Improvements in Phase Adjusting and Regulating Methods and Means for Alternating Current Apparatus.
Year: 1897

page_text: Date of Application, 5th Oct., 1897
Complete Specification Left, 5th July, 1898-Accepted, 13th Aug., 1898
PROVISIONAL SPECIFICATION.
[Communicated from abroad by Egbert M. Tingley, of Wilkinsburg, County
of Allegheny, and Oliver Blackburn Shallenberger, of Rochester, County
of Beaver, both in the State of Pennsylvania, United States of America,
Electrical Engineers.]
Improvements in Phase Adjusting and Regulating Methods and
Means for Alternating Current Apparatus.
I, REGINALD BELFIELD, of 32, Victoria Street, in the County of London,
Electrician, do hereby declare the nature of this invention to be as follows:-
My invention relates to phase adjusting and regulating methods and means for
alternating current apparatus, and more particularly to such means employed in
connection with measuring and indicating instruments, although I do not limit
myself to this particular application of my invention.
It is often necessary in the utilisation of alternating currents to provide
means whereby a particular piece of apparatus shall be acted upon by two
alternating magnetic fields, the energy of the fields being supplied from a single
source of alternating current. For example in those alternating current meters
now well known in which a rotatable disc is subjected to the influence of two
magnetic fields, it is desirable that these two magnetic fields should differ in
phase by 90°. Means have heretofore been described for. approximately securing
such a phase relationship by inserting a properly designed inductance coil in
the shunt circuit. In order, however, to secure a phase angle of exactly 90° an
additional correcting or adjusting means is usually necessary.
The present invention is designed to provide methods and means for attaining
such results. I do this by superimposing on the current flowing in one or both
of the coils another current different in phase or by establishing an inductive
relation between one of the coils and the main circuit in place of a direct
electrical connection.
The invention will be more readily understood by reference to the accompanying
drawings which are diagrams illustrating the application of the invention to a
measuring instrument, the operation of which depends upon two magnetic
fields.
Figure 1 illustrates a meter in which the current in the series coil is advanced
by such an amount as will bring it into quadrature with the magnetic field of
the shunt coil.
Figures 2, 3, and 4 illustrate modifications.
Figure 5 is a diagram representing the various electromotive forces, currents,
and phase angles involved in the apparatus illustrated in Figures 1 and 2.
Figure 6 is a similar diagram relating to the apparatus illustrated in
Figure 3.
Figure 7 is a diagram illustrating a meter in which the shunt coil is not directly
connected to the main circuit.

page_text: Like letters of reference denote similar parts throughout the drawing.
Referring now to Figure 1 a is an alternating current generator for supplying
current to the translating devices b, either directly or through a transformer c. d
is one of the actuating coils of the meter provided with the magnetic core e and
connected across the work circuit. The circuit of this coil d includes an
inductance coil f in series with it, in order to retard the current approximately
ninety degrees behind the impressed electromotive force, or in other words to
secure a phase difference of ninety degrees between the current in the series coil
hereinafter mentioned, and the current in the shunt coil. g is the rotatable
armature of the meter, which is preferably in the form of a disc, as indicated.
h, h are two coils connected in series in the work circuit, and located on the
opposite side of the disc from the coil d. While two of these coils are shewn, a
single coil may be employed, if desired, provided it is properly located with
reference to the coil d. In order to obtain a phase difference of exactly ninety
degrees between the series coil current and the current in the shunt coil an
inductive resistance i is located in shunt to the series coil or coils of the meter,
of such proportions as to provide a lagging component and thus advance the
current in the series coils the necessary amount with reference to that in the
shunt coil to produce the quadrature relation desired. The same result may
be secured by employing in lieu of this inductive resistance i a suitably designed
and proportioned converter, the primary of which is connected in series in the
work circuit. Such a converter is shewn at k in Figure 2.
The relation of the various electromotive forces currents and phase angles
involved in the apparatus above described is shewn in Figure 5, in which line Ŏ E
represents at a given instant the shunt current, line OA the current in the main
circuit, line OD, which is equal and parallel to line B A, the current in the inductive
shunt shewn in Figure 1, and also the magnetising current for the core of the
converter shewn in Figure 2. The line 0 B which constitutes one side of the
parallelogram constructed on lines O A. and O D, therefore, represents the current in
the series coils, which is 90 degrees from the current in the shunt coils represented
by line O E. The line OC represents the electromotive force on the terminals of the
series coils of Figure 1, or on the primary of the series converter of Figure 2, such
electromotive force being slightly in advance of the current in the coils h. The
angle AOB may be termed the angle of compensation since it represents
the element of correction applied to the series current.
In the arrangement shewn in Figure 3 a non-inductive shunt is applied to the
terminals of the shunt coil in lieu of the inductive shunt around the series coils.
This non-inductive shunt obviously has no effect upon the current in the series
coils, such as that produced by the inductive shunt of Figure 1, and the series con-
verter of Figure 2, but it serves to provide a component in advance of that in the
shunt coil and thus to retard the current in the shunt coil with reference to that in
the series coils the necessary amount to give the quadrature relation, as indicated
in Figure 6, in which line O¹ D¹ represents at a given instant the current in the
series coils of the meter, line 0¹, A¹, the main shunt current, line B¹ A¹ the current
in the non-inductive shunt l, line O¹ B¹ the current in the shunt coil of the meter,
and line O¹ C¹ the electromotive force on the terminals of the shunt coil, and the
angle D O¹ B¹ the phase angle between the current in the shunt coil and the shunt
electromotive force, this angle being 90 degrees as desired. The angle A¹ O¹ B¹
is the angle of compensation in this modification.
Instead of employing either an inductive shunt to the series coils or a non-
inductive shunt to the shunt coil of the meter, both of these correcting means may
be employed if desired as indicated in Figure 4.
It will be understood that the self-induction in the shunt to the coils h h of
Figure 1 and in the converter k of Figure 2 must always exceed that in the said
coils h h in order to secure the desired adjustment of the phase angle. On the
other hand when the resistance is employed, as indicated in Figures 3 and 4, it
must have less self-induction than the coils d.

page_text: The correct proportioning of the coils will obviously depend upon the conditions
to be met in any particular case and may be readily determined by anyone skilled
in the art.
In the arrangement shewn in Figure 7 the shunt coil d is not directly connected
to the work circuit, but is in the secondary circuit of a transformer m having two
primary coils and p both shunting the work circuit. The currents in the coils n
and p are however different in phase, the coil n being in series with a non-inductive
resistance while the coil p which is in parallel with coil n is connected with an
inductive resistance in series. The transformer is here represented as of the ring
type, and the primary coils are so connected as to produce a rotary field in a manner
well understood, and by suitably locating the secondary coils s with reference to
the primary coils as regard angular position any desired phase relation between the
secondary current and the primary electromotive force may be obtained. In con-
structing the apparatus the parts should be so proportioned that the phase angles
of the two primary circuits are not affected to any considerable extent by the
reaction of the primary coils of the transformer.
The phase angle of the secondary current may be adjusted or varied by varying
the resistance q or the inductance coil and by varying the number of turns or the
angular position of the primary coils, as well as by varying the angular position of
the secondary coil. In practice it will be found convenient to construct the trans-
former so as to secure as approximately as practicable in ordinary manufacturing
work the phase relation desired and to effect the final adjustment by varying the
resistance q.
It is not essential that the transformer shall be of the rotating field type here
shewn, this form having been shewn merely for the purpose of illustration; any
suitable transformer or combination of transformers in which two primaries produce
a resultant effect in a single secondary circuit may be used in place of the particular
type of transformer shewn.
In certain cases where the electromotive force or the periodicity is sufficiently
high, a condenser may be used in place of the resistance q, to increase the difference
in phase between the currents in the primary coils.
While my invention is illustrated and described in connection with an instrument
for measuring electrical energy and is primarily intended for use in such relations,
I do not desire or intend to limit it as regards the particular apparatus with which
it is employed.
Improvements in Phase Adjusting and Regulating Methods and
Means for Alternating Current Apparatus.
I, REGINALD BELFIELD, of 32, Victoria Street, in the County of London,
Electrician, 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:-'
My invention relates to phase adjusting and regulating methods and means for
alternating current apparatus, and more particularly to such means employed in
connection, with measuring and indicating instruments, although I do not limit
myself to this particular application of my invention,

page_text: .
It is often necessary in the utilization of alternating currents to provide
means whereby a particular piece of apparatus shall be acted upon by tw
alternating magnetic fields, the energy of the fields being supplied from a single
source of alternating current. For example in those alternating current meters
now well known in which a rotatable disc is subjected to the influence of two
_magnetic fields, it is desirable that these two magnetic fields should differ in
phase by 90°. Means have heretofore been described for approximately securing
such a phase relationship by inserting a properly designed inductance coil in the
shunt circuit. In order, however, to secure a phase angle of exactly 90° an
additional correcting or adjusting means is usually necessary.
The present invention is designed to provide methods and means for attaining
such results. I do this according to one method by establishing an inductive
relation between one of the coils and the main circuit in place of directly
connecting said coils to the circuit, or I superimpose on the circuit flowing in one
of the coils another current differing in phase by shunting said coil with a
non-inductive resistance.
In order that the invention may be clearly understood I will describe the same
with reference to the accompanying drawings which are diagrams illustrating the
application of the invention to a measuring instrument, the operation of which
depends upon two magnetic fields which differ in phase by 90°.
Figure 1 illustrates a meter having two coils in series with the main circuit and
a third coil the magnetic field of which is in quadrature with the magnetic
fields of the series coils said coil being energized by means of a current which is
derived inductively from the main circuit.
Figure 2 is a diagram illustrating a modification in which the single coil of the
meter is joined as a shunt to the main circuit, the two other coils which in
Figure 1 are shewn in series being energized by current from a transformer in the
main circuit.
Figure 3 illustrates a further modification in which the shunt coil of the meter is
itself shunted with a non-inductive resistance.
Figure 4 is a diagram representing the various electromotive forces, currents,
and phase angles involved in the apparatus illustrated in Figure 2.
Figure 5 is a similar diagram relating to the apparatus illustrated in
Figure 3.
Like letters of reference denote similar parts throughout the drawings.
Referring now to Figure 1, a is an alternating current generator for supplying
current to the translating device b; h are actuating coils of the meter connected
in series with the main circuit of the generator a, and d is a third coil the magnetic
field of which is required to be in quadrature with the fields produced by
the coils hh; e is the rotary disc or armature of the meter. It will be
observed that the meter is of a well-known type, commonly known as the
Shallenberger meter. In meters of this description the coil, corresponding to the
coil d is usually joined as a shunt to the work circuit. According to the present
invention, however, said coil is not directly connected to the work circuit but is in
the secondary circuit of a transformer m baving two primary coils n and p
both shunting the work circuit. The currents in the coils n and p are however,
different in phase, the coil n being in series with a non-inductive resistance q
while the coil p which is in parallel with coil n is connected with an inductive
resistance in series. The transformer is here represented as of the ring type,
and the primary coils are so connected as to produce a rotary field in a manner
well understood, and by suitably locating the secondary coils 8 with reference to
the primary coils as regards angular position any desired phase relation between
the secondary current and the primary electromotive force may be obtained.
It will be readily understood without further explanation that the magnetic field
which is set up by the secondary current flowing in coil & may be adjusted as to
phase with reference to the current flowing through the coils h h by adjusting the
phase of the secondary current given out by the coils 8 8 of the transformer, and

page_text: a difference of phase of 90° between the magnetic fields set up by the coils d
and h may therefore readily be produced. In constructing the apparatus the
parts should be so proportioned that the phase angles of the two primary circuits
are not affected to any considerable extent by the reaction of the secondary coils
of the transformer.
1
The phase angle of the secondary current may be adjusted or varied by varying
the resistance q or the inductance coil and by varying the number of turns or the..
angular position of the primary coils, as well as by varying the angular position
of the secondary coil. In practice it will be found convenient to construct the
transformer so as to secure as approximately as practicable in ordinary manu-
facturing work the phase relation desired and to effect the final adjustment by
varying the resistance q.
It is not essential that the transformer shall be of the rotatating field type here
shewn, this form having been shewn merely for the purpose of illustration; any
suitable transformer or combination of transformers in which two primaries produce
a resultant effect in a single secondary circuit may be used in place of the particular
type of transformer shewn.
In certain cases where the electromotive force or the periodicity is sufficiently
high, a condenser may be used in place of the resistance q, to increase the difference
in phase between the currents in the primary coils.
Referring now to Figure 2 the work circuit is here illustrated as being supplied
through a transformer c, the coil d is joined as a shunt to said circuit, and has
included in series with it an inductive resistance f, the coils h h are, however, not
connected directly in series with the work circuit, but are supplied with current
through the converter k. By reason of the coil f the current in the coil dis
retarded approximately 90° behind the impressed electromotive force. The
phase of the current in the coils h h is through the agency of the converter k caused
to be behind the impressed electromotive force, and by suitably proportioning the
inductive resistance and the converter k the difference of phase between the
currents in the coils d'and h may be made exactly 90°. Figure 4 shews the relation
of the various electromotive forces, currents and phase angles involved in this
apparatus, the line O F represents the electromotive force impressed on the circuit.
The line O C represents the back electromotive force due to the inductance of the
converter. The line O G represents the electromotive force supplied to the work
circuit which is in phase with the current therein which is also the current flowing
through the primary winding of the converter k, this current is represented by the
line OA. OE represents the current through the shunt coil d of the meter.
OD represents the magnetizing current of the converter and by completing the
parallelogram of which OD is the diagonal and O A one side, the line O B will be
obtained, represents the current through the secondary coil of the converter k, the
magnetizing current being the resultant of the current through the primary and
secondary windings. By adjusting the magnetizing current which may be done
by altering the magnetic circuit of the converter k or by other well-known means,
the current through the secondary coil thereof which passes through the coils h h
of the meter can be caused to lack 90° behind the current in the shunt coil of the
meter, that is as is indicated in Figure 4 by the fact that the line O B is at right
angles to the line O E.
In the arrangement shewn in Figure 3 a non-inductive shunt is applied to the
terminals of the shunt coil. This non-inductive shunt obviously has no effect upon.
the current in the series coils, such as that produced by the converter of Figure 2,
but it serves to provide a component in advance of that in the shunt coil and thus
to retard the current in the shunt coil with reference to that in the series coils the
necessary amount to give the quadrature relation, as indicated in Figure 5, in
which line O¹ D' represents at a given instant the current in the series coils of the
meter, line 01 A¹, the main shunt current, line B¹ A¹ the current in the non-
inductive shunt (, line O' B' the current in the shunt coil of the meter, and line 0¹ C¹
the electromotive force on the terminals of the shunt coil, and the angle D' ()¹ B¹

page_text: the phase angle between the current in the shunt coil and the electromotive force,
this angle being 90° as desired. The angle A¹ 01 B¹ is the angle of compensation
in this modification. The correct proportioning of the coils will obviously depend
upon the conditions to be met in any particular case and may be readily determined
by anyone skilled in the art.
"
While my invention is illustrated and described in connection with an instrument
for measuring electrical energy and is primarily intended for use in such relations,
I do not desire or intend to limit it as regards the particular apparatus with which
it is employed.
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 - :
1. The method of adjusting an existing difference of phase between two magnetic
fields produced by two coils caused by placing an inductive resistance in series
with one of the coils, which consists in shunting this coil with a non-inductive
resistance so as to still further retard the phase of the current flowing in said coil,
as described.
2. The modification of my invention wherein one of the coils is not directly
connected with the main circuit but is included in the secondary circuit of a
transformer the other of the coils having an inductive resistance in series as
described.
3. The method of obtaining a desired difference of phase between two magnetic
fields produced by two coils, which consists in energizing one of the coils from a
transformer wound with two or more primary coils the currents in said primary
coils having a difference of phase, substantially as described.
4. An electric measuring instrument provided with the various means of securing
a desired difference of phase between the two operative magnetic fields, substantially
as described with reference to the accompanying drawings.
Dated thin th
T1000
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.