RU2267827C2 - Three-phased device for switching between branches of transformer windings - Google Patents

Abstract

FIELD: electric engineering, possible use in construction of devices for switching between branches of windings belonging to force transformers under load.

SUBSTANCE: three-phased device for switching between branches of windings belonging to transformer under load has body made of dielectric with bottom and lid, contactor, including three-phased contactor mechanisms with commutating and additional contacts, forming groups, in its body, resistors, through which additional contacts are connected to linear outputs of adjusting winding of transformer, mechanism for switching between contactors and immovable contacts positioned on the walls of body for connection to transformer and to selectors of phase branches of transformer windings, while immovable contacts of phase selectors can be connected to phase branches of adjusting winding of transformer. Mechanisms of three-phased contactors are mounted in the same body, and their contact groups are shifted relatively to each other in phase-wise manner along body axis by means of mounting of contact groups of one or two phases on dielectric substrates.

EFFECT: simplified construction, increased operational reliability of three-phased device for switching between branches of windings belonging to transformer under load.

4 cl, 5 dwg

Description

The invention relates to the field of electrical engineering and can be used in the design of three-phase switch branches of the windings of power transformers under load.

A known device for switching branches (solders) of the transformer windings under load according to Japanese patent No. 62-62443, H 01 F 29/04, 1987 contains a contactor and a selector of the solder.

The contactor and the selector have their own housings, located one above the other, and are designed to regulate single-phase voltage.

A disadvantage of the known design is the need for three such switching devices for regulating the voltage of the three phases, respectively, significantly increasing material costs and the cost of the transformer.

The well-known contactor of a switching device for regulating the voltage of a transformer under load according to the copyright certificate of the former USSR No. 520686, Н 02 Р 13/06, Н 01 F 29/04, 1976 contains switching, auxiliary and arcing contacts with a resistor.

The disadvantage of the contactor of the known device is the design complexity, while the contactor is also designed to regulate the voltage of one phase, and to regulate three phases, three contactors are needed, which increases material costs.

The well-known three-phase switch branches (solderings) of the transformer windings under load according to European patent No. 0185530, N 01 H 9/00, 1986 contains contactors and selectors solder.

The contactor of each phase contains a dielectric housing with a bottom and a cover, in which a contactor mechanism with switching and additional contacts forming a contact group and resistors is installed.

The contactor mechanism is installed at the bottom of the housing, and fixed contacts are installed on the walls of the housing for connection to a transformer and a selector.

The contactors and the selectors of the three phases are located in two nodes, while the contactors of the two phases are axially located in one node, and below them is the selector of one phase, electrically connected to the contactor close to it.

In the other node, the contactor of the third phase and the selectors of the two phases are axially arranged.

The lower selector is electrically connected to the upper contactor of the first node, and the upper selector is connected to the contactor located above it.

The kinematic connection of the contactors and voters is provided by a switching mechanism, the elements of which are located in the covers of the upper contactors and between the contactors and the voters.

Such a switch arrangement provides voltage regulation in three-phase systems, reduces the plan area occupied by the switch and slightly reduces the consumption of materials.

This design is taken as a prototype.

The disadvantage of the prototype is the increased material consumption and high cost, since for the manufacture of such a three-phase switch, it is practically necessary to manufacture three single-phase contactors and three selectors, then connect them electrically and kinematically to a three-phase system.

The basis of the invention is the task of developing the design of a three-phase switch branches of the transformer windings under load, which simplifies the design, reduces material consumption and cost and increases operational reliability.

The solution to this problem provides a three-phase switch of branches of the transformer windings under load, comprising a dielectric housing with a bottom and a cover, a contactor including three-phase contactor mechanisms installed in the housing with switching and additional contacts forming contact groups, resistors through which additional contacts are connected to linear conclusions of the transformer adjustment winding, contactor switching mechanism and fixed contacts located on the housing walls for connections with the transformer and with the selectors of the branches of the phases of the transformer windings, while the fixed contacts of the phase voters have the ability to connect to the phases of the phases of the regulating winding of the transformer due to the fact that the mechanisms of the contactors of the three phases are installed in one housing, and their contact groups are phase-shifted relative to each other axis of the housing by installing contact groups of one or two phases on dielectric supports.

To reduce the dimensions, the resistors located in the dielectric housings and installed under contact groups remote from the bottom of the housing were used as supports.

To increase the reliability between the mechanisms of the contactors of the three phases, dielectric partitions are installed.

To reduce the number of main nodes, phase branch selectors are placed in one housing, and their contacts are located in planes that are phase-wise removed from each other by a distance corresponding to the interfacial insulation distance.

The technical result achieved by using the invention:

- reduced material consumption, since the mechanisms of the contactors of the three phases are made in one common housing of the three-phase switch with the switching mechanism installed in the cover;

- the dimensions of the three-phase switch are reduced due to the rational arrangement in the plan and height of the contact groups of the contactors of the three phases and the installation of interphase partitions made of a dielectric;

- reduced the height of the three-phase switch due to the location of the voters of the three phases in one housing in combination with the optimal layout of the contactors of the three phases;

- significantly reduced the cost of the switch by reducing the number of main nodes;

- increased operational reliability due to the simplification of the kinematic connection of nodes and provided the electrical strength of the interphase gaps.

The inventive three-phase switch branches of the transformer windings under load is illustrated by the following description and drawings, where:

Figure 1 - General view of a three-phase switch branches of the transformer windings under load;

Figure 2 is a sectional view of Figure 1;

Figure 3 - control circuit of one phase of the switch;

4 is a variant of the layout of the phases of the contactor switch;

5 is a sequence diagram of the switching contacts of the contactor mechanisms of three phases, for example, one phase X.

According to the invention, the three-phase switch of the branches of the transformer windings comprises a contactor 1 located axially above the voters 2 of the branches of the windings, a switching mechanism 3 with a drive 4 and a selector 5 for reversing the switching (see Figure 1).

The contactor 1 has the mechanisms of the contactors of the three phases 6 X, Y, Z installed in the housing 7 of dielectric material with a bottom 8 and a cover 9 (see Figure 2).

Each contactor mechanism of the three phases 6 has two arms 10, 11 with the main (commuting) contacts 12, 13 and additional 14, 15, 16, 17.

Contacts 14, 15 are auxiliary, and contacts 16, 17 are arcing and are connected to linear inputs X _l , Y _l , Z _{l of the} control winding (PO) through resistors 18, 19 (see Figure 3).

These contacts of the mechanisms of the contactors of the three phases 6 form contact groups 20, phase-wise spaced relative to each other along the axis of the housing 7 due to the installation of one or two contact groups 20 of the contactors of the three phases on the dielectric supports 21 (see Figure 2).

As supports 21, resistors 18, 19 located in dielectric housings and phase-wise mounted above or below the contact groups 20 of three-phase contactor mechanisms can be used (see Figure 4).

On the wall of the housing 7 of the contactor 1, fixed contacts 22 are installed for connecting to a transformer and contacts 23 for connecting to the voters 2 phase branches of the transformer windings (see Figure 1).

Between the mechanisms of the contactors of the three phases 6 are installed partitions 24 of the dielectric (see Figure 2, Figure 4).

Voters 2 of three phases are placed in one housing 25 of a dielectric with fixed contacts 26 connected to the branches of the winding (PO) of the transformer (see Figure 2).

Fixed contacts 26 voters of 2 phases X, Y, Z are divided into two rows: even contacts - X 2, 4, 6, 8, 10, Y 2, 4, 6, 8, 10, Z 2, 4, 6, 8, 10 and odd contacts - X 1, 3, 5, 7, 9, Y 1, 3, 5, 7, 9, Z 1, 3, 5, 7, 9.

The even contacts in each phase are offset relative to the odd ones along the height of the housing 25. The contacts of the phases X, Y, Z are installed in planes that are spaced apart from each other along the axis of the housing by a distance corresponding to the interfacial insulation distance.

A bakelite shaft 27 is installed along the axis of the housing 25 with slip rings 28 connected to the respective arms 10, 11 of the contactor 1. The movable contacts 29 of the lamella type are mounted on the coaxial bakelite shafts 30, 31 (see Figure 2).

The selector 5 has a shaft 32 with movable contacts 33 fixed thereon and a sector 34 with fixed contacts X 11, 13, Y 11, 13, Z 11, 13.

The kinematic connection of the voter 2 and the selector 5 with the switching mechanism 3 of the contactor 1 is carried out by means of the shaft 35 and the Maltese gears 36 (see Figure 2).

For the switch to work, it is necessary to switch the contacts of the selector 2 and transfer the contacts of the contactor 1.

The contactor operation sequence is shown in FIG. 5.

Position "a" corresponds to the operating position of the switch: contacts 13, 15, 17 are closed, and contacts 12, 14, 16 are open.

Position "b" indicates the beginning of the switch: the main contacts 12 and 13 are open, and the additional contacts 15 and 17 are closed.

All current passes through auxiliary contacts 15.

In the "in" position, the contacts 15 open, and the current passes through the resistor 19 and the arcing contacts 17.

The position "g" indicates the moment of the "bridge", i.e. the moment when both arcing contacts 16 and 17 are closed, which leads to the closure of the winding stages (PO) through resistors 18 and 19.

The magnitude of the circulating current in this stage of the winding (PO) is determined by the value of the resistances of the resistors 18 and 19, connected in series to the circuit of the closed stage of the winding (PO).

With the further movement of the contacts to the "e" position, the arcing contacts 17 of the arm 10 open, and the contacts 16 of the arm 11 remain on.

With the subsequent movement of the contacts to the positions "e" and "g" auxiliary contacts 14 and the main contacts 12 of the arm 11 are sequentially closed.

The position "g" corresponds to the operating position of the switch on the switched branch of the winding (PO) of the transformer.

In the position of figure 3, the main winding of the phase X of the transformer is connected to the control winding (PO) through the contacts X 10 and X 11 of the selector 5, and the adjustment through contact X 6 of the selector 2 and the contacts of the contactor 1 are connected to the linear contact X _L.

When the movable contacts of the voter 2 move to the contact X 5, the magnetic flux increases, which is directed according to the flow of the main winding.

The inventive three-phase switch allows after reversing, which occurs when the contacts of the selector are switched to the fixed contact X 13, to change the direction of the magnetic flux of the control winding (PO) to the opposite, which increases the range of regulation of the switch.

Claims (4)

1. Three-phase switch of branches of transformer windings under load, comprising a dielectric housing with a bottom and a cover, a contactor including three phase contactor mechanisms installed in the housing with switching and additional contacts forming contact groups, resistors through which additional contacts are connected to the linear terminals of the control transformer windings, contactor switching mechanism and fixed contacts located on the walls of the housing for connecting to and from the transformer phase transformer winding branches, while the stationary phase voter contacts have the ability to connect the transformer control windings to the phase branches, characterized in that the contactor mechanisms of the three phases are installed in one housing, and their contact groups are phase-shifted relative to each other along the housing axis by installing contact groups of one or two phases on dielectric supports. 2. The switch according to claim 1, characterized in that the resistors are used as supports, located in dielectric housings and installed under contact groups remote from the bottom of the housing. 3. The switch according to claim 1 or 2, characterized in that between the mechanisms of the contactors of the three phases are installed partitions of a dielectric. 4. The switch according to any one of claims 1 to 3, characterized in that the phase branch selectors are placed in one housing, and their contacts are located in planes that are phase-wise removed from each other by a distance corresponding to the interfacial isolation distance.

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