SU985834A1 - High-voltage transformer winding capacitive ring - Google Patents

Description

The invention relates to electrical engineering and can be used in the production of high voltage transformers connected to a power line and exposed to thunderstorm impacts. A capacitive ring is known, which contains a dielectric ring core, covering the surface of the skeleton electrode, having a gap to prevent its short-circuit, and a siege of the electrode junction key to the winding. The epuetpou of such a ring is formed by K (the ethereal surface of the jVl core. The disadvantage of this design is the high resistance of the eletrode, which leads to arcing and flow; lightning impulses of voltage, while the effectiveness of a ring as an electrostatic screen requires that the liver ijo the entire electrode is of almost the same electric potential. However, this leads to an increase in eddy currents and electric power losses in the electrode. It is also known to have a capacitive ring containing the dielectric core, an electrode on the core surface formed by turns of insulated metal strip with a gap between the first and the outermost. the coils and the electrode connecting element to the winding, U) and the electrode coils are drifted 1 2. Its disadvantage is the formation of a voltage difference between the electrode connecting point to the winding and the points from it (the greatest difference stress - between the extreme turns). As the operating voltage increases, the impulse lightning voltage acting on the transformer increases. As a result, the inductance of the capacitive ring together with the capacitance on the adjacent

portions of the winding create an inductive-capacitive circuit, in which, when lightning effects on the transformer, electromagnetic oscillations are formed, which are not tolerable by the requirement of screening efficiency. The soldering of the turns leads to an increase in the vortex flows and the loss of electricity in the ring electrode.

In addition, the soldering of the electrode coils entails an increase in the labor of the capacitance and an increase in costs, since the repacking is performed mostly manually.

The purpose of the invention is to simplify the design, reduce heating and increase the dielectric strength of the ring by adopting a USSug electric oscillations in the insulated coils of the electrode.

The goal is achieved by the fact that in a capacitive ring containing

dielectric backbone, electrode on The surfaces of the core formed by the turns of the Insulated Metal Tape with a gap between the first and the last turns, as well as the electrode connecting element to the winding, the electrode connecting element to the winding are connected to the middle turn of the electrode, forming two symmetrical branches of the electrodes turns.

The proposed solution significantly improves the electrical parameters of the capacitor ring, since the inductance of the formed two electrode branches is reduced due to the halving of the number of turns, as well as due to the oncoming pulse currents in these branches x. Branch capacity. reduced by half.

The drawing shows the proposed capacitive ring (even the turns are blackened),

The capacitive ring winding of the transformer of High voltage contains a coil core 1 of dielectric material and an electrode covering the surface of the core and formed by coils 2 insulated from one another and wound from a single metal tape with a gap between the outermost and last turns 3 and 4 , Chiolo turns in the electrode - any (even turns are blackened). To connect the electrode to the winding (not shown), element 5 is connected to the middle turn of the electrode, forming two symmetrical branches of the turns of the electrode.

During operation, the pulse currents of the branches of the capacitive ring have opposite directions and their magnetic fluxes are subtracted.

Using the proposed solution allows to improve the electrical characteristics of the capacitive ring: the period of natural oscillations is reduced and the amplitude of oscillations decreases to acceptable values.

It is established that the greatest amplitude of oscillations does not exceed 10% of the coil voltage. The labor and manufacturing costs of the ring are reduced by reducing manual operations.

Claims (2)

1.Gerasimova L.S. Technologists and mechanization of the production of windings and insulation of power transformers. M., Energie, 1979, p. 293. 2. Sapozhnikov A.V. Designing transformers. M.-L., SEI, 1959, with. 134.