Improvements in Systems of Electrical Distribution.
Year: 1894

page_text: Date of Application, 7th Dec., 1894
Complete Specification Left, 4th Oct., 1895-Accepted, 9th Nov., 1895
PROVISIONAL SPECIFICATION.
Improvements in Systems of Electrical Distribution.
I, REGINALD Wood, of 57 Gower Street, in the County of London, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to the application to electrical distributing systems of
electric generators and motors, also combined generators and motors, for the
purpose of determining the consumers' electric tension, and maintaining that
tension constant notwithstanding variations in the tension of the main generators
or in consumption of the electric energy and differences in the resistance of the
feeders by which the energy is supplied to different parts of the system.
I shall explain my invention referring to the accompanying diagram Fig. 1
illustrating its application in two cases, namely, first, when the object is to
maintain at the lamps the same electric tension as that at the main generators,
which would in that case be maintained constant, and, secondly, when the object is,
as it generally would be, to maintain at the lamps a tension less than that at the
main generators which would then he suitably varied. There is also a third case
in which the object is to maintain at the lamps a tension greater than that of the.
main generator, which then would be suitably varied.
Referring now to the diagram Fig. 1 which shews my invention applied to a
5-wire system of distribution. A indicates the main generators, TU are omnibus
bars, BCY are three positive feeders and bey the corresponding negative or
return feeders, P are feeding points, E F G H I are the 5 wires supplying the
lamps or other consumers L on 4 circuits. In each of these circuits I arrange a
balancing machine J, the field magnet of which has. two sets of coils, indicated in
the figure, for the sake of clearness, by two separate pairs of circles K and K.
The coils K are all connected in parallel with the terminals of any source of
electricity at constant tension, and are shewn connected to the feeders Bb at the
terminals of the machines Mi farthest from the main generators A.
The coils K¹ are in series with the armatures of the machines J, which
armatures are mechanically connected so as to revolve together. In the
feeders Yy which have appreciable resistance I arrange an energising
machine M having its field magnet coils wound compound with two opposing pairs
of coils, the one pair N being in series with the armature and the feeder, the
other pair O being connected in parallel across the terminals of the armature in
the feeders Bb each of which contains a similar machine M', but, as these feeders
have no appreciable resistance, the coils N are omitted. The armatures of the
machines M and M¹ are mechanically connected to the armatures of the
machines J and revolve with them. The coils O may be connected in parallel
to any source of electricity the tension of which can be varied in proportion as
the tension of M' is varied. The induction in the machines M M' is low.
The balancing machines J operate in the following manner. Assuming that in
one or other of the four circuits, say for instance the circuit HI, there is a demand
for less current than in the other circuits or some of them, then the machine J,
which is in the circuit HI, acts as a motor, its armature driving the other
armatures whereby more current is sent into their circuits. Thus the machines J
operate to balance the currents in the several circuits, taking up excess of energy
from some of them and contributing energy to others of them.
Besides operating
in this manner, the machines J drive at constant speed the energising machines M

page_text: which, when the coils O are short circuited, act as series generators to maintain
constant the tension at the lamps, each supplying energy to
resistance in the feeder in which it is situated.
overcome the
Thus the machines J, even when their balancing function is not required, serve
by driving the machines M, to maintain constancy of tension at the feeding
points.
In other words, the operation may be described thus. If the main generators
are maintained at normal pressure the armatures J act as motors and drive at
normal speed the armatures M in fields excited by the coils N only, which
therefore act as series generators and add to the feeders the energy lost in them,
and thus the consumers are supplied at normal pressure.
Now, as a second illustration let the short circuit over the coils ().be removed
the armatures M being considered as being in fields partly created by the coils O
and partly created by the coils N, and the MO machines being assumed to be
nearer to the main generator A than the M N machines. Let the tension of the
main generator be increased gradually from nothing to a value exceeding the
normal tension of the consumers.
Whatever tension, within limits, is applied to the coils O of the machines M'O,
the armatures M' will attain normal speed giving a back tension of the same value
as that applied. Consequently whatever be the excess of the tension of the main
generator A over the consumers' normal tension, the machines M' O will attain
normal speed, in which case the tension of the machines J must be normal, and the
tension over the machines M' O must be equal to the excess of the tension of A
over that of the consumers.
The lamps are therefore fed at normal tension because the tension resulting
from the effect of the N coils or the M armatures is the same as before, and is still
added on to the difference resulting from the combination of the main generator A
and the effect of the coils on the M armatures, this difference being
automatically maintained at the consumers' normal tension, and the current to the
J machines in the first illustration is thus decreased in the second illustration by
an amount such that the decrease in the power of these machines equals the power
produced by the action of the O coils on the M armatures. In the above
explanation, the effect of the coils O has been separated from that of the coils N
for the sake of clearness. In reality an armature M in the combined field
produced by the coils O and N becomes motor or generator according as the
effect of the coils O or that of the coils N predominates.
Two feeders of appreciable resistance are shewn connected to T U but there
may obviously be any number. In other words the operation may be described
thus. However much, within limits, the tension of the main generator A exceeds
the normal tension of the consumers, the effect is that the current produced by
the combination of the main generator A and the coils O acting on the
armatures M is maintained at normal tension, and the armatures M acted on by
the coils O acting in combination with the armature J drive at normal speed the
armatures M acted on by the coils N which act as before as series generators and
add to the feeders the energy lost in them. Thus the consumers are supplied at
normal tension.
Further increase of the excess of the main generator tension is attended with a
like result, the current to the J machines being again reduced.
A change in demand is met in the usual way by a corresponding change in
the power of the main generators. For instance, a decrease in demand in any
feeder leads to an increased main generator pressure, which assuming the other
feeder currents to remain constant weakens the field of the generators M and
strengthens the field of the motors M, and this is equivalent to decreasing the
power required from the machine and increasing their power to drive. The
speed therefore tends to rise, less current going to J, the pressure over which
rises, and some lamps receive too high a pressure which is reduced by reducing
the power of the main generators, thus meeting the change in demand.

page_text: The third case is exactly analogous to the second. The coils O would be dis-
connected-and again connected-so that the current in them is in the reverse
direction to a separate source of electricity maintained at a tension proportional to
the excess of the tension required at the lamps over that of the main generator.
All the M armatures then act as generators driven by the J machines, the O coils
producing such an effect on the M armatures as to make the main generator and
the M O machines combined equivalent to main generators at lamp tension and the
M N machines as before supplying the energy required to overcome the resistance
of the feeders. The operation would be the same if the current in the O coils
were simply reversed and the coils K connected to a source of electricity the
tension of which is maintained constant.
The two armatures M or M' belonging to a pair of feeders need not have
separate field magnets but they may be wound on one core and have only one field
magnet.
When transformers, the armatures of each of which are on one core, and the
number of which is varied with the load, are interposed between the feeder and
the distributing wires, the coils N have their number of convolutions increased,
and a coil is added which carries a current proportional to the current in each
transformer.
It is obvious that the compound wound energising and de-energising machines
would require magnet copper out of all proportion to their nett output, and that
great waste of energy by heat would be occasioned by the neutralisation of
excitation if this neutralisation took place on the magnets of the energising and
de-energising machines themselves. The energising and de-energising machines
have their magnets therefore wound with one coil, contacts with which can be
made from the outside at certain points separated by a different number of con-
volutions. The neutralisation of excitation is effected on a very small dynamo
acting as a contact shifter, the armature of which moves a contact bar which makes
connection between the coil on the energising or de-energising machine magnet
and a coil on the magnet of the contact shifter.
Referring to Figure 2 which represents a de-energising machine or motor, A is
a main generator, T is the positive omnibus bar, U is the negative omnibus bar,
O, is the coil of the de-energising machine, R its magnet poles, e el are commu-
tators of armatures of the positive and negative machines respectively wound on
one core M; Cc are the feeders, positive and negative respectively, M' is the
de-energising armature. Vare the magnet poles of the contact shifter. N¹ is the
series coil of the contact shifter. 03 is a separate coil with contact points corre-
sponding to those of O₂. is the armature of the contact shifter. n the contact
bar of the contact shifter. Q any suitable constant source of electricity.
The current passes from the positive omnibus bar T by the commutator e
through the positive de-energising armature on the core M to the positive
feeder C.
The return current from the negative feeder e passes by the commutator e¹
through the negative de-energising armature on the core M, thence through
the coil N¹ on the magnet of the contact shifter back to the negative omnibus
bar U.
The two feeder currents in the armatures on the core M are in the field produced
by the coil Og.
The current from M' passes through the coil O, by the contact barn through
the coil O, back to M¹. The direction of the current in O, is opposite to that
in N 1.
A current of constant strength from Q always passes through the armature 7.
The operation is shewn thus :-Suppose that the current in N, is enough for one
lamp only, the effect of N₁ will be negligible and that of O₁ must also be
negligible, therefore the position of the contact bar n will be stand the bar will
be stationary. The full number of convolutions O₂ will be active, and the tension
of e and e, equal to that of M₁.

page_text: Now let the current in N, increase, V becomes magnetised and acts on / so as to
move n counterclockwise. The effect of this is to increase the active convolutions
in O, and decrease them in O2. The movement continues until the effect of the
active convolutions on Os equals that of N₁. So that the tension of e and ₁₁ is
decreased by an amount proportional to the current in N1.
For the amount by which the pressure of e and e₁ is less than the full amount is
proportional to the idle convolutions on O₂, i.e. to the active convolutions on 03
that is to the effect of N₁.
When the current in N₁ decreases again V becomes magnetised in the opposite
direction and the armature moves clockwise. It will thus be obvious that the
neutralisation of excitation is effected by N, and O, and is utilised to keep active
in O₂ only the necessary convolutions.
1
The numbers of convolutions in N, and of active convolutions in O₂ + O̟ are the
same respectively as the numbers in N and O coils of Fig. 1. The number of
convolutions in N₁ and O, might be divided by any number, say 2. Then if n
moved and cut out convolution on O, it must at the same time cut out
in Og
and in all cases the resistance of the convolutions cut out in O, must be equal to the
resistance of the convolutions put in at the same time in O₂.
As will be evident from the above, in the case of the de-energising machine shewn
in Fig. 2 the separate coil or O coil of Fig. 1 is divided into two parts O₂ Os of
which O, is placed on the magnet of the de-energising machine and O3 on the
magnet of the contact shifter. On the other hand in the case of the energising
machine or generator shewn in Fig. 3 it is the series or N coil of Fig. 1 which is
divided into N, and N, of which N, is placed on the magnet of the energising
machine and N, on the magnet of the contact shifter, and since the resistance of the
coil N is very
low there is no necessity for the convolutions cut in and out at the
same time to be of the same resistance.
Referring to Fig. 3 (in which reference letters such as are used in Fig. 2 are
applied as far as possible to corresponding parts) which represents an energising
machine the current to the positive feeder Y passes from the positive omnibus bar T
by the commutatore through an energising armature on the core M. The return
by the negative feeder y passes by e, through the other armature on the core M
and through the coil N, by contact bar a through the coil N, back to the negative
omnibus bar U. The two feeder currents in the armature on the core M are in the
field produced by the coil N 2.
The current from M₁ passes through the coil O₁ in a direction opposite to that of
the current in N3. Q always sends a constant current through 7.
1°
The operation is as follows:-The effect of the current in N, suppose equals that
of the current in O₁. V is not magnetised and therefore is stationary in the
position shewn. If now a demand for more current is made on the feeder, the effect
of N increases and V becoming magnetised n moves clockwise until the effect of N3
equals that of O₁. The effect of N, has thus been increased by an increase in the
number of its active convolutions. A decrease in the tension of M, would produce
the same effect, whilst an increase in the tension of M, or a decrease in the current
in N, leads to a counter clockwise movement of n and a decrease in the number of
active convolutions on N 2.
In cases where there is a considerable number of feeders requiring a corre-
sponding number of energising and de-energising machines which it would be
inconvenient to arrange all on one set of shafting with the balancing machines, I
divide the energising and de-energising machines into groups, each group consisting
of one energising machine or several of them, and one de-energizing machine or
several of these, all those of the group being selected in such a manner that the
power given out by the de-energising machines is nearly that required for the
energising machine. A group of this kind is on one line of shafting with a machine
which can act as a generator or motor introduced in one of the main circuits or
several such machines and consequently there are as many such lines of shafting as
there are groups such as are above referred to.

page_text: The results obtained by means of Fig. 1 may also be obtained by a modification
in which the pairs of feeders are treated in couples, a long pair and a short pair
being treated together and a contact shifter may be used. Thus confining attention
for the moment to feeders Y y, Cc in Fig. 1 it is evident that the addition of tension
required in Y will be equal to the reduction of tension required in Cc if the
tension applied to Yy, Cc has a certain intermediate valve. The energising
armatures of Yy may therefore be wound on the same cores as the de-energising
armatures of Cc care being taken that the correct intermediate tension be applied
to Yy, Cc. The windings of the magnets must be such that the number of
ampère-turns is equal to half the difference between the product of the number of
convolutions in N in feeder Y Fig. 1 into the current in feeder Y Fig. 1 and the
product of the number of convolutions in N in feeder C Fig. 1 into the current in
feeder C Fig. 1. The correct tension is applied to the feeders Yy, Cc by con-
necting Y to C and to c and connecting YC through a de-energising armature to
the positive bar T and connecting y c through a de-energising armature to the
negative omnibus bar U. These two de-energising armatures may be on the same
core.
Referring to Fig. 4 A is the main generator, M' the de-energising armature,
shunt coil not shewn.
Y y, C c c long and short feeders respectively. Q is an
accumulator or other constant source of electricity sending a current through Z
which is the armature of contact shifter. V is its pole piece. N, N, the coils on
its magnets, n is the contact bar, R is the pole piece of the combined energising
and de-energising machine for the two pairs of feeders, N, is its coil, M its armature
core, eg 63 64 65 commutators for its four armatures. The circuit, of the feeder Y
passes from the positive omnibus bar T through a de-energising armature M 1
through the coil N 4 by the contact bar n through the coil N, by commutator e 2
through an energising armature on the core M and so to the consumers. The return
by y passes by the commutator e, through an energising armature on the core M
and so through M¹ back to the negative omnibus bar U.
The circuit of the feeder C passes through a de-energising armature M₁ through
the coil N by the commutator et through a de-energising armature on the core M
and so to the consumers. The return by the feeder c passes by the commutator es
through a de-energising armature on the core M and so through M¹ back to the
negative omnibus bar U.
The armatures M M are mechanically coupled to J armatures as in Fig. I
whereby their speed is maintained constant.
The operation is explained as follows:-As the tension of the main generator A
is increased from a small amount to a value considerably above that of the
consumers, the speed of the J M¹ and J M machines rises as explained with
reference to Fig. 1.
When M attains normal speed the tension applied to the feeder terminal of M'
is a definite amount namely half the sum of the tensions lost in the feeder
circuits Y, C, and equal tension is maintained at the consumers' ends of Y and C.
This follows from the resistances of the circuits and the winding of the magnet
of M. These equal tensions are also normal because M cannot attain normal
speed until J attains it and J must then be receiving normal tension and there
is a connection by the inner wires from the J machines to the lamps at the end
of feeders Y and C as in Fig. 1 and therefore these lamps receive the same
tension as the J machines. And since M' attains normal speed at the same time
as M, M then gives the difference in tension between that of the main generator A
and that at the feeder terminal of M¹.
Suppose now that there is an increase in the number of lamps at the end of C
more current flows along C in consequence of the decrease in resistance and this
weakens the magnet field of M by moving the contact bar in the direction of
clock hands. Therefore the lamps on C would. become bright and those on Y
dull, were it not that there is a decrease of tension over M which automatically

page_text: raises that at its feeder terminal thereby readjusting the tension over the lamps
on Y and C to normal. A decrease of load on Y is followed by a similar result.
On the other hand a decrease in load on C or increase ou Y is followed by an
increase of tension over M and a readjustment, of the tensions over the lamps on Y
and C to normal by a movement of the contact bar in the direction opposite to
clock hands.
Referring to Fig. 5, in which letters are used as far as possible to indicate the
same things as in Fig. 1, A is the main generator T, U, positive and negative omnibus
bars respectively, O M are de-energising machines J K K' are balancing machines,
J and M' being mechanically coupled. L are lamps or other consumers of energy,
EFGHI are the five wires of the 5-wire system. F G H should be connected
through as in Fig. 1. They are left unconnected for the sake of clearness.
the above were described with reference to Fig. 1, as was also the operation
of J M¹ in maintaining, in spite of variation of the tension of the main generator A
and in the number of consumers L, constancy of speed of J M¹ and constancy of
tension over each and all of J.
is the pole piece. the armature.
All
s the commutator. p, q, coils of a contact
shifter, u is insulation, y y¹ prolongations of the armature shaft.
ww₁ are contact
pieces, o o, are contact bars capable of making contact respectively between wy
and w₁ 1
ow and w₁ are shewn in the plane of the paper for the sake of
clearness. In reality they should be at right angles to the plane of the paper and
to the shaft yy, having been turned in opposite directions through a right angle.
o o rotate with y y₁.
a b c d e
a b c d e₁ are connections.
y are generators and m are motors preferably of equal tension connected in series
and to the wires a b c d e and a, ₁₁ d₁ ei as shewn. One pair of feeders ffi is
shewn.
The circuit off passes from the positive omnibus bar T by f to a and then either
direct by the contact piece w to the contact bar o, or, through one or more of the
machines m org and so by a contact piece w to the contact bar o, and then through
the coil g by f to the feeding point P. The circuit of fi is exactly symmetrical
the coil however being omitted. Similar parts in the circuit of fi are indicated
by letters similar to those in the circuit off but with a suffix. The accumulator t
always sends a constant current through the armature z.
The circuit of the coil p is by E through M' by fam d wo y and back to p.
The current in the coil p opposes that in the coil
9.
It is obvious that as the contact bars o o, are moved from e e₁ to d d₁ to a a₁
to b₁ to c c, at each step the tension applied to the feeders ff is increased by an
amount corresponding to the tensions of the machines
The operation may be described thus:-
9 m.
Supposing that the coil p and the accumulator t are disconnected and that the
armature is rotated by hand until the tension applied to the feeders is such that
the lamps at P' receive normal tension that is the tension of J and the armature z
held in that position, then obviously the tension of M' and the m or g machine or
machines in the circuit of the feeder is equal to the tension lost over the feeder.
Let the coil be connected up, and the number of its convolutions be made such
that its effect is equal and opposite to the effect of the coil p. It now the accumu-
lator t be connected up the armature will remain stationary.
Supposing then that the armature is stationary in the position shewn, let the
load ou the feeder be increased. The effect of q overcomes that of p and moves
the armature so that O O₁ move in the direction of a a, respectively, and
continue the moving until they are in such a position that the effect of p is increased
so as to be equal to that of q.
On the other hand a reduction of load on the feeder leads to the coil p over-
coming the coily and the movement of 2 is in the opposite direction and continues
until the effect of p is decreased so that it equals that of q.

page_text: Thus the consumers at the end of f f¹ are supplied at constant tension.
preventer and continuity preserver should be added to o 01.
A spark
bc there-
Any m armature and any o armature may be wound on the same core.
If for instance there are more wires beyond c and c, and if between a
are many armatures in parallel, an armature might be used of higher tension
connected from a to c.
The m and g armatures are constrained to run at constant speed by being
mechanically coupled to the J armatures.
Dated this 7th day of December 1894.
ABEL & IMKAY,
Agents for Applicant.
Improvements in Systems of Electrical Distribution.
I, REGINALD WOOD, of 57 Gower Street in the County of London, 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 relates to the application to electrical distributing systems of
electric generators, motors, and accumulators, also combined generators and motors,
for the purpose of determining the consumers electric tension, and maintaining that
tension constant notwithstanding variations in the tension of the main generators or
in consumption of the electric energy and differences in the resistance of the feeders
by which the energy is supplied to different parts of the system.
I shall explain my invention referring to the diagrams accompanying my
Provisional Specification Fig. 1 illustrating its application in two cases, namely,
first, when the object is to maintain at the lamps the same electric tension as that
at the main generators, which would in that case be maintained constant, and
secondly, when the object is, as it generally would be, to maintain at the lamps a
tension less than that at the main generators which would then be suitably varied.
There is also a third case in which the object is to maintain at the lamps a tension
greater than that of the main generator, which then would be suitably varied.
Referring now to the diagram Fig. 1 which shews my invention applied to
a 5-wire system of distribution, A indicates the main generators, T U are omnibus
bars, BCY are three positive feeders and bey the corresponding negative or
return feeders, P are feeding points, E F G H I are the five wires supplying the
lamps or other consumers L on 4 circuits. In each of these circuits I arrange a
balancing machine J, the field magnet of which has two sets of coils, indicated in
the figure, for the sake of clearness, by two separate pairs of circles K and K.
The coils K are all connected in parallel with the terminals of any source of
electricity at constant tension, and are shewn connected to the feeders Bb at the
terminals of the machines M' farthest from the main generators A.
The coils K are in series with the armatures of the machines J, which armatures
are mechanically connected so as to revolve together. In the feeders Cc Y y
which have appreciable resistance I arrange an energising machine M having its
field magnet coils wound compound with two opposing pairs of coils, the one pair N
being in series with the armature and the feeder, the other pair O being connected
in parallel across the terminals of the armature in the feeders Beach of which
contains a similar machine M', but, as these feeders have no appreciable resistance,
the coils N are omitted. The armatures of the machines M and M' are mechanically
connected to the armatures of the machines J and revolve with them. The coils Ó
may be connected in parallel to any source of electricity the tension of which can.
be varied in proportion as the tension of M is varied in any other way. The.
43

page_text: acumes AAT IS IOW. I sometimes mechanically couple an
engine to the machines J and M'..
In some cases in the second illustration I add to the magnets of M¹ two coils,
one being connected between E and I so as to assist the coil O, the other being so
connected to any constant source of electric energy that, when the former added
coil is supplied at the normal tension between E and I, the latter added coil exactly
neutralises it.
It has been assumed that the resistance of the armature MT with its fee ler would
be negligible. But cases will arise in practice, in which, however low the resistance
of the armature M', and however large the machine M' be made in proportion to
the work it has to perform, the effect of the M' armature current will be
appreciable, and in these cases the machine will require treating by any method of
compounding for armature drop and counteracting armature reaction, so that the
tension over the armature M¹ and over its coil O is equal to the electro-motive
force of the armature M' due to the coil O.
Under certain conditions that may occur in practice, in order that a change in
main generator tension may be accompanied by a corresponding change in the
magnetic induction of the magnetic circuit of M', it is advisable that the armature
circuit of M' should have large, of J should have small, and the coil O of M'
small, and the K coils large inductance, that the magnetic circuit of M' should be
sufficiently laminated, and that the inertia of the revolving parts of J M¹ should be
large. For the same purpose a specially wound alternating current transformer may
be used with three coils: one connected across the main generator terminals to
operate on change of main generator tension on the two other coils, one of which
is so connected as to oppose change in K and the other to help change in
O of M¹.
The balancing machines J operate in the following manner. Assuming that in
one or other of the four circuits, say for instance the circuit H I there is a demand
for less current than in the other circuits or some of them then the machine J,
which is in the circuit H I, acts as a motor, its armature driving the other armatures
whereby more current is sent into their circuits. Thus the machines J operate to
balance the currents in the several circuits, taking up excess of energy from some
of them and contributing energy to others of them. Besides operating in this
manner, the machines J owing to an equal increase of current to each of them in
the motor sense, so that they may even all be motors both balance and drive at
constant speed the energising machines M which, when the coils O are short
circuited there being no residual magnetism in the M' magnetic circuit act as series
generators to maintain constant the tension at the lamps, each supplying energy to
overcome the resistance in the feeder in which it is situated.
Thus the machines J even when their balancing function is not required serve by
driving the machines M to maintain constancy of tension at the feeding points.
In other words the operation may be described thus. If the main generators are
maintained at normal pressure the armatures J act as motors and drive at normal
speed the armatures M in fields excited by the coils N only, which therefore act
as series generators and add to the feeders the energy lost in them, and thus the
consumers are supplied at normal pressure.
Now whilst the system is operating as above, as a second illustration let the
short circuit over the coils O be removed, the armatures M running at normal
speed, being considered as being in fields partly created by the coils O and partly
created by the coils N, and the M O machines being assumed to be nearer to the
main generator A than the M N machines. The machines J are being fed at
normal tension and are therefore running at normal speed. Let the tension of the
main generator be increased gradually from normal consumers' tension.
Whatever tension within limits is applied to the coils of the machines MO
the armatures M' running at normal speed give a tension of the same value as that
applied, and precautions having been adopted such that the tension over O responds
to a change of main generator tension, and the induction through M' and therefore

page_text: the electromotive force of M² responds to a change of tension over O, before the
change of main generator tension has time to alter the speed of J or the tension
over J, it follows that, the main generator tension having been increased as above,
the excess of main generator tension over normal consumers' tension is absorbed by
the M' machines and the tension over the J machines remains normal consumers'
tension and the speed of the machines remains normal.
In practice through unforseen contingencies it might occur that this division of
tension between the two machines did not obtain, so it is ensured that the excess
tension shall be absorbed by the M'O machines at constant speed and not by the
J machines attaining more than normal speed or running below normal speed while
the M¹ O machines remain imperfectly operative by the fact that, if more than
normal tension is over the J machines, the first added coil on the M¹ magnets
overcomes the second added coil, assists the O coil and continues its assistance
until the tension between E and I is normal and the M' O machines absorb the
excess tension at normal speed. And on the contrary if less than normal tension
is over the J machines the second added coil on the M¹ magnets overcomes the
first added coil, opposes the O coil and continues its opposition until the tension
over the J machines is normal and the M' O machines absorb the excess tension at
normal speed.
In many cases it will be found convenient to connect an accumulator between E
and I.
Since the machines M' O absorb the excess tension the lamps are therefore fed
at normal tension because the tension resulting from the effect of the N coils on
the M armatures is the same as before, and is still added on to the difference
resulting from the combination of the main generator A and the effect of the
O coils on the M armatures, this difference being automatically maintained at the
consumers' normal tension, and the current to each of the J machines in the first
illustration is thus decreased in the second illustration by an amount such that the
decrease in the power of all these machines equals the power produced by the action
of the O coils on the M armatures so that the J machines may even all be generators
and still maintain the balance of current between the circuits. In the above
explanation, the effect of the coils O has been separated from that of the. coils N
for the sake of clearness. In reality an armature M in the combined field
produced by the coils O and N becomes motor or generator according as the effect
of the coils O or that of the coils N predominates.
Two feeders of appreciable resistance are shewn connected to T U but there
may obviously be any number. In other words the operation may be described
thus: However much, within limits, the tension of the main generator A exceeds
the normal tension of the consumers, the effect is that the current produced by the
combination of the main generator A and the coils O acting on the armatures M
is maintained at normal tension, and the armatures M acted on by the coils O
acting in combination with the armatures J drive at normal speed the armatures M
acted on by the coils N which act as before as series generators and add to the
feeders the energy lost in them. Thus the consumers are supplied at normal
tension.
Further increase of the excess of the main generator tension is attended with a
like result, the current to the J machines being again reduced.
So long as the excess of main generator over normal consumers' tension is being
increased as above, the magnetic induction in the M¹ magnetic circuit is
proportional to the tension over O. But if this excess be now decreased the
magnetic induction in the M' magnetic circuit, as evidenced by hyteresis, does
not decrease in like proportion. And it is necessary in some instances, by
applying electric current to a coil on the M¹ magnets, to have in action on
the M magnetic circuit back Ampère turns in opposition to the current in
the O coils, so that, during the time that this want of proportionality or excess of
magnetic induction would otherwise exist, the back Ampère turns correct for it, and
make the actual magnetic induction in the M¹ magnetic circuit proportional to the
B

page_text: tension over O. If variable electric tension be available, these back Ampère
turns can be switched in and out of the coil as required, by means of a switch
which makes suitable connection between the coil and the supply. The switch can
be arranged so that motion in one direction switches in the back Ampère turns,
and motion back again switches them out again. These motions of the switch can
be automatically caused by a small polarised armature or a small armature
carrying a current if the switch be mechanically coupled to the armature shaft.
For this purpose the armature lies partly in the fields of two magnetic circuits
excited in series or parallel with the coils O. One of these magnetic circuits
contains iron similar and similarly disposed to that of the M₁ magnets, the other
does not; and the number of turns of wire and the direction of current on each are
adjusted so that, whilst the tension over the coil O is increased from zero, at which
point residual magnetism has been eliminated, the switch armature is stationary,
and in this position there are no back Ampère turns in operation, that is the switch
does not make connection between the coil and the electric supply.
If now the tension over the coil O is decreased, the induction in the magnetic
circuit not containing iron decreases more rapidly than the induction in the
magnetic circuit containing iron, and the field belonging to the former is weakened
more than the field belonging to the latter. Consequently the armature and switch
are moved, and as the switch gradually moves it gradually switches back Ampère
turns on the M¹ magnet and also on the iron magnet of the instrument, for which
latter purpose a coil is placed on the iron magnet in series or parallel with the coil
on the M¹ magnet. The motion of the switch continues until the two fields of the
instrument are of equal effect, that is until the magnetic induction in the circuit
containing iron has been reduced by the back Ampère turns so that it is proportional
to the magnetic induction in the circuit which does not contain iron. And the
number of turns in the coil on the M¹ magnets is adjusted so that with the switch
in this position the magnetic induction in the M¹ magnetic circuit is proportional to
the tension over the coil O. As the tension over the coil O continues to be
decreased the back Ampère turns are increased, until the limit required is reached
when on further decrease of the tension over they remain constant. On the
other hand on again increasing the tension over the magnetic circuit not
containing iron overcomes the other circuit and the switch is moved back, thus
switching out back Ampère turns, until, as tension continues to be increased, all the
back Ampère turns are switched out and the magnetic induction in M' is again,
without the extraneous aid of back Ampère turns, proportional to the tension
over O. Instead of controlling the connection between a supply of electric energy
and coils on the iron magnet of the instrument and on the M' magnets the switch
may be made to control a resistance in the coil O, and in the exciting coil on the
iron magnet of the instrument. In some instances this will meet all requirements.
The M magnets may themselves form part of the iron circuit of the instrument.
A change in demand is met in the usual way by a corresponding change in the
power of the main generators.
For instance a decrease in the demand by any feeder leads to increased main
generator pressure. Owing to the windings of the feeder machines the other
feeder currents remain constant so long as the speed of the feeder machines remains
constant; but the increased main generator pressure weakens the fields of the
generators M and strengthens the fields of the motors M, thereby decreasing the
power required from the machines and increasing their power to drive, and thus
making the J machines less motors and more generators which would tend to
increase the pressure over the lamps connected to them and the speed of the
machines. The excessive pressure and speed are avoided by reduction of the power
of the main generator.
The third case is exactly analogous to the second. The coils O would be
disconnected and again connected so that the current in them is in the reverse
direction to a separate source of electricity maintained at a tension proportional
to the excess of the tension required at the lamps over that of the main generator.

page_text: All the M armatures then act as generators driven by the J machines, the O coils
producing such an effect on the M armatures as to make the main generator and
the MO machines combined equivalent to main generators at lamp tension and
the M N machines as before supplying the energy required to overcome the
resistance of the feeders. The operation would be the same if the current in
the O coils were simply reversed and the coils K connected to a source of electricity
the tension of which is maintained constant.
The two armatures M or M' belonging to a pair of feeders need not have
separate field magnets but they may be wound on one core and have only one field
magnet.
When transformers, the armatures of each of which are on one core, and the
number of which is varied with the load, are interposed between the feeder and
the distributing wires, the coils N have their number of convolutions increased
and a coil is added which carries a current proportional to the current in each
transformer.
The position of the balancing and feeder machines is not of course confined
to the station. The winding of these machines may be varied in any suitable
manner for special purposes. For instance a balancing and feeder machine may
be carried by a locomotive the excitation being under control both as to strength
and direction if requisite.
I sometimes make a correction for hysteresis in all these machines, and I some-
times vary the number of convolutions in the coils K'even reversing the connection
of some of them when requisite.
In order to increase the range of the machine, I sometimes divide the field
magnet and armature magnetic circuit of the J K K¹ machine into two sub-
stantially parallel magnetic circuits, more or less insulated from one another by
the interposition between them of a layer of feebly magnetic material bounded if
necessary by an electric current. The one magnetic circuit is excited by the
coils K, the other, being so disposed and excited that at no load it carries
practically no induction, bears also the coils K¹, which even above full load do
not saturate it. It is obvious that the current in the armature conductors will
perform all the functions of the coils K' if the symmetrical line of the latter
magnetic circuit be properly disposed with regard to the line joining the brushes.
In order that the four armatures J may be wound on one core and running in a
field produced by a pair of K coils may perform the function of balancing without
any cross induction which may of course be otherwise counteracted suitable means
being adopted to commutate each armature about the symmetrical position, for the
series coils K' may be substituted low pressure series wound dynamos, worked at a
low induction that is small J K' machines, the substantial function of which would
be to add in either direction the pressure lost over the resistance of J J K¹: The
small J K machine would be constrained to run at constant speed. Suitable
means might be adopted to commutate them in the symmetrical position or the
lead of their brushes would be constant. The wires E and I are shewn divided
between the feeding points but I sometimes connect these through.
It is obvious that the compound wound energising and de-energising machines
would require magnet copper out of all proportion to their nett output, and that
great waste of energy by heat would be occasioned by the neutralisation of
excitation if this neutralisation took place on the magnets of the energising and
de-energising machine themselves. The energising and de-energising machines
have their magnets therefore wound with one coil, contacts with which can be
made from the outside at certain points separated by a different number of
convolutions. The neutralisation of excitation is effected on a very small dynamo
acting as a contact shifter, the armature of which moves a contact bar which
makes connection between the coil on the energising or de-energising machine
magnet and a coil on the magnet of the contact shifter.
Referring to Fig. 2 which represents a de-energising machine or motor, A. is a
main generator, T is the positive omuibus bar, U is the negative omnibus bar.

page_text: O, is the coil of the de-energising machine, R its magnet poles, e e¹ are com-
mutators of armatures of the positive and negative machines respectively wound
on one core M; Cc are the feeders, positive and negative respectively, M' is the
de-energising armature. Vare the magnet poles of the contact shifter. N¹ is the
series coil of the contact shifter. O, is a separate coil with contact points
corresponding to those of O₂ is the armature of the contact shifter.
contact bar of the contact shifter. Q any suitable constant source of electricity.
The current passes from the positive omnibus bar T by the commutator e
through the positive de-energising armature on the core M to the positive
feeder C.
n the
The return current from the negative feeder c passes by the commutator e¹
through the negative de-energising armature on the core M, thence through the
coil N on the magnet of the contact shifter back to the negative omnibus
bar U.
The two feeder currents in the armatures on the core M are in the field
produced by the coil O 2.
The current from M₁ passes through the coil O₂ by the contact bar n
through the coil 03 back to M'. The direction of the current in O is
opposite to that in N₁.
A current of constant strength from Q always passes through the armature l.
The operation is shewn thus:-Suppose that the current in N¹ is enough for
one lamp only, the effect of N₁ will be negligible and that of O, must also be
negligible, therefore the position of the contact bar n will be stand the bar will
be stationary. The full number of convolutions O₂ will be active, and the tension
of e and el equal to that of M₁.
Now let the current in N, increase, V becomes magnetised and acts on / so as
to move n counterclockwise. The effect of this is to increase the active con-
volutions in O, and decrease them in O₂. The movement continues until the
effect of the active convolutions on O, equals that of N₁. So that the tension
of e and e, is decreased by an amount proportional to the current in N 1.
For the amount by which the pressure of e and e¹ is less than the full amount is
proportional to the idle convolutions on 02 i.e. to the active convolutions on 03
that is to the effect of N₁.
When the current in N 1 decreases again V becomes magnetised in the opposite
direction, and the armature l moves clockwise. It will then be obvious that the
neutralisation of excitation is effected by N 1 and O3, and is utilised to keep active
in O2, only the necessary convolutions.
The numbers of convolutions in N 1 and of active convolutions in O₂ + 03 are
the same respectively as the numbers in N and O coils of Figure 1. The number
of convolutions in N 1 and O, might be divided by any number, say 2. Then if n
moved and cut out 1 convolution on O 3, it must at the same time cut out 2 in 02,
and in all cases the resistance of the convolutions cut out in O3 must be equal
to the resistance of the convolution in at the same time in O 2.
As will be evident from the above, in the case of the de-energising machine
shown in Figure 2 the separate coil or O coil of Figure 1 is divided into two
parts O, O 3 of which O, is placed on the magnet of the de-energising machine
and 03 on the magnet of the contact shifter. On the other hand, in the case of
the energising machine or generator shewn in Figure 3, it is the series or N coil
of Figure 1, which is divided into N 2 and N.3 of which N 2 is placed on the
magnet of energising machine, and N 3 on the magnet of the contact shifter, and
since the resistance of the coil N is very low, there is no necessity for the
convolutions cut in and out at the same time to be of the same resistance.
Referring to Figure 3, (in which reference letters such as are used in Figure 2
are applied as far as possible to corresponding parts) which represents an energising:
machine the current to the. position feeder Y passes from the positive omnibus
bar T by the commutator e through: an energising armature on the core M. The
return by the negative feeder y passes by e', through the other armature on.

page_text: the core M and through the coil N 3, by contact bar n, through the coil N 2, back
to the negative omnibus bar U. The two feeder currents in the armatures on the
core M, are in the field produced by the coil N 2.
The current from M 1, passes through the coil O³, in a direction opposite to that
of the current in N 3-Q always sends a constant current through 1.
The operation is as follows:-The effect of the current in N 3, suppose equals
that of the currents in O 1. V is not magnetised and therefore is stationary in
the position shewn. If now a demand for more current is made on the feeder, the
effect of N 3, increases and V becoming magnetised n moves clockwise, until the
effect of N 3, equals that of O 1. The effect of N 2, has thus been increased by an
increase in the number of its active convolutions. A decrease in the tension of M 1
would produce the same effect, whilst an increase in the tension of M 1, or a
decrease in the current in N 3, leads to a counter-clockwise movement of n, and
a decrease in the number of active convolutions on N 2.
In cases where there is a considerable number of feeders requiring a corre-
sponding number of energising and de-energising machines which it would be
inconvenient to arrange all on one set of shafting with the balancing machines, I
divide the energising and de-energising machines into groups, each group consisting
of one energising machine or several of them, and one de-energising machine or
several of these, all those of the group being selected in such a manner, that
the power given out by the de-energising machines is nearly that required for the
energising machine. A group of this kind is on one line of shafting with a
machine which can act as a generator or motor, introduced in one of the main
circuits or several such machines, and consequently there are as many such lines of
shafting as there are groups, such as are above referred to.
For the same purpose as the apparatus described in Figures 2 and 3, there may.
be used another modification of the apparatus in Figure 1, in which for the effect
of the coils O, in the feeders Yy, Cc is substituted, the equal effect of a certain
number of convolutions of the coils N, these convolutions of each N coil being
made of the same resistance, and connected in parallel to a source of current, the
pressure of which is always maintained proportional to the pressure over M¹ and
opposes the pressure of the main generators A.
The results obtained by means of Figure 1, may also be obtained by a
modification in which the pairs of feeders are treated in couples, a long pair and
a short pair being treated together, and a contact shifter may be used. Thus
confining attention for the moment to feeders Yy, C c, in Figure 1, it is evident
that the addition of tension required in Yy will be equal to the reduction of
tension required in Cc, if the tension applied to Yy Cc has a certain intermediate
valve. The energising armatures of Yy may therefore be wound on the same
cores, as the de-energising armatures of Cc care being taken that the correct
intermediate tension be applied to Yy, Cc. The windings of the magnets must be
such that the number of Ampère turns is equal to half the difference between the
product of the number of convolutions in N in feeder Y. Figure 1, into the current
in feeder Y Figure 1, and the product of the number of convolutions in N in
feeder C Figure 1, into the current in feeder C, Figure 1. The correct tension
is applied to the feeders Yy Cc by connecting Y to C, and y to c and
connecting Y. C. through a de-energising armature to the positive bar T
and connecting y c through a de-energising armature to the negative omnibus
bar U. These two de-energising armatures may be on the same core.
Referring to Figure 4; A is the main generator M₁ the de-energising armature
shunt coil not shewn. Yy, Cc, long and short feeders respectively.
Q is an
accumulator or other constant source of electricity sending a current through'l,
which is the armature of contact shifter. V. is its pole piece N4 N 6 the coils on
its magnets, n is the contact bar, R is the pole piece of the combined energisingiand
de-energising machine for the two pairs of feeders. N 5 is its coil, M its armature
core, e 2 e 3 e 4 e 5 commutators for its four armatures. The circuit of the feeder Y

page_text: passes from the positive omnibus bar T, through a de-energising armature M 1,
through the coil N 4, by the contact bar n through the coil N 5, by com-
mutator e 2 through an energising armature on the core M, and so to the consumers.
The return by y passes by the commutator e3 through an energising armature on
the core M, and so through M¹ back to the negative omnibus bar U.
The circuit of the feeder C passes through a de-energising armature M 1 through
the coil N 6 by the commutator e4 through a de-energising armature on the
core M, and so to the consumers. The return by the feeder c passes by the com-
mutator e 5 through a de-energising armature on the core M, and so through M
back to the negative omnibus bar U.
The armatures M. M' are mechanically coupled to J armatures as in Figure 1
whereby their speed is maintained constant.
The operation is explained as follows: As the tension of the main generator A
is increased from a small amount to a value considerably above that of the
consumers, the speed of the J, M' and J. M. machines rises as explained with
reference to Figure 1.
When M attains normal speed the tension applied to the feeder terminal of M
is a definite amount, namely, half the sum of the tensions lost in the feeder
circuits Y. C. and equal tension is maintained at the consumer's ends of Y and C.
This follows from the resistances of the circuits and the winding of the magnet
of M. These equal tensions are also normal because M cannot attain normal
speed until J attains it, and J must then be receiving normal tension, and there
is a connection by the inner wires from the J machines to the lamps at the end of
feeders Y and C, as in Figure 1, and therefore these lamps receive the same
tension as the J machines. And since M¹ attains normal speed at the same time
as M, M then gives the difference in the tension between that of the main
generator A, and that at the feeder terminal of M'.
Suppose now that there is an increase in the number of lamps at the end of C
more current flows along C in consequence of the decrease in resistance, and this
weakens the magnet field of M. by moving the contact bar in the direction of
clock hands. Therefore the lamps on C would become bright and those on Y
dull, were it not that there is a decrease of tension over M¹ which automatically
raises that at its feeder terminal, thereby re-adjusting the tension over the lamps
on Y and C to normal, a decrease of load on Y is followed by a similar result.
On the other hand a decrease in load on C or increase on Y is followed by an
increase of tension over M' and a re-adjustment of the tensions over the lamps
on Y and C to normal by a movement of the contact bar in the direction opposite
to clock hands.
Referring to Figure 5, in which letters are used as far as possible to indicate
the same things as in Figure 1. A is the main generator T, U, positive and
negative omnibus bars respectively, O M' are de-energising machines J. K K' are
balancing machines, J and M' being mechanically coupled. L are lamps or other
consumers of energy. E F G H are the five wires of the 5-wire system.
F G H should be connected through as in Figure 1. They are left unconnected
for the sake of clearness. All the above were described with reference to Figure 1
as was also the operation of J. M' in maintaining in spite of variation of the
tension of the main-generator A, and in the number of consumers L, constancy of
speed of J M¹ and constancy of tension over each and all of J.
is the pole piece, z the armature, & the commutator p. q, coils of a contact
shifter u is insulation y y' prolongations of the armature shaft. ww1 are contact
pieces o o1 are contact bars capable of making contact respectively between w, y
and w1 y 1 o, w, and o 1 w 1 are shewn in the plane of the paper for the sake of
clearness. In reality they should be at right angles to the plane of the paper and
to the shaft y. y 1 having been turned in opposite directions through a right
angle o, o rotate with y y¹.
a b c d 1 boldll
AMA

page_text: 9 are generators, and m are motors preferably of equal tension, connected in
series and to the wires a, b, c, d, e and a1 b1 c1 dl el as shewa. One pair of
feeders ff1 is shewn.
The circuit off passes from the positive omnibus bar T by f to a, and then
either direct by the contact piece w to the contact bar o, or through one or more
of the machines m or q, and so by a contact piece w to the contact bar o, and then
through the coil q by f to the feeding point P. The circuit of fl is exactly
symmetrical, the coil 7 however being omitted. Similar parts in the circuit of fl
are indicated by letters similar to those in the circuit off, but with a suffix.
accumulator t always sends a constant current through the armature z.
The circuit of the coil p is by E, through M' by f. a. m. d. w.
back to p.
The current in the coil p opposes that in the coil q.
The
º y and
It is obvious that as the contact bars o, o₁ are moved from eel to d, d1
to a, a 1 to bb1 to c, cl at each step the tension applied to the feeders ƒfƒ¹ is
increased by an amount corresponding to the tensions of the machines g, m.
The operation may be described thus:-
Supposing that the coil P
and the accumulator t, are disconnected and that the
armature, is rotated by hand until the tension applied to the feeders is such that
the lamps at P receive normal tension, that is the tension of J, and the armature z
held in that position, then obviously the tension of M' and the m or g machine or
machines in the circuit of the feeder is equal to the tension lost over the feeders.
Let the coil p be connected up and the number of its convolutions be made such
that its effect is equal and opposite to the effect of the coil q. If now the
accumulator t be connected up, the armature z will remain stationary.
Supposing then that the armature z is stationary in the position shewn. Let the
load on the feeder be increased. The effect of overcomes that of p and moves
the armature Z, so that O. 01 move in the direction of a al respectively, and
continue the moving until they are in such a position that the effect of p is
increased so as to be equal to that of 9.
On the other hand a reduction of load on the feeder leads to the coil p overcoming
the coil q and the movement of Z is in the opposite direction and continues until
the effect of p is decreased, so that it equals that of 4.
Thus the consumers at the end offf are supplied at constant tension. A spark
preventer and continuity preserver should be added to o o'..
Any m armature and any g armature may be wound on the same core.
If for instance there are more wires beyond c c and if between a b, bc, there
are many armatures in parallel, an armature might be used of higher tension
connected from a to c.
The m and g armatures are constrained to run at constant speed by being
mechanically coupled to the J armatures, or are treated in groups as the M machines
of Fig. 1 but the method and result of coustraint may be altered.
Obviously for the gm machines, may be substituted accumulators or other
sources and absorbers respectively of electric energy.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a system of electrical distribution, connecting the terminals of the
generator to the feeders in the manner shewn in Fig. 1 through feeder machines
of the kinds indicated at O M' and O M N and connecting the circuits through
balancing machines of the kind indicated at J K K¹ substantially as and for the
purpose set forth.
2. In combination with a dynamo machine having two field magnet coils,
apparatus substantially as described with reference to Figs. 2 and 3 for determining
such difference as may be required between the effects of the two coils.
3. In combination with several armatures supplying several feeders and revolving

page_text: in one magnetic field excited by the difference of the effects of two coils, apparatus
such as is referred to in the preceding claim for determining the said difference
and a machine M' interposed between the generator and each couple of feeders,
substantially as described with reference to Fig. 4.
4. In combination with feeder machines O M' and balancing machines J K K¹
such as are referred to in Claim 1, generators g and motors m with automatic
commutating switches o, for determining consumers' tension, substantially as
described with reference to Fig. 5.
5. A feeder machine such as O M N Fig. 1, having two field magnet coils, the
one N in series with the armature M, and the other coil O otherwise excited,
substantially as and for the purpose set forth.
6. In any system of electrical distribution the combination of a shunt machine
such as O M¹ (Fig. 1) with a balancing machine such as J K K' or several of
these with a generator, substantially as described.
Dated this 4th day of October 1895.
ABEL & IMRAY,
Agents for the Applicant.