DE407844C - Circuit to achieve effective coverage of the anode currents of a rectifier fed by two transformers - Google Patents

Description

GERMAN EMPIRE

ISSUED JANUARY 2, 1925

REICH PATENT OFFICE

PATENT LETTERING

CLASS 21 d GROUP 34

(A ₃₅₅₅₄ VIIII2i dV

General Electricity Society in Berlin *).

Circuit to achieve an effective coverage of the anode currents
a rectifier fed by two transformers.

Patented in the German Empire on June 1, 1921 .

In mercury vapor rectifiers, it is known that the direct current is proportional to

As is well known, the transformers bad from _ms i:] / p, where p is the number of phases. this

used, namely the worse, the larger _r ührt therefore, that the current in the full

is the number of phases for which the equal,

Richter is built. ^{Altitude only} during - period m of the

The rms value of the anode current is available to then flow to the appropriate phase

* j The patent seeker indicated as the inventor:

Christian Krämer in Berlin-Pankow.

skip the next phase. The utilization ■ is better, however, if the one; forces individual phases to partially overlap. In order to achieve this overlap, it has become known to feed the anodes of several rectifiers or one and the same rectifier from different multi-phase systems, the phases of which are mutually shifted by up to 180 °. ; ίο The currents of these different multiphase currents are linked together magnetically, e.g. B. by inductors or current transformers. The overlap achieved in this way depends very much on the load and requires the installation of special equipment, such as choke coils and transformers, of extremely large dimensions, and is therefore associated with disproportionately high costs.

Another attempt at coverage; was made by connecting two rectifiers in series, which are transformers fed with staggered phases. This has the disadvantage that the i Achieve the desired voltage using two rectifiers for half the voltage! are required. There in every vessel, so! j for every partial voltage, 25 volts are lost, the efficiency is reduced by half. The entire arrangement requires twice the number of apparatus and is therefore expensive and unreliable.

According to the invention is now a device; hit and circuit for mercury arc rectifiers, by that cost no effort by large majority is achieved, gets a perfect coverage of the \ individual streams almost i8o °, and; Although this overlap is achieved by using two separate transformers, the primary windings of which are connected one behind the other, while the secondary windings are connected in parallel, but are arranged out of phase with one another.

The invention is explained with reference to FIGS. 1 and 2. In this U ₁ X ₁ , V ₁ V ₁ , W ₁ Z _{1 designate} the three phases of the primary winding of the transformer A and UX, VY, WZ those of the transformer B. The secondary windings ti, v, w belong to the transformer A and U ₁ , V ₁ , W ₁ to the transformer B. The corresponding primary windings are behind each other, the secondary sides, however, parallel and against each other, as can be seen in Fig. 2.

The secondary terminals u, V, W _1, U _x , V ₁ , W ₁ are connected to the correspondingly designated anodes of the rectifier G , the cathode K. of which forms the positive pole of the system. The zero points of the secondary windings are connected and form the negative pole.

In Fig. 2, the windings and phases of transformers A and B are shown in a polar diagram for easier understanding. It follows from this that it does not matter whether the primary or secondary phases are reversed. The only condition is that the phase windings are connected in series.

The extent to which this circuit works is shown in FIGS. 3 and 4 Oscillograms. Fig. 3 shows the load current for a normal six-phase Circuit, Fig. 4, on the other hand, with the new circuit. The anode current is over i8o ° extended, so its rms value is

to direct current in the ratio of —t =: i.

The circuit diagrams Fig. 5 and 6 show how the method can be extended to twelve-phase arrangements. Here, the primary winding of the transformer B is connected in delta and thus the rotation of the secondary six-phase winding of this transformer against the six-phase secondary winding of the transformer A is achieved.

Claims (1)

Patent claim: Circuit to achieve an effective coverage of the anode currents of one of rectifier fed by two transformers, characterized in that the primary windings of the two transformers are kept one after the other, while those connected to one another at the zero point Secondary windings that feed the individual anodes of the rectifier, connected in parallel, but against each other are shifted in phase by 180 °. 1 sheet of drawings. 6ERL1H. OEbM) Sc * IK ßfcft ftfiifittsBRÜßKEKfit.