Improvements relating to the Method and Means Employed for Coupling Alternating Current Dynamo Machines in Synchronal 'Relation, and to the Control of Motive Power Engines used* for Driving the same.
Year: 1889

page_text: Date of Application, 17th May, 1889
Complete Specification Left, 17th Feb., 1890-Accepted, 22nd Mar., 1890.
"
PROVISIONAL SPECIFICATION.
Improvements relating to the Method and Means Employed for
Coupling Alternating Current Dynamo Machines in Synchronal
'Relation, and to the Control of Motive Power Engines used* for
Driving the same.
We, WILLIAM LOWRIE, Engineer, and CHARLES JAMES HALL, Electrician, both of
117 Bishopsgate Street, in. the City of London, do hereby declare the nature of this
invention to be as follows:
In the specification accompanying our application for Letters Patent, No. 1167,
bearing date the 22nd January 1889, entitled. "Improvements in and relating to
switches and switch! connections for electric current circuits," we described, amongst
other things, a means for establishing electric connection between two alternating
current dynamo machines, through the unit switch blocks therein described; indi-
cating the phases of the current from the machines by means of the light from a
glow lamp, placed on the switch board, in circuit with a coil of each armature.
Our present invention relates to an improved method of, and means for, coupling
together alternating current generating dynamo machines so that their phases or
alternations are synchronous, and, indirectly, to the control of one or more engines
employed for driving the same.
By our invention we electrically connect in parallel, two or more alternating
current dynamo machines so that they may be generating and supplying electric
energy throughout a system of mains for lighting or other purposes. To do this,
efficiently, it is necessary that their alternations, in either direction, should exactly
synchronize, and when the machines are thus electrically connected, that their
'synchronous relation should be maintained. Our method is as follows:
We mount a glow lamp; having a certain maximum candle power at 100 volts,
(for example), upon a switch board; in the manner described in our before named
specification; or in any other convenient manner. This we connect with the armature
coils of two of the machines to be coupled, suitable switches being placed in the
circuit. Should the armature coils be of a higher potential, collectively than the
potential of the lamp used, it is reduced in any convenient manner to that of the lamp.
If the machines are generating high tension currents, we may take any part or section
of the armature coils that will furnish the required amount of potential; or; we may
reduce the same by incans of suitable secondary generators to one half the potential
of the lamp. Conversely, if the machines are supplying current at a lower potential
than that required, we may, by suitable secondary convertors, raise the potential to
equal that of the lamp. When both alternating current machines are running at their
'appointed speed, and are put in circuit with the lamp, the phases or alternations of
the current are manifested by the light of the lamp. When the phases are exactly
opposed to each other, no light is given by the lamp, because the opposing currents
neutralize each other; but when the phases exactly coincide with each other, the lamp
gives out its full candle power, because it is in series with the two machines and is
receiving current of the maximum potential of 100 volts.
The machines are arranged in parallel to supply the mains as before stated, and
when it is desired to switch in an additional machine it is run as nearly as possible at
the appointed speed, and. when the lamp indicates by its full sustained power that the
alternations of the current in the armature coils exacly coincide, (that is, are
.synchronous), the machines are electrically coupled together by a suitable switch
arranged for that purpose.
The linking together of two machines, in unison; in this manner; is so complete
that we have found, where each. has been driven by a separaté steam engine of

page_text: 200 effective horse power, (when exerting full power) that we could not only reduce the
steam pressure in one of the engines, but could shut it off entirely, without disturbing
the synchronous relation of the current alternations, as manifested in the lamp. This
is important where the amount of energy expended in the working circuits varies
greatly and as the synchronism indirectly controls the motive power engines, it
admits of employing several or differing powers of the same each, however, con-
tributing its quota of power to the general effect.
It will be understood that while the alternating current generating machines are
arranged to work in parallel, in relation to the working circuit or circuits, the
glow lamp is placed in series with the said machines; and that the collective potential
of the current supplied from the machines (either directly or through a convertor) is
equal to the voltage of the lamp, whatever that may be,
Also, that we may use, for coupling the machines, the unit switch blocks described
in our beforenamed specification, or any other kind suitable for the object in
.view.
Dated this 17th day of May 1980
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements, relating to the Method and Means Employed for
Coupling Alternating Current Dynamo Machines in Synchronal
Relation, and to the Control of Motive Power Engines used for
Driving the same.
We, WILLIAM LOWRIE, Engineer, and CHARLES JAMES HALL, Electrician, both of
117, Bishopsgate Street, in the City of London, 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:-
In the specification of our application for Letters Patent, No. 1167, bearing date
the 22nd January 1889, entitled "Improvements in and relating to switches and
.switch connections for electric current circuits," we described, among other things, a
means for establishing electrical connection between two alternating current dynamo
'machines, through the unit switch blocks therein described, shown, and claimed. The
phases of the current from the machines were indicated by means of light from a glow
lamp placed on a switch board, in circuit with a coil of each armature.
The glow
lamp was conveniently mounted upon one corner of the said switch board, which also
had mounted upon it, various terminal blocks, with their several circuit connections.
The glow lamp was arranged in a circuit which comprised a coil of each armature of
two alternating current dynamo machines, and a small connecting switch. When it
was desired to couple together the said two current generators, the machines were
run as nearly as possible at the same speed, and when their phases synchronized-as
indicated by the light of the glow lamp-the machines were switched together by the
plugging of corresponding terminals. Our present invention relates to an improved
method of and means for coupling together alternating current dynamo machines, so
that their phases or alternations are synchronous. It furthermore relates, indirectly,
to the control of one or more engines employed for driving the same.
By our invention we electrically connect in parallel two or more alternating current.
dynamo machines so that they may be generating and supplying electric energy
throughout a system of mains, for lighting or other purposes. To do this efficiently
it is necessary that their alternations in either direction-should exactly synchronize,
and, when the machines are thus electrically connected, that their synchronous
relation should be maintained. Our method is as follows:-
:-
We mount a glow lamp having a certain maximum candle. power at 100 volts,
(for example), upon a switch board as described in our before named specification;
or in any other. convenient. manner. This we electrically connect with the arinature
coils of two of the machines to be coupled; suitable switches being inserted in..the

page_text: circuit. Should the current from the armature coils be, collectively, of a higher
potential than the potential of the lamp used, it is reduced in any convenient manner
to the standard voltage of the lamp. If the machines are generating high tension
currents, we may take any part or section of the armature coils that will provide the
required potential; or we may reduce the, same by means of suitable secondary
generators so that the potential of the current from each machine is equal to one half
the voltage of the lamp. Conversely, if the machines are supplying current.at a
lower potential than that required, we may, by suitable secondary generators, raise
the potential to the standard, voltage of the lamp as above stated. When both
alternating current machines are running at their appointed speed, and are put in
circuit with the lamp, the phases or alternations of the current are manifested by the
light of the lamp. When the alternating current phases are exactly opposed to each
other, no light is given by the lamp, because the opposing current alternations
neutralize each other; but when the phases,exactly coincide, the lamp gives out its
full candle power, because it is in series with the two machines, and is receiving
current of the maximum potential of 100 volts.
The machines are arranged in parallel to supply the mains as before stated, and
when it is desired to switch in an additional machine it is run as nearly as possible
at the appointed speed, and when the lamp indicates (by its full sustained power) that
the alternations of the current in the armature coils. exactly coincide-that is, are
synchronous the machines are electrically coupled together by a suitable switch
adapted to that purpose.
The linking together in unison of two machines in this manner, is so complete,
that we find where each has been driven by a separate steam engine of 200 effective
horse power, (when exerting full power), that we cannot only reduce the steam
pressure in one of the engines, but can shut it off entirely without disturbing the
synchronous relation of the current alternations, as manifested in the lamp. This is
important where the amount of energy expended in the working circuit varies greatly;
and, as the synchronism indirectly controls the motive power engines, it not only
governs their speed but admits of employing several or differing powers of the
same each, however, contributing its quota of power to the general effect.
It is to be understood that while the alternating current generating machines are
arranged to work in parallel-in relation to the working circuit or circuits-the glow lamp
is placed in series with the said machines. Also, that the collective potential of the
current supplied by the machines (either directly, or through a secondary generator),
is equal to the voltage of the lamp, whatever that may be. Furthermore, that while
the unit switch blocks described in our before named specification is well adapted
for coupling the machines, any other kind, suitable for the object in view, may be
employed instead.
In the accompanying drawing, the figure is a diagramatic representation of the
means employed in carrying out our invention. In this, a, a are two alternating
current generating dynamo machines, each respectively driven by a separate steam
engine, b. From each machine arinature electric conductors c, c' are led to two
terminals d, d' of two separate unit switch blocks, the other two terminals of. each
switch block being indicated by the letters, 1. From the terminals d, d', of. each
switch block electrical communication is made with the primary or high tension coils
of the secondary generators e, e¹, and thence, by induction, with the secondary or
low. tension coils of the same: the two latter being electrically connected by the
conductors e and e³. A small glow lamp f. and controlling switch g placed. in the
circuit e³, and arranged in a convenient position with reference to the unit switch
blocks.
The terminals h, of the two unit switch blocks, are electrically connected together
by the respective conductors 2 and 3, and are also connected to terminals i, in two
other separate switch blocks having the corresponding terminals j, j'. The latter
named blocks control the working circuits k, k¹, and both these circuits are shown at
work in the diagram, being supplied by current from the dynamo marked a; the

page_text: three controlling unit switch blocks being properly plugged as indicated by the lines
marked A, A; B, B; and C, C.
.1
The test glow lamp f, is assumed to be (for example) of 100 volts potential, and
is placed in series; while the converters e; el are each adapted to reduce a potential
of the current derived from. its corresponding dynamo machine to 50 volts. Con
sequently, if both dynamo.machines are running their appointed speed, and are put in
circuit with the lamp f by means of the small switch g, the phases or alternations
of the current will be shown by the light rising from darkness (when the phases are
opposed) to the full or candle power brightness, (when the phases coincide); due to
the current at the full potential of 100 volts passing through the lamp: As the phases
of the current (shown by the light) begin to coincide, the light increases in brightness-
The intervals of full light become longer-and when sustained at its standard
candle power, the lamp indicates that the armature coils are electrically synchronous.
.At this point. the unit switch block (indicated by the lines marked D, D), which
serves to connect, the second or idle machine with the working dynamo is plugged,
so that the two machines a and a¹ are linked together to work in paralle!, while the
lamp is placed in series in relation thereto. Any number of pairs of alternating
.current machines may thus be coupled..
It will be noticed that in the diagram the secondary generators or induction
apparatus e. and e! are inserted in the lamp circuit either to reduce or increase the
potential of the current derived from each machine to one half of the voltage of the
lamp, but other means may be adapted to this end (as previously described) in which
.case.secondary generators e. and eare omitted.:
Having now particularly described and ascertained the nature of our said Inven-
tion, and in what manner the same is to be performed; we declare that what we
'claim is
1. The herein described method and means for electrically coupling together
alternating current dynamo machines in synchronal relation, substantially as
.described.
2. The combination of two alternating current. dynamio machines, electrical con-
nections adapted for the parallel working of the said dynamo machines, an indicating
lamp, and electrical couplings or switches, substantially as and for the purpose
described..
3. The combination of two alternating current dynamo 'machines each having a
separate motive power engine for driving the same, electrical connections. adapted
for the parallel working of the said dynamo machines, an 'indicating lamp, and
electrical couplings or switches, substantially as and for the purpose described.'
.
4. The combination of two alternating current dynamo machines; electrical con-
nections, adapted for the parallel working of the said dynamo machines, an electrical
circuit in series relation to the said machines and having an indicating glow lamp
therein, and two secondary generators placed in the said series circuit each adapted to
supply current of the potential of one half the voltage of the lamp substantially as
:described.
5. The combination of two alternating current dynamo machines with electrical
connections for working together in parallel with a series circuit having an indicating
lamp therein, and electrically connected with a coil of each armature of the said
machines. adapted to supply current to the said lamp at one half of its potential,
substantially as described.
Dated this 17th day of Fal
KANA
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicants..