US2599137A - Spare connected polyphase transductor - Google Patents

Description

J1me 1952 H. M. SORENSEN 2,599,137

SPARE CONNECTED POLYPHASE TRANSDUCTOR Filed April 20, 1949 /n yen for /"/Gr4; /6/ 7 55mm 5617 5/ a VQAV QQ/arney,

Patented June 3, 1952 SPARE CONNECTED POLYPHASE TRAN SDUCTOR Harald M. Stirensen, Fruens Boge, Denmark, assignor to Allmanna Svenska Elektriska Aktieeden, a Swedish corporabolaget, Vasteras, SW tion Application April 20, 1949, Serial No. 88,649

In Sweden April 24, 1948 4 Claims.

In Figs. 2 and 3 of the U. S. Patent Specification No. 2,372,112, two forms of a twelve pulse transductor (direct current saturable reactor) are disclosed, which have been composed of two six pulse transductors, (hereinafter referred to as constituent transductors), the phase of one of these having been rotated 15 in the forward direction and of the other 15 in the rearward direction with respect to the impressed threephase voltage. In describing these two forms, the inventor has supposed that the long winding elements designated by 9 and the short winding elements designated by II which are directly joined together are wound on cores belonging to the same threephase star, i. e. on a core all windings of which are connected between the alternating current terminals and the same direct current terminal. Under this presumption, the rule stated in the patent specification is applicable, that the connection which is most favorable in respect of the voltage, 1. e. that illustrated in Fig. 2 of the patent, is unfavorable in respect of the direct current magnetisation because the direct current ampereturns of the long and short winding elements will oppose each other on each separate core. It has now been found, that by mounting the shorter ones of the winding elements directly connected together on the same cores as the longer winding elements of the other threephase star, the connection according to Fig. 2 of the patent which is most favorable in respect of the voltage can be used and in spite thereof the direct current ampereturns of both windings on the same core will act in the same direction, whereby direct current power is saved under otherwise equal conditions. A mounting of this character forms the object of the present invention.

In the accompanying drawing, Fig. 1 shows a diagram corresponding to that of Fig. 2 of the U. S. Patent 2,372,112, although with different reference symbols, while Fig. 2 shows a modified form of the same diagram with the winding elements of only one phase. Fig. 3 shows a complete diagram of connections of one of the sixpulse transductors corresponding to Fig. 2.

In the Patent 2,372,112 it has been assumed, that for instance the short winding element I5 (Fig. 1) which is directly connected to the long element I, is mounted on the same core as the long element 2 forming part of the same threephase star as the element I, i. e. is connected between the alternating current terminals 1 and the same direct current terminal 8 as the ele-- ment I. If this is the case, the direct current ampereturns of the element I5 must oppose the direct current ampereturns of the element 2 mounted on the same core. It has now been found, however, that the winding element l5 may as well be mounted on the same core as the long winding element 5 which is connectedto f Since the magnetisation of the core of the element 5 is displaced in phase by 180 with respect to that of the core of the element 2, the element I5 must be reversed as compared with the original connection disclosed in the Patent 2,372,112 in order to give the same voltage vector, and the direct current ampereturns of the winding I5 will then also be reversed so as to act in the same sense as those of the winding element 5. The connection according to Fig. 1 will thus be identical to that of Fig. 2 of the patent referred to, but the mounting of the elements on the different cores has been varied in the manner just described.

The connection may be modified according to Fig. 2, in which the long winding elements lie adjacent to the direct current terminals and the short winding elements adjacent to the alternating current terminals, instead of vice versa. In Fig. 2, only the winding elements of one phase and their connections are illustrated.

Fig. 3 shows the complete diagram of connections for one half of a transductor according to Fig. 1, modified according to Fig. 2. The constituent transductor thus illustrated, which may constitute one half of a twelve pulse transductor, one third of the eighteen pulse one etc., has six cores, each carrying two winding ele-- ments. The longer ones of these winding elements are designated by I-6 and the shorter ones by H-IB. The elements are connected in zig-zag between the alternating current terminals 1 and the direct current terminals 8, 9 in such a manner, that for instance the elements I and I5 are connected in series between the direct ourrent terminal 8 and the alternating current terminals I, while on the other hand, for instance the elements 4 and I2 are connected in series between the direct current terminal 9 and the alternating current terminals. The elements I, 2, 3 and I4, I5, It thus belong, with respect to their connections, to one of the threephase stars, while the elements 4, 5, 6 and II, l2, I3 belong to the other threephase star. The element l4, which belongs to the first-named threephase stor, is, however, mounted on the same core as the element 4 which belongs to the second threephase star, and so forth for the other phases. Of one long and one short element connected in series between one direct current terminal and one alternating current terminal and thus belonging to the same threephase star, the short element always lies on the same core as a long element belonging to the other threephase star.

Especially in transductors having a higher number of pulses than twelve, each threeph-ase star could be composed of three winding elements connected in zig-zag instead of two, such elements being still so dimensioned that the vector sum of each series of elements differs in phase from the two nearest ones by an even fraction of 120. Of such three series-connected windin elements, one is always longer than the others and can thus be referred to as the main winding element. In such cases, the rule is valid, that at least one of the shorter windings shall be mounted on a core carrying the longer or main winding of the. other threephase star.

I claim as my invention:

1. A polyphase transductor having windings adapted to be traversed by both alternating and directv current, comprising at least two constituent transductors, each constituent transductor comprising two three phase sections, each such section including three windings each composed of two winding parts, three alternating current terminals, one winding of each section being connected to each of such terminals, a pair of direct current terminals, all the windings of one section being connected to one of such direct current terminals and all the windings of the other section being connected to the other direct current terminal, and a plurality of magnetic cores supporting said windings, each core supporting two winding parts one from each three phase section, the winding parts of each winding being supported on different cores.

2. In a transductor as claimed in claim 1, in which said Winding includes a short winding part and a long winding part, each core supporting a short winding part and a long winding part.

3. In a transductor as claimed in claim 2, the winding parts on each core being connected to different alternating current terminals.

4. In a transductor as claimed in claim 1. the winding parts on each core being connected to difierent alternating current terminals.

HARALD M. soRENsEN.

No references cited.

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