Low-jitter and low-self-discharge probability gas switch and method for reducing self-discharge probability of low-jitter and low-self-discharge probability gas switch

Abstract

The invention relates to a gas switch, in particular to a low-jitter and low-self-discharge-probability gas switch and a method for reducing the self-discharge probability of the gas switch, and solves the technical problem that the self-discharge probability of the gas switch is difficult to reduce below 0.01% under the condition that an electrode of an existing gas switch keeps jittering and the service life is not reduced. The inner edges and the outer edges of the discharge parts at the large ends of the upper electrode and the lower electrode of the low-jitter and low-self-discharge-probability gas switch are provided with the chamfers, so that the distortion degree of an electric field is improved, the triggering performance of the gas switch is improved, and meanwhile, the discharge parts of the upper electrode and the lower electrode are provided with the circular grooves, so that the discharge area is reduced, and the self-discharge probability of the gas switch is reduced. According to the method for reducing the self-discharge probability of the gas switch with low jitter and low self-discharge probability, the self-discharge probability of the gas switch can be reduced to below 0.01% under the condition that jitter is kept and the service life is not reduced, and the use requirement of a large Marx generator device is met.

Description

Technical Field

[0001] The present invention relates to a gas switch, and particularly to a gas switch with low jitter and low self-discharge probability and a method for reducing the self-discharge probability thereof. Background Art

[0002] High-power gas switches are widely used in primary pulse sources. They have characteristics such as high working voltage, strong current-carrying capacity, and large charge transfer. They are key devices for generating initial electrical pulses and play a decisive role in energy utilization efficiency, power amplification factor, and waveform regulation. The Marx generator device is a common primary pulse source and is widely used in large pulsed power devices. A large Marx generator device contains hundreds or even thousands of gas switches. It is required that the gas switches be charged to the working voltage first and then triggered to discharge. The system self-discharge probability during the charging process increases rapidly with the increase in the number of gas switches. Therefore, the low self-discharge probability of gas switches is a prerequisite for the long-term stable operation of the Marx generator device. In addition, in order to meet the synchronization and stability requirements for the parallel operation of multiple Marx generator devices, very strict requirements are also imposed on the trigger jitter and service life of gas switches under low self-discharge probability.

[0003] Chinese Patent CN202011527159.0 discloses "a low-jitter and long-life three-electrode gas switch", which can meet the usage requirements of low jitter and long life of large Marx generator devices, but its self-discharge probability is relatively large, reaching 0.04%. It is difficult to reduce the self-discharge probability of existing gas switches to less than 0.01% while maintaining the jitter and service life unchanged. Summary of the Invention

[0004] The purpose of the present invention is to solve the technical problem that it is difficult to reduce the self-discharge probability of existing gas switch electrodes to less than 0.01% while maintaining the jitter and service life unchanged, and to provide a gas switch with low jitter and low self-discharge probability and a method for reducing the self-discharge probability thereof.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A gas switch with low jitter and low self-discharge probability, characterized in that it includes an insulating housing, an upper electrode, a lower electrode, a trigger electrode, a positioning block arranged in the insulating housing, and a plurality of gas nozzles;

[0007] The insulating housing is of a cuboid structure, including an upper side plate, a lower side plate, a front side plate, and a rear side plate; a left cover plate is arranged at its left end, and a right cover plate is arranged at its right end; mounting holes are respectively arranged on the upper side plate and the lower side plate for mounting electrode connectors; a connection hole is arranged on the left cover plate for mounting a trigger connector, and a plurality of gas nozzle mounting holes are arranged on the right cover plate;

[0008] Both the upper electrode and the lower electrode are stepped cylindrical structures, which are respectively arranged on the inner sides of the upper side plate and the lower side plate. The large ends of the two stepped cylinders are arranged parallel and opposite to each other, and the small ends are connected to the electrode connectors. The large ends of the stepped cylindrical structures are set as the discharge parts. The edge of the discharge part close to the small end is provided with a first chamfer, the edge of the end face of the discharge part is provided with an outer edge chamfer, and a groove is arranged at the center of the end face. The edge of the notch of the groove is provided with an inner edge chamfer.

[0009] There are two positioning blocks, which are relatively arranged on the inner sides of the left cover plate and the right cover plate, and support mounting holes are arranged on both opposite end faces.

[0010] The trigger electrode includes a wedge-shaped disc and two support bars. The wedge-shaped disc is located between the upper electrode and the lower electrode. The upper end face and the lower end face are both set as wedge-shaped surfaces that are recessed inward. A central through hole coaxial with the upper electrode and the lower electrode is arranged at the center. The diameter of the central through hole is smaller than the diameters of the upper electrode and the lower electrode, and larger than the diameter of the groove. One ends of the two support bars are symmetrically connected to both sides of the wedge-shaped disc along the radial direction, and the other ends are arranged in the corresponding support mounting holes. The inner edge of the wedge-shaped disc is provided with a second chamfer. In the axial section of the wedge-shaped disc, the included angle between the arc center of the second chamfer and the connection line between the inner edge chamfer and the outer edge chamfer of the corresponding upper electrode or lower electrode and the axis of the wedge-shaped disc is θ 1 , and the inclination angle of the wedge-shaped surface of the wedge-shaped disc is θ 2 , θ 2 = θ 1 ;

[0011] One end of the trigger connector is located outside the left cover plate, and the other end sequentially passes through the connection hole and the support mounting hole and is electrically connected to the support bar.

[0012] The air nozzle is arranged in the air nozzle mounting hole and is communicated with the inner cavity of the insulating housing through the support mounting hole on the positioning block to realize the inflation or deflation of the inner cavity of the insulating housing.

[0013] Further, the groove is a circular groove, which is used to increase the degree of electric field distortion.

[0014] Further, the outer edges of the small ends of the upper electrode and the lower electrode are provided with third chamfers.

[0015] Further, blind holes are arranged at the other ends of the support bars. The other end of the trigger connector sequentially passes through the connection hole and the support mounting hole and is inserted into the blind hole to be electrically connected to the support bar.

[0016] Further, the connection part between the wedge-shaped disc and one end of the support bar is set as an arc surface.

[0017] Further, the thickness of the thinnest part of the inner edge of the wedge-shaped disc is 2 mm, and the radius of the second chamfer is 0.5 mm; the materials of the upper electrode, the lower electrode, and the trigger electrode are all stainless steel or tungsten copper alloy.

[0018] Further, the distance between the discharge parts of the upper electrode and the lower electrode is 20 mm.

[0019] Meanwhile, the present invention also provides a method for reducing the self-discharge probability of the above-mentioned gas switch with low jitter and low self-discharge probability, which is characterized in that it includes the following steps:

[0020] 1. Simulate the upper electrode, the lower electrode, and the trigger electrode of the gas switch, and calculate the static electric field strength distribution under the working voltage condition;

[0021] 2. Keep the trigger electrode unchanged, adjust the outer edge chamfers of the discharge parts of the upper electrode and the lower electrode, calculate the static electric field strength distribution of the gas switch under the working voltage condition, analyze the degree of electric field distortion and the change in the discharge area, and according to the simulation results, take the chamfer size corresponding to the maximum degree of electric field distortion as the outer edge chamfer size of the discharge parts of the upper electrode and the lower electrode; the discharge area is the area where the surface electric field strength of the upper electrode and the lower electrode is greater than or equal to the average electric field strength;

[0022] 3. Keep the trigger electrode unchanged, simulate the grooves in the discharge parts of the upper electrode and the lower electrode, calculate the static electric field strength distribution of the gas switch under the working voltage condition, analyze the degree of electric field distortion and the change in the discharge area, and according to the simulation results, select the groove size corresponding to the maximum degree of electric field distortion and the minimum discharge area;

[0023] 4. Keep the trigger electrode unchanged, adjust the inner edge chamfers of the discharge parts of the upper electrode and the lower electrode, calculate the static electric field strength distribution of the gas switch under the working voltage condition, analyze the degree of electric field distortion and the change in the discharge area, and according to the simulation results, select the inner edge chamfer size corresponding to the maximum degree of electric field distortion and the minimum discharge area;

[0024] 5. Reduce the aperture of the central through hole of the trigger electrode, calculate the static electric field strength distribution of the gas switch under the working voltage condition, analyze the degree of electric field distortion and the change in the discharge area, and select the aperture of the central through hole of the trigger electrode corresponding to the maximum degree of electric field distortion;

[0025] 6. Judge whether the self-discharge probability of the gas switch is less than or equal to 0.01%. If so, complete the design of reducing the self-discharge probability of the gas switch; otherwise, repeat steps 2 to 5 until the self-discharge probability of the gas switch is reduced below 0.01%.

[0026] The beneficial effects of the present invention:

[0027] 1. A gas switch with low jitter and low self-discharge probability according to the present invention has chamfers provided at the inner and outer edges of the discharge parts at the large ends of the upper electrode and the lower electrode, which is beneficial to increasing the degree of electric field distortion and improving the triggering performance of the gas switch. At the same time, circular grooves are provided in the discharge parts of the upper electrode and the lower electrode, which is beneficial to reducing the discharge area and lowering the self-discharge probability of the gas switch to less than 0.01%.

[0028] 2. A gas switch with low jitter and low self-discharge probability according to the present invention has circular grooves provided in the discharge parts of the upper electrode and the lower electrode. A central through hole coaxial with the upper electrode and the lower electrode is provided at the center of the wedge-shaped disc of the trigger electrode. The diameter of the central through hole is smaller than the diameters of the upper electrode and the lower electrode, and larger than the diameter of the circular groove. When a pre-discharge occurs at the leading edge of the trigger pulse, the intense ultraviolet light emitted is beneficial to irradiating a larger area of the main discharge gap, generating a larger number of free electrons on the surfaces of the upper electrode and the lower electrode, and can effectively reduce the jitter of the trigger delay time.

[0029] 3. A gas switch with low jitter and low self-discharge probability according to the present invention has wedge-shaped surfaces that are recessed inwardly provided on both the upper and lower end surfaces of the wedge-shaped disc, which is beneficial to increasing the degree of electric field distortion during triggering and can improve the triggering performance of the gas switch.

[0030] 4. A gas switch with low jitter and low self-discharge probability according to the present invention, the included angle between the line connecting the chamfer center of the arc surface of the wedge-shaped disc and the inner and outer edge chamfer connection points of the large end end surfaces of the upper electrode and the lower electrode and the axis of the wedge-shaped disc is θ 1 , and the inclination angle of the wedge-shaped surface of the wedge-shaped disc is θ 2 . When θ 2 = θ 1 the degree of electric field distortion is increased.

[0031] 5. A gas switch with low jitter and low self-discharge probability according to the present invention has blind holes provided at the other ends of the support bars, making the connection between the other ends of the trigger connectors passing through the connection holes, support mounting holes and inserting into the blind holes and the support bars more stable.

[0032] 6. A method for reducing the self-discharge probability of a gas switch according to the present invention can reduce the self-discharge probability of the gas switch to less than 0.01% while maintaining the jitter and lifespan unchanged, meeting the usage requirements of large Marx generator devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic structural diagram of an embodiment of a gas switch with low jitter and low self-discharge probability according to the present invention;

[0034] Figure 2 is a cross-sectional view of an embodiment of a gas switch with low jitter and low self-discharge probability according to the present invention;

[0035] Figure 3Schematic diagram of the upper electrode in an embodiment of a gas switch with low jitter and low self-discharge probability according to the present invention;

[0036] Figure 4 Cross-sectional view of the upper electrode in an embodiment of a gas switch with low jitter and low self-discharge probability according to the present invention;

[0037] Figure 5 Schematic diagram of the trigger electrode in an embodiment of a gas switch with low jitter and low self-discharge probability according to the present invention;

[0038] Figure 6 is Figure 5 Cross-sectional view along A-A in

[0039] Figure 7 is Figure 5 Cross-sectional view along B-B in

[0040] Figure 8 Installation schematic diagram of the upper electrode and the trigger electrode in an embodiment of a gas switch with low jitter and low self-discharge probability according to the present invention;

[0041] Figure 9 Schematic diagram of the static maximum electric field intensity when the distance between the upper electrode and the lower electrode of the simulated gas switch is 20 mm, the diameter is 40 mm, the outer edge chamfer is R6, the thickness of the non-chamfered area is 5 mm, and the diameter of the central through hole of the trigger electrode is 40 mm;

[0042] Figure 10 Schematic diagram of the static maximum electric field intensity when the outer edge chamfers of the upper electrode and the lower electrode are adjusted to R10 and the thickness of the non-chamfered area is 1 mm in an embodiment of the present invention;

[0043] Figure 11 Schematic diagram of the static maximum electric field intensity when the outer edge chamfers of the upper electrode and the lower electrode are adjusted to R8 and the thickness of the non-chamfered area is 3 mm in an embodiment of the present invention;

[0044] Figure 12 Schematic diagram of the static maximum electric field intensity when the distance between the upper electrode and the lower electrode is adjusted to 24 mm, the outer edge chamfer is R6, and the thickness of the non-chamfered area is 3 mm in an embodiment of the present invention;

[0045] Figure 13 Schematic diagram of the static maximum electric field intensity when the outer edge chamfers of the upper electrode and the lower electrode are adjusted to R8, the thickness of the non-chamfered area is 3 mm, and a groove is provided in the discharge part in an embodiment of the present invention;

[0046] Figure 14 Schematic diagram of the static maximum electric field intensity when the outer edge chamfers of the upper electrode and the lower electrode are adjusted to R8, the inner edge chamfer is R3, and the thickness of the non-chamfered area is 3 mm in an embodiment of the present invention;

[0047] Figure 15 Schematic diagram of the static maximum field strength when the aperture of the central through-hole of the trigger electrode in the embodiment of the present invention is reduced to 32 mm;

[0048] Figure 16 Schematic diagram of the static maximum field strength when the aperture of the central through-hole of the trigger electrode in the embodiment of the present invention is reduced to 28 mm.

[0049] Description of the reference numerals:

[0050] 1 - Insulating housing, 11 - Upper side plate, 12 - Lower side plate, 13 - Front side plate, 14 - Rear side plate, 15 - Left cover plate, 16 - Right cover plate; 2 - Upper electrode, 21 - Discharge part, 3 - Lower electrode, 4 - Trigger electrode, 41 - Wedge-shaped disc, 42 - Central through-hole, 43 - Support bar, 44 - Blind hole, 5 - Positioning block, 6 - Gas nozzle mounting hole, 7 - Electrode connecting piece, 8 - Trigger connecting piece, 9 - Groove. Detailed implementation manners

[0051] As Figure 1 、 Figure 2 shown, a gas switch with low jitter and low self-discharge probability includes an insulating housing 1, an upper electrode 2, a lower electrode 3, a trigger electrode 4, a positioning block 5, and a plurality of gas nozzles arranged in the insulating housing 1; the insulating housing 1 is in a cuboid structure and includes an upper side plate 11, a lower side plate 12, a front side plate 13, and a rear side plate 14. A left cover plate 15 is provided at the left end of the insulating housing 1, and a right cover plate 16 is provided at the right end; mounting holes are respectively provided on the upper side plate 11 and the lower side plate 12 for mounting the electrode connecting piece 7; a connection hole is provided on the left cover plate 15 for mounting the trigger connecting piece 8, and a plurality of gas nozzle mounting holes 6 are provided on the right cover plate 16; there are two positioning blocks 5, which are oppositely arranged on the inner sides of the left cover plate 15 and the right cover plate 16, and support mounting holes are provided on both opposite end faces.

[0052] As Figure 3 、 Figure 4As shown, the upper electrode 2 and the lower electrode 3 are both stepped cylindrical structures, which are respectively arranged inside the upper side plate 11 and the lower side plate 12. The large ends of the two stepped cylinders are arranged parallel to each other, and the small ends are connected to the electrode connecting member 7. Third chamfers are provided on the outer edges of the small ends of the upper electrode 2 and the lower electrode 3 to shield the electric field intensity at the root triple junction points (i.e., the junction points of metal, air, and insulating medium) of the upper electrode 2 and the lower electrode 3, preventing surface flashover along the inner surface of the insulating housing 1. The large ends of the stepped cylindrical structures are set as the discharge parts 21. The edge of the discharge part 21 close to the small end is provided with a first chamfer, reducing the degree of distortion and preventing breakdown of the insulating housing 1. The outer edge chamfer is provided at the end face edge of the discharge part 21, which can increase the degree of electric field distortion and reduce the discharge area. A groove 9 is provided at the center of the end face of the discharge part 21, and an inner edge chamfer is provided at the edge of the groove opening of the groove 9. In this embodiment, the outer edge chamfer is connected to the inner edge chamfer. In other embodiments, there is a 0.2 mm transition section between the outer edge chamfer and the inner edge chamfer.

[0053] As Figure 5 , Figure 6 , Figure 7 shown, the trigger electrode 4 includes a wedge-shaped disc 41 and two support bars 43. The wedge-shaped disc 41 is located between the upper electrode 2 and the lower electrode 3. The upper end face and the lower end face are both set as wedge-shaped faces that are recessed inward, increasing the degree of electric field distortion. A central through hole 42 coaxial with the upper electrode 2 and the lower electrode 3 is provided at the center. The diameter of the central through hole 42 is smaller than the diameters of the upper electrode 2 and the lower electrode 3, and larger than the diameter of the groove 9, increasing the degree of electric field distortion. For the convenience of processing, one end of the two support bars 43 is symmetrically connected to both sides of the wedge-shaped disc 41 along the radial direction, and the connection part is set as an arc surface. The other end is provided with a blind hole 44 and is located in the corresponding support mounting hole.

[0054] As Figure 8 shown, the inner edge of the wedge-shaped disc 41 is provided with a second chamfer. In the axial section of the wedge-shaped disc 41, the included angle between the line connecting the arc center of the second chamfer and the connection part of the inner edge chamfer and the outer edge chamfer of the corresponding upper electrode 2 or lower electrode 3 and the axis of the wedge-shaped disc 41 is θ 1 , and the inclination angle of the wedge-shaped surface of the wedge-shaped disc 41 is θ 2 , θ 2 = θ 1 , increasing the degree of electric field distortion.

[0055] One end of the trigger connecting member 8 is located outside the left cover plate 15, and the other end sequentially passes through the connecting hole, the support mounting hole and is inserted into the blind hole 44 to be electrically connected to the support bar 43 for fixation. The air nozzle is arranged in the air nozzle mounting hole 6 and is communicated with the inner cavity of the insulating housing 1 through the support mounting hole on the positioning block 5 to realize inflation or deflation of the inner cavity of the insulating housing 1.

[0056] In this embodiment, the materials of the upper electrode 2 and the lower electrode 3 are stainless steel or tungsten copper alloy. The two electrode structures are the same, being stepped cylindrical and symmetrically arranged. The large-end diameter of the upper electrode 2 and the lower electrode 3 is 40 mm, the thickness is 14 mm, the diameter of the circular groove 9 is 17.6 mm, and the depth is 5 mm. The inner and outer chamfer radii of the discharge part 21 are 3 mm and 8 mm respectively, and the edge chamfer near the small end is 3 mm. The small-end diameter of the stepped cylindrical structure is 25 mm, the thickness is 3 mm, and the chamfer radius is 2 mm. The electrode connecting part 7 at the center position is 15 mm long.

[0057] The material of the trigger electrode 4 is stainless steel or tungsten copper alloy. The total length of the wedge-shaped disc 41 and the two support bars 43 is 260 mm. A blind hole 44 with a depth of 16 mm is opened at the center of one end of the support bar 43. One end of the trigger electrode 4 connecting part is inserted into this straight hole to connect with the support bar 43, and the other end is fixed and connected to the wedge-shaped disc 41 by screws. The core of the trigger electrode 4 is the middle wedge-shaped disc 41. The diameter of the wedge-shaped disc 41 is 68 mm, the inner ring diameter is 30 mm, the outer ring diameter is 56 mm. The transition between the wedge-shaped disc 41 and the support bar 43 is an arc with a radius of 40 mm. The thickness of the thinnest part of the wedge-shaped disc 41 is 2 mm, the second chamfer radius is 0.5 mm. When the aperture of the central through hole 42 is between 28 mm and 32 mm, θ 2 = θ 1 .

[0058] Through the gas switch trigger discharge characteristic experiment in this embodiment, it is obtained that: dry air is filled into the gas switch through the gas nozzle. Under the conditions of working voltage ±90 kV, trigger pulse amplitude 180 kV, working air pressure 7 bar, and undervoltage ratio 55%, the gas switch is triggered and discharged 10,000 times. The discharge jitter of the gas switch is only 1.0 ns, and no self-discharge phenomenon occurs, that is, the self-discharge probability is reduced to less than 0.01%.

[0059] A method for reducing the self-discharge probability of a gas switch, based on the above gas switch with low jitter and low self-discharge probability, is characterized by including the following steps:

[0060] 1] Simulate the upper electrode 2, lower electrode 3, and trigger electrode 4 of the gas switch, and calculate their static field strength distributions under the working voltage conditions;

[0061] 2] Keep the trigger electrode 4 unchanged, adjust the outer edge chamfers of the discharge parts 21 of the upper electrode 2 and the lower electrode 3, calculate the static field strength distributions of the gas switch under the working voltage conditions, analyze the degree of its electric field distortion and the change of the discharge area, and according to the simulation results, take the chamfer size corresponding to the maximum electric field distortion degree as the outer edge chamfer size of the discharge parts 21 of the upper electrode 2 and the lower electrode 3; the discharge area is the area where the surface field strength of the upper electrode 2 and the lower electrode 3 is greater than or equal to the average field strength;

[0062] Although increasing the edge chamfer of the outer edge of the discharge parts 21 of the upper electrode 2 and the lower electrode 3 can effectively reduce the maximum working electric field strength, the electric field strength in the central area of the gas switch increases due to the inward extension of the chamfer, resulting in an increase in the discharge area. Calculate the average field strength based on the distance between the upper electrode 2 and the lower electrode 3 and the working voltage of the gas switch, and take the area where the surface field strength of the upper electrode 2 and the lower electrode 3 is greater than or equal to the average field strength as the discharge area.

[0063] 3. Keep the trigger electrode 4 unchanged, simulate the groove 9 in the discharge parts 21 of the upper electrode 2 and the lower electrode 3, calculate the static field strength distribution of the gas switch under the working voltage condition, analyze the degree of electric field distortion and the change of the discharge area, and select the groove size corresponding to the maximum degree of electric field distortion and the minimum discharge area according to the simulation results.

[0064] The inward depression of the central area of the large-end discharge parts 21 of the upper electrode 2 and the lower electrode 3 will not affect the electric field strength in their working areas, but the electric field strength in the central area of the gas switch decreases, that is, the discharge area is effectively reduced.

[0065] 4. Keep the trigger electrode 4 unchanged, adjust the inner edge chamfer of the discharge parts 21 of the upper electrode 2 and the lower electrode 3, calculate the static field strength distribution of the gas switch under the working voltage condition, analyze the degree of electric field distortion and the change of the discharge area, and select the inner edge chamfer size corresponding to the maximum degree of electric field distortion and the minimum discharge area according to the simulation results.

[0066] 5. Reduce the aperture of the central through hole 42 of the trigger electrode 4, calculate the static field strength distribution of the gas switch under the working voltage condition, analyze the degree of electric field distortion and the change of the discharge area, and select the aperture of the central through hole 42 of the trigger electrode 4 with the maximum degree of electric field distortion; when the aperture of the trigger electrode 4 is smaller than the diameters of the upper electrode 2 and the lower electrode 3 and larger than the diameter of the circular groove 9, the field strength near the trigger electrode 4 becomes higher.

[0067] 6. Judge whether the self-discharge probability of the gas switch is less than or equal to 0.01%. If so, complete the design of reducing the self-discharge probability of the gas switch; otherwise, repeat steps 2 to 5 until the self-discharge probability of the gas switch is reduced below 0.01%.

[0068] As Figure 9 shown, use electromagnetic simulation software to simulate the upper electrode 2, the lower electrode 3, and the trigger electrode 4 of the existing gas switch; the distance between the upper electrode 2 and the lower electrode 3 is 20 mm, the diameter is 40 mm, the outer edge chamfer of the discharge part 21 at the large end is R6, and the thickness of the non-chamfered area (i.e., the main electrode thickness) is 5 mm; the diameter of the central through hole 42 of the trigger electrode 4 is 40 mm; under the condition of a working voltage of ±90 kV, the calculated static maximum field strength of the gas switch is 140 kV / cm; as Figure 10As shown, when the outer edge chamfer of the discharge part 21 at the large ends of the upper electrode 2 and the lower electrode 3 is R10 and the thickness of the non-chamfered area is 1 mm, the static maximum electric field strength of the gas switch is calculated to be 123 kV / cm under the condition of a working voltage of ±90 kV; from Figure 9 、 Figure 10 It can be seen that although increasing the outer edge chamfer can effectively reduce the maximum working electric field strength, the electric field strength in the central area of the gas switch (i.e., the discharge area where the upper electrode 2 and the lower electrode 3 face each other) increases instead due to the inward extension of the chamfer. At the same time, the adjustment space (i.e., the thickness of the non-chamfered area) of the main upper electrode 2 and the lower electrode 3 of the gas switch is severely compressed, which is not conducive to the design of the self-breakdown switch.

[0069] As Figure 11 shown, when the outer edge chamfer of the discharge part 21 at the large ends of the upper electrode 2 and the lower electrode 3 is R8, the thickness of the non-chamfered area is 3 mm, and the distance between the upper electrode 2 and the lower electrode 3 is 20 mm, the static maximum electric field strength under the condition of a working voltage of ±90 kV is 130 kV / cm. As Figure 12 shown, when the outer edge chamfer of the discharge part 21 at the large ends of the upper electrode 2 and the lower electrode 3 is R6, the thickness of the non-chamfered area is 3 mm, and the distance between the upper electrode 2 and the lower electrode 3 is 24 mm, the static maximum electric field strength under the condition of a working voltage of ±90 kV is 125 kV / cm, and the electric field strength in the middle area is significantly reduced, and the electric field distribution in the main discharge area changes slightly. From Figure 9 、 Figure 11 、 Figure 12 It can be seen that when the adjustable dimension of the thickness of the non-chamfered area is the same, increasing the outer edge chamfer of the discharge part 21 and increasing the distance can both effectively reduce the maximum working field strength, and the reduction effects are basically the same. However, for the central area, adjusting the distance between the upper electrode 2 and the lower electrode 3 can more effectively reduce the electric field strength compared to the outer edge chamfer of the discharge part 21. If the gas pressure of the gas switch is the same, increasing the distance can significantly reduce the self-discharge probability in the central area compared to increasing the chamfer.

[0070] As Figure 13 shown, when the outer edge chamfer of the discharge part 21 at the large ends of the upper electrode 2 and the lower electrode 3 is R8 and the thickness of the non-chamfered area is 3 mm, continue to adjust the groove 9 of the discharge part 21 at the large ends of the upper electrode 2 and the lower electrode 3. The static maximum electric field strength is 130 kV / cm under the condition of a working voltage of ±90 kV; from Figure 11 、 Figure 13 It can be seen that the electric field distribution in the main discharge area remains basically unchanged, and the inward depression in the central area does not affect the electric field strength in the working area (chamfered area).

[0071] As Figure 14As shown, when the outer edge chamfer of the discharge part 21 at the large ends of the upper electrode 2 and the lower electrode 3 is adjusted to R8, the inner edge chamfer is adjusted to R3, and the thickness of the non-chamfered area is 3 mm, the static maximum field strength is 139 kV / cm under the working voltage of ±90 kV, which is Figure 9 basically the same as the maximum field strength of the initial structure in

[0072] As Figure 15 shown, when the aperture diameter of the central through hole 42 of the trigger electrode 4 is adjusted to shrink to 32 mm, the static maximum field strength is 140.8 kV / cm under the working voltage of ±90 kV, and the increase is not significant; to further verify the accuracy of the simulation results, a 0.2-mm transition zone is added at the junction of the two rounded corners, and at the same time the mesh is further refined, and the calculation results hardly change; under the trigger condition (-180 kV), the main electrode field strength is concentrated between the outer side of the R8 rounded corner and the R8-R3 transition section, and the discharge area basically coincides with the static field.

[0073] As Figure 16 shown, when the aperture diameter of the central through hole 42 of the trigger electrode 4 is adjusted to shrink to 28 mm, the static maximum field strength is 141.5 kV / cm under the working voltage of ±90 kV, and the field strength near the trigger electrode 4 becomes higher; under the trigger condition (-180 kV), the main electrode field strength shrinks more inward, and the coincidence degree becomes better.

Claims

1. A low jitter, low self-discharge probability gas switch, characterized in that: It comprises an insulating shell (1), an upper electrode (2) arranged in the insulating shell (1), a lower electrode (3), a trigger electrode (4), a positioning block (5), and a plurality of gas nozzles; The insulating housing (1) is a rectangular parallelepiped structure, comprising an upper side plate (11), a lower side plate (12), a front side plate (13) and a rear side plate (14); a left cover plate (15) is provided at the left end thereof, and a right cover plate (16) is provided at the right end thereof; mounting holes are provided on the upper side plate (11) and the lower side plate (12) respectively, for mounting electrode connectors (7); a connecting hole is provided on the left cover plate (15) for mounting a trigger connector (8), and a plurality of gas nozzle mounting holes (6) are provided on the right cover plate (16); The upper electrode (2) and the lower electrode (3) are both stepped cylindrical structures, and are respectively arranged on the inner side of the upper side plate (11) and the lower side plate (12), the large ends of the two stepped cylinders are arranged parallel to each other, and the small ends are connected to the electrode connector (7); the large end of the stepped cylindrical structure is arranged as a discharge portion (21), the edge of the discharge portion (21) close to the small end is provided with a first chamfer, the end face edge of the discharge portion (21) is provided with an outer edge chamfer, the center of the end face is provided with a groove (9), and the notch edge of the groove (9) is provided with an inner edge chamfer; There are two positioning blocks (5), which are arranged on the inner sides of the left cover plate (15) and the right cover plate (16) relative to each other, and the two opposite end surfaces are both provided with support mounting holes; The trigger electrode (4) comprises a wedge-shaped disc (41) and two support bars (43); the wedge-shaped disc (41) is located between the upper electrode (2) and the lower electrode (3); the upper end surface and the lower end surface of the wedge-shaped disc (41) are both arranged as inwardly concave wedge-shaped surfaces; a central through hole (42) coaxial with the upper electrode (2) and the lower electrode (3) is arranged at the center; the diameter of the central through hole (42) is smaller than the diameter of the upper electrode (2) and the lower electrode (3), and larger than the diameter of the groove (9); one end of the two support bars (43) is opposite to the inner surface of the wedge-shaped disc (41); The wedge-shaped disc (41) is connected to both sides of the wedge-shaped disc (41) in the radial direction, and the other end is arranged in the corresponding support mounting hole; the inner edge of the wedge-shaped disc (41) is provided with a second chamfer; in the axial section of the wedge-shaped disc (41), the angle between the arc center of the second chamfer and the connecting line of the inner edge chamfer and the outer edge chamfer of the corresponding upper electrode (2) or lower electrode (3) and the axis of the wedge-shaped disc (41) is θ1, and the inclination angle of the wedge surface of the wedge-shaped disc (41) is θ2, θ2=θ1; One end of the trigger connection member (8) is located outside the left cover plate (15), and the other end passes through the connection hole and the support installation hole in sequence to be electrically connected to the support bar (43); The air nozzle is arranged in the air nozzle mounting hole (6) and is connected to the inner cavity of the insulating shell (1) through the support mounting hole on the positioning block (5) to achieve inflation or deflation of the inner cavity of the insulating shell (1).

2. The low jitter, low self-discharge probability gas switch according to claim 1, characterized in that: The groove (9) is a circular groove, which is used to increase the degree of electric field distortion.

3. The low jitter, low self-discharge probability gas switch according to claim 2, characterized in that: The outer edges of the small ends of the upper electrode (2) and the lower electrode (3) are provided with a third chamfer.

4. The low jitter, low self-discharge probability gas switch according to claim 1, 2 or 3, characterized in that: The other end of the support bar (43) is provided with a blind hole (44); The other end of the trigger connection member (8) passes through the connection hole and the support installation hole in sequence and is inserted into the blind hole (44) to be electrically connected to the support bar (43).

5. The low jitter, low self-discharge probability gas switch according to claim 4, characterized in that: The connection between the wedge-shaped disc (41) and one end of the support bar (43) is configured as an arc surface.

6. The low jitter, low self-discharge probability gas switch according to claim 5, characterized in that: The thickness of the thinnest part of the inner edge of the wedge-shaped circular disk (41) is 2 mm, and the second chamfer radius is 0.5 mm; The materials of the upper electrode (2), the lower electrode (3) and the trigger electrode (4) are all stainless steel or tungsten-copper alloy.

7. The low jitter, low self-discharge probability gas switch according to claim 6, characterized in that: The distance between the discharge portion (21) of the upper electrode (2) and the discharge portion (21) of the lower electrode (3) is 20 mm.

8. A method for reducing the self-discharge probability of a low-jitter, low-self-discharge probability gas switch according to any one of claims 1 to 7, characterized in that: The following steps are involved: 1] Simulate the upper electrode (2), the lower electrode (3), and the trigger electrode (4) of the gas switch, and calculate the static field intensity distribution under the working voltage condition; 2] Keeping the trigger electrode (4) unchanged, adjusting the outer edge chamfers of the discharge portion (21) of the upper electrode (2) and the lower electrode (3), calculating the static field strength distribution of the gas switch under the working voltage condition, analyzing the degree of electric field distortion and the change in the discharge region area, and according to the simulation results, taking the chamfer size corresponding to the maximum electric field distortion degree as the outer edge chamfer size of the discharge portion (21) of the upper electrode (2) and the lower electrode (3); the discharge region is the region where the surface field strength of the upper electrode (2) and the lower electrode (3) is greater than or equal to the average field strength; 3] Keeping the trigger electrode (4) unchanged, simulate the groove (9) in the discharge portion (21) of the upper electrode (2) and the lower electrode (3), calculate the static field intensity distribution of the gas switch under the working voltage condition, analyze the degree of electric field distortion and the change of the discharge area area, and select the groove size corresponding to the maximum degree of electric field distortion and the minimum discharge area area according to the simulation results; 4] Keeping the trigger electrode (4) unchanged, adjusting the inner edge chamfers of the discharge portion (21) of the upper electrode (2) and the lower electrode (3), calculating the static field intensity distribution of the gas switch under the working voltage condition, analyzing the degree of electric field distortion and the change in the discharge area, and selecting the inner edge chamfer size corresponding to the maximum degree of electric field distortion and the minimum discharge area according to the simulation results; 5] reducing the aperture of the central through hole (42) of the trigger electrode (4), calculating the static field intensity distribution of the gas switch under the working voltage condition, analyzing the degree of electric field distortion and the change in the discharge area, and selecting the aperture of the central through hole (42) of the trigger electrode (4) with the largest degree of electric field distortion; 6] Determine whether the self-discharge probability of the gas switch is less than or equal to 0.01%. If so, the design of reducing the self-discharge probability of the gas switch is completed; otherwise, repeat steps 2] to 5] until the self-discharge probability of the gas switch is reduced to below 0.01%.

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