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April 18, 1933.
1,904,465
E. HOROWITZ
ELECTRICAL REGULATOR
Filed Jan. 15, 1931
Fig.1.
I Fig.2.‘
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CURRENT
CUPPEN T
.
_
Inventor“.
Eugen I-Iorovvit’z,
His Attorney.
1,904,465
Patented Apr. 18, 1933
UNITED STATES
PATENT OFFICE
EUGEN, HOROWITZ, OFYHALENSEE' GERMANY, ASSIGNOR TO GENERAL ELECTRIC
COMPANY, A CORPORATION OF NEW YORK
ELECTRICAL
REGULATOR
Application ?led January 15, 1981, Serial No. 508,858, and in Germany‘ February 11, 1880.
My invention relates to electrical regulators of a resistance material whose electrical re
changes with changes in, voltage
and particularly to quick acting regulators sistance
across it or, current through it.
for dynamo electric machines.
'
Various quick acting regulators have been
Present day electrical power transmission devised
for the purpose of overcoming the 55
5 networks are almost exclusively constant
difficulty but for one reason
voltage alternating current ‘systems contain above'described
or
another,
such
as high cost or delicacy or
ing synchronous dynamo electric machines.
In order that the variations in power ?ow complexity they have not "been wholly satis
10
16
in such systems shall not cause correspond factory.
An object of my invention is to provide 60
ing voltage variations, it is customary to pro a novel
quick acting electricallregulator which
vide the synchronous machines with auto is extremely
simple and inexpensive.
matic voltage regulators which control the Another object
of my invention is to pro
excitation of these machines in accordance
vide
a
quick
acting
electrical regulator which
with the tendency of the voltage tode art
no moving parts or electric valves. 65
from the rated voltage'of the machines. or involves
My invention will be better understood
a given value of power transfer, the excita from
the following description taken in con
tiondof the synchronous machines is therefore nection With the accompanying drawing and
?xe .
“20
Now it is well known that the value of
power transfer at which interconnected syn
chronous machines‘will fall out of synchro
nism is proportional to the degree of excita
tion of these machines. Under ordinary cir
its scope will be pointed out in the appended
70
claims.
In the drawing Figs. 1 and 2 represent re
spectively the voltage-current and the resist
ance-currentv characteristics of a resistance
element employed in a preferred embodiment
cumstances of load change the usual voltage of
my invention, Fig. 3 illustrates a very sim- 75
2 ‘ regulators in performing their function of
ple
embodiment of my invention applied to an
maintaining constant voltage will prevent alternating
generator, Fig. 4 is a
the machines from falling out of step with modi?cation current,
of
Fig.
increases in load. However, these regulators modification of Fig. 3. 3, Fig. '5 is a further
usually involve moving parts having a cer
Referring now to Fig. 3 of the accompany- 8°
30
tain amount of inertia and in addition these ing drawing 1 is the armature of a three
moving parts are usually damped in order’
alternating current generator which
to prevent hunting. They, therefore, operate phase
as a ?eld winding 2 which is energized from
with a certain unavoidable time delay.
There are times when networks are sub
3
the armature 3 of an exciter. This exciter
has a shunt ?eld ’winding 4. Connected in 35
jected to sudden disturbances involving the the circuit of the ?eld winding 2 is a special
instantaneous application of large loads, such
resistance element 5, across which is con
as the occurrence of short ‘circuits or during nected the secondary winding of a current
certain switching operations. At such times transformer 6 which is in one of the external
40
it not infrequently happens that the syn
of armature 1.
chronous machines pull apart because the conductors
As
shown
in Fig. 1 the current through the
regulators have not acted quickly enough.
resistance
element
rapidly with
In accordance with my invention I provide increases in voltage5 increases
across it while Fig. 2
extremely simple means, involving no mov
another aspect of the character
ing, fragile or expensive parts, which acts illustrates
instantaneously to vary the excitation of a istics of resistance element 5 in that it shows 9‘
dynamo electric machine in accordance with, how the resistance decreases rapidly with
variations in an electrical condition of this increases in current through the element.
machine and which may either be used alone Any resistance elements possessing the gen
or as an auxiliary regulator to the ordinary eral characteristics illustrated by Figs. 1 and '
regulator. I attain this end through the use 2 may be employed! Some of these resist- 1
1,904,466
2
ances, like carbon for example, depend for to synchronous motors or condensers, in both
their action upon a change in thermal con
of which it is desirable to increase the ex- Y
dition which is brought about by the increase citation rapidly as load changes on such ma
in heating due to the increase in current chines occur. It will also be obvious to those
through them. Such resistance elements are skilled in the art that my invention is not i
not as quick acting as those whose electrical limited in its application to alternating cur
resistance changes as a function of the ap
rent machines.
Of course, with direct cur
plied voltage only and consequently I prefer rent machines the need for quick excitation is
to use a resistance element of the latter type. not as great as with alternating current ma
One such element is a synthetic voltage-de
pendent resistance material consisting of a
?red mixture of carborundum, clay and car-'
bon which has the property of instantaneous
ly reducing its electrical resistance with in
creases in applied voltage. Such a synthetic
resistance is described and claimed in Patent
chines. Nevertheless, the regulating ar
rangement illustrated in Fig. 3 would be use
which is assigned to the assignee of the pres
change in the excitation circuit.
ful as an adjunct to the ordinary slow acting 4
regulator which is applied to a direct current
machine. Thus, as the load change on the
direct current machine occurs the change in
current will induce the voltage in the sec
winding of current transformer 6
No. 1,822,742, granted September 8, 1931, on ondary
an application of Karl B. McEachron, and which will produce the desired resistance
With the arrangement illustrated in Fig.
'
The operation of the embodiment of my 3 the resistance of the secondary winding of
' invention illustrated in Fig. 3 is as follows. current transformer 6 should be high with
As the load on the main generator increases respect to the resistance of element 5 for best
the voltage induced in the secondary wind- operation. This is because some of the direct
current ?owing in the ?eld winding 2 will
25 ing of current transformer 6 increases pro
portionately with the increase in load cur tend to ?ow through the secondaryl winding
rent. Consequently the voltage applied of current transformer 6 instead of all ?ow
across resistance element 5 increases with the ing through resistance element 5. If this
result that its electrical resistance decreases current is high enough it will produce satu
ent application.
instantaneously an amount. which is propor
30
tional but not necessarily directly propor
ration in current transformer 6 with the re
sult that its secondary voltage will no longer
tional to the increase in load current of the be a true index of the current ?owing in the
main generator. The e?'ect of this decrease external circuit of the main generator. To
in the resistance in the ?eld circuit of the eliminate the possibility of such an occur
35
rence a condenser may be placed in the cir
rent and consequently the excitation of the cuit of secondary winding 6. Such an ar—
main generator is to increase the ?eld cur
main generator. The arrangement illus rangement is illustrated in Fig. 4. This
trated in Fig. 3, therefore, accomplishes the ?gure also differs from Fig. 3 in that the
desired result of quickly increasing the ex resistance element 5 is in the exciter ?eld
citation of a dynamo electric machine in ac circuit instead of in the main generator ?eld
cordance with the increases in load upon it. circuit. With this arrangement equal changes
It should be understood that the embodi in electrical resistance of element 5 pro
ment of my invention illustrated in Fig. 3 duce larger changes in the excitation of the
' is merely a preferred embodiment and that main generator than when resistance ele
45 in its broadest aspects my invention is not ' ment 5 is in the main generator ?eld circuit.
The operation of the‘ arrangement illus
limited to the use of a series element whose
trated
in Fig. 4 is fundamentally the same as
electrical resistance decreases with‘ increase
50
in current or terminal voltage. For example. the operation of the arrangement illustrated
it will occur to those skilled in the art that in Fig. 3. The function of condenser 7 is to
the same result may be secured through the prevent the ?ow of direct current in the sec
55
increases with'increases in current through thus preventing saturation by the direct cur—
it, such as a length of pure iron wire, which .rent which otherwise would tend to ?ow in
is connected in parallel with the ?eld winding . this winding.
Due to the fact that an alternating voltage
without'departing from my invention in its
use of an element whose electrical resistance ondary winding of current transformer 6
_is impressed across resistance element 5 in
.
Although in Fig. 3 I have illustrated my both Figs. 3 and 4 an alternating voltage will
invention as applied to a three-phase syn be inserted in the ?eld winding circuit of the
chronous generator it will readily occur to main generator of Fig. 3 and in the ?eld
those skilled in the art that my invention is winding circuit of the exciter in Fig. 4. Ir
broadest aspects.
60
65
not limited in application to such a machine “most practical applications of my invention
and that the number of phases may be as this e?ect. however. will be negligible be
man) or as few as desired. Furthermore, cause of the large inductance of the ?elr
it will also be obvious to those skilled in the winding of the main generator of Fig. 3 and
art that my invention is equally applicable of both the main generator and the exciter 0;‘
3
1,904,465
Fig. 4. However, any possibility of adversely dynamo electric machine com rising, a ?eld
10
affecting the wave form of the main generator
in this manner may be avoided by inserting
a recti?er between the secondary winding of
the current transformer 6 and the resistance
element 5. Such an arrangement is illus
trated in Fig. 5 where a full wave dry con
tact recti?er 8 is inserted between the second
ary winding of current transformer 6 and
the resistance element 5. My invention is ob
winding circuit for said mac ine, a resist
ance element whose electrical resistance de
creases instantaneously with increases in
voltage applied to it connected in said excita
tion controlling circuit, a current transform
70
er in the external circuit of said machine and
means connecting the secondary winding of
said current transformer across said resist
ance.
75
viously not limited to the use of a full wave
4. In combination, an alternating current
recti?er but I refer such a recti?er to a circuit, a dynamo electric machine connected
15
half-wave recti er because when, the latter to said circuit, an excitation controlling cir
is used the secondary winding of current cuit for said machine, a resistance element
transformer 6 is virtually open circuited dur
whose electrical resistance varies inversely
ing alternate half cycles. During overload with changes in voltage applied thereto con~
and short circuit conditions this might have nected in said excitation controlling circuit,
80
the effect of injuring the insulation of the a current transformer connected in said ?rst
current transformer due to the high voltages mentioned circuit, and a full wave recti?er
20 produced.
‘
connected between said element and the sec
The operation of the embodiment of my ondary windin of said current transformer.
invention illustrated in Fig. 5 is essentially
In witness w ereof, I have hereunto set my
‘ the same as the operation of the embodiments hand this 20th day of December 1930.
26
illustrated in Figs. 3 and 4. As the increases
in‘ load occur on the main generator the volt
EUGEN noaowrrz.
85
so
age of the secondary winding of the current‘
transformer 6 increases and this voltage
applied to resistance 5 as a direct current
30
voltage. This has the e?ect of greatly re
ducing the resistance of element 5 with the
5.335
result-that the excitation of-the main gen
erator is quickly increased. It should be
' noted that in the arrangement illustrated in
85
Fig. 5 that therecti?er 8 also prevents a ?ow
of direct current in the secondary winding
of current transformer 6.
40
'
100
.
While I have shown and described particu
lar embodiments of my invention it will be
obviousto those skilled in the art that changes
and modi?cations maybe made wthout de
105
parting from'my invention and I, therefore,
aim in the appended claims to cover all such
changes and modi?cations as fall within the _ '
true spirit and scope of my invention.
What I claim as new and desire to secure
110
by Letters Patent of the United States, is:
I. In combination, a dynamo electric ma
chine, an excitation controlling circuit‘ for
said .dynamo electric machine, a resistance
element whose electrical resistance changes
116
said resistance 1n accordance with variations
in an electrical condition of said machine.
120
instantaneously with the voltage which is
applied to it connected in said circuit, and
means for varying the voltage applied to
2. In combination, a dynamo electric ma
chine, an excitation controlling circuit for
said machine, a resistance element whose elec
trical_ resistance decreases instantaneously
with lncreases in voltage applied to it con
nected 111 said circuit, and means for increas
mg the voltage applied to said element in
a?cordance with increase in load on said ma
3. A quick acting voltage regulator for a
125
0 me.
130

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