EA002371B1 - Vacuum high-voltage switch - Google Patents

Abstract

A vacuum high-voltage switch, comprising a frame, poles with vacuum arc-suppressing chambers, insulating rods with compression springs, a switch shaft, an electromagnetic drive, block-contacts of the switch position, manual off-mechanism, boards of protection and control circuits, characterized in that said poles with vacuum arc-suppressing chambers are arranged vertically in series on the frame and kinematically connected via the isolating rods comprising compression springs, the switch shaft mounted horizontally beneath the poles, said shaft is connected via the regulating rod with one electromagnetic drive, in which a laminated core, in and off coils, an armature and constant magnets form two magnetic circuits , capable to retain the armature in its both extreme positions, wherein the electromagnetic drive comprises a mechanism of switching-in blocking, and the switch shaft is connected kinematically to the block-contacts of the switch position.

Description

The invention relates to the field of high-voltage apparatus engineering, including high-voltage vacuum circuit breakers (hereinafter referred to as circuit breakers), mainly mounted on withdrawable elements of switchgear cabinets (hereinafter referred to as switchgear) in a metal shell.

Known vacuum high-voltage circuit breakers contain three phase poles with vacuum chambers mounted on a common frame, which houses the spring, or electromagnetic, kinematically connected to the movable contacts of the interrupter chambers [1].

All well-known vacuum circuit breakers with electromagnetic drives, commercially available in Ukraine and abroad, are made in such design solutions: the electromagnetic (solenoid) drive can be mounted in a frame on which the circuit breaker poles are mounted, or a separate electromagnetic drive connected to the circuit breaker frame, and through a system of rods connected to the rods of movable arcing contacts of the vacuum chambers. In all known embodiments of such vacuum circuit breakers, the holding device has a mechanical locking device for holding the circuit breaker in the on position.

The new generation of vacuum circuit breakers has switching electromagnets (solenoids) and a permanent magnet holding device installed under each phase of the circuit breaker pole.

The circuit breakers produced by the joint venture RZVA in Rivne should be attributed to such circuit breakers developed in Ukraine, this is a vacuum circuit breaker type BBKE-10 (Ukrainian patent No. 25132A) and a vacuum circuit breaker manufactured by TAVRIDA ELECTRIC, Sevastopol, this is a vacuum circuit breaker type BB / TEL-10 (patent of the Russian Federation No. 2020631C).

A new generation of foreign vacuum circuit breakers should include a VBT-10-20 / 1600 type vacuum circuit breaker (developed by VEI, and the manufacturer of GNPP Kontakt, Saratov, Russian Federation).

To obtain the expected result and for the largest number of essential features similar to the essential features of the proposed invention, the vacuum circuit breaker type BB / TEL-1 0 manufactured by TAVRIDA ELECTRIC, Sevastopol, was taken as a prototype.

The present invention, like the prototype, consists of the following main parts: poles with vacuum interrupter chambers (hereinafter referred to as the VDK) in insulated cast cases, a frame into which an electromagnetic drive is mounted (the prototype has three drives), a switch shaft, capacitor boards, control and protection circuits, block contacts of the switch position, manual shut-off mechanism, front panel, counter, position indicator and harnesses of secondary circuits.

Significant disadvantages of the prototype include the fact that the design limits the use of mechanical blocking of the drive, the functional value of which is to prevent the circuit breaker from being switched on in an intermediate (between working and control) position within the switchgear cabinet.

In the design of the prototype, three tripping springs are used (one in each pole), which trips and fixes the circuit breaker in the off position. In the present invention, there are no breaking springs.

The design of the prototype uses three phase-by-phase electromagnetic actuators with a magnetic latch in the on position. In contrast, the proposed invention uses an electromagnetic drive common to all three poles with two magnetic latches in both its extreme positions, having two magnetic circuits — on and off — formed by a pair of permanent magnets.

The basis of the invention is the task of creating a vacuum circuit breaker for switching electrical circuits under normal and emergency conditions in three-phase alternating current networks of frequency 50 (60) Hz with a rated voltage of 10 kV using new design and technological solutions that will eliminate the disadvantages of the prototype, as well as simplify and improve the manufacturability of the design. Such a switch should provide high reliability and the absence of the need for repairs throughout the entire life of the circuit, reducing the current consumption of electromagnets when the circuit breaker is turned on with reduced dimensions and weight.

Thus, the goal in a high-voltage circuit breaker having a frame, poles with a VDK, is achieved according to the invention in that the poles with vacuum arcing chambers mounted vertically in a row on the frame are kinematically connected through insulating rods containing preload springs and a circuit breaker shaft horizontally mounted under the poles , and regulating traction with one electromagnetic drive made of a charged magnetic circuit, on and off coils, anchors, permanent magnets and at the same time equipped with two ma magnetic latches, made in the form of two magnetic chains of permanent magnets, holding the anchor in both its extreme positions, the electromagnetic drive containing a locking mechanism and the switch shaft kinematically connected to the contact contacts of the switch position.

It is the use of a regulating rod with spherical bearings in the circuit breaker, a circuit breaker shaft and one electromagnetic drive, horizontally mounted under the poles according to the original kinematic scheme, that made it possible to ensure the minimum overall dimensions of the circuit breaker and at the same time not to extend the control circuit and circuit breaker protection circuits outside the frame (for the circuit prototype control and protection circuits are installed outside the frame in a separate unit). In this case, the contact contacts of the switch position are kinematically connected to the switch shaft.

The use of a new electromagnetic drive, which performs the function of tripping and does not require the presence of tripping springs (installed on the prototype in each phase), has greatly simplified the design of the switch.

The original, simple and technologically advanced design of poles and multi-function drives makes it possible to carry out many variants of circuit breaker configurations with various kinematic pole connections with a drive, depending on the switchgear requirements for circuit breaker layout, and the circuit breaker is made a highly reliable, small-sized device with minimal consumption currents for its control.

The use of such and other constructive solutions is, in the authors' opinion, an advantage of the newly created vacuum circuit breaker compared to circuit breakers that are mass-produced both in Ukraine and abroad.

The creation of such a switch in combination with a new type of withdrawable element, which contains a separate movement mechanism, made it possible to create a new series of switchgear with a high, doubled degree of protection for service personnel due to the fact that the switch is moved from the operating position to the control position and vice versa when the switchgear is closed [2 ]. Such switchgear was also created at the RZVA joint venture and was called the switchgear KU-10Ts, and the newly created vacuum circuit breaker was ΥΜ18-10. The present invention is a new type of vacuum high-voltage switch, which relates to a new generation of high-voltage switching devices. Small overall dimensions, improved technical and economic indicators, high operational qualities of control and protection schemes make it possible to complete switchgear of any type, both foreign and domestic production.

In FIG. 1 shows a vacuum high-voltage switch in a switchgear cabinet;

in FIG. 2 - vacuum high-voltage switch on a withdrawable element with a separate movement mechanism;

in FIG. 3 - vacuum high-voltage switch UM18-10;

in FIG. 4 - vacuum high-voltage switch (front view without front panel);

in FIG. 5 - vacuum high-voltage switch (top view);

in FIG. 6 - vacuum high-voltage switch (section AA);

in FIG. 7 - vacuum high-voltage switch (section BB);

in FIG. 8 - electromagnetic drive of a vacuum high-voltage switch.

The high-voltage vacuum switch 1 (see Fig. 1) is designed to complete switchgear cabinets 2. A withdrawable element with separate movement mechanism 3 (Fig. 2) allows you to move the switch mounted on the moving part from the working position to the control one and vice versa along the slots in the stationary parts.

The switch consists of three poles with VDK 4 (Fig. 3) mounted on the frame 5 (Fig. 3) with a place for grounding 6 (Fig. 3) and sockets of the plug connectors 7 (Fig. 3). On the front panel 8 (Fig. 3) there are openings of the lever for operative shutdown of the switch 9 (Fig. 3), a mechanical indicator of position 10 (Fig. 3) and an on-off switch 11 (Fig. 3).

In the frame of the switch of FIG. 4, the inclusion lock-up mechanism 12, the counter 13, the plugs of the connectors 14, the mounting brackets of the protection and control circuit boards 15, 16, 17 and 18, the control circuit board 19, the rotation axis of the control board 20, the capacitor board 22, the trip coil 23 of the electromagnetic drive 24 , the coil 25 and the indicator on and off position of the switch 26.

In FIG. 5, the control rod 27, the shaft of the circuit breaker 28, the bearings of the shaft of the circuit breaker 29, the bracket for attaching the circuit board of protection circuits 30, the nuts of fastening of the electromagnetic drive 31, the bracket for attaching the plate of capacitors 32, cover 33, three groups of contact blocks for the switch 34 position, contactor 35, bracket are placed for mounting the contactor 36, the harness of the secondary circuits 37, the front panel 38, the bracket 39, the rubber ring 40, the circuit board 41 and the axis 42.

In FIG. 6 shows a section A-A of the circuit-breaker frame, namely, lock washers 43, fixing the axes of the joints of the insulating rods 44, containing mechanisms for compressing the vacuum chambers with the levers of the circuit-breaker shaft.

In addition, in FIG. 6, rubber bushings 45 and counter spring 46 are placed.

In FIG. 7 shows a section B-B of the circuit-breaker frame, where the screws securing the block contacts of the circuit-breaker position 47, rubber gaskets 48, and the axis 49 connects these block contacts to the circuit-breaker shaft. They are mounted in accordance with the variants of the circuit diagrams and have a certain number of opening and closing contacts.

In FIG. 8 shows the electromagnetic drive of a high-voltage vacuum circuit breaker, namely, a guide 50, a charged magnetic circuit 51, an armature 52, permanent magnets 53 and a guide 54, magnetic on and off circuits, and also the gap between the armature and the magnetic circuit of the drive.

The locking mechanism performs the function of locking the circuit breaker. It consists of a bracket, a stem and a spring holding the rod in the lower unlocked position. In the frame of the switch there is a necessary hole with a diameter of 20 mm (see. Fig. 4), placed under the rod. If through the indicated hole to press the rod and move it to the upper position, then the switch is mechanically locked.

The switch operates as follows.

In the disconnected position of the circuit breaker, the VDK contacts are open, the armature 52 (Fig. 8) of the electromagnetic drive is held in the extreme disconnected position by means of a magnetic latch. In this position, the anchor (Fig. 8) is acted upon by the retraction forces of three VDKs (atm. Pressure) and the traction forces of the permanent magnets 53 (Fig. 8) directed in the opposite direction.

In the on position, the armature 52 (Fig. 8) of the electromagnetic actuator is held by the pulling force of the permanent magnet (Fig. 8), that is, a magnetic latch. In this case, the VDK contacts are closed and preloaded by Belleville spring springs. In this position, the forces act on the anchor 52 (Fig. 8): the retraction force of the VDK, the force of action of the magnetic latch, as well as the force of the belleville compression springs directed in the opposite direction. The resulting holding force is approximately 800 N. The switch is securely locked in the on position even under shock and vibration conditions. The contact contacts of the position of the switch 34 (Fig. 5) when switching to the on position are switched.

To turn on the switch, it is necessary to pass a direct current through the switching coil 25 (Fig. 4), at which the force in the magnetic circuit of the inclusion, despite the large gap between the armature 52 (Fig. 8) and the magnetic circuit 51 (Fig. 8), will exceed the attractive force permanent magnets 53 (Fig. 8) of the armature 52 (Fig. 8) in the magnetic tripping circuit, where there is no similar gap.

As soon as the traction force reaches a sufficient value (the amount of pulling), the armature 52 (Fig. 8) of the electromagnetic drive begins to move with acceleration and sets in motion the entire kinematic circuit of the switch. Anchor 52 (Fig. 8) through the inclusion rod, the intermediate shaft acts on the control rod 27 (Fig. 5), connected to the shaft of the switch 28 (Fig. 5) and rotates it. In this case, the insulating traction of the poles 44 (Fig. 6), mounted on the levers of the main shaft, begin to move up. After the VDK contacts are closed, the compression springs installed in the insulation rods 44 (Fig. 6) begin to compress. Touching the armature 52 (Fig. 8) of the magnetic circuit 51 (Fig. 8) indicates that the switch is turned on and it is locked in this position by a magnetic latch. The smaller the gap between the armature 52 (Fig. 8) and the magnetic circuit 51 (Fig. 8) of the magnetic circuit becomes, the greater the traction force of the permanent magnets 53 (Fig. 8).

Therefore, the switch is turned on as a result of the combined action of the magnetomotive force of the switching coil 25 (Fig. 4) with current and the action of permanent magnets 53 (Fig. 8), which have a high energy intensity.

In this case, the position indicator of the switch 26 (Fig. 4) moves together with the armature 52 (Fig. 8) of the electromagnetic drive 24 (Fig. 4), and the inscription ON appears in the window of the front cover 10 (Fig. 3). To open the circuit breaker, it is necessary to pass a direct current through the trip coil 23 (Fig. 4) of the electromagnetic drive in the direction at which the force acting on the armature 52 (Fig. 8) will exceed the resulting holding force of the magnetic latch. The holding force in the on position is equal to the difference between the forces of attraction of the permanent magnets 53 (Fig. 8), the attraction of the VDK of the three poles 4 (Fig. 3) and the force of the three groups of spring-loaded pole poles of the circuit breaker of approximately 800 N.

After decompression by the magnitude of the stroke of the preload springs, the VDK contacts begin to open and the process of extinction of the electric arc begins.

The tripping process ends with the anchor 52 (Fig. 8) of the electromagnetic actuator 24 (Fig. 4) closing the magnetic trip circuit and thereby clearly locks the circuit breaker in the off position with a magnetic latch, which is provided by the permanent magnets of the actuator 53 (Fig. 8). The position indicator of the switch 26 (Fig. 4) moves with the anchor 52 (Fig. 8), and the inscription OFF appears in the window of the front cover 10 (Fig. 3).

The newly created vacuum high-voltage circuit breaker provides for blocking7 re-activation. Its essence is that when you save the turn on command and the simultaneous turn off command, the switch turns off and does not turn on again. To enable the circuit breaker to turn on again (after tripping), the ON command must be removed, and then re-submitted.

A prototype of a vacuum high-voltage circuit breaker manufactured at SP RZVA showed high reliability in operation during electromechanical tests and fully confirmed its reliable operability during switching tests at the SRC VVA, Moscow.

According to the authors, such a vacuum high-voltage circuit breaker is necessary for the operating organizations of the national economy’s energy networks.

Information sources

1. GOST 687-78. AC circuit breakers for voltages above 1000 V. General specifications. Publishing house of standards. 1981

2. IEC 298. Complete switchgear of alternating current in a metal sheath for a voltage of 1 to 72.5 kV. M. 1981

Claims (1)

CLAIM Vacuum high-voltage switch containing a frame, poles with vacuum arcing chambers, insulating rods with preload springs, switch shaft, electromagnetic drive, switch position contacts, manual shutdown mechanism, protection and control circuit boards, characterized in that poles with vacuum arc chambers mounted vertically in a row on the frame and kinematically connected through insulating rods containing preload springs with a switch shaft installed horizontally under the poles, which It is connected through a regulating rod with a single electromagnetic drive, in which the laminated magnetic core, the on and off coils, the armature and the permanent magnets form two magnetic circuits of the permanent magnets capable of holding the armature in both its extreme positions, and the switch shaft is kinematically connected to the auxiliary contacts of the switch position.