US1771816A - Regulating transformer - Google Patents

Description

July 29, 1930. w PETERSEN 1,771,816

REGULATING TRANSFORMER Filed Oct. 2, 192a Fig.6.

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Patented July 29, 1930 PATENT OFFICE wALnnm PETERSEN, or namas'ranr, GERMANY BEGULATING TRANSFORMER Application flled.0ctober 2, 1926, Serial No. 139,126, and in Germany September 23, 1925.

' effected under voltage or load.

The subject-matter of the present invention avoids this disadvantage by enabling the variation of the transformation ratio of a transformer to be effected in such a manner that by the provision of at least two parallel magnetic circuits within one and the same primary winding and of regulating windings suitably distributed and coupled to control the flux distribution to the said magnetic, circuits as desired so that variable voltages are induced in the secondary windings. The regulating operation is thus transferred from the primary or secondary windings to the particular regulating windings provided therefor, this arrangement having the great advantage that only low voltages or small currents require to be controlled, as the number of turns of the regulating windings and therefore the voltages induced therein may be chosen independently of those of either the primary or sec-' ondary windings. 1 v

The invention is illustrated in the .ac'companying diagrammatic drawings which {5 show, by way of example, a number of difterent arrangements embodying-the invention.

Figure 1 shows one leg portion of a single or polyphase transformer in cross section;

Figure 2 is a sideelevationthereof;

Figures3, land 5 show also by side elevation one leg portion of three different trans former constructions; v Figure 6 gives a diagrammatic reproduction of a transformer with a controlling de- 4 vice for the regulating windings.

the number of turns 8 o Inthe transformer construction shown in Figure 1, which represents only one leg portion of'the transformer, the core' of the represented leg portion of the transformer is subdivided into two core sections a, and a The primary winding, which surrounds both core sections, is indicated at 0, while the spools of the secondary winding are indicated lat d d andthe regulating windings at f v t The two halves of the secondary winding oZ and 03 are oppositely connected, and the two regulating windings f and f ,can be coupled in normal series connection or so connected in series that the corresponding electromotive forces are of respectively opposite directions, as indicated in the draw- Tor a constant voltage impressed on the primary winding 0 the total flux N traversing the core-sections is constant. This flux divides into two flux portions N and N traversing the core sections a and a respectively in the inverse ratio of the number of turns S 1 and 8 ofthe regulating windings f and f The voltage induced by theitotal flux N in t he secondary winding (1 of the core a will be denoted by E =kNs ==-constant (4) similarly the voltage induced by'the flux portion N in'the secondary. winding d having a nugnben of turns 8 will be denotedby and, similarly, the voltage induced by the flux portion, N -in the secondary winding d having a number of turns 8 will be denoted by zz z n By reference to Equations 2 and 3, I obwith opposing connection of J and d it will be apparent that the secondary voltage In the case in which the numbers of turns of the two secondary winding sections are equal to one another, that is to say 21 22 Equation 7 will take the following form The large range of regulation expressed by Equation 7 may be further increased, if the two regulating windings, instead of being directly coupled together are coupled through an ordinary transformer, or an auto-transformer having a variable transformation ratio." This transformation ratio may be defined by the equation.

E82: ai.

in which E is the voltage of the side of the intermediate transformer connected to f and E is the voltage of the side of the intermediate transformer connected to f The factor a can have a positive or negative value, as desired.

- A further constructional example is shown in Figure 2. In this figure the secondary winding section al is omitted; as regards the remaining elements the core sections (1 and a the primary winding 0 and the regulating windings f and f are the same as in Figure 1, Z) I) being the yoke of a single or polyphase transformer.

The operation of regulation is the same as before, the total flux N remaining constant and being distributed by means of the regulating windings in any desired ratio between the two core sections a and a Equation 8 of the simplified switching corresponds to s E 31 E 31+ 32 (9) In the further constructional examples shown in Figures 3 and 4, the core is constructed as before, with at least two core sections, a and a in Figure 3, a a a in Figure 4, which are connected by means of magnetic brid es h h etc. In the simple example s own in Figure 3 the core section a only carries the coils d d d etc. of the secondary winding. The regulating windings are indicated at f and f 9 and g and Z and Z The primary winding is indicated at 0 and the yoke at b.

In this construction the flux, which has an inducing action on the secondary winding can be varied in each (3011 section qtnte 1nde-- pendentlyof the other coil sections. If, for example, f (9 Z is short-circuited, and f (9 Z is open-circuited, the effective flux will exclusively traverse the core section (1 By a parallel connection of f and f and by varying the number of turns of f and f and flux can, as in the case of Figures 1 and 2, be transferred to the upper part of the core section a By short-circuiting f and opencircuiting f the total effective flux will traverse the winding d (Figure 3) and will pass through the bridge [L as indicated in Figure 3. In a manner readily understood the flux traversing the windings (Z and d can be transferred or deviated in any desired stages from al to a In the further constructional example of Figure 5, b, b are the yokes of a single or polyphase transformer, a (1 the core sections of the transformer leg, h a connecting bridge between the two core sections, 0 the primary winding of the leg, (Z a secondary winding located on the connecting bridge 72., and e, f, i and Z0 are the regulating windings.

In the low voltage condition of the secondary winding (1 the regulating windings e and f as also the winding 1' and is having equal numbers of turns, are connected in parallel with one another. The effective flux traverses the core sections a and a the bridge it being not traversed by fiuX. If it is desired that cl should be inductively influenced to the full extent by the effective flux, e and is must be short-circuited, and f and 6 connected in parallel with one another. The flux takes the path through across it and through i. If, on the other hand, f and i are short-circuited and e and 7c are connected in parallel with one another, the flux will pass through it in the opposite direction to t at given above.

The substantially continuous or graduated adjustment of the voltage on the winding d will evidently take place as in the constructional examples of Figures 1 or 2. The regulating windings e and is on the one hand, and f and i on the other hand, have corresponding characteristics, so that, forthis reason, a and k on the one hand, and f and i on the other hand, can be connected in circuit to one winding corresponding to f and f in Figures 1 and 2. In the utilization of the inventive idea in a reactance coil, which is a light- 1y loaded transformer without a SBCOlldfll; winding, the secondary windings (Z and 2 are dispensed with, for instance, in the constructional form of Figures 1 and 2.

The core sections a,, a, can be constructed so as to have diiferent magnetic reluctances.

If, for instance, (1 has a low magnetic reluctance, whilst a has a high magnetic reluctance, the primary winding will constitute a small reactance when the regulating winding has deviated the flux to (1. When, on the contrary, the flux is deviated to a, by the regulating winding, the primary winding will increase-in reacta'nce.

In order to show how the regulating windings may be controlled, a control device is represented in Figure 6 .for re ating the connections of these windin s. n this figure the movable element M' w ich as shown is divided into three conducting sections separated by insulated parts may be moved over a series of contacts to change the connections of the regulating windings. This figure shows a sim 1e conventional switching arrangement w ereby the re ulating windings may be connected in parall el or in series and also whereby either windinglf or f, may be.

open circuited while the ot er is short circuited. It is apparent that additional contacts and connections may be employed to change the number of turns in either of these windings to vary the regulating efiect. Any convenient mechanism may be employed to move the element M over the contacts in either direction to bring about the desired connections.

As in all transformers, the foregoing conditions are reversible, the primary and secondary windings being interchangeable. Furthermore the improved transformer can serve, for example, to efiect transformation.

from constant current in the windings (I and d to constant voltage in the winding 0.

What I claim is 1. A regulatin transformer comprising a magnetic core subdivided into a plurality of core sections, a primary winding with its turns extending around all of said core sections, a secondary winding having its turns on parts thereof and independent regulating windings inductively related to said core sections, arranged to be excited by said primary winding and controlling means to connect said regulating windings in regulable manner with respect to each other and to said core sections so as to allow a variation of the magnetic flux distribution with respect to the secondary winding.

2. A regulating transformer comprising a magnetic core subdivided into a plurality of core sections, at least one magnetic connection bridge between said core sections, a rimary winding with its turns extending around all of said core sections, a secondary winding having its turns on parts thereof and independent regulating windings inductively related to said core sections, arran ed to be excited by said primary winding an controlling means to connect said regulating windings in regulable manner with respect to each other and to said core sections and connection ranged to be excited by said primary winding and controlling means to connect said regulating windings in regulable manner with respect to each other and to said core sections so as to allow a variation of the magnetic flux distribution with respect to the secondary winding.

In witness whereof I have hereunto signed my name this 17th day of Se tember, 1926.

WALDEMAR P TERSEN.

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