RU2574078C2 - Three-position vacuum load disconnecting switch - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: three-position vacuum load disconnecting switch comprises one or several phases joined by the common frame. Each phase has a base insulator with current lead and vacuum arc-quenching chamber placed in a protective insulating case with spring-actuated mechanism of contacts opening and contact arm rotating in vertical plane around the axis in the case, the master fixed contact connected electrically to the current lead and vacuum arc-quenching chamber, and the master movable contact installed at the other base insulator. Cam lifter is installed additionally at the master movable contact and coupled electrically to it; at the frame there is an additional metal base with fixed ground contact and the third base insulator with the second current lead coupled by a flexible current conductive link with a movable contact. The master movable contact performs rotational motion in horizontal plane. When switched on, it closes the master fixed contact, at turn to angle of 90° it forms visible rapture while at turn to angle of 180° it closes the ground contact. At closing and opening the master contacts, impacting the contact arm, the cam lifter leads to preliminary closure and opening of contacts and current switching inside the vacuum arc-quenching chamber.

EFFECT: combining functions of cutoff, disconnecting and grounding switch in one mechanism with control from the same wire.

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Description

The invention relates to electrical engineering, to the field of high-voltage vacuum circuit breakers, and more specifically to vacuum circuit breakers.

Load breakers are designed for switching rated currents, but must withstand through-current short circuits. They are controlled, as a rule, by manual drives. The load switches also perform the functions of a disconnector and can have a built-in earthing switch, which is also controlled by a manual drive.

Known technical solutions [1, 2] of vacuum circuit-breakers, the principle of which is that the current through the vacuum arcing chamber passes only at the time of switching (on or off). In the on position, the vacuum interrupter (VDK) is shunted by the main contacts, of which one is movable and the other is stationary. In the disconnected position, the vacuum chamber is not under the influence of mains voltage, since a visible gap is created between the main contacts. The opening and closing of the contacts of the VDK itself is carried out by a spring mechanism, which is directly affected by a cam mounted on a movable contact. Moreover, the synchronization of the moment of closing-opening of the VDK contacts and the main contacts provides a special cam profile.

The advantage of this design is that the VDK is small, and the design itself is simple and relatively inexpensive.

The disadvantage is that the vacuum chamber does not have external protection against the influence of climatic factors of the external environment, which does not allow the use of such a design for outdoor circuit breakers.

Closest to the proposed technical solution is the technical solution proposed in [3], in which the circuit breaker contains one or several phases connected by a common frame, each of which has a current lead installed on the support insulator, a vacuum arrester with a spring mechanism located in the protective insulating casing opening of contacts and a contact lever that rotates in a vertical plane around an axis in the housing, as well as the main fixed contact, electrically connected to the current lead m and the vacuum interrupter chamber and mounted on the other support insulator main movable contact which makes rocking movement in the vertical plane. Moreover, an auxiliary contact is installed on the main movable contact, which, when performing switching operations, interacts with the contact lever on the housing and ensures the closure and opening of the VDK contacts.

The disadvantage of this technical solution is that the circuit breaker cannot perform the grounding operation, it has only two “on” and “off-wired” positions. To perform the grounding operation, an additional installation on the circuit breaker of a separate shaft with grounding knives and an additional manual drive for control is supposed. In this case, a blocking should be provided between the circuit breaker and grounding drives, eliminating the possibility of erroneous personnel actions.

In addition, to control the movable contacts of the circuit breaker and the ground electrode, which make a rocking movement in the vertical plane, considerable effort is required on the handle of the drive, since it is necessary to raise and lower the link connecting the drive and the switch. When installing the switch on a pillar support, the standard rod length (usually a metal pipe) is about 6 m.

The aim of the invention is to eliminate these disadvantages.

This goal is achieved by the fact that the three-position vacuum switch-disconnector contains one or several phases connected by a common frame, and each of the phases has a support insulator with a current lead and vacuum arcing chambers placed in a protective insulating case with a spring-loaded contact opening mechanism and a contact lever that rotates in a vertical plane around an axis in the housing, the main fixed contact, electrically connected to a current lead and a vacuum arcing chamber, as well as The main movable contact mounted on the second support insulator.

The novelty of the proposed technical solution lies in the fact that the cam follower is additionally placed on the main movable contact and electrically connected to it, and a metal support is additionally installed on the frame, on which the ground contact and the third support insulator with the second current supply are connected, connected by a flexible, conductive connection with moving contact, while the main moving contact rotates in the horizontal plane and when turned on, it closes with the main fixed contact, turning 90 ° forms a visible gap, and when turning 180 ° it closes with the ground contact, and when the main contacts are closed and open, the cam follower, acting on the contact lever, causes the contacts to pre-close and open and the current is switched inside the vacuum interrupter .

The design and operation of the three-position vacuum disconnector-switch (RVNV) is illustrated in FIG. 1-4.

In FIG. 1 shows the RVNV in the on position. In FIG. 2 shows the RVNV in the disconnected position. In FIG. 3 shows the RVNV in the earthed position. In FIG. 4 shows a protective insulating casing with a vacuum interrupter chamber (VDK) and a spring contact opening mechanism.

The three-position vacuum switch-disconnector contains the following main parts and assemblies (Fig. 1): frame 1, support insulator of the main fixed contact 2, current lead 3, protective insulating housing 4, in which a vacuum arcing chamber 5 (Fig. 4) is installed with a spring the contact opening mechanism 6 and the contact lever 7 (Fig. 1), which rotates around the axis 8 in the vertical plane, the main fixed contact 9, which is electrically connected to the current supply 3 and the fixed contact of the vacuum chamber 5. The main The contact pin 10 is installed on the support insulator 11, which rotates in a horizontal plane, the rotational force from the drive is transmitted through the shaft 12. A cam follower 13 is installed and electrically connected to the main contact 13. The third support insulator 14 is mounted on a metal support 15, on which the ground contact 16 is also installed. The second current lead 17 is connected by a flexible electrically conductive connection 18 with the main movable contact 10.

In the “on” position (Fig. 1), the main movable contact 10 closes with the main fixed contact 9. The current from the first current lead 3 passes through closed contacts 9 and 10, a flexible connection 18 through the second current lead 17. In this case, the cam follower 13 interacts with the contact lever 7 through the roller 19 low section of its profile and the contacts in the vacuum chamber remain open. Current does not pass through the VDK. The circuit breaker (Fig. 2) is turned off by turning the shaft 12 connected to the support insulator 11 of the movable contact 10 counterclockwise. First, the VDK contacts are closed by the action of the pusher 13 with a high section of their profile on the contact roller 19 and the lever 7. Then the main contacts 9 and 10 open, after which the current passes through the closed VDK contacts, the lever 7, the roller 19, the pusher 19 and the main movable contact (Fig. 2). Upon further rotation of the main movable contact 10, it moves away from the stationary 9 by a distance sufficient to withstand the returning mains voltage, and at the moment (shown in dashed line in Fig. 2), when the cam follower 13 interacts with the roller 19 with a low profile section, the VDK contacts under the action of the spring mechanism 6 (Fig. 4) open. After opening the VDK contacts, the current is turned off. When the movable contact 10 is rotated through an angle of 90 °, the switch becomes in the “DISPOSED” position (Fig. 2).

To perform the operation “GROUNDING” (Fig. 3), the shaft 12 is rotated through an angle of 180 ° with respect to the “ON” position. In this case, the main movable contact 10 is closed with the grounding contact 16. Thus, the power line connected to the current supply 17 through a flexible connection 18 and the movable contact 10 is grounded.

The inclusion of RVNV is carried out in the reverse order by rotating the shaft 12 in the opposite direction.

The advantage of the proposed technical solution in comparison with the known ones is that the RVNV can carry out the operations “ON (DISABLED)” - “DEPARTMENT” - “EARTHING” by turning one control shaft. This eliminates the possibility of errors in the actions of personnel, eliminates the need for special locking, simplifies and facilitates the design.

Information sources

1. RF patent 2247439, MKI H01H 33/66, publ. 02/27/2005.

2. The patent of Germany 102005002139, MKI H01H 33/66, publ. 07/27/2006.

3. Patent of Germany 19918077, MKI H01H 33/66, publ. 11/09/2009.

Claims (1)

Three-position vacuum disconnector-switch, containing one or several phases connected by a common frame, each phase having a support insulator with a current supply and a vacuum arcing chamber located in a protective insulating case with a spring contact breaking mechanism and a contact lever that rotates in a vertical plane around axis in the housing, the main fixed contact, electrically connected to the current lead and the vacuum interrupter chamber, and also mounted on another support ohm insulator, the main movable contact, characterized in that the cam follower is additionally placed and electrically connected to the main movable contact, and a metal support is additionally mounted on the frame, on which the ground contact and the third support insulator with the second current supply are connected, connected by a flexible, conductive connection with a movable contact, while the main movable contact rotates in the horizontal plane and when turned on, it closes with the main fixed contact, and turning through an angle of 90 ° forms a visible gap, and when turning through 180 ° it closes with a grounding contact, and when the main contacts are closed and open, the cam follower, acting on the contact lever, causes preliminary contact closure and opening and current switching inside the vacuum interrupter.

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