вход по аккаунту


Патент USA US2403393

код для вставки
July 2, 1946.
‘ 2,403,393
maa April 1s, 194s
FeJcJeT-‘som> ,
*by JvÉ/my ZM
His Attorney.
Patented ~'July 2,l 1946
2.403.393' " ’
Justin Peterson, Swampscott, Mass., assignor to
General ElectricA Company, a corporation of
New York
Application _April 16, 1943, Serial No. 483,353
11 Claims. (Cl. 171-119)
This invention relates to electrical regulators
and more particularly to improvements in static
constant current transformers.
ferent core type of core and a different winding
Referring now to the drawing and more par- .
By a “static constant current transformer” is
ticularly to Fig. 1, a shell-type iron core I is
meant an electrical transformer which without
shown as provided with flux leakage paths 2. In
the use of moving parts will supply constant out~
the legs of these leakage paths are cut windows 3
put current with substantial variations in input
so that the leakage paths `have restricted sections.
f voltage, or load impedance, or both.
Mounted on the center leg of the core on oppo
The invention operates on the principle of two
site sides of the leakage paths are coils 4 and 5,
linear reactances of opposite sign effectively con 10 while an additional coil B is closely coupled to
nected in parallel with each other and in series
coil 5. 'Coils 4 and 5 have equal numbers of
between the source of current supply and the
turns and they are connected in series with each
load.A The volt-ampere characteristics of these
other through a-oapacitor l. this series connec
linear reactances are parallel so that over a sub
tion being such that the polarities of the coils 4
stantial range of voltage the vector sum (arith 15 and l are in opposition. A variable voltage in- ‘
metical difference) between their currents is con»
putcircuit l is connected across a portion of the
coil 4 by means of an adjustable tap or slider `8
stant. One reactance is inductive and the lin
earity of its working range is obtained by mag
so that adjustment can be made for changes in
netic saturation of a restricted portion of an iron
the level or average value of the voltage of the
core and the substantial linear working range 20 input circuit 8. It will thus be seen that the coil
extends between the point of saturation of the
4 is in effect an autotransformer and that there
restricted section and the point of saturation of
fore it is effectively two windings, one of which
the main body of the core. The other reactance
is connected between the conductors of circuit 8
is a capacitor.
and the other of which is connected between its
The invention is characterized by the use of a 25 two ends or terminals.
single magnetic core which by means of properly
A constant current load or output circuit i0 is
proportioned windings and flux leakage paths
connected across the coil B.
permits the use of a high voltage low current and
The operation of Fig. 1 may be explained by
reference to Fig. 2. In this figure the curve Il
therefore economical capacitor and also per
mits the operation at, any desired voltage ratio 30 is the volt-ampere characteristic of the leakage
between the input and the output circuits. This
reactance of the transformer shown in Fig. l.
is accomplished by making the leakage reac
That is to say, the ordinates of the curve Ii rep~
resent the voltage difference between the input
tance of the transformer the inductive reactance
of the regulating circuit and by connecting the
circuit 8 and the output circuit I0 due to leakage
capacitor into the system by means of coupling 35 reactance effects if the'circult through the capac
windings on the transformer so as effectively to
itor l were open. In order to eliminate the com
connect it in parallel circuit relation with the
plication introduced by a voltage ratio other than
transformer leakage reactance.
i it is assumed for purposes of the present expla
An object of the invention is to provide a new
nation that the number of turns of the coil 4
and improved electrical regulator.
which are connected across the input circuit '8
and which constitute the primary winding of
Another obiect of the invention is to provide
the transformer are equal to the number of turns
a novel, compact,l inexpensive and light-weight
of the coil i which constitute the secondary wind
static constant current transformer.
ing of the transformer and that consequently this
The invention will be better understood from
the following description taken in connection 0f“ transformer has a 1:1 ratio. With the circuit
through the capacitor open the coil 5 and remain
with lthe accompanying drawing and its scope
portion of the coil 4 have no effect on the
_will be pointed out in the appended claims.
action. Under these circumstances the ordinates
In the drawing Fig. 1 is an embodiment of the
or voltage of the curve li would be the leakage
invention having a so-calledshell-type core, Fig. 5 0 reactance voltage drop in the transformer and
2 is a set of volt-ampere curves for illustrating
the abscissae of the curve would be the load cur
the operation of the invention, Fig. 3 is a modifi
rent of the transformer. The bend at the point
cation of the invention utilizing a core-type con
i2 in the curve il is caused by the magnetic sat- .
struction and a different winding arrangement.
uratfon of 4the restricted portions of the leakage
and Fig. 4 is another modidcation using a dif- 55 paths 2 which are formed by the windows 3.
These windows are in eiîect air gaps which are
ing that the difference between the
bridged by the restricted portions. The second
and reactor currents or the resultant current of
bend` in the curve I I at I3 occurs when the main
body or .portion of the leakage path 2 saturates
the system is constant.
and, as will be seen, this occurs at substantially
type and in addition to the two usual legs and
higher values of voltage and current than those
corresponding to point- I2. Between these two
points the volt-ampere characteristic of the leak
interconnecting yokes it has a third leakage leg
I4 provided with restricted saturating sections I5.
age reactance of the transformer is substantially
In Fig. 3 the core I3 is of the so-called core
Coils 4 and 5 corresponding to those in Fig. l are
mounted on the two coil legs of the core and both
linear and this is the working range of the regu 10 these coils constitute autotransformers, the vari
able voltage input circuit 8 being connected across
lating action of the invention. Thus, the range
of voltage which is consumed by the transformer
a portion of the coil 4, as in Fig, l, and the con
in its regulating action in maintaining constant
stant current output circuit In being connected
.output current with variations in input voltage
across a portion of the coil 5.
and variations in load impedance is the differ 15
That the >capacitor l is in fact connected in
ence between the voltages corresponding to points
shunt circuit relation with the leakage reactance
I2 and I3 which are labeled Vmin and Vmax in
of the transformer can perhaps be understood
more clearly by assuming in Fig. 3 that the input
The closing of the circuit of the coils 4 and 5
circuit B_and the output circuit I0 are both con
through the capacitor -I in eiïect connects the 20 nected across all of their respective coils 4 and
capacitor in parallel or shunt circuit relation wi th
5 respectively. This corresponds to a 1:1 ratio
the transformer leakage reactance. One way to
of transformation for the transformer as a whole
explain that this is so is as follows: With the
and if the capacitor l 'is omitted it will be seen
output circuit I0 open, practically all of the flux
that the transformeris in effect short circuited.
of the exciting or primary winding will flow 25 In other words, the current from the supply cir
through the coils 4 and 5 because the flux path - cuit to the load circuit can flow directly through
through these coils does not include any re
the conductors interconnecting the coils 4 and 5
stricted section so that its reluctance is lower
so that there will be no leakage reactance eiîect
than that ofthe leakage paths. Under these cir
or voltage drop between the input and output
cumstances the'voltages induced in the coils 4 30 circuits. However, when this connection between
and 5 are equal and are opposite in their series
the coils is completed through the capacitor, then
circuit so that no voltage appears across the ter
it is as though the leakage reactance of the trans
minals of the capacitor. This is, of course, as it
former were shunted by the capacitor. Obvious
should be because with no load current flowing
ly, if this is true for the special case of a 1:1
there is no leakage reactance voltage drop 35 ratio it will also be true for any other ratio
through the transformer. If no load current
transformation so that the input and output cir
flows in the output circuit I0 the load ampere
cuits may be connected across any desired por
turns in the primary winding or primary portion
tions of the windings 4 and 5.
of the coil 4 and-in the secondary coil 6 oppose
II_t‘he operation of Fig. 3 is the same as that of
Fig. 2.
each other; that isto say, they both try to send
~flux through the center leg of the core in op
Fig. 1,
1n Fig, 4 the core I3 differs from that of Fig. 3
posite directions with the result that they both
in that the leakage leg I5 is the center leg and
send'ñux in the leakage paths _2in the Asame
two pairs of coils are mounted on the core, the
direction. These primary and secondary wind
coils 5 and 6 being on one leg and corresponding
ing leakage fluxes induce voltages in the coils
to those in Fig. 1 and the coil 4 being on another
4 and 5 which are additive in their series circuit
leg and corresponding to the similarly numbered
by reason of the fact that the coils are wound in
opposite directions or are reversely connected.
The result is that the voltage across the capacitor b
’I is proportional to the leakage flux which is an
coil in Fig. l. The fourth coil I6 is mounted on
the same leg with the coil 4 and constitutes the
primary winding of _the transformer.
The operation of Fig. 4 is the same as that of
other way of saying that it is proportional to the
Fig. 1.
leakage reactance drop in the transformer. Con
From the above description it will be seen that
sequently, the capacitor is eiïectively connected in
the invention is characterized by the use of two
shunt circuit relation with the transformer leak 55 pairs of windings, the windings of each pair he
age reactance.
ing closely coupled with respect to each other
The ohmìc value of the capacitor is so chosen
but the two pairs of windings being loosely cou
that its volt-ampere characteristic is substan
pled with respect to each other. However, the
tially parallel to the volt-ampere characteristic
two windings' constituting each pair may either
of the leakage reactance of the transformer be 60 be separate coils or may be parts of the same
tween the points I2 and I3. The 'circuit there-.
coil depending upon whether the relationship is
fore acts like one having a reactor with a char
acteristic similar to that of curve II and a ca
that of an insulating transformer or an auto
transformer and this is a matter of choice. Al
pacitor similar to that of curve I2 connected in
though the various coils of each pair have been
parallel with each other and in series with the 65
mounted side by side on their respective
circuit. The result is that over a range of volt
core legs it will be understood that tl' ey may also
age between Vmm _and Vmx across the parallel
be mounted concentrically, that is to say, one on
combination of the capacitor and reactor, the dif
top of the other; and this in practice is usually
ference between the currents in the capacitor
and reactor, which corresponds to the resultant 70 preferable as it is more conducive to close cou
pling and 10W leakage.
current which can get through the parallel com
bination, will be constant. Thus, as shown in
By making the number of turns cf the wind-~
Fig. 2, the horizontal distance between the curves
ings 4 and 5 relatively high the capacitor current
II and I2 over the `working range of the circuits
ca_n be reduced to any’desired value and its oper
between the points I2 and I3 is a constant show 75 ating voltage can be raised to any desired value,
thus making for >the use of an economical size of
While there have been shown and described
particular embodiments of .this invention, it will
be obvious to those skilled in the art that various
changes and modifications can be made therein
without departing from the'invention and, there
fore, it is aimed inthe appended claims to cover
ings without reducing tlieìcoupling between the
windings of each pair, said leakage path having '
a normally saturated section, a capacitor, and
means> for connecting one winding of each pair
in a closed series circuit with said capacitor, said
last-mentionedwindings yhaving equal turns and
having their polarities in opposition in said closed
circuit, said capacitor having a volt-ampere
characteristic which is parallel to the volt-am
all such changes and modifications as fall within
the true spirit and scope of the invention.
10 pere characteristic of the leakage reactance of »
What I claim as new and desire to secure by
said transformer,
Letters Patent of the United States is:
7. In combination, a transformer having input‘
1. In combination, a transformer having input
and output terminals, means for giving said
and output terminals, vmeans for giving said trans
transformer an abnormally high leakage ñux,
»former an abnormally high leakage re'actance, a 15 winding means on said transformer having a re
capacitor, and means for impressing across said
sultant voltage induced therein which is propor
capacitor a voltage which is proportional to the
tional to the leakage flux of said transformer, and
leakage reactance voltage drop of said trans
a capacitor connected to said Winding means so
former, said leakage reactance having a volt
as to have said voltage impressed across its ter
ampere characteristic corresponding to that of a 20 minals, said capacitor having a reactance which
saturation curve, said capacitor lhaving a volt
is numerically equal to .the ratio of said voltage
ampere characteristic which is substantially .par
to the current of said transformer over a pre
allel to the characteristic of said leakage reactance
above the knee of said curve.
2. In combination, a variable alternating volt
determined current range. „
8. In combination, a transformer having a con
tinuous magnetic leakage ilux path with a satu
rated restricted section between all of the pri
load circuit, a transformer interconnecting said
mary winding and all of the secondary Winding,
circuits, said transformer having a pair of coils
a. capacitor, and coupling means for energizing
with the same number of turns, a primary wind
said capacitor with a voltage which is propor
ing closely coupled to one of said coils, a secondary
to the leakage ñux of said transformer..
winding closely coupled to the other of said coils, 30 tional
9. In combination, a transformer having a con"age supply circuit. a constant alternating-current ,
said transformer having-` a core provided with a
tinuous magnetic leakage iluk path with a nor- '
normally saturated magnetic shunt for the leak
mally saturated restricted section and a normally
age flux of said coils, a. capacitor, and means for
unsaturated main- portion. a capacitor, and at
connecting said coils in series with said capacitor 35
one coupling coil on said transformer for _
in a closed circuit in which the polarities of said , vleast
energizingsaid capacitor with a voltage which
coils are in opposition, the volt-ampere char
is proportional to the leakage flux of said trans~
acteristic of said capacitor being substantially
former, the volt-ampere characteristic of said
parallel to and displaced from a portion of the
capacitor being substantially parallel to a prede
volt-ampere characteristic of the leakage re- 40 termined portion of the curve representing the ,
actance between said coils.
relation between the voltage proportional to said '
3. In combination, a'magnetic core having two
leakage iiux and the transformer' current. '
coil receiving sections, two equal coils mounted
10. In combination, a transformer, a magnet
respectively on said sections, said sections having
icall-y saturable leakage ilux path on said trans
a common magnetic shunt for their leakage iiux, 45 former, winding means on said transformer hav
at least a portion of said shunt being normally
ing induced therein a voltage proportional to said
magnetically saturated,~ exciting means for said
iiux, said voltagehaving an over-all non-_
core relatively closely coupled to one of said coils,
linear relation to the transformer current by
output means relatively closely coupled to the
reason of the saturation of said leakage flux path
other of said coils, and capacitive means for com 50 .and
having a substantially linear working range
pleting a series connection between said two coils. . within said over-all non-linear relation. and a ca
4. In combination, a transformer having a con
pacitor connected to said winding means so as
tinuous magnetic leakage flux path with a sat
to have said voltage impressed across its ter
urated restricted section magnetically between all`
of the primary winding and all of the secondary
winding, a capacitor, and coupling means for im
pressing across said capacitor a voltage which is
proportional tothe leakage reactance voltage drop
of-1said transformer.
minals, said capacitor having a linear volt-am- »
pere relation which is substantially parallel to
saidlinear working range.
11. In combination, a single magnetic core, a
’ pair of equal coils mounted on said core, a leak- ,
-age 'flux path with a. magnetically saturable re
5. In combination, a transformer having a con
tinuous magnetic leakage iiux path with a nor 60 stricted section for decoupling said coils and pro- i
viding a. non-linear leakage reactance between
mally saturated restricted section and a normally .
them which has a substantially linear working
unsaturated main portion, a capacitor,l and cou
range, a primary Winding on said core closely
coupled to one of said coils, a secondary winding
tional to the‘leakage reactance voltage drop of 65 on said core closely coupled to the other od said
pling coils on said transformer for impressing ,
across said capacitor a voltage which is proper#
said transformer, the volt-ampere characteristic
of said capacitor being substantially parallel to
the normal volt-ampere characteristic of the
'.coils, a capacitor, said coils and capacitor being
serially connected in a closed circuit in which the
‘ induced voltages of said coils are in opposition,
said capacitor having a linear reactance whose
6. In combination, a transformer having a. 70 volt-ampere characteristic is substantially par
allel to the substantially linear working range 0I
magnetic core, two pairs of windings on said core,
leakage reactance of said transformer. `
.said core having a magnetic leakage path for re- '
ducing the coupling between said palrso! wind
said leakage reactance.
Без категории
Размер файла
553 Кб
Пожаловаться на содержимое документа