CN111641110A

CN111641110A - Pseudo spark switch

Info

Publication number: CN111641110A
Application number: CN202010630490.9A
Authority: CN
Inventors: 李建北; 董攀; 黄刚; 陈宇航; 陈欣; 陈弹蛋; 向军; 李天涛; 刘平; 彭宇飞; 龙继东; 李�杰
Original assignee: Institute of Fluid Physics of CAEP
Current assignee: Institute of Fluid Physics of CAEP
Priority date: 2020-07-03
Filing date: 2020-07-03
Publication date: 2020-09-08

Abstract

The invention discloses a pseudo spark switch, which comprises a pseudo spark switch body, wherein the pseudo spark switch body comprises a cathode sealing piece, an insulating shell, a hollow cathode, a hollow anode and an anode sealing piece, and further comprises a trigger electrode, an insulator, a trigger power supply and a discharge circuit, so that the pseudo spark switch is triggered to work through the discharge of the discharge circuit, the working efficiency of the pseudo spark switch is improved, and the pseudo spark switch can be suitable for a working scene with high time requirement.

Description

Pseudo spark switch

Technical Field

The invention relates to the technical field of gas discharge switches, in particular to a pseudo spark switch.

Background

A pseudo spark switch is a gas discharge switch operating on the left side of the paschen curve and having internal gas pressures on the order of tens of pascals, similar to a hydrogen thyristor. The cathode and the anode of the pseudo spark switch are both of hollow structures and work in a hollow cathode effect state. When the hollow cathode discharges, the plasma inside the pseudo spark switch forms a virtual anode under the action of the hollow cathode. A cathode sheath layer is formed between the virtual anode and the hollow cathode, the electric field in the cathode sheath layer is very strong, and after electrons obtain energy in the cathode sheath layer, the electrons collide with gas molecules to form high-density plasma, so that the working current of the pseudo-spark switch can reach 200 kA. When the working current is reversed, the hollow anode of the pseudo spark switch is changed into a hollow cathode, and the reverse current passing capacity can reach 90% of the working current under the hollow cathode effect state, so that the pseudo spark switch is widely applied to the technical field of high-power pulse. The existing pseudo spark switch is generally provided with a hydrogen storage device which is used for adjusting the working state of the pseudo spark switch, but the hydrogen storage device needs to be heated by an external power supply for about 5 minutes before releasing hydrogen, so that the efficiency is influenced, and the pseudo spark switch is not suitable for certain working scenes with high requirements on time response.

Disclosure of Invention

The technical problem to be solved by the invention is that the existing pseudo spark switch is not suitable for some scenes with high time requirement because the hydrogen storage device needs to be preheated for about 5 minutes before being used, and the efficiency is influenced, so that the pseudo spark switch without the hydrogen storage device is provided, and the pseudo spark switch can be suitable for working scenes with high time response requirement by directly filling inert gas in the pseudo spark switch to save hydrogen heating time.

The invention is realized by the following technical scheme:

a pseudo spark switch comprises a pseudo spark switch body, wherein the pseudo spark switch body comprises a cathode sealing piece, an insulating shell, a hollow cathode, a hollow anode and an anode sealing piece, and the pseudo spark switch also comprises a trigger electrode, an insulator, a trigger power supply and a discharge circuit;

one end of the insulating shell is connected with an anode sealing piece, the other end of the insulating shell is connected with a cathode sealing piece, the insulating shell, the anode sealing piece and the cathode sealing piece form a closed cavity, and inert gas is filled in the closed cavity; in the closed cavity, the anode sealing piece is connected with the hollow anode, the cathode sealing piece is connected with the hollow cathode, the cathode sealing piece, the insulator and the trigger electrode are sequentially arranged from outside to inside, and one surface of the trigger electrode, which is close to the anode sealing piece, of the insulator is superposed; the trigger electrode is connected with one end of the trigger power supply, the other end of the trigger power supply is connected with the cathode feed connector of the discharge circuit, the anode feed connector of the discharge circuit is connected with the anode sealing piece, the cathode feed connector of the discharge circuit is connected with the cathode sealing piece, and the cathode sealing piece is grounded.

Further, the discharge circuit comprises a charging power supply, a diode, a high-voltage capacitor and a charging current-limiting resistor;

the anode of the charging power supply is connected with the anode of the diode, and the cathode of the diode is connected with one end of the high-voltage capacitor and then is used as an anode feed joint of the discharging circuit; and the negative electrode of the charging power supply is connected with one end of the charging current-limiting resistor, and the other end of the charging current-limiting resistor is connected with the other end of the high-voltage capacitor and then used as a cathode feed joint of the discharge circuit.

Further, the upper surface of the insulator is plated with a layer of metal film, and the metal film is made of a material of which the conductivity reaches a preset value in the working state of the pseudo spark switch.

Further, the thickness of the metal film is 100-300 nm.

Further, the insulating shell is made of ceramic materials.

Furthermore, the cathode sealing piece and the anode sealing piece are made of kovar alloy.

Further, WCu alloy materials are adopted for the hollow cathode and the hollow anode.

Further, the inert gas in the closed cavity is Ne gas.

Further, the anode feed connector and the cathode feed connector are both of a coaxial structure.

Further, the pseudo spark switch is a cylinder, the length of the cylinder is 45mm-55mm, and the diameter of the cylinder is 35mm-45 mm.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the hydrogen storage device is removed, the pseudo spark switch works by discharging through the discharging circuit, and the hydrogen heating time is saved, so that the pseudo spark switch can be suitable for a working scene with high time response requirement; the size of the pseudo spark switch can be effectively reduced by removing the hydrogen storage device.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

fig. 1 is a schematic structural diagram of a pseudo spark switch according to the present invention.

Fig. 2 is a schematic diagram of the improved pseudo spark switch body structure of the present invention.

Reference numbers and corresponding part names in the drawings:

1-trigger electrode, 2-insulator, 3-cathode sealing piece, 4-insulating shell, 5-hollow cathode, 6-hollow anode, 7-anode sealing piece, 8-metal film, 9-anode feed connector, 10-cathode feed connector and 11-trigger power supply.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Examples

As shown in fig. 1, the invention provides a pseudo spark switch, which comprises a pseudo spark switch body, wherein the pseudo spark switch body comprises a cathode sealing member 3, an insulating shell 4, a hollow cathode 5, a hollow anode 6 and an anode sealing member 7, and further comprises a trigger electrode 1, an insulator 2, a trigger power supply 11 and a discharge circuit.

One end of the insulating shell 4 is connected with an anode sealing member 7, the other end of the insulating shell is connected with a cathode sealing member 3, the insulating shell 4, the anode sealing member 7 and the cathode sealing member 3 form a closed cavity, and inert gas is filled in the closed cavity; in the sealed cavity, an anode sealing piece 7 is connected with a hollow anode 6, a cathode sealing piece 3 is connected with a hollow cathode 5, the cathode sealing piece 3, an insulator 2 and a trigger electrode 1 are sequentially arranged from outside to inside, and the trigger electrode 1 is superposed with one surface of the insulator 2 close to the anode sealing piece 7; the trigger electrode 1 is connected with one end of a trigger power supply 11, the other end of the trigger power supply 11 is connected with a cathode feed connector of a discharge circuit, an anode feed connector of the discharge circuit is connected with an anode sealing member 7, a cathode feed connector 10 of the discharge circuit is connected with a cathode sealing member 3, and the cathode sealing member 3 is grounded.

Specifically, the cathode sealing piece 3, the insulator 2 and the trigger electrode 1 are sequentially arranged from outside to inside, the distance between the trigger electrode 1 and the cathode sealing piece 3 is 0.5mm, and the trigger electrode 1 and the insulator 2 are overlapped on one surface close to the anode sealing piece 7, so that the working voltage required by the pseudo spark switch is lower, and the reliability of the pseudo spark switch in the triggering process is improved.

When the trigger power supply 11 is closed, the trigger discharge circuit discharges, the trigger electrode 1 and the hollow cathode 5 generate breakdown discharge under the voltage provided by the trigger power supply 11, and plasma is generated in the hollow cathode 5. Electrons generated by the trigger electrode 1 through breakdown discharge move to the hollow anode 6 under the action of an electric field generated by the hollow cathode 5 and the hollow anode 6, the breakdown discharge occurs between the hollow cathode 5 and the hollow anode 6, the pseudo spark switch starts to work, and the trigger power supply is turned off. The trigger power source 11 in the present embodiment means a device for generating a negative pulse voltage signal.

Further, the discharge circuit comprises a charging power supply, a diode, a high-voltage capacitor and a charging current-limiting resistor.

The anode of the charging power supply is connected with the anode of the diode, and the cathode of the diode is connected with one end of the high-voltage capacitor and then serves as an anode feed joint 9 of the discharging circuit; the negative pole of the charging power supply is connected with one end of a charging current-limiting resistor, and the other end of the charging current-limiting resistor is connected with the other end of the high-voltage capacitor and then used as a cathode feed joint 10 of the discharging circuit.

The pseudo spark switch trigger voltage in this embodiment is 500V.

Specifically, the charging power supply charges the high voltage capacitor prior to using the pseudo spark switch. After charging is finished, the trigger power supply 11 is turned on, breakdown discharge occurs between the trigger electrode 1 and the hollow cathode 5, electrons generated by the breakdown discharge of the trigger electrode 1 move to the hollow anode 6 under the action of the hollow anode 6, plasma is generated by the hollow cathode 5, the pseudo spark switch starts to work under the action of the plasma, then the discharge is maintained by the high-voltage capacitor until the charge stored in the high-voltage capacitor is released, the discharge is finished, and the pseudo spark switch finishes working. The negative electrode of the trigger power supply 11 is connected with the trigger electrode 1, so that electrons generated by the trigger electrode 1 can be attracted by the anode more easily, the pseudo spark switch can be conducted more quickly, the conducting time is shortened, and the response speed of the pseudo spark switch is improved.

Further, the upper surface of the insulator 2 is plated with a metal film 8, and the metal film 8 is made of a material whose conductivity reaches a predetermined value in a state where the pseudo spark switch is operated.

The preset value is a preset value for judging that the conductivity of the metal film 8 needs to be satisfied in the working state of the pseudo spark switch. The preset value is a value close to the conductivity of the semiconductor, and the specific size can be determined by a user according to actual conditions. The metal film in the present embodiment includes, but is not limited to, materials with good conductivity such as Cu and Al.

Specifically, a layer of metal film 8 is plated on the upper surface of the insulator 2 to enhance the electric field near the hollow cathode 5, reduce the surface work function of the insulator 2, increase the electron emission probability, more easily initiate the discharge process, reduce the trigger voltage, and improve the reliability of the operation of the pseudo spark switch.

Further, the thickness of the metal thin film 8 is 100 to 300 nm.

Further, the insulating housing 4 is made of a ceramic material.

Further, kovar alloy is used for the cathode seal member 3 and the anode seal member 7.

Further, the hollow cathode 5 and the hollow anode 6 are made of WCu alloy material.

Specifically, the hollow cathode 5 and the hollow anode 6 are made of WCu alloy material to have both the characteristics of the refractory metal W and the heat conductive metal Cu.

Further, the inert gas in the closed cavity is Ne gas.

Further, the anode feed tab 9 and the cathode feed tab 10 are both coaxial structures.

Furthermore, the pseudo spark switch is a cylinder, the length of the cylinder is 45mm-55mm, and the diameter of the cylinder is 35mm-45 mm.

Specifically, the size of the pseudo spark switch can be made into a cylinder with the length of 45mm-55mm and the diameter of 35mm-45mm by removing the hydrogen storage device, so that the size of the pseudo spark switch is effectively reduced.

By closing the trigger power supply, breakdown discharge occurs between the trigger electrode and the hollow cathode in the pseudo spark switch, the hollow cathode generates plasma, the pseudo spark switch is triggered to work under the action of the plasma, and discharge is carried out through the discharge circuit. The pseudo spark switch is filled with inert gas, a hydrogen storage device is not needed to be used for generating gas for the pseudo spark switch to work, the hydrogen heating time is saved, the working efficiency is improved, and the pseudo spark switch can be suitable for working scenes with high time requirements. In addition, the volume of the pseudo spark switch can be effectively reduced by removing the hydrogen storage device; the cathode sealing member, the insulator and the trigger electrode are sequentially arranged from outside to inside, the trigger electrode is overlapped with one surface of the insulator, which is close to the anode sealing member, to form a surface-following trigger mode, and a layer of metal film is plated on the upper surface of the insulator, so that the trigger voltage of the pseudo-spark switch is reduced, and the working reliability of the pseudo-spark switch is improved.

In particular, the above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A pseudo spark switch comprises a pseudo spark switch body, wherein the pseudo spark switch body comprises a cathode sealing piece (3), an insulating shell (4), a hollow cathode (5), a hollow anode (6) and an anode sealing piece (7), and is characterized by further comprising a trigger electrode (1), an insulator (2), a trigger power supply (11) and a discharge circuit;

one end of the insulating shell (4) is connected with an anode sealing piece (7), the other end of the insulating shell is connected with a cathode sealing piece (3), the insulating shell (4), the anode sealing piece (7) and the cathode sealing piece (3) form a closed cavity, and inert gas is filled in the closed cavity; in the closed cavity, the anode sealing piece (7) is connected with the hollow anode (6), the cathode sealing piece (3) is connected with the hollow cathode (5), the cathode sealing piece (3), the insulator (2) and the trigger electrode (1) are sequentially arranged from outside to inside, and the trigger electrode (1) and one surface, close to the anode sealing piece (7), of the insulator (2) are overlapped; the trigger electrode (1) is connected with one end of the trigger power supply (11), the other end of the trigger power supply (11) is connected with a cathode feed connector (10) of the discharge circuit, an anode feed connector (9) of the discharge circuit is connected with the anode sealing piece (7), the cathode feed connector (10) of the discharge circuit is connected with the cathode sealing piece (3), and the cathode sealing piece (3) is grounded.

2. A pseudo-spark switch as claimed in claim 1 wherein said discharge circuit includes a charging source, a diode, a high voltage capacitor and a charging current limiting resistor;

the anode of the charging power supply is connected with the anode of the diode, and the cathode of the diode is connected with one end of the high-voltage capacitor and then is used as an anode feed joint (9) of the discharging circuit; and the negative electrode of the charging power supply is connected with one end of the charging current-limiting resistor, and the other end of the charging current-limiting resistor is connected with the other end of the high-voltage capacitor and then is used as a cathode feed joint (10) of the discharging circuit.

3. A switch according to claim 1, wherein the insulator (2) is coated on its upper surface with a metal film (8), said metal film (8) being made of a material having an electrical conductivity which reaches a predetermined value in an operating state of said switch.

4. A pseudo-spark switch according to claim 3, wherein the thickness of said metal thin film (8) is 100 to 300 nm.

5. A pseudo-spark switch according to claim 1, wherein said insulating housing (4) is made of a ceramic material.

6. A switch according to claim 1, characterised in that the cathode seal (3) and the anode seal (7) are made of kovar.

7. A pseudo-spark switch according to claim 1, wherein said hollow cathode (5) and said hollow anode (6) are made of WCu alloy material.

8. A pseudo-spark switch as claimed in claim 1, wherein the inert gas in said closed chamber is Ne gas.

9. A pseudo-spark switch according to claim 1, wherein the anode feed connection (9) and the cathode feed connection (10) are of coaxial construction.

10. A pseudo-spark switch as claimed in claim 1, wherein said pseudo-spark switch is a cylinder, said cylinder having a length of 45mm-55mm and a diameter of 35mm-45 mm.