Improvements in the Means or. Apparatus for Regulating the Speed of Dynamo-electric Machines Used for Distributing Electrical Energy. OF-ELECTRIC MACHINES FOR DISTRIBUTINGRICAL GY
Year: 1884

page_text: Improvements in the Means or. Apparatus for Regulating the
Speed of Dynamo-electric Machines Used for Distributing
Electrical Energy.
[Communicated from abroad by Marcel Deprez, of 1, Boulevard Saint Denis,
Paris, France, Electrical Engineer.]
PROVISIONAL SPECIFICATION.
I JOHN CLAYTON MEWBURN of 169 Fleet Street in the City of London Patent
Agent do hereby declaro the nature of my Invention for IMPROVEMENTS IN THE
MEANS OR APPARATUS FOR REGULATING THIE SPEED OF DYNAMO-ELECTRIC
MACHINES USED FOR DISTRIBUTING ELECTRICAL ENERGY to be as follows:-
In every industrial application of the distribution of energy by electricity one
of the main conditions to fulfil is that of the complete independence of each
receiving machine. It is necessary in the first place that the normal working of
the machinery or tools to be actuated be never altered, that the speed of the
dynamo machine be at no time modified by the stoppage of the other receiving
machines, and in the second place that the power or energy given out be never
affected by the variations of work which may be required of it from zero up to the
maximum power of which it is capable.
The means or apparatus for regulating which form the subject of my invention
and which I will proceed to describe are intended to attain the above objects.
Upon the inductor of the receiving machine I place two windings of wire which
for distinction I will call respectively e and E. The wire e is put in tension with
the ring and communicates with the line; the other E is independent of the induced
body or ring and its ends are connected with the binding screws of a small auxiliary
dynamo machine. The winding e is determined experimentally so that the magnetic
field which it engenders gives rise in the ring to a counter electro-motive force
equal to half that of the line while the machine turning at its normal speed develops
the maximum of which it is capable.
The winding E on the contrary, more powerful than the winding e is so selected
that it can when actuated by the auxiliary machine create a magnetic field
developing in the circuit of the induced body an electro motive force equal to that
of the line and double that which is due to the winding c. The auxiliary maching

page_text: may be of any suitable kind but with a magnetic field variable by the grouping of
the wires of the inductor. Its rotary movement is fixed in a given relation with
that of the main machine and centrifugal governor or other speed regulator
controls the movement of the brushes of the regulating commutator of the
machine.
All the receiving dynamo machines of the same installation thus made work
together, each of them will turn at its normal speed corresponding to non-action of
the winding E.
At the moment, on the contrary, when for any cause all the machines except one
nre entirely stopped by cutting them out of the general circuit, that one will tend
to increase its speed. But this increase of speed involves as I have already
explained increased speed of the auxiliary machine and therefore the speed
governor acts on the regulator of the magnetic field of this machine and this under
the action of a magnetic field of more and more power will almost instantaneously
cause to pass into the winding E of the main machine, a current which giving rise
as I have said to an electro motive force in the ring circuit equal to that of the line
will lead to a complete stoppage, the current passing no longer into the circuit e
and consequently into the induced body. The speed then decreasing the current
becomes weaker in the auxiliary winding and equilibrium is effected immediately
to keep the main machine at its normal speed whatever be the number of machines
in connection and the variations of the resisting work imposed upon the main
machine. With this arrangement it further follows that the energy given out can
never get below 50% since the counter electro motive force has for its minimum
the value, which moreover it cannot reach with the installation above described.
Besides, the putting in and out of action of the machinery or tools which the
main machine actuates cannot affect its speed, the work which it produces remains
always proportionate to that which is required of it, and when the whole works are
stopped the machine turning at the same speed develops no more work than that
which the small auxiliary machine requires.
According to another arrangement, I take a dynamo-electric machine and regulate
it so that the receiver in its normal work imparts to it a rotary speed nearly
approaching but below that which corresponds to the discharge or unpriming
(désamorcement) of the small machine. From the well known properties of dynamo
machines it will at once bo seen that if the speed at which the small machine
becomes charged or primed be a little exceeded this immediately engenders a
powerful current which will give rise in E to an intense magnetic field. Conse-
quently the electro magnetic force of the main machine increases to the point of
equilibrium with that of the source.
The same phenomenon for attaining the same object can be obtained in a
different way. It is clear that an addition or a reduction of inert resistances in the
circuit of the small machine provoked by a speed governor can instantaneously by
priming or unpriming (charging or discharging) the small machino give to the
circuit E all its power or on the contrary neutralize it.
This independence of each receiving dynamo machine can also be obtained in a
manner analogous to but different from those already described; that is to say,
while retaining the two windings of wire on the inductors of the machine I can
dispense with the auxiliary machine and employ an arrangement in which the
winding E of the inductors is traversed by a current derived from the main line.
In this case however there is an obstacle to be avoided. In the transmission and
distribution of energy by electricity the tensions of the electric current being very
high it would be necessary in this derivation to employ a wire which is very long
and as fine as the intensity of the circulation would permit and this would lead
to considerable expense-In order to obviate this I place in the circuit of the
winding E a carbon or mercury rheostat whose commutator can be actuated by a
centrifugal governor. Under these conditions when a current is sent into the
machine, this being at rest, the effect of the winding E is almost null, and the feeble
intensity which circulates in the circuit of the ring allows nevertheless of starting

page_text: (démarrage). From this moment the governor beginning gradually to turn succes-
sively suppresses the resistances of the rheostat and consequently increases the
intensity of the magnetic field, until the speed which likewise increases has
attained its proper rate. It is easy to see that the complete regulation of the
receiving machine is again attained by this arrangement because as soon as an
increase of speed tends to manifest itself the resistance of the rheostat diminishing
immediately the counter electro motive force increases likewise so, that the normal
equilibrium is at once established.
A
The employment of a rheostat can also be combined with that of an auxiliary
machine for producing a constant magnetic field in the receiving machine. In this
combination the circuit E of the inductors is excited by an auxiliary dynamo,
machine whose rotation is dependent on that of the receiving machine whilo in the
circuite is a rheostat with centrifugal speed governor arranged so that when at
rest all resistance is suppressed. Under these conditions the starting is effected,
and in proportion to increase of the speed the resistances become added to the
circuit c so as to annihilate it gradually in order to leave entirely to the auxiliary
machine the excitation of the inductors.
Whichever of the arrangements above described is employed in the distribution
of energy by electricity there should be placed in the circuit c a rheostat whose
resistances can be successively cut out by hand.
Owing to the high tensions of the generating current at the moment of starting'
the resistance of each receiving machine being small in relation to that of the line'
the addition of inert resistances is necessary in the circuit of derivation of each.
machine in order to avoid their destruction. Thus the intensity of the current,.
first very weak, which traverses the machine increases gradually until the speed
which likewise increases bas given riso to a counter electro motive force sufficient'
to ensure good action.

page_text: I JOHN CLAYTON MEWBURN of 169 Fleet Street in the City of London Patent
Agent, do hereby declare the nature of my invention for "IMPROVEMENTS IN
THE MEANS OR APPARATUS FOR REGULATING THE SPEED OF DYNAMO-ELECTRIC
MACHINES USED FOR DISTRIBUTING ELECTRICAL ENERGY," and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
In every industrial application of the distribution of energy by electricity one of
the main conditions to fulfil is that of the completo independence of each receiving
machine. It is necessary in the first place that the normal working of the
machinery or tools to be actuated be never altered, that the speed of the dynamo
machine be at no time modified by the stoppage of the other receiving machines,
and in the second place that the power or energy given out be never affected by
the variations of work which may be required of it from zero up to the maximum
power of which it is capable.
The means or apparatus for regulating which form the subject of the present
invention and which I will proceed to describe with the aid of the annexed
drawings are intended to attain the above objects.
Take a receiving machine as indicated at M in Figures 1 and 1º, Figure 1 bring
a diagrammatic view and Figure 1 shewing the general arrangement. Let A be
one of the branches of the inductor, B the ring, C the collector and d d the
brushes.
Upon the inductor place two windings of wire e and E. The wire e is put in
tension with the ring and communicates with the line; the other E is independent
of the induced body or ring and its ends are connected with the binding screws of
a small auxiliary dynamo machine m. The winding e is determined experimentally
so that the magnetic field which it engenders gives rise in the ring to a counter-
electro-motive force equal to half that of the line while the machine turning at its
normal speed develops the maximum of which it is capable.
The winding E on the contrary, more powerful than the winding c is so selected
that it can when actuated by the auxiliary machine m create a magnetic field
developing in the circuit of the induced body an electro motive force equal to that
of the line and double that which is due to the winding c. The auxiliary machine m
may be of any suitable kind but with a magnetic field variable by the grouping of
the wires of the inductor. Its rotary movement is fixed in a given relation with
that of the machine M and a centrifugal governor or other speed regulator
controls the movement of the brushes of the regulating commutator of this
machine m.
All the receiving dynaino machines of the sanic installation thus made work
together, each of them will turn at its normal speed corresponding to non-action
of the winding E.
At the moment on the contrary when for any cause all the machines except one
are entirely stopped by cutting them out of the general circuit, that one will tend
to increase its speed. But this increase of speed involves as I have already
explained increased speed of the machine m and therefore the speed governor acts
on the regulator of the magnetic field of this machine m and this under the action
of a magnetic field of more and more power will almost instantaneously cause to
pass into the winding E of the machine 'A a current which giving rise as I have
said to an electro-motive force in the ring circuit equal to that of the line will lead

page_text: to a complete stoppage, the current passing no longer into the circuit and
consequently into the induced body. The speed then decreasing the current
becomes weaker in the auxiliary winding and equilibrium is effected immediately
to keep the machine M. at its normal speed whatever be the number of machines in
connection and the variations of the resisting work imposed upon the machine 'M.
With this arrangement it further follows that the energy given out can never get
below 50° since the counter electro motive force has for its minimum the value,
which moreover it cannot reach with the installation above described.
Besides, the putting in and out of action of the machinery or tools which the
machine M actuates cannot affect its speed, the work which it produces remains
always proportionate to that which is required of it, and when the whole works
are stopped the machine turning at the same speed develops no moro work than
that which the small machine m requires.
According to another arrangement, I take a dynamo-electric machine and
regulate it so that the receiver (M) in its normal work imparts to it a rotary
speed nearly approaching but below that which corresponds to the discharge or
unpriming (désamorcement) of the small machine m. From the well known
properties of dynamo machines it will at once be seen that if the speed at which
the small machine becomes charged or primed be a little exceeded this immediately
engenders a powerful current which will give rise in E to an intense inagnetic field.
Consequently the electro magnetic force of the machine 'M increases to the point
of equilibrium with that of the source.
The same phenomenon for attaining the same object can be obtained in a different
way. It is clear that an addition or a reduction of inert resistances in the circuit of
the small machine provoked by a speed governor can instantaneously by priming
or unpriming (charging or discharging) the small machine give to the circuit E all
its power or on the contrary neutralizo it.
This independence of each receiving dynamo machine can also be obtained in a
manner analagous to but different froin those already described; that is to say
while retaining the two windings of wire on the inductors of the machine I can
dispense with the auxiliary machine m, Figure 1 and employ an arrangement
illustrated by Figure 2 in which the winding E of the inductors is traversed by a
current derived from the main line. In this case however there is an obstacle to
be avoided. In the transmission and distribution of energy by electricity the
tensions of the electric current being very high it would be necessary in this
derivation to employ a wire which is very long and as fine as the intensity of the
circulation would permit and this would lead to considerable expense. In order to
obviate this I place in the circuit of the winding E a carbon or mercury rheostat
whose commutator can be actuated by a centrifugal governor. Under these
conditions when a current is sent into the machine, this being at rest, the effect of
the winding E is almost null, and the feeble intensity which circulates in the circuit
of the ring allows nevertheless of starting (démarrage). From this moment the
governor beginning gradually to turn successively suppresses the resistances of the
rheostat, and consequently increases the intensity of the magnetic field, until the
speed which likewise increases has attained its proper rate. It is easy to see that
the complete regulation of the receiving machine is again attained by this
arrangement because as soon as an increase of speed tends to manifest itself, the
resistance of the rheostat diminishing immediately, the counter-electro motive
force increases likewise, so that the normal equilibrium is at once established.
The employment of a rheostat can also be combined with that of an auxiliary
machine for producing a constant magnetic field in the receiving machine. In this
combination which is illustrated by Figure 3 the circuit E of the inductors is
excited by an auxiliary dynamo machine m whose rotation is dependent on that of
the receiving machine while in the circuit e is a rheostat R with centrifugal speed
governor arranged so that when at rest all resistance is suppressed. Under these
conditions the starting is effected, and in proportion to increase of the speed the

page_text: resistances become added to the circuit e so as to annihilate it gradually in order
to leave entirely to the machine m the excitation of the inductors.
Whichever of the arrangements above described is employed in the distribution
of energy by electricity there should be placed in the circuit e a rheostat e (sec
Figures 1, 2 and 3 whose resistances can be successively cut out by hand.
Owing to the high tensions of the generating current at the moment of starting
the resistance of each receiving machine being small in relation to that of the line
the addition of inert resistances is necessary in the circuit of derivation of each
machine in order to avoid their destruction. Thus the intensity of the current,
first very weak, which traverses the machine increases gradually until the speed
which likewise increases has given rise to a counter-electro motive force sufficient
to ensure good action.
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
1 claim is
1. The means or apparatus herein before described for regulating the speed of
dynamo electric machines used for distributing electrical energy.
2. The employment on the inductors of a receiving dynamo electric machine of
two windings of wire, one of them, which is always in tension with the circuit of
the ring or induced body being derived from the main line, while the other is
actuated either by a second derivation from the line with the addition of a rheostat
or by an auxiliary machine worked by the receiving machine itself, substantially as
and for the purpose set forth.
3. The employment for the purposo described of an auxiliary machine for the
excitation of the inductors of a receiving dynamo electric machine, the said auxiliary
machine receiving its movement from the receiving machine itself, substantially as
set forth.
4. The employment of a derivation from the main line for exciting the inductors
of a receiving dynamo-electric machine, with the addition of a rheostat brought
into play by the movement of a centrifugal speed governor directly actuated by
the receiving machine, substantially as set forth.
5. The employment of a machine for exciting the inductors of a receiving
dynamo electric machine the action of such exciting machine being felt only when
the speed of the receiving machine increases and then either by means of a
centrifugal speed governor adding to or reducing inert resistances in its circuit
or because the normal speed is below but very near that which corresponds to its
charging or priming, substantially as set forth.
6. The employment for exciting the inductors of a receiving dynamo electric
machino of a machine having a variable magnetic field and whose regulating
commutator is actuated by a centrifugal speed governor substantially as set forth.
Dated this 7th day of October 1884.
J. C. MEWBURN.