Improvements in the Method of and Apparatus for Distributing Electrical Energy by Alternating Currents from Central Stations.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Method of and Apparatus for Distributing
Electrical Energy by Alternating Currents from Central Stations.
I, GISBERT KAPP of Stanley Villa, Wimbledon in the County of Surrey Electrical
Engineer do hereby declare the nature of this invention to be as follows:-
My Invention has for its object improvements in the apparatus and methods for
distributing electrical energy by alternating currents from a central station over an
extended area. The system now commonly employed is to generate at the station
alternating currents of high pressure, to carry these by comparatively small cables to
the distant places of consumption and to transform them there by means of alternate
current transformers into alternating currents of low pressure which are utilized for
lighting or other purposes. Each pair of secondary terminals of each transformer
may be connected with a separate secondary circuit or when the distribution is on the
parallel system all the secondary circuits may be connected so as to form one net
work of mains from which branch off the leads which supply the low pressure current
to the lamps or other translating devices. In this case it is necessary to insure
constancy of potential difference (pressure) between the primary terminals of all
the transformers of which the secondary terminals are connected to the common net
work of mains, and to attain this object it has hitherto been customary to insert
rheostats or variable artificial resistances into the cables or feeders which connect the
dynamos at the station with the transformers outside. These rheostats are usually
placed at the station and are there controlled, their resistances being increased or
diminished as the current flowing through the feeders diminishes or increases in
accordance with the varying requirements throughout the district. The pressure to
be kept at the station must necessarily exceed that between the primary terminals of
the transformers by an amount which is equal to or slightly greater than the greatest
loss of pressure on any feeder and some energy is wasted in heating the rheostats.
In my improved method I dispense with the rheostats or artificial resistances
altogether and keep at the dynamo terminals exactly the same pressure as that
which must be maintained between the primary terminals of the transformers. This
TD 077

page_text: pressure, as before mentioned, is a constant. I obtain the increase of pressure
necessary in each feeder for overcoming its electrical resistance by inserting into it
at the station the secondary coil of a regulating transformer, the primary coil of
which is coupled as a shunt across the terminals of the dynamo. When several
dynamos are used I may couple them in parallel by means of two main bars and the
connections of the primary coils of the regulating transformers are then made with
these main bars. I provide one of these regulating transformers to cach pair of
feeders. The primary or fine wire terminals of these regulating transformers are
permanently connected with the main bars and the secondary coils are divided into
sections and connected with a suitable switch so that by adjusting the switch a
greater or lesser number of turns of the secondary coil can be inserted in series into
one feeder of each pair. The coupling up of the regulating transformers is such
that the electromotive force produced in their secondary coils is added to the electro-
motive force of the current in the feeders. I set the switch of each regulating
transformer so that the electromotive force produced in the secondary coil is just
sufficient to overcome the resistance of the feeder at the current then flowing. The
pressure available at the distant end of each pair of feeders is then exactly equal to
that constantly maintained between the main bars at the station. The regulating
switch at each regulating transformer must therefore be set in accordance with the
indications of a current indicator inserted into each pair of feeders and this may be
done either by hand or I may employ the following automatic device. Into each pair
of feeders I insert a solenoid or other electro-magnetic instrument the movable part
of which actuates a relay switch, having as many contacts as the regulating switch
of the regulating transformer belonging to that pair of feeders. In connection with
the relay switch is a number of relay electro-magnets and according to the position
of the relay switch either one or another of these magnets becomes energized, the
current being taken either from batteries or from dynamos supplying the exciting
current to the main dynamos. All the relay magnets have one common armature,
which is mechanically connected to the lever of the regulating switch so that the
movement of that lever follows the movement of the movable part of the electro-
magnetic instrument inserted into the feeder. I may arrange the secondary coils and
the regulating switch of one or more of the regulating transformers in such a manner
that when the current in the corresponding feeders decreases beyond a certain
minimum the regulating switch interrupts completely the flow of current through
these feeders.
גו
11
TY 1000
WILLIAM E. HEYS,
Agent for the Applicant.

page_text: Apparatus
Electrical Energy by Alternating Currents from Central Stations.
I, GISBERT KAPP of Stanley Villa, Wimbledon, in the County of Surrey, Electrical
Engineer, 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 has for its object improvements in the apparatus and method for
distributing electrical energy by alternating currents from a central station over an
extended area. The system now commonly employed is to generate at the stations
alternating currents of high pressure, to carry these by comparatively small cables to
the distant places of consumption and to transform them there by means of alternate
current transformers into alternating currents of low pressure which are utilized for
lighting or other purposes. Each pair of secondary terminals of each transformer
may be connected with a separate secondary circuit or when the distribution is on the
paralel system all the secondary circuits may be connected so as to form one net
work of mains from which branch off the leads which supply the low pressure current
to the lamps or other translating devices. In this case it is necessary to insure
constancy of potential difference (pressure) between the primary terminals of all the
transformers of which the secondary terminals are connected to the common net
work of mains, and to attain this object it has hitherio been customary to insert
rheostats or variable artificial resistances into the cables or feeders which connect
the dynamos at the station with the transformers outside. These rheostats are usually
placed at the station and are there controlled, their resistances being increased or
diminished as the current flowing through the feeders diminishes or increases in
accordance with the varying requirements throughout the district. The pressure to
be kept at the station must necessarily exceed that between the primary terminals of
the transformers by an amount which is equal to or slightly greater than the greatest
loss of pressure on any feeder and some energy is wasted in heating the rheostats.
In my improved method I dispense with the rheostats or artificial resistances
altogether and I keep at the dynamo terminals exactly the same pressure as that
which must be maintained between the primary terminals of the transformers. This
pressure, as before mentioned, is constant. I obtain the increase of pressure necessary
in each feeder for overcoming its electrical resistance by inserting into it at the
station the secondary coil of a regulating transformer, the primary coil of which is
coupled as a shunt across the terminals of the dynamo. When several dynamos are
used I may couple thein in parallel by means of two main bars and the connections
of the primary coils of the regulating transformers are then made with these main
bars.
I provide one of these regulating transformers to each pair of feeders. The
primary or fine wire terminals of these regulating transformers are permanently
connected with the main bars and the secondary coils are divided into sections and

page_text: connected with a suitable switch so that by adjusting the switch a greater or lesser
number of turns of the secondary coil can be inserted in series into one feeder of
each pair. The coupling up of the regulating transformers is such that the electro-
motive force produced in their secondary coils is added to the electromotive force of
the current in the feeders. I set the switch of each regulating transformer so that
the electromotive force produced in the secondary coil is just sufficient to overcome
the resistance of the feeder at the current then flowing. The pressure available at
the distant end of each end of feeders is then exactly equal to that constantly
maintained between the main bars at the station. The regulating switch at each
regulating transformer must therefore be set in accordance with the indications of a
current indicator inserted into each pair of feeders and this may be done either by
hand or by means of the following automatic device. Into each pair of feeders 1
insert a solenoid or other electro magnetic instrument the movable part of which
actuates a relay switch, having as many contacts as the regulating switch of the
regulating transformer belonging to that pair of feeders. In connection with the
relay switch is a number of relay electromagnets and according to the position of
the relay switch either one or another of these magnets becomes energized, the
current being taken either from batteries or from the dynamos supplying the exciting
current to the main dynamos. All the relay magnets have one common armature,
which is mechanically connected to the lover of the regulating switch so that the
movement of that lever follows the movement of the movable part of the electro-
magnetic instrument inserted into the feeder. I may arrange the secondary coils and
the regulating switch of one or more of the regulating transformers in such a manner
that when the current in the corresponding feeders decreases beyond a certain
minimum the regulating switch interrupts completely the flow of current through
these feeders.
I will proceed to more particularly describe my Invention with reference to the
accompanying sheet of drawings.
Fig. 1 shows the general arrangement of the distributing circuits arranged
according to my Invention. B₁ B2 are the main bars at the station connected to the
poles of the alternate current dynamo or dynamos. R1 R2 R3 are the regulating
transformers the primary coils of which are connected in parallel to the main
bars B B² whilst their secondary coils are connected up in such way that the electro-
motive force created in them aids the current which flows through the mains or
feeders M1 M2 M3 respectively. T T T are transformers installed in different points
of the district to be supplied, and L represents the lamps or other translating devices
supplied with current from these transformers. The secondary conductors coming from
each transformer T may either form distinct and separate groups or net works of
mains or two or more may be connected as shown by the dotted lines 1, 2. Each
regulating transformer should be so proportioned that the electromotive force
developed in its secondary coil equals or exceeds slightly the greatest loss of pressure
which can ever occur under normal conditions on its respective main and which loss
occurs at the time when the maximum of current is flowing. The primary coil of the
regulating transformer is permanently connected to the bars B' B2 and the secondary
coil may either be permanently inserted between bar B₁ and the corresponding feeder
as in R which arrangement 1 adopt when the consumption of electric energy at the
far end of the feeder is fairly constant; or the secondary coil may be divided into
sections and a greater or lesser number of sections may be inserted between the
bar B and the corresponding feeder by means of the contact lever pivoted at P. This
arrangement I adopt when the consumption of electric energy at the far end of the
feeder is variable as will be generally the case when the current is required for
lighting. The regulating transformer R¹ is shown subdivided into four sections and
the contact lever is so set as to introduce the current into the third and fourth section,
the first and second section of the secondary winding being in this case inoperative.
This position of the contact lever corresponds to about half of full supply. For full
supply the lever would be set so as to introduce the current into the first section
causing it to traverse the whole of the secondary winding. In the regulating

page_text: transformer R³ there are three sections and in the position of the contact lever shown,
the current entering at P passes direct to the feeder without traversing any of the
sections. The contact lever would be set into this position when the call for current
is so small as to make the loss of pressure in the feeder a negligible quantity, in which
case it would not be necessary to raise the pressure above the amount existing
between the main bars B1 B².
Fig. 2 shows a more detailed view of the contact lever of the regulating trans-
former R³ and of the automatic gear for working it. This lever is pivoted at P which
point is connected with B' the contacts a, b, c, d, are connected with the respective
sections of the secondary coil of the regulating transformer as shown in Fig. 1 and
His an insulated handle by which the lever may be set on to any contact in
accordance with the strength of current flowing at the time as indicated by an
ampere meter. To avoid burning up of a section if the lever should be left at an
intermediate position bridging two contacts, the insulating parts (shown cross lined)
are made rather wide and the contact lever is in two parts h, k, with insulation g
between. The two parts are joined by a conductor having sufficient resistance, or
self induction, or both, to prevent the passage of an excessive current. Instead of
setting the contact lever by hand I may adopt the following automatic device. The
rear end of the contact lever is provided with a soft iron armature A' playing over
electromagnets F, A, B, C, D, E. These magnets can be excited by a continuous
current from a battery 4 or from the exciting dynamos, the current being controlled
by the lever mo of a relay switch which in its turn is controlled by the regulating
device S interposed with the feeder circuit M³. In the drawing I have shown this
regulating device in the form of a solenoid, but any other suitable device may be
employed such for instance as two coils attracting each other or a conductor heated
more or less by the current and subject to changes of form resulting therefrom.
The position of the relay switch mo determines which of the electromagnets is
excited. In the position shown, magnet A is excited and all the other magnets are
inert, the current passing from through A to a¹ and back to q. Should the current
in feeder M³ increase beyond a certain limit the core will be sucked down against the
force of the adjustable spring by which it suspended and the lever mo which is
pivoted at m will move on to the next contact 6. Now the magnet B will become
excited and pull the armature A' over it, moving the contact lever to b. In this
position the alternating current from the main bar B1 passes through Pb into the
third section of the regulating transformer R and obtains there an increase of electro-
motive force sufficient to make up for the loss of pressure caused by the increased
current flowing through the feeder M³. A further increase of current will produce a
further movement of the contact lever hand if, owing to a short circuit or heavy leak
in the feeder M³, the current should becoine excessive, the lever mo will be pushed
to the lowest contact e¹ and the armature A¹ will fly to the corresponding magnet E
thus interrupting the feeder current altogether. The feeder current may also be
automatically interrupted if the consumption of current falls below a certain
minimum. In this case the relay switch mo will be raised to the contact f¹ and the
armature A will move over the corresponding magnet F. In this position the
lever will pass on to the insulation and cut off the current.
If I desire to couple two or more dynamos in parallel to the main bars B¹ B² I
adopt the arrangement shown in Fig. 3. In addition to the bars B¹ B² I use an
anxiliary bar B connected with B2 by means of an induction coil J₁ of such pro-
portions that under normal pressure only one quarter or one half of the maximum
current given by one dynamo can pass through. V is a transformer at the station
and a battery of lanips capable of absorbing about half the energy at one dynamo
and vis a voltmeter. J J are ampere meters and B1 B are two more auxiliary bars.
I and II are dynamos, the former supplying current to the main bars B' B² and the
latter about to be coupled up. For working in parallel I find it advantageous to use
dynamos which have a certain amount of self induction in the armature and when this
is insufficient 1 increase it by the insertion of induction coils t¹ t². The connections
between the dynamos and bars are made by means of switches w, x, y, z. The

page_text: operation is as follows. Let, as before described, dynamo I be running and
supplying current to the feeders M² M² M³ through their respective regulating
transformers R1 R2 R³. I start dynamo II and run it up until it has attained
approximately its normal speed. I close switches and y² and regulate the exciting
current until the voltaicter v shows that the standard pressure has been attained.
I next close switches w and 22. A certain amount of current will now flow through the
induction coil J¹ and this will bring dynamo II into step with dynamo I. I regulate
now the exciting current of dynamo II until the ampère meter shows that no more
current passes through J¹. I then close the switch w² and gradually switch off the
lamps v. By this means the load on dynamo II is gradually transferred from the
local transformer V to the main bars B₁ B. I finally open switches and y² and
further regulate the power supplied to dynamo II and the exciting current until this
dynamo gives the same current as dynamo I.
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) In a system for the distribution of Electric energy by alternating currents
from a central station; regulating transformers combined with the feeders M, for
raising the pressure by an amount approximately equal to the loss of pressure arising
from the resistance of the feeder; substantially as hereinbefore described with
reference to the accompanying drawings.
(2) In a system for the distribution of electric energy by alternating currents from
a central station in which regulating transformers are employed; subdividing the
secondary coil of the regulating transformer into sections into any number of which
the primary current may be led, for the purpose of adjusting the amount by which
the pressure in the feeder is raised by the transformer; substantially as liereinbefore
described.
(3) In a system for the distribution of electric energy by alternating currents from
a central station in which regulating transformers having sectional secondary coils
are employed; a multiple contact switch operated by hand and constructed and
arranged substantially as and for the purpose herein before described.
(4) In a system for the distribution of electric energy by alternating currents from
a central station in which regulating transformers having sectional secondary coils are
employed; an automatic multiple contact switch constructed arranged and operated
substantially as and for the purpose hereinbefore described with reference to Figs. 1
and 2 of the accompanying drawings.
Dated this 19th day of Danamhor A
1000