RU1809471C - Three-phase reactance coil of zero sequences - Google Patents

Abstract

Usage: electrical engineering, limiting the currents of single-phase earth faults in electrical networks to a fireproof value. SUMMARY OF THE INVENTION: the device comprises parts of windings (1, 2, 3, 4, 5, 6) located on the rods (7, 8) of the magnetic circuit. Parts of the windings are connected to a three-phase winding. The winding of each phase is formed by two semi-windings (1, 6), (2, 4), (3, 5). The semi-windings are connected in series and are located on different terminals of the magnetic circuit. Said connection of the windings makes it possible to reduce the asymmetry of the inductive scattering resistances, and hence the distortion of the three-phase voltage introduced by the reactor. 2 ill.

Description

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The invention relates to electrical engineering, in particular to three-phase zero sequence reactors.

The aim of the invention is to improve the quality of the voltage at the outlet of the reactor by reducing the asymmetry of the inductive resistance of the scattering of its windings.

In FIG. 1 is a schematic illustration, -

a reactor for a double rod magnet wire; in FIG. 2 shows the connection of parts of the reactor phase windings.

The reactor contains six parts (semi-windings) of phases 1, 2, 3, 4, 5, 6, located

, -

on the rods x of the two-core magnetic conductor. Half-windings 1/2, 3 are concentrically placed on the first core 7 of the magnetic wire, half-windings 4, 5, 6 are on the second

W rod 8. All half windings have -

turns, the radial size (width) of each half-winding is b, the size of the channels between the half-windings is equal to C, and the average diameter of the windings is D, the height of the windings is h. The winding of each phase is formed by two half-windings connected in series and placed on different rods of the magnetic circuit.

In this case, the inner half-windings 1 and b of the rods 7 and 8 form the winding of one phase (for example, phase A), the middle half-winding 2 of the rod 7 and the outer half-winding 4 of the rod 8 form the winding of the second phase (for example, phase B), and the outer half-winding 3 of the rod 7 and the middle half-winding 5 of the rod 8 forms a winding of the third phase (e.g., phase C).

The present invention extends to a reactor with a three-core (multi-core) magnetic core, in which all of the foregoing is true for any pair of adjacent spaced rods, on each rod of which parts of the windings of three phases are concentrically placed.

From the known expression for this reactor follows

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i0br - - -3 a) tio (y)

 2 (D 4-b + c) d 4- a D (2d + b / 3) + -fa (D-b-c- Y + a2 (p - b - c 5 +

+ a2D (2 (5 + b / 3). t0

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12 b

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b + c D

5 10

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25 30 35

40

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Sob., Due to the inductive voltage drop in this reactor, is theoretically almost two times less than in the known.

The voltage drop in the reverse sequence in the reactor at actual sizes will be 0.4-0.5%, the nominal voltage instead of 1-1.5% in the known reactor. With a usually acceptable value of 2%, such a decrease is significant.

The reactor operates as follows. The reactor is included in the dissection of all three phases of the line supplying the protected section of the network. During normal operation of the reactor, undesirable small voltage drops and voltage distortion occur. If one phase of the network closes behind the reactor to ground, i.e., with the most frequent damage, usually requiring disconnection of the damaged section of the network, in this case the entire network continues to operate normally, because the reactor reduces the fault current to a safe value.

Since the resistance of the reactor to the zero sequence current is very large, the closing current is very small. A short circuit not energized by a significant current may disappear by itself. If it does not disappear on its own, the reactor ensures continuous operation of the network without causing a fire and the ability to prepare personnel to remove the short circuit at a convenient time.

Thus, when applying this proposal, at no additional cost, a voltage distortion reduction of more than two is achieved.

Claims (1)

Gain Formula A three-phase zero sequence reactor containing a three-phase winding, divided into parts by each phase, a core magnetic circuit, on each of the two rods of which the inner, middle and outer parts of the windings of three phases are concentrically arranged, connected in series to each phase, characterized in that, for the purpose of improving the quality of the voltage at the outlet of the reactor by reducing the asymmetry of the inductive scattering resistances, the inner part of the winding of the first phase of one rod is connected to the inner part of the winding another rod of the same phase, the middle part of the winding of the second phase of the first rod is connected to the outer part of the winding of the second rod of the same phase, the outer part of the winding of the third phase of the first rod is connected to the middle part of the second rod.