A permanent magnet ring network cabinet

Abstract

The present invention proposes a permanent magnet ring network cabinet, which includes a cabinet body, a first transverse partition, a permanent magnet circuit breaker and a first annular block. The first transverse partition is horizontally fixed in the cabinet body, a through hole is opened on the first transverse partition, the permanent magnet circuit breaker includes a permanent magnet mechanism and a circuit breaker mechanism, the permanent magnet mechanism and the circuit breaker mechanism are both vertically arranged and the circuit breaker mechanism is fixed under the permanent magnet mechanism, the permanent magnet circuit breaker is inserted into the through hole, the first annular block is sleeved on the outer side wall of the permanent magnet circuit breaker and fixed to the permanent magnet circuit breaker, the first annular block is located above the first transverse partition, so that the permanent magnet circuit breaker can be fixed on the first transverse partition, thereby completing the fixation of a single permanent magnet circuit breaker.

Description

Technical Field

[0001] The invention relates to the field of permanent magnetic ring main unit, and in particular to a permanent magnetic ring main unit with a permanent magnetic circuit breaker. Background Art

[0002] The ring main unit used in domestic and foreign power systems has circuit breakers and intelligent controllers installed corresponding to the three connected busbars in the front half of the cabinet, and the corresponding three busbars in the outlet device in the back half of the cabinet extend out of the cabinet. At present, there is a permanent magnetic mechanism to control the circuit breaker, but the permanent magnetic circuit breaker in the ring main unit is often formed into a whole with three permanent magnetic circuit breakers, and then the whole is fixed on the ring main unit to control the on and off of the three solid insulated busbars. This method limits the position of the three connected busbars, and the distance between the inlet or outlet of some special equipment is far, which causes the ring main unit to gather the busbars, pass through the three permanent magnetic circuit breakers, and then disperse the busbars to correspond to the outlets that are farther away. This method makes the busbar wiring and fixing complicated, and requires more busbars, so it is necessary to separate the three permanent magnetic circuit breakers and fix a single permanent magnetic circuit breaker. Summary of the invention

[0003] In view of this, the present invention proposes a permanent magnetic ring main unit capable of fixing a single permanent magnetic circuit breaker.

[0004] The technical solution of the present invention is implemented as follows: the present invention provides a permanent magnet ring network cabinet, which includes a cabinet body, a first transverse partition, a permanent magnet circuit breaker and a first annular block, wherein the first transverse partition is horizontally fixed in the cabinet body, a through hole is opened on the first transverse partition, the permanent magnet circuit breaker includes a permanent magnet mechanism and a circuit breaker mechanism, the permanent magnet mechanism and the circuit breaker mechanism are both vertically arranged and the circuit breaker mechanism is fixed under the permanent magnet mechanism, the permanent magnet circuit breaker is inserted in the through hole, the first annular block is sleeved on the outer wall of the permanent magnet circuit breaker and fixed to the permanent magnet circuit breaker, and the first annular block is located above the first transverse partition.

[0005] On the basis of the above technical scheme, preferably, it also includes a vertical partition, a second horizontal partition, an isolating switch and a controller, the vertical partition is vertically fixed on the upper and lower inner walls of the cabinet, the first horizontal partition and the second horizontal partition are horizontally arranged on both sides of the vertical partition and the two ends are respectively fixed to the vertical partition and the inner wall of the cabinet, the controller is fixed on the second horizontal partition, the permanent magnetic circuit breaker and the isolating switch are respectively electrically connected to the controller, and the busbar is connected to the permanent magnetic circuit breaker and the isolating switch.

[0006] Further preferably, the number of the busbars, permanent magnetic circuit breakers and disconnectors is three, three busbar insertion holes are opened on the side of the cabinet, and three busbar outlet holes are opened on the side of the cabinet opposite to the three busbar insertion holes, and the three busbars are respectively inserted from the busbar insertion holes and connected from the busbar outlet holes.

[0007] More preferably, the system further comprises three grounding switches, and the three busbars are electrically connected to the three grounding switches respectively.

[0008] On the basis of the above technical scheme, preferably, it also includes a second annular block, a third annular block, a fourth annular block, a bolt and a first nut, the first annular block is sleeved on the outer wall of the permanent magnet mechanism and fixed to the permanent magnet mechanism, the second annular block is sleeved on the outer wall of the circuit breaker mechanism and fixed to the circuit breaker mechanism, the third annular block is fixed on the top of the first annular block and has a first through hole, the fourth annular block is fixed on the bottom of the second annular block and has a second through hole relative to the first through hole, the bolt passes through the first through hole and the second through hole, and the first nut is fixed to the first annular block and the second annular block by being threadedly connected to the bolt.

[0009] On the basis of the above technical scheme, preferably, the circuit breaking mechanism includes a stud bolt, a second nut, an insulating pull rod, a conductive rod, a contact, a vacuum arc extinguishing chamber and a sealed pole, the stud bolt is vertically arranged, the second nut is fixed above the stud bolt by a threaded connection, an insulating pull rod is vertically fixed below the stud bolt, a conductive rod is vertically fixed below the insulating pull rod, a contact is arranged directly below the conductive rod, the vacuum arc extinguishing chamber is sleeved outside the conductive rod and the contact, the top and bottom of the sealed pole are provided with openings, and the contacts and the stud bolts are inserted into the openings.

[0010] More preferably, the permanent magnet mechanism includes a driving rod, and the driving rod is fixed directly above the stud bolt.

[0011] More preferably, a first internal thread is provided below the driving rod, the driving rod is fixed to the stud bolt by a threaded connection, a second nut is located between the stud bolt and the driving rod, and the second nut is tightened relative to the driving rod to fasten the driving rod to the stud bolt.

[0012] Further preferably, the circuit breaking mechanism also includes a third nut, an internal thread is opened under the insulating pull rod, the insulating pull rod is fixed to the stud bolt by a threaded connection, the third nut is located between the stud bolt and the insulating pull rod, and the third nut is tightened relative to the insulating pull rod to fasten the insulating pull rod to the stud bolt.

[0013] More preferably, the material of the vacuum interrupter is composed of the following components in percentage by mass: 15% polyphenylene sulfide, 52% silica, 5% chlorobutyl rubber, 10% aluminum oxide, 5% silicon carbide, 4% nitrile rubber, 5% graphene and 4% copper oxide.

[0014] The permanent magnet ring main unit of the present invention has the following beneficial effects compared with the prior art:

[0015] (1) By providing a first annular block, the first annular block is sleeved on the outer wall of the permanent magnetic circuit breaker and fixed to the permanent magnetic circuit breaker, and the first annular block is located above the first transverse partition, so that the permanent magnetic circuit breaker can be fixed on the first transverse partition;

[0016] (2) By providing a first annular block, a second annular block, a third annular block, a fourth annular block, a bolt and a first nut, the first annular block is sleeved on the outer wall of the permanent magnet mechanism and fixed to the permanent magnet mechanism, the second annular block is sleeved on the outer wall of the circuit breaker mechanism and fixed to the circuit breaker mechanism, the third annular block is fixed above the first annular block and has a first through hole, the fourth annular block is fixed below the second annular block and has a second through hole opposite to the first through hole, the bolt passes through the first through hole and the second through hole, the first nut is threadedly connected with the bolt to fix the first annular block and the second annular block, so that the permanent magnet mechanism and the circuit breaker mechanism are fixed;

[0017] (3) The material of the vacuum interrupter is composed of the following components in percentage by mass: 15% polyphenylene sulfide, 52% silica, 5% chlorobutyl rubber, 10% aluminum oxide, 5% silicon carbide, 4% nitrile rubber, 5% graphene and 4% copper oxide. Compared with the existing ceramic vacuum interrupter, the material has better thermal stability and thermal conductivity and is less brittle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a front view structural diagram of a permanent magnetic ring main unit of the present invention;

[0020] Figure 2 It is a side structural diagram of a permanent magnetic ring main unit of the present invention;

[0021] Figure 3 It is a stereoscopic diagram of a third annular block and a fourth annular block of a permanent magnetic ring network cabinet of the present invention;

[0022] Figure 4 The present invention is a structural diagram of a permanent magnetic circuit breaker of a permanent magnetic ring main unit. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] like Figure 1 As shown, combined Figure 2-4 A permanent magnet ring network cabinet of the present invention includes a cabinet body 1, a first transverse partition 2, a permanent magnet circuit breaker 3, a first annular block 4, a vertical partition 5, a second transverse partition 6, an isolating switch 7, a controller 8, a grounding switch 9, a second annular block 10, a third annular block 20, a fourth annular block 30, a bolt 40 and a first nut 50.

[0025] The cabinet 1 is used to place various electrical components. The cabinet 1 has three busbar insertion holes 11 on its side, and three busbar outlet holes on the side opposite to the three busbar insertion holes. The three busbars are inserted into the busbar insertion holes 11 and are outlet from the busbar outlet holes.

[0026] The first transverse partition 2 is used for placing the permanent magnetic circuit breaker 3. Specifically, the first transverse partition 2 is horizontally fixed in the cabinet 1. A through hole is opened on the first transverse partition 2, and the permanent magnetic circuit breaker 3 is inserted in the through hole.

[0027] The permanent magnetic circuit breaker 3 is used to control the rapid on and off of the circuit. Specifically, the permanent magnetic circuit breaker 3 includes a permanent magnetic mechanism 31 and a circuit breaker 32. The permanent magnetic mechanism 31 and the circuit breaker 32 are both arranged vertically and the circuit breaker 32 is fixed below the permanent magnetic mechanism 31. The circuit breaker 32 is fixed below the permanent magnetic mechanism 31, so that the busbar does not need to pass through the first transverse partition 2, and the wiring is simpler.

[0028] The permanent magnet mechanism 31 includes a closing coil, an opening coil, a moving iron core, a yoke, a permanent magnet, an armature and a driving rod 311. When the circuit breaker is in the opening position, the moving iron core is at the upper part, and the gap between the moving iron core and the upper yoke is small, and the corresponding magnetic resistance is also small, while the gap between the moving iron core and the lower yoke is large, and the corresponding magnetic resistance is also large, so most of the magnetic lines of force formed by the permanent magnet are concentrated in the upper part, thereby generating a large upward attraction force, which tightly adsorbs the moving iron core on it. When the circuit breaker is to be closed, the closing coil passes the closing current to generate an induced magnetic field, which generates a downward attraction force on the moving iron core. As the closing current increases, the downward attraction force increases from small to large. When the closing current reaches a certain critical value, the direction of the combined force on the moving iron core is downward, and it begins to move downward. When the moving iron core reaches the lower part, the magnetic field generated by the permanent magnet and the closing coil firmly adsorbs the moving iron core to the lower part. After a few seconds, the closing current disappears, and the magnetic field generated by the permanent magnet keeps the moving iron core in the lower position. At this point, the circuit breaker completes the closing operation. Based on the same principle, when the opening coil is energized, the moving iron core moves upward and is also held in the opening position by the permanent magnet.

[0029] More specifically, the permanent magnet mechanism 31 includes a driving rod 311, and the driving rod 311 is fixed directly above the stud bolt 321. In this way, the movement of the driving rod 311 in the permanent magnet mechanism 31 can drive the stud bolt 321 to move, thereby completing the on and off of the permanent magnet circuit breaker 3.

[0030] More specifically, the circuit breaker mechanism 32 includes a stud bolt 321, a second nut 322, an insulating rod 323, a conductive rod 324, a contact 325, a vacuum interrupter 326 and a sealed pole 327. The stud bolt 321 is vertically arranged, the second nut 322 is fixed above the stud bolt 321 by threaded connection, the insulating rod 323 is vertically fixed below the stud bolt 321, the conductive rod 324 is vertically fixed below the insulating rod 323, the contact 325 is arranged directly below the conductive rod 324, the vacuum interrupter 326 is sleeved outside the conductive rod 324 and the contact 325, the top and bottom of the sealed pole 327 are provided with openings, the contact 325 and the stud bolt 321 are inserted into the openings. The second nut 322 is used to prevent the driving rod 311 from moving upward too far after the yoke is damaged, causing the conductive rod 324 to move upward too far, causing damage to the vacuum interrupter 326.

[0031] More specifically, the permanent magnet mechanism 31 includes a driving rod 311, and the driving rod 311 is fixed directly above the stud bolt 321. In this way, the movement of the driving rod 311 can drive the conductive rod 324 to move, thereby controlling the on and off of the circuit.

[0032] More specifically, a first internal thread is provided below the driving rod 311, the driving rod 311 is fixed to the stud 321 through a threaded connection, the second nut 322 is located between the stud 321 and the driving rod 311, and the second nut 322 is tightened relative to the driving rod 311 to fasten the driving rod 311 to the stud 321. The second nut 322 is used to fasten the driving rod 311 to the stud 321.

[0033] More specifically, the circuit breaker mechanism 32 further includes a third nut 328, a second internal thread is provided below the insulating rod 323, the insulating rod 323 is fixed to the stud 321 through a threaded connection, the third nut 328 is located between the stud 321 and the insulating rod 323, and the third nut 328 is tightened relative to the insulating rod 323 to fasten the insulating rod 323 to the stud 321. The third nut 328 is used to fasten the insulating rod 323 to the stud 321.

[0034] More specifically, the material of the vacuum interrupter 326 is composed of the following components in percentage by mass: 15% polyphenylene sulfide, 52% silica, 5% chlorobutyl rubber, 10% aluminum oxide, 5% silicon carbide, 4% nitrile rubber, 5% graphene and 4% copper oxide. Compared with the existing ceramic vacuum interrupter, the vacuum interrupter 326 has better thermal stability and thermal conductivity and is less brittle.

[0035] The first annular block 4 is used to enable the permanent magnetic circuit breaker 3 to be fixed on the first transverse partition 2. Specifically, the first annular block 4 is sleeved on the outer wall of the permanent magnetic circuit breaker 3 and fixed to the permanent magnetic circuit breaker 3. The first annular block 4 is located above the first transverse partition 2. Since the permanent magnetic mechanism 31 and the circuit breaker mechanism 32 are substantially the same in size, in some cases, the bottom area of ​​the permanent magnetic mechanism 31 is smaller than the bottom area of ​​the circuit breaker mechanism 32. After the permanent magnetic circuit breaker 3 is inserted into the through hole, the first annular block 4 is sleeved on the outer wall of the permanent magnetic circuit breaker 3, so that the permanent magnetic circuit breaker 3 can be fixed on the first transverse partition 2, thereby completing the fixation of a single permanent magnetic circuit breaker.

[0036] The vertical partition 5 is used to fix the second transverse partition 6. Specifically, the vertical partition 5 is vertically fixed to the upper and lower inner walls of the cabinet 1, and the first transverse partition 2 and the second transverse partition 6 are horizontally arranged on both sides of the vertical partition 5 and fixed to the vertical partition 5 and the inner wall of the cabinet 1 at both ends.

[0037] The second transverse partition plate 6 is used to fix the controller 8. Specifically, the controller 8 is fixed on the second transverse partition plate 6.

[0038] The isolating switch 7 is used to control the circuit to be disconnected when an accident occurs to the permanent magnetic circuit breaker 3. Specifically, the permanent magnetic circuit breaker 3 and the isolating switch 7 are electrically connected to the controller 8 respectively, and the busbar is connected to the permanent magnetic circuit breaker 3 and the isolating switch 7.

[0039] More specifically, there are three busbars, three permanent magnetic circuit breakers 3 and three isolating switches 7. Each busbar is inserted from the busbar insertion hole 11, connected to the permanent magnetic circuit breaker 3 and the isolating switch 7, and then taken out from the busbar outlet hole.

[0040] The controller 8 is used to control the three permanent magnetic circuit breakers 3 and the three disconnecting switches 7 .

[0041] The grounding switch 9 is used to prevent short circuit, and the three busbars are electrically connected to the three grounding switches 9 respectively.

[0042] The second annular block 10, the third annular block 20, the fourth annular block 30, the bolt 40 and the first nut 50 are used to fix the permanent magnet mechanism 31 and the circuit breaker mechanism 32. Specifically, the first annular block 4 is sleeved on the outer wall of the permanent magnet mechanism 31 and fixed to the permanent magnet mechanism 31, the second annular block 10 is sleeved on the outer wall of the circuit breaker mechanism 32 and fixed to the circuit breaker mechanism 32, the third annular block 20 is fixed on the top of the first annular block 4 and has a first through hole, the fourth annular block 30 is fixed on the bottom of the second annular block 10 and has a second through hole relative to the first through hole, the bolt 40 passes through the first through hole and the second through hole, and the first nut 50 is threadedly connected with the bolt 40 to fix the first annular block 4 and the second annular block 10. In the prior art, the permanent magnet mechanism 31 and the circuit breaker mechanism 32 are fixed by an external fixing frame at the connection, and then the three permanent magnet mechanisms 31 and the three circuit breaker mechanisms 32 are fixed as a whole. However, since the permanent magnet circuit breaker is single and the first annular block 4 is arranged at the connection between the permanent magnet mechanism 31 and the circuit breaker mechanism 32, a new fixing method is used to fix the permanent magnet mechanism 31 and the circuit breaker mechanism 32. This method makes new use of the first annular block 4, which is simpler to fix than the prior art and is also convenient for disassembling the permanent magnet mechanism 31 and the circuit breaker mechanism 32.

[0043] Experimental example

[0044] The vacuum interrupter material of the present invention is compared with common commercially available ceramic vacuum interrupter materials to further confirm the performance of the vacuum interrupter material of the present invention:

[0045] The commercially available ceramic vacuum interrupter material is a ceramic vacuum interrupter manufactured by Yueqing Haoxin Electric Power Technology Co., Ltd. The vacuum interrupter material of the present invention is composed of the following components in percentage by mass: 15% polyphenylene sulfide, 52% silica, 5% chlorobutyl rubber, 10% aluminum oxide, 5% silicon carbide, 4% nitrile rubber, 5% graphene and 4% copper oxide.

[0046] The preparation process of the vacuum interrupter material of the present invention is as follows: according to the components of 15% polyphenylene sulfide, 52% silicon dioxide, 5% chlorobutyl rubber, 10% aluminum oxide, 5% silicon carbide, 4% nitrile rubber, 5% graphene and 4% copper oxide, each material is weighed and put into a pulverizer for pulverization, and the material is discharged after pulverization for 30 hours to obtain a ceramic mixed powder, and wax is weighed, the wax ratio is 23% of the mass percentage of the material, and the material is put into a pulping machine for heating, and the temperature is controlled at 1500°C. After the wax is completely melted, the ceramic mixed powder is added, stirred for 6 hours, and after stirring evenly, it is added into a hot die casting machine, kept at 80°C, and molded by a mold and high-pressure air injection molding, the pressure is above 0.6MPa, and demolded after cooling. After bisque firing, the pot is dewaxed at 1100°C, and then sintered into porcelain at 2000°C.

[0047] The thermal conductivity of the vacuum interrupter material is tested using the laser flash method according to the test standard of ASTM-E1461. A beam of laser is hit on the upper surface of the sample, and the temperature change of the lower surface is measured with an infrared detector. The time taken for the vacuum interrupter material of the present invention to drop to 50°C is 93 seconds shorter than that of ordinary commercially available materials. The consumed time indicates that the thermal conductivity of the vacuum interrupter material is 11% higher than that of ordinary commercially available materials.

[0048] When testing thermal stability, the current pressure difference will cause arc ignition during use, generating instantaneous high temperature, sometimes up to 1000°C or more, which often softens the ceramic, leading to aging in a short period of time and shortening the service life. Therefore, the vacuum arc chamber material of the present invention and the ordinary commercially available material are placed at a high temperature of 1300°C at the same time to detect the softening of the two materials. After being kept at a high temperature of 1300°C for 50 hours, the softening of the two materials is detected. After being kept at a high temperature of 1300°C for 50 hours, the vacuum arc chamber material of the present invention is deformed when a force of 96N is applied. After being kept at a high temperature of 1300°C for 50 hours, the ordinary commercially available material is deformed when a force of 18N is applied. By comparison, it can be seen that the vacuum arc chamber material of the present invention has higher thermal stability.

[0049] When testing the brittleness, at room temperature, increasing pressure is applied to the vacuum interrupter material of the present invention and ordinary commercially available materials at the same time. The ordinary commercially available material is damaged when a force of 320N is applied, and the vacuum interrupter material is damaged when a force of 410N is applied. The vacuum interrupter material is less brittle.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A permanent magnet ring main unit, comprising a cabinet body (1), a first transverse partition (2) and a permanent magnet circuit breaker (3), characterized in that: Also includes a first annular block (4); The first transverse partition (2) is horizontally fixed in the cabinet (1), and a through hole is provided on the first transverse partition (2); The permanent magnetic circuit breaker (3) comprises a permanent magnetic mechanism (31) and a circuit breaker mechanism (32), wherein the permanent magnetic mechanism (31) and the circuit breaker mechanism (32) are both arranged vertically and the circuit breaker mechanism (32) is fixed below the permanent magnetic mechanism (31), and the permanent magnetic circuit breaker (3) is inserted into the through hole; The first annular block (4) is sleeved on the outer wall of the permanent magnetic circuit breaker (3) and fixed to the permanent magnetic circuit breaker (3), and the first annular block (4) is located above the first transverse partition (2); It also comprises a vertical partition (5), a second horizontal partition (6), an isolating switch (7) and a controller (8), wherein the vertical partition (5) is vertically fixed on the upper and lower inner walls of the cabinet (1), the first horizontal partition (2) and the second horizontal partition (6) are horizontally arranged on both sides of the vertical partition (5) and the two ends are respectively fixed to the vertical partition (5) and the inner wall of the cabinet (1), the controller (8) is fixed to the second horizontal partition (6), the permanent magnetic circuit breaker (3) and the isolating switch (7) are respectively electrically connected to the controller (8), and the busbar is connected to the permanent magnetic circuit breaker (3) and the isolating switch (7); The invention also comprises a second annular block (10), a third annular block (20), a fourth annular block (30), a bolt (40) and a first nut (50); the first annular block (4) is sleeved on the outer wall of the permanent magnet mechanism (31) and fixed to the permanent magnet mechanism (31); the second annular block (10) is sleeved on the outer wall of the circuit breaker mechanism (32) and fixed to the circuit breaker mechanism (32); the third annular block (20) is fixed above the first annular block (4) and is provided with a first through hole; the fourth annular block (30) is fixed below the second annular block (10) and is provided with a second through hole opposite to the first through hole; the bolt (40) passes through the first through hole and the second through hole; the first nut (50) is threadedly connected with the bolt (40) to fix the first annular block (4) and the second annular block (10).

2. A permanent magnet ring main unit as claimed in claim 1, characterized in that: The number of the busbars, permanent magnetic circuit breakers (3) and disconnectors (7) is three each. The cabinet (1) is provided with three busbar insertion holes (11) on its side. The cabinet (1) is provided with three busbar outlet holes on its side opposite to the three busbar insertion holes. The three busbars are respectively inserted into the busbar insertion holes (11) and are respectively outlet from the busbar outlet holes.

3. A permanent magnet ring main unit as claimed in claim 2, characterized in that: It also comprises three grounding switches (9), and the three busbars are electrically connected to the three grounding switches (9) respectively.

4. A permanent magnet ring main unit as claimed in claim 1, characterized in that: The circuit breaker mechanism (32) comprises a stud bolt (321), a second nut (322), an insulating rod (323), a conductive rod (324), a contact (325), a vacuum arc extinguishing chamber (326) and a sealed pole (327); the stud bolt (321) is vertically arranged; the second nut (322) is fixed above the stud bolt (321) by threaded connection; an insulating rod (323) is vertically fixed below the stud bolt (321); a conductive rod (324) is vertically fixed below the insulating rod (323); a contact (325) is arranged directly below the conductive rod (324); the vacuum arc extinguishing chamber (326) is sleeved outside the conductive rod (324) and the contact (325); openings are provided at the top and bottom of the sealed pole (327); the contact (325) and the stud bolt (321) are inserted into the openings.

5. A permanent magnet ring main unit as claimed in claim 4, characterized in that: The permanent magnet mechanism (31) comprises a driving rod (311), and the driving rod (311) is fixed directly above the stud bolt (321).

6. A permanent magnet ring main unit as claimed in claim 5, characterized in that: A first internal thread is provided below the driving rod (311), and the driving rod (311) is fixed to the stud bolt (321) through a threaded connection. A second nut (322) is located between the stud bolt (321) and the driving rod (311), and the second nut (322) is tightened relative to the driving rod (311) so that the driving rod (311) is fastened to the stud bolt (321).

7. A permanent magnet ring main unit as claimed in claim 4, characterized in that: The circuit breaker mechanism (32) further comprises a third nut (328); a second internal thread is provided below the insulating rod (323); the insulating rod (323) is fixed to the stud bolt (321) through a threaded connection; the third nut (328) is located between the stud bolt (321) and the insulating rod (323); the third nut (328) is tightened relative to the insulating rod (323) so that the insulating rod (323) is fastened to the stud bolt (321).

8. A permanent magnet ring main unit as claimed in claim 4, characterized in that: The material of the vacuum interrupter (326) is composed of the following components in percentage by mass: 15% polyphenylene sulfide, 52% silicon dioxide, 5% chlorobutyl rubber, 10% aluminum oxide, 5% silicon carbide, 4% nitrile rubber, 5% graphene and 4% copper oxide.

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