RU2304819C1 - High voltage vacuum switch - Google Patents

Abstract

FIELD: high voltage device engineering, namely, a series of vacuum switches intended for usage in unitized distribution devices.

SUBSTANCE: vacuum switches of specific series of all types have unified dimensions, new frame, new poles cast of epoxide compound, and are capable of operation with nominal currents up to 3150A, nominal breaking currents up to 40kA. In accordance to invention, independent action electromagnetic drive is built into switch frame, which contains capacitor for preliminary energy accumulation, connected to feeding network through current-limiting resistor, resistance value of which is directly proportional to time constant of capacitor charging and proportional to capacity of capacitor, while aforementioned capacitor for realization of "enable" and "disable" operations is connected to coils for enabling and disabling electromagnet of the drive via commutation block.

EFFECT: decreased consumption current of drive and increased reliability of operation.

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Description

The invention relates to the field of high-voltage apparatus engineering, in particular to vacuum high-voltage circuit breakers (hereinafter referred to as circuit breakers), mainly mounted on withdrawable elements of enclosures of complete switchgears (hereinafter referred to as switchgear) in metal shells.

Known vacuum high-voltage circuit breakers contain three phase poles with vacuum chambers [1] mounted on a common frame in which a spring or electromagnetic drive is placed, which is kinematically connected to the movable contacts of the vacuum interrupter chambers [2] (hereinafter referred to as VDK). According to the classification [3], all drives of high-voltage circuit breakers are subdivided into drives of dependent (direct) action, consuming energy during the operation of switching on directly from the auxiliary source of electrical energy, and drives of independent (indirect) action, performing the operation of switching on due to the energy previously stored before performing an operation, such as flywheel (inertial), pneumatic, pneumohydraulic, spring.

Well-known vacuum circuit breakers, commercially available in the CIS countries and abroad, with electromagnetic drives of dependent (direct) action, turn on the circuit breaker, consume current through the secondary circuit during the operation of switching, and at the same time compress or stretch the disconnecting springs and the compression spring of the VDK contacts .

The new generation of vacuum circuit breakers has one or three electromagnets of inclusion (solenoid) with holding devices on mechanical or magnetic latches installed under each or under some pole of the circuit breaker, in which are placed the contact spring of the VDK contacts and the breaking spring. At the same time, the circuit breaker is controlled using the control and protection unit, the mechanical and electrical blocking block of the inclusion and other blocks made by separate elements and installed outside the circuit breaker frame, or using the electromechanical drive control elements integrated into the circuit breaker frame.

This type of circuit breaker includes vacuum circuit breakers with drives of the dependent action of the BB / TEL series of TAVRIDA ELECTRIC firm (US Pat. No. 2020631), a vacuum circuit breaker (Ukrainian Pat. No. 493 U, 02/28/2000 Bull. No. 1), etc.

According to the largest number of essential features, a vacuum circuit breaker with an electromagnetic drive of dependent action according to the patent of Ukraine No. 493 U can be taken as a prototype.

The design solutions of the prototype significantly limit the possibility of using such switches in cabinets of a newly created type, for example, KU-6S and KU-10S with rated currents from 630 A to 3150 A and rated tripping currents from 20 kA to 40 kA, designed for operation in switchgear systems of their own the needs of power plants in earthquake-resistant design and in electrical installations of industrial enterprises.

The new development of the vacuum circuit breaker should provide convenience and control of the main operating parameters in operation, and the high-voltage circuit breaker itself should be one complete product, i.e. all control and protection units, switching, capacitor, mechanical and electrical blocking unit for switching on and others should be placed in the frame of the switch.

The basis of the present invention is the task of developing a modern series of vacuum circuit breakers with an electromagnetic drive for switching electrical circuits under normal and emergency conditions within a three-phase alternating current frequency of 50 (60) Hz with a rated voltage of 6 kV and 10 kV. In this case, the electromagnetic drive of the circuit breaker must consume from a source located outside the circuit breaker a current of not more than 3 A at a voltage of 220 V. In addition, the reliability of the circuit breaker must be increased.

The task of limiting the amount of current consumed by the drive, as well as increasing the reliability of the circuit breaker, especially with dependent power of its drive, is achieved due to the fact that an independent electromagnetic drive is integrated in the circuit breaker frame, which contains a capacitor for preliminary energy storage connected to the mains through a current-limiting resistor whose resistance value is directly proportional to the constant of the charging time of the capacitor and inversely proportional to the capacitance a capacitor, and the specified capacitor to perform operations "enable" and "disconnect" is connected to the on and off coils of the drive electromagnet through the switching unit. In this case, the current consumption of the drive is not more than 3 A at a voltage of 220 V is provided by the presence of a current-limiting resistor in the charging circuit of this capacitor. The resistance value of the resistor is determined by the dependence R = τ / C, where C is the capacitance of the capacitor, τ = 2.5 ... 3.5 s is the charging time constant of the capacitor, selected to ensure that the circuit breaker runs O-0.3 s-BO- 20 s-VO according to GOST 687-78. An increase in the reliability of the circuit breaker is ensured by the fact that the circuit breaker uses an independent electromagnetic drive, the operation of which does not depend on a power source located outside the circuit breaker, namely, power interruption, voltage reduction, etc. during operations on and off the circuit breaker.

The proposed vacuum circuit breaker, like the prototype, consists of insulating molded poles with a VDK, which are mounted vertically in a row on the frame and are kinematically connected through insulating rods with an electromagnetic drive, which is equipped with two magnetic latches, made in the form of two magnetic chains of permanent magnets holding the armature the electromagnet in its two extreme positions, in contrast to the prototype, in which the locking in the on position is made on two mechanical latches, and in the off position, both ensures, with the help of one or two tripping springs.

The creation of such a series of switches with the use of new design and technological solutions allows to introduce improvements that are not found in the switches taken as a prototype.

The proposed high-voltage vacuum circuit breaker can be attributed to circuit breakers that open a new series (under the brand name of the manufacturer - BPC.) For the diagnosis and testing of the main operating parameters of such a circuit breaker, the RITES diagnostic system was used for the first time directly during its operation and maintenance.

The diagnostic unit includes an electronic diagnostic and testing unit in a shielded case, an inductive linear displacement sensor, an inductive end position sensor. To diagnose the circuit breaker (in laboratory or operating conditions), you need a computer with the appropriate software, which allows you to test the following parameters: intrinsic on and off times, the simultaneous closing and opening of contacts, the speed of contacts when turning on and off, the course of the contacts, the stroke mechanism of the contact input , the number of switching and so on.

These properties are significant because their combination provides the achievement of a positive application of this invention in a vacuum high-voltage circuit breaker. All this allowed to create a new type of switch, which is one complete product. The constructively claimed solution for an independent electromagnetic drive with a built-in capacitor provides increased circuit breaker reliability, reduced drive current consumption, which makes it possible to use it in various switchgear designs with various power supplies of the secondary circuit breakers.

The original, simple and technologically advanced design of the control and protection unit, the switching unit, the capacitor unit and the interlocking unit makes it possible to use any circuit breaker options and layouts. At the same time, the circuit breaker becomes a highly reliable, small-sized high-voltage apparatus with minimum drive currents, which makes it possible to use it not only in general industrial design, but also earthquake-resistant for use in nuclear energy facilities.

Therefore, for the first time in the general frame of the circuit breaker, in order to ensure on-time switching on and off, as well as diagnosing and testing the main operating parameters, functionally interconnected control and protection units, a switching unit, a capacitor unit, a diagnostic unit made on printed circuit boards, an electrical unit and mechanical closing lock, and to reduce the drive’s current consumption as an energy storage device used to turn on and off the circuit breaker, set Credited capacitor connected across the secondary circuit connections to the network, providing its precharge.

Other objectives and advantages of the present invention will become apparent from the following detailed description of an example of its implementation and the accompanying drawings, in which:

Figure 1 depicts a sliding element with a vacuum high-voltage switch installed in the working position in the switchgear cabinet;

Figure 2 is a General view of the switch (side view) with a diagram of the installation of the lever for operational manual shutdown;

Figure 3 - General view of the switch in front (view A);

Figure 4 is a General view of the switch (side view) with an image of the placement of the main components and parts;

5 is a General view of the switch (front view with the facade panel removed). Layout solution for placing blocks, assemblies and parts.

A vacuum high-voltage switch mounted on a sliding element is designed for installation in switchgear cabinets of the new KU-6S and KU-10S series, as well as cabinets of other series.

The switch consists of the following main parts: three poles 1 (Figure 4) installed on the frame 2, in which the shaft 3 is installed, the mechanical and electrical interlock block 4, the counter 5 for accounting for the operation of the circuit breaker, and also mounted on the frame for additional mounting poles of supporting insulators 6.

In the frame of the switch (Figure 5) there is an independent electromagnetic drive containing a terminal row 7, a switching unit 8, a pointer 9, a capacitor discharge toggle switch 10, the switch position contacts 11, a capacitor 12, a locking mechanism lever 13, a microswitch 14, an electromagnet 15, board 16 of the control and protection unit, shaft 17 of the shutdown mechanism.

The current consumption of the drive is not more than 3 A at a voltage of 220 V is provided by the presence of a current-limiting resistor in the charging circuit of this capacitor. The resistance value of the resistor is determined by the dependence R = τ / C, where C is the capacitance of the capacitor, τ = 2.5 ... 3.5 s is the charging time constant of the capacitor, chosen to ensure that the circuit breaker performs O-0.3 s-BO- 20 s-VO according to GOST 687-78.

The switch operates as follows.

The circuit breaker is turned on with the help of an electric signal supplied to the control unit and protection board 16 (Figure 5), which leads to the operation of the switching unit 8 and the subsequent partial discharge of the capacitor into the switching coil of the electromagnet 15, which leads to the displacement of the armature of the electromagnetic drive. Using a kinematic chain, the movement is transmitted to the two-arm lever mounted on the shaft 3 (Figure 4), the other end of which is connected via a rod to the VDK of pole 1 (Figure 4). After closing the VDK contacts, the Belleville springs installed in the insulating poles of the poles begin to compress, creating the necessary contact pressing force. The movement of the armature ends with an emphasis in the magnetic circuit and its fixation on the magnetic ″ latch ″, which determines the on position of the switch.

Operational shutdown of the circuit breaker in normal operation occurs by applying a signal to the control and protection unit 16 (FIG. 5), which leads to the action of switching unit 8, and that, in turn, leads to partial discharge of the capacitor 12. The capacitance of the capacitor 12 is discharged to the coil of shutdown of the electromagnet 15, which leads to the tripping of the switch. The armature of the electromagnet will begin to move up, and the insulating rod in the pole down. In the first section of the anchor movement, the VDK contacts continue to be closed, and the compressed disk springs expand, providing the necessary initial speed of the VDK contacts during the extinguishing process. After the Belleville springs are unclenched by the magnitude of their stroke, the VDK contacts begin to open, making an arcing. The movement of the armature up ends with an emphasis on the magnetic circuit and its fixation on the magnetic "latch", which determines the disconnected position of the switch. After partial discharge of the capacitor, when the operation is turned on or off, it is automatically recharged.

Shutdown in emergency operation of the circuit breaker occurs after the protection circuits on the circuit board of the block 16 (Figure 5) control and protection, which leads to the action of block 8 switching, and that, in turn, to the discharge of the capacitor 12 to the trip coil of the electromagnet 15 (Fig .5). After that, the circuit breaker trips.

The lock on the switch located in the intermediate position of the switchgear is carried out by moving the lever 13 (Figure 5), which leads to mechanical blocking of the rotation of the shaft 3 (Figure 4) and the breakdown of the electrical circuit by the microswitch 14 (Figure 5), that is, the switching signal on the control board and protections is not received.

The vacuum circuit breaker belongs to a new type of high-voltage apparatus, the design of which provides minimum dimensions, improved technical and economic indicators, high operational reliability and the ability to control the main operating parameters, a wide range of standard designs for rated currents from 630 A to 3150 A and rated tripping currents from 20 kA up to 40 kA and a high switching resource, which allows you to complete it with any types of switchgear, both domestic and foreign production.

The prototype of the circuit breaker was developed and manufactured at JSC RZVA (Ukraine, Rivne) and during electromechanical and switching tests it fully confirmed its high reliability and performance. In mass production, such switches of the ВРС-6 and ВРС-10 types of various standard designs will be manufactured under the ВРС trademark.

According to the authors, such a switch can take its rightful place in the national economy for use in operating organizations of industrial energy systems, as well as thermal power plants and nuclear power plants.

Information sources

1. Afanasyev V.V., Yakunin E.N. Drives for high voltage circuit breakers. L .: Energoatomizdat. Leningra. branch. 1982 g.

2. Evdokunin GA, Tiller G. Modern vacuum switching equipment for medium voltage networks. SPb. - Publisher Sizova M.P., 2000, - 114 p.

3. GOST 687-78 "AC circuit breakers for voltages above 1000 V".

Claims (1)

A vacuum high-voltage switch containing a frame, poles with vacuum interrupter chambers, an electromagnetic drive with a switching unit, a contact switch for the position of the switch and a manual tripping mechanism, characterized in that an independent electromagnetic drive is incorporated in the switch frame, which contains a capacitor for preliminary energy storage, connected to the mains through a current-limiting resistor whose resistance value is directly proportional to the conden and the capacitor is inversely proportional to the capacitance of the capacitor, and the indicated capacitor is connected to the on and off coils of the drive electromagnet through the switching unit for “turn on” and “disconnect” operations.

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