US1376011A - Electric apparatus - Google Patents

Description

J. J. FRANK.

ELECTRIC APPARATUS.

APPLICATION man APR.25. 1919.

1,376,01 1 Patented Apr 26, 1921.

Inventor John J.T 'r-ank,

b f/ 4920M:

His ttornes.

UNITED STATES PATENT OFFICE.

JOHN J. FRANK, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION 01 NEW YORK.

ELECTRIC APPARATUS.

Specification of Letters Patent- Patented Apr. 26, 1921.

Application filed April 25, 1919. Serial No. 292,609.

T 0 all whom it may concern:

Be it known that I, JOHN J. FRANK, a citizen of the United States, residingat Pittsfield, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Electric Apparatus, of which the following is a specification.

My invention relates to electrical apparatus comprising wholly or in part a winding. ()ne object of my invention is to provide such electrical apparatus in which the reactance and the stresses due to the magnetic action are uniform in their distribution, or more nearly uniform than heretofore. Another object of my invention is to provide an improved high current winding, and electrical apparatus comprising a high current winding, having taps whereby the voltage of the high current winding may be varied with a minimum unbalancing of the reactance and of the stresses due to the magnetic action. Still another object of my invention is to provide a method of operating an electrical winding whereby the reactance and the stresses due to the magnetic action are continued uniform, or more nearly uniform than heretofore, as the number of operating turns is increased or diminished.

My invention is particularly applicable to electrical apparatus comprising wholly or in part ahelical winding wherein a plurality of conductors are disposed one outside another in coil groups, and also is particularly applicable to transformers in which there are a plurality of windings. It will be understood, however, that my invention is not limited to such a winding or to such a device, but from a broader aspect comprehends as well any other winding and any other apparatus in which there is a winding in which conductors in different coil groups are, in effect, connected in series to form a plurality of lots of series connected conductors traversing the same coils.

My invention will be understood most readily from the accompanying drawing and following description wherein I have illustrated and described in some detail the best embodiments of my invention of which I am now aware. Figure 1 is an outline elevation of a transformer embodying my invention. Fig. 2 is a perspective view of the low voltage, high current, windingof the device of,

Fig. 1; while Fig. 3 is 3. dia rammatic vie illustrating the mode of ciinnections 811i ployed in Fig. 2.

ln the transformer of Fig. 1, the core is provided with a winding leg 2. about which are placed the windings. The windings of the transformer illustrated comprises a high voltage winding and a low voltage winding the low voltage winding illustrated is of helical type and is adapted for currents of yery high value. The high voltage winding is made up of two sections 3 and 4, each section comprising three disk coils of a familiar type. These two sections 3 and 4 are separated, and one section is disposed at each end of the low voltage winding 5. It is immaterial to my invention how'the coils of the two sections-3 and 4 are connected but for the purpose of the present explana tion of my invention they may be considered to be connected in series. The construction of the low voltage, high current, winding 5 will be better understood from Fig. 2.

As appears especially from Fig. 2, the low voltage winding 5 is in the form of a helix. Five conductors 10, 11, 12, 13 and 14, dis posed one above another radially. or one outside another radially (14 being at the inside of the winding and 10 at the outside thereof), are carried in the form of a continuous helix from one end of the low voltage winding to the other end thereof. Each turn of the five conductors forms in efli'eot a coil or coil group of a plurality of conductors, these coil groups 16, 17, 18, 19 and 20 being separated from each other, as appears from both ig. 1 and Fig. 2, for the purpose of providing ventilating spaces whereby the heat ge'nerated within the conductors 10-14 is more readily dissipated. The conductors 10-14 are insulated from each other and are connected in series by cross connectors later described and which may be observed at the right of Fig. 2; a tap is brought out adjacent each cross connector whereby one or any other number of these conductors may be used to convey current in series. It will be observed that each of the conductors 10-14 is carried, as it were, through every coil or coil group of the winding; in effect, as windings are more com: monly considered, each of the plurality of conductors of each coil is connected in series with the similarly located conductors in the other coils whereby lots of series connected conductors are provided in the drawing, conductor 10 forming one lot. conductor 11 a second lot, etc. (fine (and in carrying out the method of my invention, the most commonly used) of the terminals of Fig. 2 is terminal 25 which is connected directly to conductor 12; as will be seen especially from Fig. .2, and as before indicated, conductor 12 occupies or constitutes the central layer and turn of each coil group. Terminal 25 is connected to the lower end of the conductor 12, and the upper end of conductor 12 is connected to tap 26. A terminal or connection board 27, suitably supported from the core 1, is provided for supporting in proper relation terminal 25, tap 26, and the other taps and terminals hereinafter described in connection with winding 5. Terminal 26 comprises also, or is attached to, connector 29 through which the upper end of conductor 12 is connected to the lower end of conductor 11. This connector 29 (like the other connectors hereafter mentioned) extends across the face of the low voltage winding 5, that is external to the same and from one end of the winding 5 to the other end thereof. The opposite end of conductor 11 is connected to tap 30, resembling tap 26, and connector 31. like connector 29, connects the upper end of conductor 11 to the lower end of conductor 13. It will be noted that the two conductors 11 and 13 are at opposite sides of conductor or layer 12 and are, radially, the nearest conductors and layers to the more central layer 12. The upper end of conductor 13 is connected to tap 32 and by connector 33 is connected to the lower'end of conductor 10. Again it should be noted that conductors 10 and 13 are at opposite sides of the central layer or conductor 12. The upper end of conductor 10 is connected to tap 34 and by means of connector 35 is connected-to the lower end of the'remaining conductor and the conductor or the opposite side of and symmetrically related to conductor 12, namely, conductor 14. The upper end of conductor 14 is connected to terminal 36. Accordingly it will be seen that by using the appropriate taps and terminals, a circuit may be completed from the line through one or any other number of the conductors or layers lO-14 of this wind- 1n %lurrent through a winding produces magnetic action which in turn results in mechanical stresses in the winding itself, in any adjacent core, and in any'adj acent'winding also carrying current. In order that these mechanical stresses may be resisted or neutralized,- it is desirable that they be uniformly distributed over the whole faces of the coils or coil groups so far as possible, or in other words, that they appear as though originating from the mean or central turn or layer of each coil; it is also desirable that the magnetic center of the winding continue at the same point when different numbers of conductors are carrying current. My invention as thus described provides a winding in which these results may be obtained although the number of operating conductors be changed, and also provides a winding in which the reactance or action of the winding 5 by reason of leakage magnetic fiux, is substantially constant in distribution and varies only inintensity as the number of operating conductors is changed. The method of my invention as employed with this or any other suitable winding, secures the desired results.

The mode of practising my invention will be understood from the following description of the preferred method of operation of winding 5 Suppose that it is desired that all five of the conductors 1014 be operated in series; in such a case the line receiving energy from, or delivering energy to, the winding 5 is connectedto the two terminals 25 and 36. It will be observed that the circuit in the winding 5 is then continuous from the ter minal 25 and lower end of conductor 12, through conductor 12, connector 29 to the lower end conductor 11, and thence through the remaining connectors and conductors to the terminal 36. If, now, it' is necessary to reduce the number of operating conductors in the winding by one, the line is continued in connection with terminal 25 but the connection to terminal 36 is broken and connection made to tap 34. It will be seen that with this connection only conductors or layers 10, 11, 12 and 13 are in operation and carrying current and these conductors (in the present instance) are in series as before; conductor or layer 14 carries no current and hence is out of operation. It will be observed that whereas with all five of the conductors in series the magnetic center of the winding is located at substantially the center of the axis of the whole winding, the magnetic center with only four conductors in series is likewise located at substantially the center of that axis; in other words, since the active length of the winding is constant irrespective of the number of conductors in operation, and since all conductors have the same axis, the magnetic center of the winding remains substantially stationary as the number of active turns is varied. It should be also observed that whereas with all five conductors in series, the stresses on the face of each coil group due to the magnetic action and reaction are substantiall concentrated, as it were, in or along the l1ne of the center of the conductor or layer 12, with only four conductors in operation the stresses are shifted only to substantially the line of the outside edge of the conductor or layer 12, which it will be noted is but a 1.sve,o11

very small shift. Also it may be seen that the reactance or action of the leakage flux is also substantially the same (except for intensity of effect) whether the five conductors are active or whether only the four conductors are in operation. If it is necessar to still further reduce the number of actlve conductors by one, the connection to tap 34 is broken and the corresponding connection made to tap 32. With this arrange ment the circuit is completed through conductors or layers 12, 11, and 13 only, and in that order counting frolnterminal 25. Again it may be observed that with only these three conductors in operation, the reactance and the stresses due to magnetic action of and on the winding 5 are almost the same as before (except perhaps in degree) and indeed are now very closely if not indeed exactly like the reactance and stresses of the original connection of all five conductors in series. It will be observed that in reducing the number of active conductors, I do so by cutting out so far as possible, conductors or. layers similarly located at op posite sides of the more central layer or layers of the winding, and cutting out each time those active conductors or layers which, radially, are farthest removed from the central layer or layers. Thus the conductor or layer 12 being the most central layer of the winding, when it is necessary to reduce the number of conductors by one I cut out one of the conductors or layers'farthest removed from the conductor 12, namely conductor 14 in the first instance above. When again it is necessary to reduce the number of active conductors I again out the active conductor or layer farthest removed from 12, and the active conductor located similarly to conductor 14 but on the opposite side of la er 12, namely conductor or layer 10. WV henever it is possible to reduce the number of layers or conductors by two, I simultaneously cut out those two layers at opposite sides of and farthest removed from the central layer or conductor 12, such as conductors 10 and 14. If the number of operating conductors is to be reduced still further, I continue to pursue the same plan and first cut out conductor 13, and thereafter conductor 11; there being but five conductors or layers in the winding illustrated, the number of conductors or layers in this winding cannot be further reduced since there now remains in operation only one conductor or layer, namely conductor 12. The opposite portion of my method and the contemplated operation of winding 5, may be understood from what has gone before; in a few words, it consists in increasing the number of conductors in operation by causing the current to traverse in addition to those conductors or layers already in service, a sufiicient number of those layers or conductors of the winding which, radially, are next nearest the more central layer or conductor and I layer or conductor. Thus with the current traversing only the conductor or layer 12, layer or conductor 11 is first added, thereafter layer or conductor 13, then conductor 10 and finally conductor 14:, or only so many of these conductors or layers in the order named, as may be necessary-to satisfy the immediate conditions.

While I have illustrated in the accompanying drawing and described above the best embodiments of my invention of which I am now aware, it will'be understood that these embodiments are merely illustrative of my invention and that my invention is not limited thereto but is set forth in the following claims.

WVhat I claim as new and desire to secure by Letters Patent of the United States, is

1. A winding comprising a plurality of coil groups in which conductors in each group are disposed one outside another radially and connected respectively in series with conductors in another coil group to form lots of series connected conductors, the lots being connected in series and taps for the windings being provided between each lot of conductors.

2. A winding comprising a plurality of coil groups in which a plurality of conductors in each group are disposed one outside another radially'and each of said plurality of conductors of each of said coil groups is connected in series with the similarly located'conductors in the other of said coil groups to form lots of conductors, the lots of conductors being connected in series and taps for the winding. being provided between each lotvof conductors.

'3. A winding comp-rising a plurality of coil groups in which a plura-llty of conductors in each group are disposed one outside another radially, the winding being distinguished by each of the said plurality of conductors of each coil group being connected in series with conductors similarly located in the other coil groups to form lots of conductors, the lots of conductors being so connected in series that one terminal of the winding is at one end of the lot adjacent the center of the coil groups, and taps for the winding being provided between each lot of conductors.

4:. A winding comprising a plurality of conductors disposed as a helix and one outside another radially, a conductor near the center of the coil groups providing one terminal of the winding, a connector from the opposite end of said conductor connecting the said conductor in series with a conductor at one side thereof, a connector connecting said second conductor in series with a conductor at the opposite side of the first mentioned conductor, and a tap for the winding connected thereto adjacent the first mentioned connection.

5. A winding comprising an odd number of conductors disposed as a helix and outside another radially,the center conductor providing one terminal of the winding, a. connector from the opposite end of said conductor connecting the said central conductor in series with a conductor immediately at one side thereof, a connector connectin said second conductor series with a 'con uctor immediately at the opposite side of the central conductor, other connectors completing the series connection of the conductor of the winding by similarly cross connecting pairs of conductors at opposite sides of the center conductor, and taps for the windings connected thereto adjacent each connector.

6. A winding comp-rising a plurality of coil groups in which conductors in each group are connected in series with conductors in another coil roup to form lots of series connected con uctors, connectors extending from one end of the winding to the other connecting said lots of conductors in series, and taps for the windings connected thereto adjacent each connector.

7. Electrical apparatus comprising a core, a winding thereon, and a second Winding on said core inductively related to the first mentioned winding, said second winding comprising a plurality of coil groups in which conductors in each group are connected in series with conductors in another coil group to form lots of series connected conductors, connectors extending from one end of the winding to the other connecting said lots of conductors in series, and taps for the windings connected thereto adjacent connectors.

In witness whereof, I have hereunto set my hand this 23rd day of April, 1919.

JOHN J. FRANK.

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