Monostable permanent magnet type rapid breaking high-voltage vacuum circuit breaker

Abstract

The invention discloses a monostable permanent magnet type rapid breaking high-voltage vacuum circuit breaker, which comprises a permanent magnet operating mechanism, an insulating pull rod unit and an arc extinguish chamber unit, and is characterized in that the permanent magnet operating mechanism unit comprises a first support mounted on a fixed support plate, and an outer magnet yoke is mounted on the first support; a coil, a static iron core and a permanent magnet are installed in an inner cavity of the outer magnet yoke, a movable iron core is inserted in the inner cavity of the coil and the inner cavity of the outer magnet yoke in an up-down sliding mode, the outer magnet yoke, the movable iron core and the static iron core are all made of permeability magnetic materials, and the insulation pull rod unit comprises an insulation pull rod. The lower end of the movable iron core penetrates through the outer magnet yoke and then is connected with the upper end of the insulating pull rod, and the lower end of the insulating pull rod is connected with a movable contact of the arc extinguish chamber unit. The monostable permanent magnet type rapid breaking high-voltage vacuum circuit breaker is simple in structural design, stable and reliable to use and free of hidden danger of demagnetization, and the opening time is smaller than or equal to 5 ms.

Description

Technical Field

[0001] The invention relates to the technical field of electrical equipment, in particular to a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker. Background Art

[0002] Vacuum circuit breaker is an electric switchgear with high vacuum in both arc extinguishing medium and contact gap insulation medium after arc extinguishing. It has the advantages of small size, light weight, suitable for frequent operation and arc extinguishing without maintenance. It is widely used in distribution network. It can be used for protection and control of electrical equipment in industrial and mining enterprises, power plants and substations. It is especially suitable for use in places requiring oil-free, less maintenance and frequent operation, as a control and protection of high-voltage electrical equipment.

[0003] The application scenarios of fast-breaking permanent magnetic circuit breakers mainly include medium-voltage overhead line power grids, which are used to disconnect and close load currents, overload currents, and short-circuit currents. At present, the circuit breakers that achieve fast disconnection on the market generally require a disconnection time of ≤5ms. The technical solutions generally use magnetically controlled switches as the main method. The disconnection and closing process is completed by magnetizing components such as the iron core and the yoke. At the same time, the disconnection time is shortened by increasing the contact pressure of the arc extinguishing chamber of the circuit breaker and the force value of the disconnecting spring. However, the problems are: first, the soft magnetic material technology is used. The magnetic permeability of soft magnetic materials is very high, but it is easily magnetized by the external magnetic field and is easily affected by the external magnetic field. There is a risk of demagnetization, which makes the switch lose reliability; second, the effect of shortening the disconnection time by increasing the contact pressure of the arc extinguishing chamber of the circuit breaker and the force value of the disconnecting spring is limited, and it is difficult to meet the market requirement of a disconnection time of no more than 5ms.

[0004] Therefore, how to design a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker that can solve the above technical problems is a subject that the inventor has devoted himself to studying. Summary of the invention

[0005] The object of the present invention is to provide a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker, which has a simple structural design, is stable and reliable in use, has no hidden danger of demagnetization, and has a breaking time of ≤5ms.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the present invention is: a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker, which includes a permanent magnet operating mechanism, an insulating pull rod unit and an arc extinguishing chamber unit, the permanent magnet operating mechanism unit includes a first support mounted on a fixed support plate, an outer magnetic yoke is mounted on the first support, the inner cavity of the outer magnetic yoke is mounted with a coil, a static iron core and a permanent magnet, the inner cavity of the coil and the outer magnetic yoke can be slid up and down with a moving iron core inserted, the outer magnetic yoke, the moving iron core and the static iron core are all made of magnetic conductive material, the insulating pull rod unit includes an insulating pull rod, the lower end of the moving iron core passes through the outer magnetic yoke and is connected to the upper end of the insulating pull rod, and the lower end of the insulating pull rod is connected to the moving contact of the arc extinguishing chamber unit.

[0007] The present invention discloses a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker, wherein a moving iron core pressing block is connected to the moving iron core, a trip spring is installed between the moving iron core pressing block and the bottom of the first support, the moving iron core pressing block is made of magnetic conductive material, and the moving iron core pressing block can slide downward with the moving iron core, thereby compressing the trip spring.

[0008] The present invention discloses a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker, wherein the magnetic conductive material is made of electrical pure iron.

[0009] The present invention discloses a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker, wherein an insert is arranged at the lower end of the insulating pull rod, and an insulating pull rod spring is installed in the inner cavity of the insert.

[0010] The present invention discloses a monostable permanent magnet type fast breaking high voltage vacuum circuit breaker, wherein the overtravel s of the circuit breaker is 2-2.5 mm, and the overtravel s satisfies: s = 1 / 2*at 2 , a=f / m; wherein a is acceleration; t is time; f is the pressure exerted on the opening spring and the insulating pull rod spring; and m is the mass of all moving objects driven by the moving iron core when it moves.

[0011] The present invention discloses a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker, wherein the arc extinguishing chamber unit comprises an arc extinguishing chamber and a moving contact and a stationary contact arranged in the inner cavity of the arc extinguishing chamber, the moving contact and the stationary contact are arranged with an upper and lower interval, and the upper end of the moving contact passes through the arc extinguishing chamber and is connected to the insulating pull rod through the connecting piece.

[0012] The present invention discloses a monostable permanent magnet fast-breaking high-voltage vacuum circuit breaker, wherein the arc extinguishing chamber and the lower ends of the static contact are both fixed on a second support, and the second support is fixed to the lower end of the fixed support plate.

[0013] The present invention discloses a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker, wherein the connecting piece is a bolt.

[0014] The present invention discloses a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker, wherein the permanent magnet is arranged between the inner wall of the outer magnetic yoke and the outer wall of the static iron core.

[0015] The present invention provides a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker, wherein the coil is arranged between the inner wall of the outer magnetic yoke and the moving iron core pressing block.

[0016] After adopting the above scheme, a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker of the present invention uses a permanent magnet operating mechanism, and the outer magnetic yoke, the moving iron core, the moving iron core block and the static iron core are all made of high-quality magnetic conductive materials. It is stable and reliable to use, has no hidden danger of demagnetization, adopts permanent magnet technology, has high coercive force, high saturation magnetization intensity, and good temperature stability; its mechanical transmission is simple, and has the characteristics of small operating energy and maintenance-free; its structural design is simple, and can reach a mechanical life of tens of thousands of times, and is suitable for frequent operation and an environment requiring precise opening and closing time and strong anti-interference ability; it is suitable for various operating voltages, and the system does not need to be specially made; its opening time is short, and the circuit breaker body opening time is ≤5ms. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a front cross-sectional structural schematic diagram of an embodiment of a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker of the present invention;

[0018] Figure 2 It is a left-side structural schematic diagram of an embodiment of a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker of the present invention;

[0019] Figure 3 The diagram is a top view of the structure of an embodiment of a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker of the present invention.

[0020] Number Description:

[0021] 1-Fixed support plate 2-Permanent magnetic operating mechanism

[0022] 3-Insulation rod unit 4-Interrupter unit

[0023] 5-First support 6-External yoke

[0024] 7-coil 8-static iron core

[0025] 9-Permanent magnet 10-Moving iron core

[0026] 11-Moving iron core block 12-Annular boss

[0027] 13- opening spring 14- insulating pull rod

[0028] 15-moving contact 16-installation slot

[0029] 17- bottom cover 18- bolt

[0030] 19-Insulation rod spring 20-Arcing chamber

[0031] 21-static contact 22-second support DETAILED DESCRIPTION

[0032] The present invention is described below based on the embodiments shown in the accompanying drawings. The embodiments disclosed this time can be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is not limited by the description of the following embodiments, but is only shown by the scope of the claims, and includes all modifications with the same meaning as the scope of the claims and within the scope of the claims.

[0033] The structure of a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker of the present invention is described below in conjunction with specific embodiments.

[0034] like Figures 1 to 3 The front cross-sectional, left and top structural schematic diagrams of a monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker embodiment of the present invention are shown, including at least one set of permanent magnet operating mechanism 2, insulating rod unit 3 and arc extinguishing chamber unit 4 installed on a fixed support plate 1. The permanent magnet operating mechanism 2, insulating rod unit 3 and arc extinguishing chamber unit 4 of this embodiment are arranged in three groups. The permanent magnet operating mechanism 2, insulating rod unit 3 and arc extinguishing chamber unit 4 of each group are connected from top to bottom.

[0035] The permanent magnetic operating mechanism 2 includes a first support 5 mounted on a fixed support plate 1, the first support 5 includes two horizontal support plates spaced apart at upper and lower positions, the two horizontal support plates are respectively fixed to the fixed support plate 1 by bolts, an annular outer magnetic yoke 6 is mounted on the first support 5, and the two horizontal support plates clamp the upper and lower ends of the outer magnetic yoke 6. The inner cavity of the outer magnetic yoke 6 is equipped with a coil 7, a static iron core 8 and a permanent magnet 9, wherein the coil is arranged in the middle of the inner cavity wall of the outer magnetic yoke 6, the static iron core 8 is located at the lower part of the inner cavity of the outer magnetic yoke 6, and the permanent magnet 9 is arranged between the inner cavity wall of the outer magnetic yoke 6 and the outer wall of the static iron core 8.

[0036] A moving iron core 10 is inserted into the inner cavity of the coil 7 and the inner cavity of the outer magnetic yoke 6, and the moving iron core 10 can slide up and down along the inner cavity of the coil 7 and the inner cavity of the outer magnetic yoke 6. A moving iron core pressing block 11 is connected to the upper part of the moving iron core 10, and the outer edge of the moving iron core pressing block 11 is close to the upper wall of the inner cavity of the outer magnetic yoke 6. An annular boss 12 is provided in the middle of the inner cavity of the outer magnetic yoke 6, and the moving iron core pressing block 11 is located above the annular boss 12. The coil 7 is provided below the annular boss 12, and the coil 7 is located between the inner wall of the outer magnetic yoke 6 and the moving iron core pressing block 11. The above-mentioned outer magnetic yoke 6, moving iron core 10, moving iron core pressing block 11 and static iron core 8 are all made of excellent magnetic conductive materials. In this embodiment, electrical pure iron is preferably used as the material of the above components. A trip spring 13 is installed between the moving iron core pressing block 11 and the lower horizontal support plate of the first support 5 . The moving iron core pressing block 11 can slide downward along with the moving iron core 10 , thereby compressing the trip spring 13 .

[0037] The insulating rod unit 3 includes an insulating rod 14. The lower end of the moving iron core 10 passes through the outer yoke 6 and is connected to the upper end of the insulating rod 14. The lower end of the insulating rod 14 is connected to the moving contact 15 of the arc extinguishing chamber unit 4. An insert 16 is provided at the lower end of the insulating rod 14. An insulating rod spring 19, a bolt 18 and a bottom cover 17 are assembled in the inner cavity of the insert 16. The bottom cover 17 and the insert 16 are engaged together by threads, and the lower end of the insulating rod spring 19 abuts against the bottom cover 17.

[0038] The overtravel s of the circuit breaker is 2-2.5 mm, and the travel s satisfies the formula: s = 1 / 2*at2, a = f / m; where a is acceleration; t is time; f is the pressure on the spring; and m is the mass of all moving objects driven by the moving iron core 10. When s decreases, t also decreases.

[0039] The arc extinguishing chamber unit 4 includes an arc extinguishing chamber 20 and a moving contact 15 and a stationary contact end 21 arranged in the inner cavity of the arc extinguishing chamber 20. The moving contact 15 and the stationary contact 21 are arranged with an upper and lower interval. The upper end of the moving contact 15 passes through the upper end of the arc extinguishing chamber 20 and is connected to the bottom cover 17 through the bolt 18. The lower ends of the arc extinguishing chamber 20 and the stationary contact 21 are fixed to the second support 22 by bolts, and the second support 22 is fixed to the lower end of the fixed support plate 1.

[0040] During use, when the circuit breaker of the present invention is closed, the coil 7 of the permanent magnetic operating mechanism 2 is energized, and the moving iron core 10 and the moving iron core pressing block 11 drive the insulating pull rod unit 3 to move downward under the action of the electromagnetic force, compressing the opening spring 13, and at the same time driving the moving contact 15 and the static contact 21 of the arc extinguishing chamber unit 4 to close and continue to compress the insulating pull rod spring 19 to complete the closing. At this time, the magnetic force generated by the permanent magnet 9 keeps the moving iron core 10 and the moving iron core pressing block 11 in the closed position; when the circuit breaker of the present invention is opened, the coil 7 of the permanent magnetic operating mechanism 2 is energized with reverse current, and the moving iron core 10 and the moving iron core pressing block 11 overcome the permanent magnetic force under the action of the electromagnetic force. Under the joint action of the opening spring 13 and the insulating pull rod spring 19, the moving iron core 10, the moving iron core pressing block 11, and the insulating pull rod unit 3 move upward to complete the opening. After adopting the above design scheme, the opening time of the circuit breaker of the present invention is between 4.2-4.8ms, which fully meets the design requirements.

[0041] The opening time is the time from when the opening coil receives the signal to when the moving contact 15 and the static contact 21 of the arc extinguishing chamber unit 4 are completely separated. The main factors affecting the opening time in the present invention are the insulating pull rod spring 19, the opening spring 13, the coil 7, the power supply voltage, the outer magnetic yoke 6, the moving iron core 10, the moving iron core block 11 and the static iron core 8. By making the outer magnetic yoke 6, the moving iron core 10, the moving iron core block 11 and the static iron core 8 all of which are made of high-quality magnetic conductive materials, they are stable and reliable in use, without the risk of demagnetization, and the opening speed is improved, and the opening time is reduced; in use, by increasing the initial pressure of the insulating pull rod spring 19 and the opening spring 13, the pressure f between the moving contact 15 and the static contact 21 is increased, the acceleration a can be increased, and thus the time opening time t can be reduced; the present invention designs the initial pressures of the insulating pull rod spring 19 and the opening spring 13 to be 1900N and 800N respectively. The weight of each component of the moving part of the moving iron core 10 of the present invention is reduced as much as possible; the controller output voltage (380V) is increased, and a suitable coil wire diameter is selected to increase the coil ampere-turns.

[0042] The monostable permanent magnet type fast-breaking high-voltage vacuum circuit breaker of the present invention is designed through the above-mentioned comprehensive design, by increasing the initial pressure of the insulating pull rod spring 19 and the opening spring 13, reasonable coil wire diameter and ampere-turns, such as using an electromagnetic coil with a wire diameter of 0.3 and a number of turns of 980, using electrical pure iron for the outer magnetic yoke 6, the moving iron core 10, the moving iron core block 11 and the static iron core 8, and reasonably setting the operation pulse duration and the controller power supply voltage, such as the operation pulse duration of 100ms and the controller power supply voltage of 380V, the circuit breaker body opening time is controlled within 5ms, and fast opening is achieved. The present invention is different from the existing circuit breaker design based on soft magnetic technology, which simply increases the force value of the opening spring and the insulating pull rod spring. The present invention can achieve fast opening while taking into account reliability and mechanical life through the above-mentioned design.

[0043] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering and technical personnel in the field shall fall within the protection scope of the claims of the present invention.

Claims

1. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker, characterized in that: It includes a permanent magnetic operating mechanism, an insulating pull rod unit and an arc extinguishing chamber unit. The permanent magnetic operating mechanism unit includes a first support installed on a fixed support plate, an outer magnetic yoke is installed on the first support, a coil, a static iron core and a permanent magnet are installed in the inner cavity of the outer magnetic yoke, a moving iron core is inserted in the inner cavity of the coil and the outer magnetic yoke so as to slide up and down, the outer magnetic yoke, the moving iron core and the static iron core are all made of magnetic conductive materials, the insulating pull rod unit includes an insulating pull rod, the lower end of the moving iron core is connected to the upper end of the insulating pull rod after passing through the outer magnetic yoke, and the lower end of the insulating pull rod is connected to the moving contact of the arc extinguishing chamber unit.

2. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker as claimed in claim 1, characterized in that: A moving iron core pressing block is connected to the moving iron core, a trip spring is installed between the moving iron core pressing block and the bottom of the first support, the moving iron core pressing block is made of magnetic conductive material, and the moving iron core pressing block can slide downward with the moving iron core, thereby compressing the trip spring.

3. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker as claimed in claim 2, characterized in that: The magnetic conductive material is made of electrical pure iron.

4. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker as claimed in claim 2, characterized in that: An insert is provided at the lower end of the insulating pull rod, and an insulating pull rod spring is installed in the inner cavity of the insert.

5. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker as claimed in claim 4, characterized in that: The overtravel s of the circuit breaker is 2-2.5 mm, and the overtravel s satisfies: s = 1 / 2*at 2 , a=f / m; wherein a is acceleration; t is time; f is the pressure exerted on the opening spring and the insulating pull rod spring; and m is the mass of all moving objects driven by the moving iron core when it moves.

6. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker as claimed in claim 4, characterized in that: The arc extinguishing chamber unit includes an arc extinguishing chamber and a moving contact and a stationary contact arranged in the inner cavity of the arc extinguishing chamber. The moving contact and the stationary contact are arranged with an upper and lower interval. The upper end of the moving contact passes through the arc extinguishing chamber and is connected to the insulating pull rod through the connecting piece.

7. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker as claimed in claim 6, characterized in that: The lower ends of the arc extinguishing chamber and the static contact are both fixed on a second support, and the second support is fixed to the lower end of the fixed support plate.

8. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker as claimed in claim 6, characterized in that: The connecting piece is a bolt.

9. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker as claimed in claim 1, characterized in that: The permanent magnet is arranged between the inner wall of the outer magnetic yoke and the outer wall of the static iron core.

10. A monostable permanent magnet type fast breaking high voltage vacuum circuit breaker as claimed in claim 2, characterized in that: The coil is arranged between the inner wall of the outer magnetic yoke and the moving iron core pressing block.

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