SU149460A1 - Device for receiving signals of high-frequency communication through three-phase networks with power transformers - Google Patents

Description

BASIC Auth. St. No. 128501 describes a method for making high frequency currents in a distribution network of up to 10 kV with three-phase power transformers and direct connection of equipment to the two phases of the secondary voltage line. In this case, in order to transfer high-frequency sitals through power three-phase transformers, a single-phase signal is transformed by operating a three-phase network in a two-phase short circuit mode (for high frequency currents). However, if power transformers with a connection class of UA-11 windings are used in an electrical network, then c. The signals are transformed only on the two phases of the low-voltage network supplied from these transformers. When creating communication channels and telemechanics for stationary installations, it is easy to choose the necessary phases and turn on the equipment on them. When creating communication channels with moving objects, when switching the supply cable, it is necessary to check the phasing at a high frequency each time, which naturally creates serious inconveniences.

The proposed method allows to eliminate this drawback and differs from the well-known fact that the primary winding of the receiving transformer is made of two identical halves, connected back-to-back, and the beginning of both windings through a capacitor connected to one phase of a three-phase AC network, and the ends of the windings capacitors are connected to other phases of the same network.

The drawing shows a schematic diagram of the described device.

No. 149460 2 A.iJftet4epekaH; apparatus 1 is connected via a shirouning filter to the two phases of the transmission line 3. Reception is carried out from a low floor; Noah network for 1 1 capacitors 4 and a linear transformer 5.

The secondary winding of this transformer, having two terminals, is connected. equipment 6. The primary winding is made of two halves with an equal number of turns. The semi-windings are connected in a counter-series manner, that is, the end of the first half-winding is connected to the end of the second one. In the drawing, the letters H and K indicate the beginning and end of the windings, and the instantaneous values of the RF signal voltage are indicated by arrows. As is seen from the drawing, at any connection of the three terminals of the linear transformer to the three phases of the low-voltage network, the high-frequency signals are transformed into the secondary winding of the transformer 5. Indeed, in lull variants, the voltage will not cause a current in the secondary winding of the transformer, since the magnetic currents in the half-windings are directed towards , the current in the primary winding will be destroyed and determined by the voltage U. In the variant /// magnetic currents, the high voltages (the voltages f / a and, will fold and in the secondary winding of the transformer will flow k, which is determined by the sum of the “algebra U2 and.

Thus, the described method makes it possible to receive signals of HF currents independently of the phasing of the low-voltage network.

Subject invention

A device for receiving signals of high-frequency communication through three-phase networks with power transformers according to aut. St. No. 128501, characterized in that, in order to eliminate phasing when connected to the mains, the primary winding of the receiving transformer is made of two identical halves, connected back-to-back, and the beginning of both windings are connected to the same phase of the three-phase AC network, and the ends of the windings through a capacitor connected to the other two phases of the same network.

/ 1and

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H, 5

H, 5

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