RU2214640C2 - Electromagnetic operating mechanism of vacuum switch - Google Patents

Abstract

FIELD: electrical engineering; operating mechanisms for high-voltage vacuum switches. SUBSTANCE: operating mechanism is equipped with magnetic pawls made in the form of two magnetic circuits holding armature in both extreme positions and has armature, making and breaking coils, laminated magnetic core of magnetic material, and permanent magnets whose like poles are oriented toward armature; the latter is disposed so that its axis is aligned with axes of making and breaking coils, and gap is disposed between armature and magnetic core in one of coils depending on position of operating mechanism. Additionally installed in operating mechanism are intermediate shaft with levers, position indicator, and manual disconnecting and ON- operation interlocking mechanisms. EFFECT: enhanced manufacturability and unitized design. 1 cl, 3 dwg

Description

 The invention relates to electrical engineering, in particular to electromagnetic drives of vacuum high-voltage switches.

 Known electromagnetic drives consist of an electromagnet (solenoid) and a mechanical holding device. Such drives are of two types: mounted in the frame of a vacuum circuit breaker and a separate version connected to the frame of the circuit breaker [1].

 The disadvantage of such drives, created on the principle of electromagnetic driving force, is their large mass and multi-link kinematic connection from the rod of the armature of the electromagnetic drive to the rods of the mechanisms for compressing the vacuum interrupter chambers (hereinafter referred to as VDK).

 The new generation of vacuum circuit breakers has a drive part with electromagnetic drives and holding devices with magnets mounted under each phase of the circuit breaker.

 This type of electromagnetic drives developed in Ukraine and made as a whole with the phase of the pole of the switch should include vacuum circuit breakers manufactured by SP RZVA (Rivne), this is a vacuum circuit breaker type BBKE-10 (Ukrainian patent 25132 A) and a vacuum circuit breaker type BB / TEL-10 (patent of the Russian Federation 2202631 C).

 Foreign analogues include vacuum circuit breakers with electromagnetic drives of the type VBT-10-20 / 1600 (developer VEI, and the manufacturer GNPP "Contact" 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 electromagnetic drive of the vacuum circuit breaker BB / TEL-10 of the Tavrida Electric enterprise in Sevastopol was adopted as a prototype.

 The proposed prototype, like the invention, consists of a control coil (in the invention of an on and off coil), magnetically soft parts: an armature, a guide (two in the invention). In addition, in the proposed prototype, a ring with magnetically hard material (two permanent magnets in the invention) and a breaking spring, which is absent in the invention, are installed.

 Significant disadvantages of the prototype include the fact that the holding force of the "magnetic latch" (the force created by the magnetic field of the magnetized control coil of the magnetically hard ring of the electromagnetic drive) is relatively small, therefore, an electromagnetic drive built on this principle is very sensitive to conditions of increased vibration and shock, which can be the cause of spontaneous tripping of the circuit breaker.

 A disadvantage of the analogue is the fact that the design limits the use of mechanical locking of the drive, the functional value of which does not allow the on state of the circuit breaker in the intermediate (between the operating and control) position within the switchgear cabinet.

 The above disadvantages reduce its operational reliability (in terms of the degree of protection of staff), and accordingly limit the scope of such switches.

 The present invention is a new type of electromagnetic drive in which the disadvantages of the analogue are completely absent.

 The basis of the invention is the task of creating this type of electromagnetic drive using new design and technological solutions, which allows to eliminate the disadvantages of the prototype. At the same time, technical and economic indicators and weight and overall parameters should be improved and the highest degree of reliability in operation should be achieved.

 The basis of the invention, namely the electromagnetic drive of the vacuum circuit breaker, is based on the principle of a two-position magnetic system of the electromagnetic drive. The armature of the electromagnetic drive in two extreme positions (“on” and “off”) is held by the magnetic field of two permanent magnets. The “on” or “off” operations will begin only when the holding forces of the permanent magnets are canceled by the excitation of one of the coils of the electromagnetic drive.

 Therefore, the task is achieved by using a multifunctional electromagnetic drive, in which, with the help of on and off coils, the drive armature moves from one extreme position to the opposite, with permanent magnets of a two-position electromagnetic drive made of rare-earth metals-iron-boron (REM-Fe- B) or intermetallic compounds of cobalt with rare-earth metals, form two magnetic circuits, the so-called “magnetic latches”, in which Anchor is being coded. In this case, the permanent magnets are installed with the orientation of the poles of the same name in the direction of the armature located between these permanent magnets, coaxially with the on and off coils and with a gap relative to the magnetic circuit in one of the coils depending on the position of the armature. In addition, the electromagnetic drive is made of soft magnetic material: an anchor, guides and a magnetic circuit made of laced W-shaped plates interconnected by upper and lower support plates.

 The task is also achieved by applying a switch position indicator in the electromagnetic drive, as well as by switching on locking mechanisms that are not available in the prototype, and manual shutdowns implemented through the switch shaft of the prototype.

 The use in the electromagnetic drive of this invention allows for the fixation of the armature not only in the on position of the switch, as in the prototype, but also in the disconnected by means of two magnetic latches.

 The present invention allows for the creation of a high-tech unified series of electromagnetic drives with different capacities required to create a new series of vacuum circuit breakers.

 In addition, the application of the invention allows for mechanical locking of the drive.

 Therefore, according to the authors, such constructive solutions have an advantage over existing electromagnetic drives of vacuum and other circuit breakers.

Figure 1 shows the placement of the electromagnetic drive in the frame of the vacuum circuit breaker;
figure 2 - electromagnetic drive of a vacuum circuit breaker (top view);
figure 3 - electromagnetic drive of a vacuum circuit breaker (side view).

 In the frame of the vacuum circuit breaker, the electromagnetic drive 1 is structurally placed (see Fig. 1), kinematically connected to the shaft of the circuit breaker 2. On the frame is a pole of the vacuum circuit breaker, consisting of an insulating rod 3 with compression springs 4, flexible conductive connection 5, lower contact 6, filled into the insulating casing 7 of the airborne complex 8 and the upper contact 9.

 Structurally, the electromagnetic drive of the vacuum circuit breaker (see top view of figure 2) consists of the following components: parts of the magnetic core 10, the armature 11, two permanent magnets 12, the actuator rod 13, bearings 14, lock washers 15, the axis 16, the guide pads 17, the locking plates of the guide block 18, the fingers 19, the on-coil 20 and the trip coil 21, as well as the off-guide guide block 22, the rollers 23, the spring 24, the shaft of the manual shut-off mechanism 25 and the trip rod 26.

 The upper 27 and lower 28 base plates (see side view of figure 3) hold the lined magnetic circuit. In addition, the drive includes a manual shut-off mechanism 29, a locking mechanism for closing the switch 30 with a stem 31 and a spring 32. The holding pin 33 makes it possible to support the intermediate shaft 34 with levers. The position indicator of the switch 35 indicates the position of the switch and the drive, which also includes support plates 36 and 37 and guides 38 and 39.

 The operation of the electromagnetic drive is as follows. The strength of the magnetic field created by the electromagnetic drive, due to its magnetic characteristics, moves the movable armature 11 (Fig. 2) from one position to the opposite and at the same time directly through the levers of the intermediate shaft 34 (Fig. 3), the shaft of the switch 2 (Fig. 1) and insulating rods 3 (figure 1) act on the movable contacts of the VDK 8 (figure 1). Such a kinematic scheme ensures minimal wear of its elements throughout the life of the vacuum circuit breaker.

 Permanent magnets 12 (FIG. 2) of the electromagnetic drive of the vacuum circuit breaker 1 (FIG. 1) hold the contacts of the VDK 8 (FIG. 1) in the extreme “on” and “off” positions due to the aforementioned “magnetic latch” system, which is based on closure of the magnetic circuit on or off, respectively, by the armature 11 (figure 2).

 To turn on the switch, it is necessary to pass a direct current through the inclusion coil 20 (Fig. 2) at which the force in the magnetic circuit of the inclusion, despite the large gap between the armature and the magnetic circuit (see Fig. 2), will exceed the value of the attractive force of the armature in the magnetic circuit shutdowns where there is no similar gap.

 Upon reaching the value of "starting", the armature 11 (figure 2) of the electromagnetic drive 1 (Fig. 1) begins to move with acceleration, setting in motion the entire kinematic circuit of the switch. In this case, the insulating traction of the poles 3 (Fig. 1), moving up, close the contacts of the VDK 8 (Fig. 1). Anchor 11 (figure 2) stops its movement by selecting the aforementioned "gap", and is fixed in this position by a "magnetic latch".

 The smaller the gap between the armature 11 (figure 2) and the magnetic circuit 10 (figure 2) of the magnetic circuit, the greater the attractive force of the permanent magnets 12 (figure 2).

 The resulting holding force is approximately 800 N. The switch is reliably fixed in the on position even under shock and vibration (which is a drawback of the electromagnetic drive of the vacuum circuit breaker, taken as a prototype).

 Therefore, the inclusion of the switch is the result of the combined action of the magnetomotive force of the inclusion coil 20 (FIG. 2) with current and the action of the permanent magnets 12 (FIG. 2) having a high energy intensity.

 To open the circuit breaker, it is necessary to pass a current through the trip coil 21 (Fig. 2) in a direction in which the force acting on the armature 11 (Fig. 2) exceeds the resulting holding force of the "magnetic latch". This force is the difference between the forces of attraction of the permanent magnets 12 (Fig. 2), atmospheric pressure on the airborne hoses 8 (Fig. 1) of three poles and the force of three groups of compression springs 4 (Fig. 1) of the switch poles.

 At the same time, moving, the armature 11 (figure 2) of the electromagnetic drive closes the magnetic circuit disconnect the drive and thereby clearly fixes the switch in the off position by a "magnetic latch" provided by the permanent magnets 12 (figure 2) of the vacuum circuit breaker. Accordingly, the operation is completed by moving the position indicator 35 (Fig. 3) located on the on-rod 13 (Fig. 2), and the inscription "OFF" appears in the window of the front wall of the switch. An essential feature of the design of the electromagnetic drive is that the locking mechanism of the switch 30 (Fig. 3) allows it to act on the rod 31 (for example, by a special mechanism of the withdrawable element) through the corresponding hole in the switch frame and move it in the guide holes of the electromagnetic drive and thereby block anchor 11 (figure 2), which accordingly makes it impossible to turn on the switch (for example, while moving the switch in the switchgear cabinet).

 Such an electromagnetic drive, created at the joint venture RZVA (Rivne), passed all standard (electromechanical, switching, etc.) tests with the newly created vacuum circuit breaker.

 According to the authors, such an electromagnetic drive of a vacuum circuit breaker is necessary for operating organizations of the national economy’s energy networks.

Sources of information
1. Afanasyev V.V., Yakunin E.N. Drives for circuit breakers and high voltage disconnectors. - L .: Energoatomizdat, Leningrad Branch, 1982

Claims (1)

 An electromagnetic drive of a vacuum circuit breaker containing a plate magnetic circuit, an armature mounted to move from one extreme position to the opposite, permanent magnets mounted in the middle of the magnetic circuit on both sides of the armature relative to the axis of the latter and oriented by the same poles towards the armature, on and off coils with a gap relative to the magnetic circuit in one of the coils depending on the position of the armature, a pointer to the position of the switch and manual switching and blocking the circuit breaker, characterized in that it is equipped with a guide, while the anchor, guides and the magnetic circuit are made of soft magnetic material and are interconnected by upper and lower support plates to ensure that the armature is fixed not only in the on position of the circuit breaker, but also in the off position, at the same time, the closing lock mechanism and the manual shut-off mechanism are installed between the upper and lower supporting plates of the magnetic circuit, and the switch position indicator is located on the armature rod.

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