Year: 1887

page_text: Date of Application, 16th Apr., 1887
Complete Left, 16th Jan., 1888
Complete Accepted, 2nd Mar., 1888
When electricity is produced at a distance from the distributing area, it is
advantageous that the current should be high in pressure and small in quantity, so
that it may be transmitted economically to the place or district to be supplied, but
for distribution it is generally preferable that the pressure should be low and the
quantity correspondingly great.
Hitherto the system of high pressure supply and low pressure distribution has
been carried out by dynamo-electric machines and transformers which generate and
reproduce alternating currents of electricity. With such currents storage batteries
cannot be used, and much inconvenience may result from a break-down of any part of
the apparatus.
My Invention relates to a system of generating, transmitting, storing, and
distributing electricity for lighting or other purposes, in which continuous currents
are generated and reproduced, and storage batteries may be employed.
At the generating station of principal centre, I employ dynamo-electric machines
of the continuous current class, and I transmit the whole or a part of the current or
currents to secondary stations or distributing centres. At the distributing centres, I
use combined electro-motors and generators, or transformers, so as to produce by the
energy of the transmitted electric current, other currents which may be different in
pressure or quantity, and I may use in conjunction therewith storage batteries or
accumulators of any suitable kind.
The generators and transformers may be wound with two or more sets of conductors
and the accumulators may be charged by the primary or secondary currents.
When a number of distributing centres are connected to one or more generating
stations, I may also connect them one to another, so that no inconvenience may arise
to any one of the united centres, by a temporary break-down of apparatus, and I may
connect the whole or any number or part of the distributing centres to the generating
station in multiple are or in series one with another.
Dated this 19th day of Anvil 1887

page_text: COMPLETE SPECIFICATION.
A System of Generating, Reproducing, and Distributing Electricity.
I, WILLIAM MAXWELL of 34 Claybrook Road, Fulham S.W. 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:-
When electricity is produced at a distance from the distributing area it is
advantageous that the current should be high in pressure and small in quantity so
that it may be transmitted economically to the place or district to be supplied, but for
distribution it is generally preferable that the pressure should be low and the quantity
correspondingly great.
Hitherto the system of high pressure supply and low pressure distribution has been
carried out by dynamo electric machines and transformers which generate and
reproduce alternating currents of electricity. With such currents storage batteries
cannot be used and much inconvenience may result from a break-down of any part of
the apparatus.
It is known that high pressure continuous currents of electricity can be converted
into low pressure currents by means of combined electro-motors and generators, but
hitherto systems of distribution based upon the use of such machines have not been
successfully applied to the purpose of district lighting owing to the absence of self
regulation in the machines and the want of any provision to obviate the inconvenience
of a break down in the generating or converting apparatus.
My invention relates to a system of generating reproducing and distributing
electricity for lighting or other purposes by means of continuous current electric
generators and reproducing transformers and secondary batteries or accumulators,
which I construct or arrange in such a manner that the system is practically self
regulating, while the distribution is not materially affected by a temporary break
down in the generating or transforming apparatus.
At the generating station or principal centre I emply automatically controlled or
self regulating dynamo electric machines to produce the high pressure currents for
transmission to the secondary stations or distributing centres where I use machines
constructed to act as combined electro motors and generators or self regulating
transformers in combination with electric accumulators.
In practically carrying out this system I generally prefer to use dynamo electric
machines constructed as described in my specification No. 9056 of 1886, this method
of construction being equally applicable to continuous current generators and to
reproducing transformers. Self regulating machines of the above type are wound
with two conductors or two sets of conductors on the armatures and on the field
magnets, and the nature of the second field magnet winding can be varied to suit the
requirements of distribution on either the series or the parallel method. Machines
having only one set of field magnet coils, can be controlled automatically by
suitable current or potential regulators.

page_text: When the primary or motor circuits of such reproducing transformers are connected
in series to the generator circuit, the current in that circuit should be maintained
constant in quantity. To effect this, a current regulator controlling a variable
resistance in the field magnet circuit of the generator can be used, or a set of low
resistance coils, arranged to demagnetize the field magnets of the generator by the
generated current, may be employed.
When the primary or inducing circuits of the reproducing transformers are
connected parallel to the transmitting mains, the current circulating in the mains
should be kept at an approximately constant potential. This regulation can he
conveniently effected by a set of low resistance auxiliary coils on the field magnets of
the primary generator connected in series with the transmitting circuit.
The reproducing transformers, whereby from the high pressure transmitted currents
are obtained currents of lower pressure and greater quantity, may be similar in
construction to the primary generators, the primary and secondary coils on their
armatures being in suitable relation to each other; and these machines may be
governed by the secondary or reproduced currents as described in the specification
No. 9056 of 1886 above referred to. The motor or inducing circuits of the reproducing
transformers consisting of the exciting coils of their field magnets, and the primary
coils of their armatures are preferably in series, and the currents produced in the
secondary coils of the armature supply the outer circuit comprising the accumulators
and the distributing or lighting mains.
The reproduction may be governed by transmitting the reproduced current or part
thereof through regulating coils on the field magnets of the reproducing transformers,
or by any suitable known regulator.
The electric accumulators or secondary batteries employed may be of any suitable
kind. These are preferably connected to the circuits of the reproducing transformers
and to the distributing mains as in dynamo installations, suitable automatic or safety
connections being employed; or, according to another arrangement, the high pressure
current can be stored by means of secondary batteries connected in series to the
transmitting circuit, these batteries being used to supply the motor current to the
reproducing transformers.
In order to provide for variation in potential resulting from the use of accumulators
or from other causes, the main leading to lights should include variable resistances
that can be automatically controlled by potential governors and electro motors with
reversing contacts, or by other suitable means. Also when it is necessary to disconnect
one or more reproducing transformers from the transmitting main, to which a number
are connected in series, an equivalent resistance can be switched in, automatically or
otherwise.
By employing adequate means of storage in combination with dynamo electric
generators and reproducing transformers, and suitably governing the currents, I can
without inconvenience connect the primary circuits of a number of reproducing
transformers in series to a transmitting main, while the distributing mains supplied
by the low potential currents from these transformers can be connected in parallel or
may be independent, according as it is desired to unite places or districts, or to supply
them separately. I am also thus enabled to employ generating and reproducing
plant continuously at a nearly uniform rate of work, and to use for transmission an
electric current of very high potential.
When it is preferred to connect the distributing centres in parallel to supply mains,
I transmit the high pressure current from the generating station to a suitably placed
secondary station where by a reproducing transformer it produces a current of lower
potential; from the secondary station supply mains proceed either to the motor
circuits of other reproducing transformers or to secondary batteries at the distributing
or lighting centres, preferably with variable resistances and current regulators in
circuit. Two or more secondary stations each supplying a number of distributing
centres can be served from one generating station.
This arrangement combines the advantages of high potential transmission from the
generating station with low potential supply to the distributing centres, and it admits

page_text: of a greater variety in the construction and use of transformers than is advisable when
they are directly connected in series to the primary circuit. Electro motors can also
be connected to the supply mains and can be used as required without seriously
affecting the lighting circuits. Also the reproducing transformers can be used as
motors by opening their secondary circuits, or conversely a motor having its armature
wound with an additional set of coils to act as an electro generator can be used as a
reproducing transformer for either light or power.
The generators and the reproducing transformers employed can be wound with more
than two conductors on their armatures so as to supply independent circuits with
currents differing in pressure, due care being taken to maintain the current in each
circuit approximately constant.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. In a system of generating reproducing and distributing electricity, the
combination of electric generators and reproducing transformers with accumulators
or secondary batteries, substantially as and for the purposes herein set forth.
2. For reproducing storing and distributing electricity the combination of
machines, acting as electro motors and generators or reproducing transformers, with
electric accumulators or storage batteries, substantially as described.
Dated this 16th day of January 1888.
ABEL & IMRAY,
Agents for the Applicant.