Miniature GIS combined electrical apparatus

Abstract

The present invention relates to the field of high-voltage electrical appliances, and particularly to a miniature GIS combined electrical apparatus. Its circuit breaker is arranged inside a metal shell filled with insulating gas and is driven by an operating mechanism; bushings or cable terminal heads at both ends of the metal shell are electrically connected to the circuit breaker through a busbar inside the metal shell, and an arrester is connected to the busbar; the bushing or cable terminal head includes an insulating core body internally embedded with a main insulation capacitor C1a and a voltage-dividing capacitor C2a, and the two are connected in series to form a capacitive voltage divider. The main insulation capacitor C1a consists of a group of capacitor screens with gradually increasing diameters and arranged alternately with insulating layers. The voltage-dividing capacitor C2a is composed of a group of capacitor screens outside the capacitor screen on the outermost side of the main insulation capacitor C1a, or the voltage-dividing capacitor C2a is a capacitive tap of the main insulation capacitor C1a. One end of the voltage-dividing capacitor C2a connected to the main insulation capacitor C1a is the signal output end; the bushing or cable terminal head further includes a current transformer CT arranged thereon; the combined electrical apparatus of the present invention has a simple structure and is convenient for assembly.

Description

Technical Field

[0001] The present invention relates to the field of high-voltage electrical appliances and relates to a miniature GIS combined electrical appliance. Background Art

[0002] GIS (GAS insulated SWITCHGEAR) is the English abbreviation for gas-insulated switchgear. GIS consists of a disconnector, a circuit breaker, an earthing switch, a current transformer CT, a voltage transformer PT, a lightning arrester, a busbar, a bushing (outgoing terminal) and corresponding connecting parts. These devices or components are all enclosed in a metal earthed enclosure, and a certain pressure of SF6 insulating gas is filled inside, so it is also called SF6 fully enclosed switchgear.

[0003] As Figure 1 shown in the structure diagram of the existing GIS combined electrical appliance, high-voltage electricity is connected through a bushing, and a lightning arrester, a voltage transformer PT, a current transformer CT, a circuit breaker and a disconnector are connected in sequence, and then output through a cable. Each component is enclosed in a grounded metal enclosure and connected through a closed busbar. A certain pressure of SF6 insulating gas is filled in the metal enclosure. The installation order of each component can be adjusted. The disconnector usually has an earthing switch, and of course, devices with independent disconnectors and earthing switches can also be used. The existing GIS combined electrical appliance has the problem of large volume, occupying a large space and being troublesome to maintain and install. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a miniature GIS combined electrical appliance with a simple structure and convenient assembly.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A miniature GIS combined electrical appliance includes a lightning arrester 2, a circuit breaker 4, an operating mechanism 5 and a metal enclosure. The circuit breaker 4 is arranged in the metal enclosure filled with insulating gas. The operating mechanism 5 is drivingly connected to the circuit breaker 4 to drive the circuit breaker 4 to close / open. Both ends of the metal enclosure are connected with bushings 1 or cable terminal heads. The bushings 1 or cable terminal heads at both ends are electrically connected to the circuit breaker 4 through a busbar enclosed in the metal enclosure. The lightning arrester 2 is connected to the busbar;

[0007] The sleeve 1 or the cable terminal head includes an insulating core body, in which a main insulation capacitor C1a and a voltage-dividing capacitor C2a connected in series with the main insulation capacitor C1a are embedded. The main insulation capacitor C1a is composed of a group of capacitor screens with gradually increasing diameters and arranged alternately with the insulating layer. The voltage-dividing capacitor C2a is composed of a group of capacitor screens outside the capacitor screen on the outermost side of the main insulation capacitor C1a, or the voltage-dividing capacitor C2a is a capacitor tap of the main insulation capacitor C1a. The main insulation capacitor C1a and the voltage-dividing capacitor C2a form a capacitive voltage divider, and one end of the voltage-dividing capacitor C2a connected to the main insulation capacitor C1a is the signal output end; the sleeve 1 or the cable terminal head also includes a current transformer CT arranged thereon.

[0008] Preferably, it further includes a disconnecting switch, which is also arranged in the metal shell, and the disconnecting switch is connected between the circuit breaker 4 and the sleeve 1 or the cable terminal head at one end of the micro-GIS combined electrical apparatus.

[0009] Preferably, the current transformer CT includes an iron core coil or an air core coil sleeved outside the insulating core body.

[0010] Preferably, a shielding capacitor C3a is also embedded in the insulating core body. The shielding capacitor C3a is composed of a group of mutually insulated and mutually nested capacitor screens wound or laid along the axial direction of the insulating core body from the high-voltage end to the low-voltage end of the shielding capacitor C3a outside the capacitor screens corresponding to the main insulation capacitor C1a.

[0011] Preferably, a signal acquisition capacitor C4a connected in series with the shielding capacitor C3a is also embedded in the insulating core body. The signal acquisition capacitor C4a is composed of a group of capacitor screens wound outside the outermost capacitor screen of the shielding capacitor C3a, or the signal acquisition capacitor C4a is a capacitor tap of the shielding capacitor C3a; one end of the signal acquisition capacitor C4a connected to the shielding capacitor C3a is the signal output end, and the output signal can replace that of the current transformer CT, and the other end of the signal acquisition capacitor C4a is grounded.

[0012] Preferably, the insulating core body uses glass fiber impregnated with epoxy resin as the insulating layer, and a semi-conductive tape or a metal tape as the capacitor screen, and the insulating core body is formed by alternately winding the insulating layer and the capacitor screen.

[0013] Preferably, at least one end of the micro-GIS combined electrical apparatus is provided with a sleeve 1, and one end of the sleeve 1 is detachably connected to the metal shell.

[0014] Preferably, the bushing 1 further includes an upper flange 12 and a lower flange 13 respectively disposed at both ends of the insulating core, an incoming line terminal 10 disposed at one end of the upper flange 12 and electrically connected to one end of the conductor 1a, and an outgoing line terminal 11 disposed at one end of the lower flange 13 and electrically connected to the other end of the conductor 1a. An installation flange 15 is sleeved on the outer side of the middle part of the insulating core; the capacitor screen of the shielding capacitor C3a is axially arranged from one end of the upper flange 12 to the grounding end of the installation flange 15 on the outer side of the capacitor screen of the corresponding main insulation capacitor C1a, and they are insulated from each other and overlapped with each other.

[0015] Preferably, an installation flange 15 is sleeved on the outer side of the middle part of the insulating core. The installation flange 15 is provided with a first signal interface and a second signal interface; the innermost first capacitor screen of the main insulation capacitor C1a is electrically connected to the conductor 1a and at the same potential. The signal output end between the main insulation capacitor C1a and the voltage dividing capacitor C2a is connected to the first signal interface, and the signal output end between the shielding capacitor C3a and the signal acquisition capacitor C4a is connected to the second signal interface.

[0016] Preferably, the bushing 1 further includes a separately provided installation female head. The installation female head includes a second female head cylinder body, a second contact assembly disposed at one end of the second female head cylinder body to seal it, and a third flange disposed at the other end of the second female head cylinder body and fixedly connected to the metal shell. The third flange is in sealing cooperation with the metal shell; one end of the bushing 1 provided with the lower flange 13 is inserted into the installation female head, the installation flange 15 is fixedly connected to the third flange, and the outgoing line terminal 11 is in cooperation with and electrically connected to the second contact assembly.

[0017] Preferably, one end of the lightning arrester 2 connected to the first bus is in plug-in fit with the metal shell, and the other end of the lightning arrester 2 protrudes outside the metal shell.

[0018] Preferably, the lightning arrester 2 includes a lightning arrester main body 20. The lightning arrester main body 20 includes a valve plate assembly 21 and a lightning arrester insulating core 23 wrapped outside the valve plate assembly 21; the valve plate assembly 21 includes a first valve plate group 21a, a second valve plate group 21b, and an elastic assembly 21c disposed between the first valve plate group 21a and the second valve plate group 21b; one end of the lightning arrester 2 is inserted into the metal shell, so that the first valve plate group 21a is completely placed inside the metal shell, and the first valve plate group 21a is electrically connected to the first bus.

[0019] Preferably, a grading capacitor C1 is provided at the position corresponding to the elastic assembly 21c and the second valve plate group 21b in the lightning arrester insulating core 23. The grading capacitor C1 is composed of a group of capacitor screens alternately arranged with insulating layers. The innermost first screen of the grading capacitor C1 is electrically connected to the valve plate assembly 21, and the outermost last screen is grounded.

[0020] Preferably, the arrester 2 further includes a first flange 25 sleeved on and fixedly connected to the middle of the arrester insulating core 23, and the first flange 25 is fixedly connected to and sealingly fitted with the metal shell.

[0021] Preferably, the arrester main body 20 further includes a first terminal 22a and a second terminal 22b respectively arranged at both ends thereof, and a first flange 25 sleeved on and fixedly connected to the middle of the arrester insulating core 23; the first terminal 22a is located at one end of the first valve plate group 21a and is connected thereto, and the first terminal 22a cooperates with the elastic component 21c to press the first valve plate group 21a tightly. The second terminal 22b is located at one end of the second valve plate group 21b and is connected thereto, and the second terminal 22b cooperates with the elastic component 21c to press the second valve plate group 21b tightly. The arrester 2 further includes an insulating female head 27 separately arranged from the arrester main body 20. The insulating female head 27 includes a female head cylinder body 270, and a contact component 272 and a second flange 271 respectively arranged at both ends of the female head cylinder body 270. The contact component 272 seals one end of the female head cylinder body 270 and is electrically connected to the first bus bar. The insulating female head 27 is inserted into the metal shell. The second flange 271 is fixedly connected to and sealingly fitted with the metal shell. One end of the insulating core 3 is inserted into the insulating female head 27. The first terminal 22a is inserted and fitted with the contact component 272, and the second flange 271 is fixedly connected to the first flange 25.

[0022] Preferably, the arrester 2 further includes a silicone rubber sheath 26 sleeved on the outside of one end of the arrester insulating core 23, located between the insulating female head 27 and the arrester insulating core 23. Both ends of the silicone rubber sheath 26 are respectively close to the first terminal 22a and the first flange 25.

[0023] Preferably, one end of the elastic component 21c cooperating with the first valve plate group 21a is the first pressing end. From the innermost first screen to the outermost last screen in the grading capacitor C1, along the axial direction of the valve plate assembly 21 from the first pressing end to the end of the second valve plate group 21b away from the elastic component 21c, they are offset in sequence and sleeved in sequence. A grading capacitor C2 is further arranged in the arrester insulating core 23. The grading capacitor C2 is composed of a group of capacitor screens alternately arranged with an insulating layer outside the outermost last screen of the grading capacitor C1. The grading capacitor C2 is connected in parallel with the grading capacitor C1. From the innermost first screen to the outermost last screen in the grading capacitor C2, along the axial direction of the valve plate assembly 21 from the first pressing end to the end of the second valve plate group 21b away from the elastic component 21c, they are offset in sequence and sleeved in sequence. The first screen of the grading capacitor C2 shares the first screen of the grading capacitor C1, and at least one end capacitor screen of the grading capacitor C2 shares at least one end capacitor screen of the grading capacitor C1.

[0024] For the miniature GIS combined electrical apparatus of the present invention, a capacitance voltage divider (also referred to as potential transformer PT herein) which can replace the potential transformer PT is formed by embedding a main insulation capacitor C1a and a voltage-dividing capacitor C2a in the insulation core of the bushing 1 or the cable terminal head, and a current transformer CT is disposed on the bushing 1. Compared with the prior art GIS totally enclosed combined electrical apparatus, the current transformer CT and the potential transformer PT are integrated on the bushing or the cable terminal head, the bushing 1 or the cable terminal head does not need to be filled with SF6 gas, the CT compartment and the PT compartment of the prior art GIS totally enclosed combined electrical apparatus are reduced, the volume of the GIS is reduced, the manufacturing cost is saved, the use of harmful gases is reduced, which is beneficial to environmental protection, the structure of the GIS totally enclosed combined electrical apparatus is simplified, and the signal output by the potential transformer PT formed by the main insulation capacitor C1a and the voltage-dividing capacitor C2a embedded in the insulation core is more accurate, avoiding the errors and interferences of the independent potential transformer PT in the prior art.

[0025] In addition, compared with the prior art GIS totally enclosed combined electrical apparatus, the preferred embodiment of the miniature GIS combined electrical apparatus of the present invention mainly has the following improvement points: 1. The potential transformer PT and the current transformer CT are integrated on the bushing or the cable terminal head; 2. The lightning arrester can be independently inserted and pulled out; 3. There is a shielding capacitor C3a for anti-interference shielding; 4. A signal acquisition capacitor C4a embedded in the insulation core and the shielding capacitor C3a form an on-line detection signal source. It has the following advantages: 1. The CT compartment and the PT compartment of the prior art GIS totally enclosed combined electrical apparatus are reduced, and the lightning arrester compartment is reduced, thereby reducing the volume of the GIS; 2. The manufacturing cost is saved; 3. The use of harmful gases is reduced, which is beneficial to environmental protection; 4. When the equipment is overhauled and maintained, there is no need to deflate and inflate, which is simple and efficient; 5. The shielding capacitor C3a can effectively shield the interference to the signal output of the capacitance voltage divider which can replace the potential transformer PT formed by the main insulation capacitor C1a and the voltage-dividing capacitor C2a, which is beneficial to improving the monitoring accuracy; 6. The signal acquisition capacitor C4a and the shielding capacitor C3a form an information collector which can replace the current transformer CT and is used for on-line monitoring of the partial discharge and dielectric loss detection of the equipment.

[0026] In addition, for the lightning arrester 2 of the present invention, the varistor assembly 21 of the lightning arrester main body 20 includes a first varistor group 21a and a second varistor group 21b. Through reasonable design, the total voltage borne by the lightning arrester main body 20 during lightning strikes can be distributed proportionally between the first varistor group 21a and the second varistor group 21b. As a result, the voltage shared by the second varistor group 21b can be effectively reduced, enabling the part of the lightning arrester 2 protruding outside the metal shell (i.e., the second varistor group 21b) to ensure good insulation of the lightning arrester 2 without the need for insulation gas (such as SF6 gas or a mixed gas containing SF6). Further, since the voltage shared by the second varistor group 21b is small, the number of capacitor screens of the grading capacitor C1 can be significantly reduced, effectively reducing the volume of the lightning arrester 2, which is convenient for use and installation. Moreover, one end of the lightning arrester 2 is electrically connected to the first bus and is inserted and cooperated with the metal shell. Compared with the prior art, the structure of the metal shell is simplified, the manufacturing cost of the metal shell is saved, and the lightning arrester 2 is inserted and cooperated with the metal shell, making the installation / dismantling simple and facilitating the maintenance and replacement of the lightning arrester 2. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of a prior art GIS completely enclosed combined electrical apparatus;

[0028] Figure 2 is a schematic structural diagram of the first embodiment of the micro GIS combined electrical apparatus of the present invention;

[0029] Figure 3 is a schematic structural diagram of the lightning arrester of the present invention;

[0030] Figure 4 is a schematic structural diagram of the lightning arrester of the present invention, Figure 3 compared with which the insulating female head and the elastic component are removed;

[0031] Figure 5 is the present invention Figure 4 magnified structural schematic diagram of part A;

[0032] Figure 6 is the present invention Figure 4 magnified structural schematic diagram of part B;

[0033] Figure 7 is a schematic structural diagram of the elastic component of the present invention;

[0034] Figure 8 is a schematic structural diagram of the insulating female head of the present invention;

[0035] Figure 9 is a schematic structural diagram of the bushing of the present invention;

[0036] Figure 10 is another schematic structural diagram of the bushing of the present invention;

[0037] Figure 11 It is a schematic structural diagram of the cable terminal head of the present invention. Specific embodiments

[0038] The following combines Figures 1-10 Given embodiments to further illustrate the specific embodiments of the micro GIS combined electrical apparatus of the present invention. The micro GIS combined electrical apparatus of the present invention is not limited to the descriptions of the following embodiments.

[0039] The micro GIS combined electrical apparatus of the present invention includes a lightning arrester 2, a circuit breaker 4, an operating mechanism 5 and a metal shell. The circuit breaker 4 is arranged in the metal shell filled with insulating gas. The operating mechanism 5 is drivingly connected to the circuit breaker 4 to drive the circuit breaker 4 to close / open. Both ends of the metal shell are connected with bushings 1 or cable terminal heads. The bushings 1 or cable terminal heads at both ends are connected to the circuit breaker 4 through a bus bar enclosed in the metal shell. The lightning arrester 2 is connected to the bus bar. The bushing 1 or cable terminal head includes an insulating core body, in which a main insulation capacitor C1a and a voltage-dividing capacitor C2a connected in series with the main insulation capacitor C1a are embedded. The main insulation capacitor C1a is composed of a group of capacitor screens with gradually increasing diameters and arranged alternately with insulating layers. The voltage-dividing capacitor C2a is composed of a group of capacitor screens outside the capacitor screen on the outermost side of the main insulation capacitor C1a, or the voltage-dividing capacitor C2a is a capacitor tap of the main insulation capacitor C1a. The main insulation capacitor C1a and the voltage-dividing capacitor C2a constitute a capacitive voltage divider that can replace a potential transformer PT. One end of the voltage-dividing capacitor C2a connected to the main insulation capacitor C1a is a signal output end. The bushing 1 or cable terminal head further includes a current transformer CT arranged thereon.

[0040] As Figure 2 shown, bushings 1 and a cable terminal head 7 are respectively arranged at both ends of the metal shell of the micro GIS combined electrical apparatus of the present invention. Of course, bushings 1 can also be arranged at both ends of the metal shell of the micro GIS combined electrical apparatus, or cable terminal heads 7 can be arranged at both ends. In addition, the micro GIS combined electrical apparatus of the present invention further includes a disconnector, and the disconnector is also arranged in the metal shell. The disconnector is connected between the circuit breaker 4 and the bushing 1 or cable terminal head at one end of the micro GIS combined electrical apparatus. The disconnector can be independent or integrated with the circuit breaker. When the micro GIS combined electrical apparatus of this embodiment is applied, its bushing 1 is connected to a high-voltage line, the disconnector 6 outputs through the cable terminal head 7, the metal shell is isolated from the external environment and grounded, and the metal shell is filled with SF6 gas, or an SF6 mixed gas, or other insulating gases.

[0041] As Figure 1The direction shown is a GIS fully enclosed combined electrical apparatus of the prior art, which includes a bushing, a lightning arrester, a potential transformer PT, a current transformer CT, a circuit breaker, an operating mechanism, a disconnector, and a cable terminal head arranged in sequence from right to left. The operating mechanism is drivingly connected to the circuit breaker. The bushing, the circuit breaker, and the disconnector are sequentially connected in series through a busbar inside the metal enclosure. The lightning arrester, the potential transformer PT, and the current transformer CT are respectively arranged in the lightning arrester compartment, the PT compartment, and the CT compartment of the metal enclosure, and are sequentially coupled to the busbar for connecting the bushing and the circuit breaker. The bushing, the lightning arrester, the potential transformer PT, the current transformer CT, the circuit breaker, and the disconnector are all arranged inside the metal enclosure, and SF6 gas, or an SF6 mixed gas, or other insulating gases are filled inside the metal enclosure to ensure good insulation of the entire GIS fully enclosed combined electrical apparatus.

[0042] In the micro GIS combined electrical apparatus of the present invention, a capacitive voltage divider composed of a main insulation capacitor C1a and a voltage-dividing capacitor C2a is embedded in the insulation core body of the bushing 1 or the cable terminal head, which can replace the potential transformer PT, and a current transformer CT is arranged on the bushing 1. Compared with the GIS fully enclosed combined electrical apparatus of the prior art, the current transformer CT and the potential transformer PT are integrated on the bushing or the cable terminal head. The bushing 1 or the cable terminal head does not need to be filled with SF6 gas, reducing the CT compartment and the PT compartment of the existing GIS fully enclosed combined electrical apparatus, reducing the volume of the GIS, saving the manufacturing cost, reducing the use of harmful gases, being beneficial to environmental protection, simplifying the structure of the GIS fully enclosed combined electrical apparatus, and the potential transformer PT composed of the main insulation capacitor C1a and the voltage-dividing capacitor C2a embedded in the insulation core body outputs a more accurate signal.

[0043] As Figure 2 shown, it is the first embodiment of the micro GIS combined electrical apparatus of the present invention.

[0044] As Figure 2 shown, the micro GIS combined electrical apparatus of the present invention includes a bushing 1, a lightning arrester 2, a circuit breaker 4, an operating mechanism 5, a disconnector 6, a cable terminal 7, and a metal enclosure. In this embodiment, the bushing 1 and the cable terminal 7 are respectively arranged at both ends of the metal enclosure. The circuit breaker 4 and the disconnector 6 are both arranged inside the metal enclosure. The operating mechanism 5 is drivingly connected to the circuit breaker 4 to drive the circuit breaker 4 to close / open. The bushing 1, the circuit breaker 4, the disconnector 6, and the cable terminal 7 are sequentially connected in series through a busbar enclosed in the metal enclosure. The lightning arrester 2 is connected to the busbar and is arranged between the bushing 1 and the circuit breaker 4. Preferably, the lightning arrester 2 is a plug-in dry-type lightning arrester, so that the micro GIS combined electrical apparatus of the present invention can reduce the lightning arrester compartment of the existing GIS fully enclosed combined electrical apparatus.

[0045] The bushing 1 includes a conductor 1a and an insulating core wrapped around the outside of the conductor 1a. A main insulation capacitor C1a and a voltage-dividing capacitor C2a connected in series with the main insulation capacitor C1a are embedded in the insulating core. The main insulation capacitor C1a consists of a group of capacitor screens with gradually increasing diameters and arranged alternately with insulating layers. The voltage-dividing capacitor C2a is composed of a group of capacitor screens outside the capacitor screen on the outermost side of the main insulation capacitor C1a, or the voltage-dividing capacitor C2a is a capacitance tap of the main insulation capacitor C1a, that is, a signal wire tap taken from the penultimate screen or the last few screens of the main insulation capacitor C1a. The main insulation capacitor C1a and the voltage-dividing capacitor C2a form a potential transformer PT, and one end of the voltage-dividing capacitor C2a connected to the main insulation capacitor C1a is the signal output end; the bushing 1 further includes a current transformer CT provided thereon.

[0046] Specifically, as Figure 2 shown in the direction, the bushing 1, the circuit breaker 4, the disconnector 6, and the cable terminal 7 are connected in series through the bus bar inside the metal casing from right to left in sequence. The disconnector 6 is arranged inside the left end of the metal casing. The bushing 1 is fitted with the right end of the metal casing, and the cable terminal 7 is fitted with the left end of the metal casing. The metal casing is filled with insulating gas. The upper end of the lightning arrester 2 is electrically connected to the first bus bar and the lower end is grounded. The operating mechanism 5 is arranged below the circuit breaker 4 and is drivingly connected thereto to drive the circuit breaker 4 to open / close.

[0047] Further, as Figure 2 shown, the metal casing includes a first part for accommodating the first bus bar connecting the bushing 1 and the circuit breaker 4, a second part for accommodating the circuit breaker 4, and a third part for accommodating the disconnector 6 and the second bus bar connecting the disconnector 6 and the cable terminal head 7; the left end of the bushing 1 is detachably connected to the right end of the first part, and the lightning arrester 2 is fitted with the first part, preferably also detachably connected. Further, the first part, the second part, and the third part are all filled with a mixed gas of SF6 and N2 at 0.4 MPa. In the mixed gas of SF6 and N2, SF6 accounts for 20% of the total volume and N2 accounts for 80% of the total volume.

[0048] Preferably, as Figure 2 and 10 shown, the current transformer CT includes an iron core coil or a hollow coil sleeved outside the insulating core, and the current transformer CT is arranged at one end of the bushing 1 connected to the first bus bar.

[0049] Preferably, as Figure 9 ​As shown, in a preferred embodiment of the bushing 1, a shielding capacitor C3a is further embedded in the insulating core of the bushing 1. The shielding capacitor C3a is composed of a group of capacitively coupled screens that are insulated from each other and nested with each other, which are wound or laid along the axial direction of the insulating core from the high-voltage end to the low-voltage end of the shielding capacitor C3a outside the capacitance screen corresponding to the main insulation capacitor C1a. It can effectively shield the interference of the output signal of the potential transformer PT composed of the main insulation capacitor C1a and the voltage-dividing capacitor C2a, which is beneficial to improving the monitoring progress. Further, a signal acquisition capacitor C4a connected in series with the shielding capacitor C3a is also embedded in the insulating core. The signal acquisition capacitor C4a is composed of a group of capacitance screens wound outside the outermost capacitance screen of the shielding capacitor C3a, or the signal acquisition capacitor C4a is the capacitance tap of the shielding capacitor C3a, that is, the signal wire tap taken out from the penultimate screen or the last few screens of the shielding capacitor C3a; one end of the signal acquisition capacitor C4a connected to the shielding capacitor C3a is the signal output end, and the output can replace the signal of the current transformer CT. The other end of the signal acquisition capacitor C4a is grounded, which is used for on-line monitoring of partial discharge and dielectric loss detection of the equipment. The signal source has high consistency, further improving the accuracy of the monitoring results and replacing the current transformer CT.

[0050] Preferably, the disconnecting switch 6 is arranged at one end of the metal shell, and the bushing 1 is arranged at the other end of the metal shell and located outside the metal shell. Specifically, the disconnecting switch 6 is arranged in the third part of the metal shell, one end of the bushing 1 is inserted and arranged in the first part of the metal shell, and the other end is located outside the metal shell.

[0051] Preferably, as Figure 3 shown, the disconnecting switch 6 is arranged at one end of the metal shell, and one end of the bushing 1 is detachably connected to the other end of the metal shell. Specifically, as Figure 2 and 3 shown in the direction, the disconnecting switch 6 is arranged in the third part of the metal shell, and the left end of the bushing 1 is detachably connected to the right end of the first part of the metal shell.

[0052] Preferably, the metal shell is made of aluminum alloy material, which is light in weight and high in strength, and will not generate eddy currents, which is beneficial to reducing the power loss during the power transmission process.

[0053] As Figure 10 shown, it is the first embodiment of the bushing 1.

[0054] The sleeve 1 includes a conductor 1a and an insulating core wrapped around the outside of the conductor 1a. The insulating core is provided with a main insulation capacitor C1a, a voltage-dividing capacitor C2a, and a shielding capacitor C3a. The main insulation capacitor C1a is composed of a plurality of coaxial capacitor screens arranged alternately with an insulating layer and having gradually increasing diameters. The voltage-dividing capacitor C2a is composed of a group of capacitor screens outside the capacitor screen at the outermost side of the main insulation capacitor C1a, or the voltage-dividing capacitor C2a is a capacitance tap of the main insulation capacitor C1a. The shielding capacitor C3a is composed of a group of mutually insulated and mutually nested capacitor screens wound or laid along the axial direction of the sleeve 1 from the high-voltage end to the grounding end of the shielding capacitor C3a outside the corresponding capacitor screen of the main insulation capacitor C1a. Further, as Figure 9 shown, the sleeve 1 further includes an incoming line terminal 10, an outgoing line terminal 11, an upper flange 12, and a lower flange 13. The upper flange 12 and the lower flange 13 are respectively arranged at both ends of the insulating core. The incoming line terminal 10 is arranged at one end of the upper flange 12 and connected to one end of the conductor 1a, and the outgoing line terminal 11 is arranged at one end of the lower flange 13 and connected to the other end of the conductor 1a. Preferably, the upper flange 12 is a Jiangjun seat, and the lower flange 13 is a grading sphere. Further, as Figure 10 shown, the sleeve 1 further includes a current transformer CT. The current transformer CT is an iron-core coil or a hollow coil and is sleeved outside the insulating core.

[0055] Preferably, the capacitance of the voltage-dividing capacitor C2a is much larger than the capacitance of the main insulation capacitor C1a.

[0056] As Figure 10 shown, the sleeve 1 further includes a mounting flange 15 sleeved in the middle of the insulating core. When the sleeve 1 is applied to the miniature GIS combined electrical apparatus of the present invention, one end of the sleeve 1 is inserted into the metal shell, and the mounting flange 15 is fixedly connected to the metal shell and is in sealing cooperation.

[0057] Further, a second embodiment of the sleeve 1.

[0058] The sleeve 1 of this embodiment further includes a mounting female head. The mounting female head includes a second female head cylinder body, a second contact assembly arranged at one end of the second female head cylinder body to seal it, and a third flange arranged at the other end of the second female head cylinder body and fixedly connected to the metal shell. The third flange is fixedly connected to the metal shell and is in sealing cooperation; the mounting female head is pre-installed on the metal shell, the third flange is fixedly connected to the metal shell and is in sealing cooperation, one end of the sleeve 1 provided with the lower flange 13 is inserted into the mounting female head, the outgoing line terminal 11 is in cooperation and electrical connection with the second contact assembly, and the mounting flange 15 is fixedly connected to the third flange, so that when maintaining or replacing the sleeve 1, it is not necessary to disassemble the sleeve mounting female head, avoiding the leakage of the insulating gas in the metal shell and the situation of repeated filling, which is beneficial to cost saving and operation efficiency improvement. Even further, as Figure 9As shown, the bushing 1 of this embodiment further includes an insulating outer sheath 14. The insulating outer sheath 14 is sleeved on the outer side of one end of the insulating core body and is located between the upper flange 12 and the mounting flange 15. The insulating outer sheath 14 is preferably a silicone rubber umbrella skirt. Specifically, the mounting flange 15 is located between the current transformer CT and the metal shell.

[0059] As Figure 9 shown, it is the third embodiment of the bushing 1.

[0060] The disconnecting switch 6 is arranged at one end of the metal shell, and one end of the bushing 1 is detachably connected to the other end of the metal shell. The difference between the bushing of this embodiment and the second embodiment is that: the bushing 1 further includes a shielding capacitor C3a and a signal acquisition capacitor C4a connected in series with the shielding capacitor C3a. The shielding capacitor C3a is composed of a group of capacitively coupled screens that are insulated from each other and nested with each other and are wound or laid along the axial direction of the bushing 1 from the high-voltage end to the low-voltage end of the shielding capacitor C3a outside the capacitive screen of the corresponding main insulation capacitor C1a. The signal acquisition capacitor C4a is composed of a group of capacitive screens wound outside the outermost capacitive screen of the shielding capacitor C3a, or the signal acquisition capacitor C4a is a capacitive tap of the shielding capacitor C3a; the signal acquisition capacitor C4a and the shielding capacitor C3a form a signal acquisition device. The end of the signal acquisition capacitor C4a connected to the shielding capacitor C3a is the signal output end, and the other end of the signal acquisition capacitor C4a is grounded. Preferably, the capacitance of the signal acquisition capacitor C4a is much larger than the capacitance of the shielding capacitor C3a.

[0061] Specifically, as Figure 9 shown in the direction, the capacitive screens of the shielding capacitor C3a are wound or laid alternately with the insulating layer from the upper end to the lower end of the insulating core body outside the main insulation capacitor C1a. Adjacent capacitive screens are insulated from each other and nested with each other, and the multiple capacitive screens of the shielding capacitor C3a are sequentially offset downward along the axial direction of the conductor 1a from top to bottom, that is, among two adjacent capacitive screens, the lower end of the upper capacitive screen is located inside the lower capacitive screen, and the lower end of the upper capacitive screen overlaps with the upper end of the lower capacitive screen.

[0062] A preferred solution is that the insulating core body uses glass fiber impregnated with epoxy resin as the insulating layer and a semi-conductive tape or a metal tape as the capacitive screen, and the insulating core body is formed by alternately winding the insulating layer and the capacitive screen. The insulating core body can also be formed by sequentially nesting and pouring a group of cylindrical capacitive screens.

[0063] Preferably, as Figure 9As shown, a first signal interface and a second signal interface are provided on the mounting flange 15; the innermost first capacitor screen of the main insulation capacitor C1a is electrically connected to the conductor 1a to be equipotential. The signal output terminal between the main insulation capacitor C1a and the voltage-dividing capacitor C2a is connected to the first signal interface. The outermost capacitor screen of the voltage-dividing capacitor C2a is grounded. The signal output terminal between the shielding capacitor C3a and the signal acquisition capacitor C4a is connected to the second signal interface. The outermost capacitor screen of the signal acquisition capacitor C4a is grounded.

[0064] Further, as Figure 9 shown, the voltage-dividing capacitor C2a is composed of a plurality of capacitor screens connected in parallel. That is, the plurality of capacitor screens of the voltage-dividing capacitor C2a are alternately grounded and connected to the signal output terminal between the main insulation capacitor C1a and the voltage-dividing capacitor C2a in turn. That is to say, the grounded capacitor screen is the first type of capacitor screen, and the capacitor screen connected to the signal output terminal between the shielding capacitor C3a and the signal acquisition capacitor C4a is the second type of capacitor screen. The first type of capacitor screen and the second type of capacitor screen are alternately arranged in turn; the signal acquisition capacitor C4a is composed of a plurality of capacitor screens connected in parallel. That is, the plurality of capacitor screens of the signal acquisition capacitor C4a are alternately grounded and connected to the signal output terminal in turn. That is to say, the grounded capacitor screen is the third type of capacitor screen, and the capacitor screen connected to the signal output terminal is the fourth type of capacitor screen. The third type of capacitor screen and the fourth type of capacitor screen are alternately arranged in turn.

[0065] For the bushing 1 of this embodiment, the signal output terminal between the main insulation capacitor C1a and the voltage-dividing capacitor C2a and the signal output terminal between the shielding capacitor C3a and the signal acquisition capacitor C4a can be respectively connected to the detection device for the insulation parameters of capacitive equipment. Compared with the existing method of measuring the insulation parameters of capacitive equipment by signal coupling (i.e., current transformer CT and voltage transformer PT coupling), without changing the operation mode of the capacitive equipment, the accuracy of measuring the insulation parameters of the capacitive equipment is improved. There is no need to add an additional current transformer, and there is no need to use a signal cable to connect to the voltage transformer in the substation to obtain a voltage signal, effectively avoiding the influence of the errors and performance of the signal coupling current transformer and voltage transformer in the prior art on the measurement result, and being applicable to the on-line monitoring of the insulation parameters of capacitive equipment; moreover, the current signals and voltage signals collected by the current transformer CT and voltage transformer PT embedded in the insulating core of the bushing 1 both come from inside the capacitive equipment, avoiding or significantly reducing external interference, with high consistency, which is beneficial to further improving the accuracy of the monitoring result.

[0066] Preferably, in the bushing 1 of the second and third embodiments, the voltage-dividing capacitor C2a is a capacitance tap of the main insulation capacitor C1a, that is, the capacitance tap taken from the second-to-last capacitance screen (or the last n capacitance screens, where n > 2 and n is an integer) of the main insulation capacitor C1a, and is the capacitance formed by the last two capacitance screens (or the last n capacitance screens) of the main insulation capacitor C1a; or, the voltage-dividing capacitor C2a is an independent capacitor connected in series with the main insulation capacitor C1a, and is composed of a plurality of capacitance screens separately wound outside the main insulation capacitor C1a in parallel.

[0067] In the bushing 1 of the third embodiment, the signal acquisition capacitor C4a is a capacitance tap of the shielding capacitor C3a, that is, the capacitance tap taken from the second-to-last screen (or the last m screens, where m > 2 and m is an integer) of the shielding capacitor C3a, and the signal acquisition capacitor C4a is formed by the last two capacitance screens (or the last m capacitance screens) of the shielding capacitor C3a, or the signal acquisition capacitor C4a is an independent capacitor connected in series with the shielding capacitor C3a, and the signal acquisition capacitor C4a is composed of a plurality of capacitance screens separately wound outside the shielding capacitor C3a in parallel. In the bushing 1 of the second and third embodiments, the voltage-dividing capacitor C2a is a capacitance tap of the main insulation capacitor C1a, and in the bushing 1 of the third embodiment, the signal acquisition capacitor C4a is a capacitance tap of the shielding capacitor C3a, which is beneficial to simplifying the production process and operation of the capacitive device of the present invention and improving the production efficiency. The voltage-dividing capacitor C2a or the signal acquisition capacitor C4a adopts the structure of an independently wound capacitor, which is convenient for adjusting the output current signal and voltage signal as needed.

[0068] As Figure 11 described, for the first embodiment of the cable terminal head 7, the cable terminal head 7 includes an insulating core 74 for accommodating one end of the cable. A stress cone 71 is provided inside the insulating core, and the insulating core 74 is tightly pressed against the stress cone 71. An upper flange 72 is provided at one end of the insulating core 74, and a grounding flange 73 is provided at the lower end. A conductive rod 76 electrically connected to one end of the cable is provided at the end of the insulating core 74 where the upper flange 72 is located, and a petticoat 75 is provided outside the insulating core 74. A main insulation capacitor C1a is embedded in the insulating core 74 for high-voltage voltage equalization insulation. The main insulation capacitor C1a is composed of a group of capacitance screens with gradually increasing diameters and arranged alternately with insulating layers. In this embodiment, a potential transformer PT and a current transformer CT are integrated in the bushing 1. The cable terminal head 7 can be provided with only the main insulation capacitor C1a for high-voltage voltage equalization insulation. Of course, the voltage-dividing capacitor C2a and the shielding capacitor C3a can also be provided according to needs.

[0069] As another embodiment of the miniature GIS combined electrical apparatus of the present invention, the bushing 1 does not integrate the potential transformer PT and the current transformer CT, and only the main insulation capacitor C1a is provided for voltage equalization insulation of high voltage. Of course, the voltage dividing capacitor C2a and the shielding capacitor C3a can also be provided according to needs. The cable terminal head 7 integrates the potential transformer PT and the current transformer CT.

[0070] Specifically, a second embodiment of the cable terminal head 7. The cable terminal head 7 includes an insulating core body, in which a main insulation capacitor C1a and a voltage dividing capacitor C2a connected in series with the main insulation capacitor C1a are embedded. The main insulation capacitor C1a is composed of a group of capacitor screens with gradually increasing diameters and arranged alternately with the insulating layer. The voltage dividing capacitor C2a is composed of a group of capacitor screens outside the capacitor screen on the outermost side of the main insulation capacitor C1a, or the voltage dividing capacitor C2a is the capacitor tap of the main insulation capacitor C1a. The main insulation capacitor C1a and the voltage dividing capacitor C2a constitute the potential transformer PT, and the end of the voltage dividing capacitor C2a connected to the main insulation capacitor C1a is the signal output end; the cable terminal head also includes a current transformer CT arranged thereon.

[0071] Preferably, the current transformer CT includes an iron core coil or a hollow coil sleeved outside the insulating core body.

[0072] Preferably, a shielding capacitor C3a is also embedded in the insulating core body of the cable terminal head 7. The shielding capacitor C3a is composed of a group of mutually insulated and mutually nested capacitor screens wound or laid along the axial direction of the insulating core body from the high voltage end to the low voltage end of the shielding capacitor C3a outside the capacitor screen corresponding to the main insulation capacitor C1a; a signal acquisition capacitor C4a connected in series with the shielding capacitor C3a is also embedded in the insulating core body. The signal acquisition capacitor C4a is composed of a group of capacitor screens outside the capacitor screen on the outermost side of the shielding capacitor C3a, or the signal acquisition capacitor C4a is the capacitor tap of the shielding capacitor C3a; the end of the signal acquisition capacitor C4a connected to the shielding capacitor C3a is the signal output end, and the other end of the signal acquisition capacitor C4a is grounded.

[0073] As Figure 3 shown, it is the first embodiment of the lightning arrester 2. The lightning arrester 2 is a dry-type lightning arrester. Of course, the lightning arrester 2 can also adopt a traditional GIS lightning arrester.

[0074] As Figure 3As shown, the lightning arrester 2 includes a lightning arrester body 20, and the lightning arrester body 20 includes a valve plate assembly 21 and a lightning arrester insulating core 23 wrapped outside the valve plate assembly 21; the valve plate assembly 21 includes a first valve plate group 21a, a second valve plate group 21b, and an elastic assembly 21c disposed between the first valve plate group 21a and the second valve plate group 21b; one end of the lightning arrester 2 is inserted into the metal shell, so that the first valve plate group 21a is completely placed inside the metal shell, and the first valve plate group 21a is electrically connected to the first busbar.

[0075] Preferably, a grading capacitor C1 is provided at a position corresponding to the elastic assembly 21c and the second valve plate group 21b in the lightning arrester insulating core 23. The grading capacitor C1 is composed of a plurality of capacitor screens alternately arranged with an insulating layer. The innermost first screen of the grading capacitor C1 is electrically connected to the valve plate assembly 21, and the outermost last screen is grounded. For the lightning arrester 2 of the present invention, the valve plate assembly 21 of the lightning arrester body 20 includes a first valve plate group 21a and a second valve plate group 21b. The total voltage borne by the lightning arrester body 20 during lightning strikes can be distributed proportionally between the first valve plate group 21a and the second valve plate group 21b through reasonable design. The upper and lower ends of the elastic assembly 21c are electrically connected to the first valve plate group 21a and the second valve plate group 21b respectively, so that the voltage borne by the second valve plate group 21b can be effectively reduced, enabling the part of the lightning arrester 2 protruding outside the metal shell (i.e., the second valve plate group 21b) to ensure good insulation of the lightning arrester 2 without the insulation of insulating gas (such as SF6 gas or a mixed gas containing SF6); further, since the voltage borne by the second valve plate group 21b is small, the number of capacitor screens of the grading capacitor C1 can be significantly reduced, thereby effectively reducing the volume of the lightning arrester 2, facilitating use and installation. Moreover, one end of the lightning arrester 2 is electrically connected to the first busbar and is in plug-in fit with the metal shell. Compared with the prior art, the structure of the metal shell is simplified, the manufacturing cost of the metal shell is saved, and the lightning arrester 2 is in plug-in fit with the metal shell, making installation / removal simple and facilitating the location and replacement of the lightning arrester 2.

[0076] Preferably, as Figures 3-6 shown, one end of the elastic assembly 21c cooperating with the first valve plate group 21a is the first pressing end. From the innermost first screen to the outermost last screen of the grading capacitor C1, along the axial direction of the valve plate assembly 21 from the first pressing end to the end of the second valve plate group 21b away from the elastic assembly 21c, they are offset in sequence and sleeved in sequence. The innermost first screen of the grading capacitor C1 is electrically connected to the upper and lower ends of the elastic assembly 1c, with the same potential, and is electrically connected to the second valve plate group 1b. Further, as Figure 3 and 4As shown, a voltage-dividing capacitor C2 is further provided inside the arrester insulation core 23. The voltage-dividing capacitor C2 is composed of a group of multiple capacitor screens alternately arranged with the insulating layer. The voltage-dividing capacitor C2 is connected in parallel with the voltage-sharing capacitor C1. From the innermost first screen to the outermost last screen in the voltage-dividing capacitor C2, they are sequentially offset and sequentially nested along the axial direction of the valve plate assembly 21 from the first pressing end to the end of the second valve plate group 21b away from the elastic component 21c; the first screen of the voltage-dividing capacitor C2 shares the first screen with the voltage-sharing capacitor C1, at least one end capacitor screen of the voltage-dividing capacitor C2 shares at least one end capacitor screen with the voltage-sharing capacitor C1, and the end capacitor screens of the voltage-dividing capacitor C2 and the voltage-sharing capacitor C1 are grounded. Of course, the end capacitor screens of the voltage-dividing capacitor C2 and the voltage-sharing capacitor C1 can also be grounded separately. Further, as Figure 6 shown, two end capacitor screens of the voltage-dividing capacitor C2 share two end capacitor screens with the voltage-sharing capacitor C1.

[0077] A preferred solution is that the arrester insulation core 23 uses glass fiber impregnated with epoxy resin as the insulating layer and a semi-conductive tape or a metal tape as the capacitor screen, and the insulating core is formed by alternately winding the insulating layer and the capacitor screen. The arrester insulation core 23 can also be formed by sequentially nesting and pouring a group of cylindrical capacitor screens.

[0078] Preferably, as Figure 4 shown, the arrester main body 20 further includes a first flange 25. The first flange 25 is sleeved in the middle of the arrester insulation core 23 and fixedly connected thereto, and the first flange 25 is fixedly connected and sealed with the metal shell. Of course, a flange cooperating with the first flange 25 is provided on the metal shell, and the two are sealed and matched. Further, as Figure 4 shown, the first flange 25 is located outside the end of the elastic component 21c connected to the second valve plate group 21b.

[0079] Preferably, as Figure 3 and 4 shown, the arrester main body 20 further includes a first terminal 22a and a second terminal 22b respectively arranged at both ends thereof. The first terminal 22a cooperates with the elastic component 21c to press the first valve plate group 21a, and the first terminal 22a is electrically connected to the first valve plate group 21a. The second terminal 22b cooperates with the elastic component 22b to press the second valve plate group 21b, and the second terminal 22b is electrically connected to the second valve plate group 21b. Further, the end capacitor screens of the valve plate assembly 21, the voltage-sharing capacitor C1, and the voltage-dividing capacitor C2 are all grounded through the second terminal 22b.

[0080] Preferably, as Figure 3 and 4As shown, the first valve plate group 21a is composed of a plurality of valve plates stacked in sequence between the first terminal 22a and the elastic component 21c, and the second valve plate group 21b is composed of a plurality of valve plates stacked in sequence between the second terminal 22b and the elastic component 21c. Further, the valve plate is a zinc oxide valve plate. For the lightning arrester of the present invention, by adjusting the number of valve plates constituting the first valve plate group 21a and the number of valve plates constituting the second valve plate group 21b, the voltage division ratio of the first valve plate group 21a and the second valve plate group 21b can be adjusted, so that the lightning arrester of the present invention can be applied to more application conditions or scenarios, greatly improving the versatility of the lightning arrester of the present invention.

[0081] Preferably, as Figure 7 shown, the elastic component 21c includes a compression spring 211c and a voltage equalizing terminal 210c, and both ends of the compression spring 211c are connected to a voltage equalizing terminal 210c respectively. Further, as Figure 7 shown, the axial cross-section of the voltage equalizing terminal 210c is a T-shaped structure. The voltage equalizing terminal 210c includes a connecting platform and a pressing platform, both of which are cylindrical structures. The diameter of the pressing platform is larger than that of the connecting platform and they are coaxial. The connecting platform is inserted into the middle of the compression spring 211c, and the pressing platform is respectively matched with the first valve plate group 21a and the second valve plate group 21b. Further, the compression spring 211c is made of metal, and the voltage equalizing terminal 210c is made of metal or made of zinc oxide.

[0082] Specifically, as Figures 3-8As shown, the first terminal 22a and the second terminal 22b are respectively arranged at the upper and lower ends of the valve plate assembly 21. The first valve plate group 21a and the second valve plate group 21b are respectively located in the upper and lower parts of the valve plate assembly 21. The elastic component 21c is located between the first valve plate group 21a and the second valve plate group 21b. The upper end of the elastic component 21c is the first pressing end, which cooperates with the first terminal 22a to press the first valve plate group 21a tightly. The lower end of the elastic component 21c cooperates with the second terminal 22b to press the second valve plate group 21b tightly; the first flange 25 is arranged on the outer side of the middle part of the arrester insulating core 23 and is located on the outer side of the lower end of the elastic component 21c; from the first screen to the last screen of the grading capacitor C1, along the axial direction of the valve plate assembly 21, from the upper end of the elastic component 21c to the lower end of the second valve plate group 21b, they are offset in sequence and sleeved in sequence (that is, in two adjacent capacitor screens, the outer capacitor screen is offset downward by a certain distance compared with the inner capacitor screen, and then the upper end of the outer capacitor screen is sleeved with the lower end of the inner capacitor screen, and an insulating layer is provided between the two adjacent capacitor screens); from the first screen to the last screen of the grading capacitor C1, along the radial direction of the valve plate assembly 21, the diameter of the capacitor screen gradually becomes larger from the inside to the outside; from the first screen to the last screen of the voltage-sharing capacitor C2, along the axial direction of the valve plate assembly 21, from the upper end of the elastic component 21c to the lower end of the second valve plate group 21b, they are offset downward in sequence and sleeved in sequence (that is, in two adjacent capacitor screens, the outer capacitor screen is offset downward by a certain distance compared with the inner capacitor screen, and then the upper end of the outer capacitor screen is sleeved with the lower end of the inner capacitor screen, and an insulating layer is provided between the two adjacent capacitor screens). Since the voltage-sharing capacitor C2 and the grading capacitor C1 share two end capacitor screens, the two end capacitor screens of the voltage-sharing capacitor C2 are offset to the lower end of the second valve plate group 21b; from the first screen to the last screen of the voltage-sharing capacitor C2, along the radial direction of the valve plate assembly 1, the diameter of the capacitor screen gradually becomes larger from the inside to the outside.

[0083] Preferably, the second terminal 2b is connected to a counter for calculating the lightning strike times.

[0084] When the arrester of this embodiment is applied to the micro GIS combined electrical apparatus of the present invention, the part of the arrester body 20 of the arrester 2 above the first flange 25 is completely inserted into the metal shell, and insulation is achieved through the insulating gas (SF6 gas or a mixed gas containing SF6) in the metal shell. The first flange 25 is fixedly connected and sealed with the metal shell at the same time. The part below the first flange 25 protrudes outside the metal shell, and insulation is achieved through the arrester insulating core 23, the grading capacitor C1, and the voltage-sharing capacitor C2.

[0085] As Figures 3-8 As shown, it is the second embodiment of the arrester 2. The arrester 2 is a plug-in dry-type arrester.

[0086] The difference between this embodiment and the first embodiment of the lightning arrester 2 lies in that: the lightning arrester 2 further includes an insulating female head 27 that is separately arranged from the lightning arrester body 20. The insulating female head 27 includes a female head cylinder body 270, a contact assembly 272 and a second flange 271 that are respectively arranged at both ends of the female head cylinder body 270. The contact assembly 272 seals one end of the female head cylinder body 270 and is electrically connected to the first busbar. The insulating female head 27 is inserted into the metal housing. The second flange 271 is fixedly connected and sealingly fitted with the metal housing. One end of the first valve plate group 21a provided in the lightning arrester insulating core 23 is inserted into the insulating female head 27. The contact assembly 272 is fixedly connected to the first terminal 22a, and the second flange 271 is fitted with the first flange 25. Further, as Figure 8 shown, the contact assembly 272 includes a contact seat 2720 connected to one end of the female head cylinder body 270 and a contact 2721 arranged in the middle of the contact seat 2720. A contact slot 27210 is provided in the middle of the contact 2721. The first terminal 22a is inserted into the contact slot 27210 and is electrically connected to it.

[0087] Preferably, the lightning arrester 2 further includes a silicone rubber sheath 26. The silicone rubber sheath 26 is sleeved outside one end of the first insulator 23 and is located between the lightning arrester insulating core 23 and the female head cylinder body 270. Both ends of the silicone rubber sheath 26 are respectively close to the first terminal 22a and the first flange 25. Further, the inner and outer sides of the silicone rubber sheath 26 are respectively in close contact with the lightning arrester insulating core 23 and the female head cylinder body 270. Further, the axial interface of the side wall of the silicone rubber sheath 26 is a right trapezoid structure. The two bottom sides of the right trapezoid respectively correspond to both ends of the silicone rubber sheath 26, and the oblique waist and the right waist of the right trapezoid respectively correspond to the outer side and the inner side of the silicone rubber sheath 26. Further, the thickness of the side wall of one end of the silicone rubber sheath 26 close to the first terminal 22a < the thickness of the side wall of one end of the silicone rubber sheath 26 close to the first flange 25.

[0088] Combined with Figures 2-3As shown in FIGS. 8, when the lightning arrester 2 of this embodiment is applied to a miniature GIS combined electrical apparatus, the insulating female head 27 is inserted into the metal housing, such that the contact assembly 272 is located inside the metal housing. The second flange 271 is fixedly connected to and sealingly fitted with the metal housing. One end of the lightning arrester main body 20 provided with the first terminal 22a is inserted into the insulating female head 27. The silicone rubber sheath 26 is sleeved on one end of the lightning arrester main body 20 between the insulating female head 27 and the lightning arrester main body 20, and the inner and outer sides of the silicone rubber sheath 26 are closely attached to the insulating female head 27 and the lightning arrester main body 20 respectively. The first terminal 22a is inserted and fitted with and electrically connected to the contact assembly 272. The first flange 25 of the lightning arrester main body 20 is fixedly connected to the second flange 270. When maintenance or replacement of the lightning arrester main body 20 is required, it is only necessary to disassemble the lightning arrester main body 20 from the insulating female head 27, which will not cause leakage of the insulating gas inside the metal housing, and avoid the situation of repeatedly filling the gas due to leakage of the gas inside the metal housing caused by disassembly or replacement of the lightning arrester 2. On the one hand, it is beneficial to save costs, and on the other hand, it improves the operation efficiency; moreover, the silicone rubber sheath 26 is beneficial to further improve the insulation performance of the lightning arrester 2.

[0089] Preferably, for the third embodiment of the lightning arrester 2, as Figure 3 shown, the lightning arrester 2 includes a lightning arrester main body 20. The lightning arrester main body 20 includes a valve plate assembly 21 and a lightning arrester insulating core 23 wrapped outside the valve plate assembly 21. The valve plate assembly 21 includes a plurality of stacked valve plates. An elastic assembly is provided at at least one end of the valve plate assembly 21 to press the valve plates. The difference from the first embodiment of the lightning arrester is that only one valve plate group is provided, and the elastic assembly 21 inside the valve plate is not provided.

[0090] The above content is a further detailed description of the present invention and creation in combination with specific preferred implementation manners. It cannot be determined that the specific implementation of the present invention and creation is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention and creation pertain, without departing from the concept of the present invention and creation, several simple deductions or replacements can still be made, which should all be regarded as belonging to the protection scope of the present invention and creation.

Claims

1. A miniature GIS combined electrical apparatus, comprising a lightning arrester (2), a circuit breaker (4), an operating mechanism (5) and a metal enclosure. The circuit breaker (4) is arranged inside the metal enclosure filled with insulating gas. The operating mechanism (5) is drivingly connected to the circuit breaker (4) to drive the circuit breaker (4) to close / open. Both ends of the metal enclosure are connected with bushings (1) or cable terminal heads. The bushings (1) or cable terminal heads at both ends are electrically connected to the circuit breaker (4) through a busbar enclosed in the metal enclosure. The lightning arrester (2) is connected to the busbar. Characterized in that: The bushing (1) or cable terminal head comprises an insulating core body. A main insulation capacitor C1a and a voltage-dividing capacitor C2a connected in series with the main insulation capacitor C1a are embedded in the insulating core body. The main insulation capacitor C1a is composed of a group of capacitor screens with gradually increasing diameters and arranged alternately with insulating layers. The voltage-dividing capacitor C2a is composed of a group of capacitor screens arranged outside the capacitor screen on the outermost side of the main insulation capacitor C1a, or the voltage-dividing capacitor C2a is a capacitor tap of the main insulation capacitor C1a. The main insulation capacitor C1a and the voltage-dividing capacitor C2a form a capacitive voltage divider. One end of the voltage-dividing capacitor C2a connected to the main insulation capacitor C1a is the signal output end. The bushing (1) or cable terminal head further comprises a current transformer CT arranged thereon.

2. The miniature GIS combined electrical apparatus according to claim 1, Characterized in that: It further comprises a disconnector, and the disconnector is also arranged inside the metal enclosure and is connected between the circuit breaker (4) and the bushing (1) or cable terminal head at one end of the miniature GIS combined electrical apparatus.

3. The miniature GIS combined electrical apparatus according to claim 1, Characterized in that: The current transformer CT comprises an iron core coil or a hollow coil sleeved outside the insulating core body.

4. The miniature GIS combined electrical apparatus according to claim 1, Characterized in that: A shielding capacitor C3a is further embedded in the insulating core body. The shielding capacitor C3a is composed of a group of mutually insulated and mutually nested capacitor screens wound or laid along the axial direction of the insulating core body from the high-voltage end to the low-voltage end of the shielding capacitor C3a outside the capacitor screens of the corresponding main insulation capacitor C1a.

5. The miniature GIS combined electrical apparatus according to claim 4, Characterized in that: A signal acquisition capacitor C4a connected in series with the shielding capacitor C3a is further embedded in the insulating core body. The signal acquisition capacitor C4a is composed of a group of capacitor screens wound outside the capacitor screen on the outermost side of the shielding capacitor C3a, or the signal acquisition capacitor C4a is a capacitor tap of the shielding capacitor C3a. One end of the signal acquisition capacitor C4a connected to the shielding capacitor C3a is the signal output end, and the output signal can replace that of the current transformer CT. The other end of the signal acquisition capacitor C4a is grounded.

6. The miniature GIS combined electrical apparatus according to claim 1, Characterized in that: The insulating core body uses glass fiber impregnated with epoxy resin as the insulating layer and a semi-conductive tape or a metal tape as the capacitor screen, and the insulating core body is formed by alternately winding the insulating layer and the capacitor screen.

7. The miniature GIS combined electrical apparatus according to claim 4 or 5, Characterized in that: At least one end of the micro GIS combined electrical apparatus is provided with a bushing (1), and one end of the bushing (1) is detachably connected to the metal shell.

8. The micro GIS combined electrical apparatus according to claim 7, characterized in that: The bushing (1) further includes an upper flange (12) and a lower flange (13) respectively arranged at both ends of the insulating core, an incoming line terminal (10) arranged at one end of the upper flange (12) and electrically connected to one end of the conductor (1a), and an outgoing line terminal (11) arranged at one end of the lower flange (13) and electrically connected to the other end of the conductor (1a). An installation flange (15) is sleeved outside the middle of the insulating core; the capacitive screen of the shielding capacitor C3a is axially arranged from one end of the upper flange (12) to the grounding end of the installation flange (15) outside the capacitive screen of the corresponding main insulation capacitor C1a, and they are insulated from each other and overlapped with each other.

9. The micro GIS combined electrical apparatus according to claim 5, characterized in that: An installation flange (15) is sleeved outside the middle of the insulating core, and a first signal interface and a second signal interface are arranged on the installation flange (15); the innermost first capacitive screen of the main insulation capacitor C1a is electrically connected to the conductor (1a) to be equipotential, and the signal output end between the main insulation capacitor C1a and the voltage dividing capacitor C2a is connected to the first signal interface, and the signal output end between the shielding capacitor C3a and the signal acquisition capacitor C4a is connected to the second signal interface.

10. The micro GIS combined electrical apparatus according to claim 8, characterized in that: The bushing (1) further includes a split installation female head, and the installation female head includes a second female head cylinder body, a second contact assembly arranged at one end of the second female head cylinder body to seal it, and a third flange arranged at the other end of the second female head cylinder body and fixedly connected to the metal shell. The third flange is in sealing cooperation with the metal shell; one end of the bushing (1) provided with the lower flange (13) is inserted into the installation female head, the installation flange (15) is fixedly connected to the third flange, and the outgoing line terminal (11) is in cooperation with and electrically connected to the second contact assembly.

11. The micro GIS combined electrical apparatus according to claim 1, characterized in that: One end of the lightning arrester (2) connected to the first bus is in plug-in cooperation with the metal shell, and the other end of the lightning arrester (2) protrudes outside the metal shell.

12. The micro GIS combined electrical apparatus according to claim 11, characterized in that: The lightning arrester (2) includes a lightning arrester main body (20), and the lightning arrester main body (20) includes a valve plate assembly (21) and a lightning arrester insulating core (23) wrapped outside the valve plate assembly (21); the valve plate assembly (21) includes a first valve plate group (21a), a second valve plate group (21b), and an elastic component (21c) arranged between the first valve plate group (21a) and the second valve plate group (21b); one end of the lightning arrester (2) is inserted into the metal shell, so that the first valve plate group (21a) is completely placed inside the metal shell, and the first valve plate group (21a) is electrically connected to the first bus.

13. The micro GIS combined electrical apparatus according to claim 12, characterized in that: A grading capacitor C1 is provided at a position corresponding to the elastic component (21c) and the second varistor group (21b) inside the arrester insulating core (23). The grading capacitor C1 consists of a group of capacitor screens alternately arranged with insulating layers. The innermost first screen of the grading capacitor C1 is electrically connected to the varistor component (21), and the outermost last screen is grounded.

14. The miniature GIS combined electrical apparatus according to claim 13, characterized in that: The arrester (2) further includes a first flange (25) sleeved on the middle part of the arrester insulating core (23) and fixedly connected thereto. The first flange (25) is fixedly connected and hermetically fitted with the metal shell.

15. The miniature GIS combined electrical apparatus according to claim 13, characterized in that: The arrester main body (20) further includes a first terminal (22a) and a second terminal (22b) respectively provided at both ends thereof, and a first flange (25) sleeved on the middle part of the arrester insulating core (23) and fixedly connected thereto; the first terminal (22a) is located at one end of the first varistor group (21a) and connected thereto, and the first terminal (22a) cooperates with the elastic component (21c) to press the first varistor group (21a) tightly. The second terminal (22b) is located at one end of the second varistor group (21b) and connected thereto, and the second terminal (22b) cooperates with the elastic component (21c) to press the second varistor group (21b) tightly; the arrester (2) further includes an insulating female head (27) separately arranged from the arrester main body (20). The insulating female head (27) includes a female head cylinder body (270) and a contact component (272) and a second flange (271) respectively provided at both ends of the female head cylinder body (270). The contact component (272) seals one end of the female head cylinder body (270) and is electrically connected to the first busbar. The insulating female head (27) is inserted into the metal shell. The second flange (271) is fixedly connected and hermetically fitted with the metal shell. One end of the insulating core (3) is inserted into the insulating female head (27). The first terminal (22a) is inserted and cooperated with the contact component (272), and the second flange (271) is fixedly connected to the first flange (25).

16. The miniature GIS combined electrical apparatus according to claim 15, characterized in that: The arrester (2) further includes a silicone rubber sheath (26) sleeved outside one end of the arrester insulating core (23), located between the insulating female head (27) and the arrester insulating core (23). Both ends of the silicone rubber sheath (26) are respectively close to the first terminal (22a) and the first flange (25).

17. The miniature GIS combined electrical apparatus according to claim 13, characterized in that: One end of the elastic component (21c) cooperating with the first valve plate group (21a) is the first pressing end. From the innermost first screen to the outermost last screen in the grading capacitor C1, they are sequentially offset and sequentially nested along the axial direction of the valve plate component (21) from the first pressing end to the end of the second valve plate group (21b) away from the elastic component (21c); a grading capacitor C2 is further provided in the arrester insulating core (23). The grading capacitor C2 is composed of a group of capacitor screens alternately arranged with an insulating layer outside the outermost last screen of the grading capacitor C1. The grading capacitor C2 is connected in parallel with the grading capacitor C1. From the innermost first screen to the outermost last screen in the grading capacitor C2, they are sequentially offset and sequentially nested along the axial direction of the valve plate component (21) from the first pressing end to the end of the second valve plate group (21b) away from the elastic component (21c); the first screen of the grading capacitor C2 shares the first screen of the grading capacitor C1, and at least one end capacitor screen of the grading capacitor C2 shares at least one end capacitor screen of the grading capacitor C1.

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