuit in proportion to the load without the employment
of apparatus specially designed or constructed for this specific purpose.
It is the usual practice to supply long feeders by means of generators, the field
magnets of which are over-compounded, that is to say, the electromotive force
increases with the load. In the case of suburban or inter-urban railways, how-
ever, it has been found necessary to employ an additional device, which has
usually consisted of a series wound generator connected in the positive branch of
the feeder circuit. The desired result is thereby obtained, but such a machine
must be of necessity specially constructed and wound for the particular purpose
for which it is used.
According to my invention, in place of a specially constructed machine, I
employ an ordinary compound machine for this purpose. This has its armature
and series winding connected in series with the main generator, and its shunt
coil is joined to the brushes of an exciter, the field magnet of which is separately
excited, being connected in series with the main circuit. As shewn in the
diagram Figure 1, 1 is the armature, 2 the series coil, and 3 the shunt coil of
the main generator, feeding the circuits 4, 5, and 6, 7. The armature of the
compound wound machine which is used to supplement the main generator is
shewn at 9, and the series magnet coil 10 is connected in series in the wire 6.
The shunt coil 11 of the supplementary machine is joined to the brushes of a
separately excited machine, the armature of which is indicated at 12 and the
field magnet coil 13 of which is also in series in the circuit 6. With this arrange-
ment as the load varies the current through the coil 13 will change, and will
consequently vary the electromotive force generated by the armature 12 and the
current through the coil 11; hence the current in both series and shunt coils
of the supplementary machine will be varied according to the load, and the
additional electromotive force supplied by said machine will also vary according
to the load.
In place of a compound generator, I may sometimes employ as a supplementary
dynamo, a shunt wound machine as shewn in Figure 2, the field magnet coil 11ª
being connected direct to the brushes of the exciter in the same manner as the
shunt coil of the compound machine illustrated in Figure 1.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. A system of electrical distribution of the kind described, in which the electro-
motive force is automatically varied in proportion to the load by means of a
supplementary shunt wound or compound wound generator, the armature of
which is in series with the main generator, the shunt coil being so connected that
its excitation varies as the load of the system varies.
2. Systems of electrical distribution provided with a supplementary generator,
arranged and operating as described, with reference to Figure 1 or to Figure 2
of the accompanying drawings.
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W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.