Light and small repetition-frequency high-voltage pulse generator

Abstract

The invention discloses a light and small repetition-frequency high-voltage pulse generator in the technical field of pulse high voltage, which comprises an insulating bracket, a row switch, an independent switch, an energy storage unit, an isolation inductor and a shell structure, and is characterized in that a plurality of switch electrode tips are symmetrically mounted on two sides of the inner wall of the insulating bracket to form the row switch consisting of a plurality of self-breakdown switches; the insulating support is made of an insulating material, can be used as a skeleton structure of the high-voltage pulse generator, and is beneficial to maintaining the stability and reliability of an internal physical structure of the high-voltage pulse generator. According to the high-voltage pulse generator, the flat multi-wing insulating bracket integrated with the gas switch structure is designed, and the energy storage unit and the isolation inductor are fixedly connected, so that the problems of low switch overvoltage coefficient, relatively long axial structure and limited light miniaturization degree of the high-voltage pulse generator can be solved; and the portable and high-reliability application requirements can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of pulsed high voltage, and specifically to a light and small repetitive high voltage pulse generator. Background Art

[0002] High voltage pulse generators usually have high impedance characteristics, characterized by generating peak voltages of dozens to hundreds of kilovolts and pulse widths ranging from sub-nanoseconds to microseconds, and are used to drive high impedance loads, such as being a trigger source for high voltage gas switches, a driver for ultra-wideband radiation sources, a driving source for pulsed X-ray machines, etc. The voltage output by the trigger source is usually dozens of kilovolts. High voltage pulses are often generated by directly discharging pulsed electrical appliances, or high voltage is generated by a pulsed transformer and then fast front pulses are generated through sharpening capacitors. When it comes to ultra-wideband driving sources, high voltage pulses with nanosecond or sub-nanosecond pulse fronts need to be generated. Usually, after the pre-stage pulse forming unit generates high voltage, the pulse front is sharpened through a high voltage hydrogen gas switch. The driving source of a hundred-kilovolt-class pulsed X-ray machine usually adopts technologies such as Marx generators or pulsed transformers, and through compact design, light and small size is achieved to meet the requirements of scenarios such as mobile use.

[0003] Existing light and small high voltage pulse generators usually use ceramic capacitors for energy storage. One ceramic capacitor or multiple ceramic capacitors in parallel are used as one stage of the Marx generator. All gas switches are arranged in a row, and rely on the ultraviolet light pre-ionization of the next-stage gas switch generated by the conduction of the pre-stage switch, so as to accelerate the establishment process of the Marx voltage. Its circuit feature is that each stage of ceramic capacitors is charged in parallel through the same group of inductors or resistors of the same size and discharges separately. Structurally, each stage of ceramic capacitors and switches are arranged in sequence along the axis. For example, the fast front compact X-ray machine reported in public in 2014 adopts the technical route of a 15-stage unipolar coaxial structure Marx generator. Each stage of the Marx is a ceramic capacitor with a rated voltage of 40 kV and a capacitance of 7.5 nF. Using a 1 MΩ solid resistor as the isolation element, the output voltage on a 75 Ω load reaches 360 kV, the pulse front is 10 ns, and the pulse width is 40 ns (Research and Development of Fast Front Compact X-ray Machine, High Power Laser and Particle Beams, 2014).

[0004] The coaxial structure Marx generator uses the same parameter isolation elements for isolation in sequence. After the pre-stage switch conducts, the voltages of the subsequent stages of switches are almost evenly distributed, and the overvoltage coefficient is relatively low, resulting in a long Marx voltage establishment time, large jitter in the output time of high voltage pulses, and even possible unstable operation phenomena, seriously affecting the normal use of the high voltage pulse generator; secondly, the existing capacitors and switches of each stage of the Marx are arranged in sequence along the axis, making the axial structure of the generator longer, resulting in limited usage scenarios; in addition, there is still a large room for optimization in the device size and weight of the existing Marx. Summary of the Invention

[0005] The object of the present invention is to provide a light and small repetitive high-voltage pulse generator, which can avoid the problems of low switching overvoltage coefficient, long axial structure and limited light and small degree existing in the high-voltage pulse generator, and can meet the application requirements of portability and high reliability.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A light and small repetitive high-voltage pulse generator includes an insulating bracket, a row of switches, an independent switch, an energy storage unit, an isolation inductor and a housing structure. On both sides of the inner wall of the insulating bracket, a plurality of switch electrode heads are symmetrically installed to form a row of switches composed of a plurality of self-breakdown switches; the insulating bracket is made of an insulating material and can serve as the framework structure of the high-voltage pulse generator, which is beneficial to maintaining the stability and reliability of the physical structure of the high-voltage pulse generator.

[0008] Inside the insulating shell of the independent switch, two switch electrode heads are symmetrically installed on both sides to form an independent self-breakdown switch.

[0009] The energy storage unit is connected to the row of switches, the independent switch and the isolation inductor to form a charging circuit and a discharging circuit. The energy storage unit is used to store the electric energy provided by an external power supply and quickly release the stored electric energy when the switch is turned on.

[0010] The isolation inductor is connected between the energy storage units. The isolation inductor is used to isolate the energy storage units. The energy storage unit and the row of switches, the independent switch form a folded Marx main discharging circuit. The Marx main discharging circuit includes multiple discharging units. Each discharging unit is composed of an energy storage unit (capacitor) and a switch. All the energy storage units are charged in parallel through the isolation inductor and discharge separately from each other. The discharging units are connected in sequence to form a series discharging circuit to generate pulsed high voltage. By partially isolating the energy storage units across levels with the isolation inductor, the overvoltage coefficient of the switch is increased, which is beneficial to the rapid conduction of the Marx main discharging circuit and makes the output of the high-voltage pulse generator more stable.

[0011] The insulating bracket is clamped on the inner wall of the housing structure. The inside of the housing structure is filled with gas. By using gas insulation, it is possible to achieve an output voltage of hundreds of kilovolts, which is beneficial to the light and small size of the high-voltage pulse generator.

[0012] As a further scheme of the present invention: the insulating bracket is a symmetric flat bracket. A plurality of through holes are formed through the side surface of the insulating bracket, and a plurality of wings perpendicular to the arrangement direction of the through holes are formed between adjacent through holes. The plurality of through holes can serve as the heat dissipation channels of the insulating bracket, which can strengthen the gas flow inside the insulating bracket, and the through holes can provide installation space for the connection between the switch structure and the insulating bracket, which is beneficial to ensuring the normal operation of the switch structure.

[0013] As a further solution of the present invention: on the upper and lower sides of the inner wall of each through-hole of the insulating bracket, two switching electrode heads are symmetrically installed through electrode head connectors, and after the switching electrode heads are installed in all through-holes, a row of switches integrated with the insulating bracket is formed.

[0014] As a further solution of the present invention: there are a total of 2n levels of energy storage units, and the energy storage units are ceramic capacitors. All ceramic capacitors are divided into two groups. The 1st, 4th, 5th, 8th, 9th... are the first group, located at the top of the insulating bracket; the 2nd, 3rd, 6th, 7th, 10th... are the second group, located at the bottom of the insulating bracket. When the ceramic capacitors from the 1st level to the 2nth level are connected in series and discharged, an n-layer folded discharge path that travels up and down along the insulating bracket is presented.

[0015] As a further solution of the present invention: on both sides inside the insulating shell of the independent switch, two switching electrode heads are symmetrically connected through electrode head connectors to form an independent self-breakdown switch. Switch connecting pieces are respectively connected to the upper ends of the first group of ceramic capacitors and the lower ends of the second group of ceramic capacitors. An independent switch is connected between two adjacent-level ceramic capacitors through a switch connecting piece.

[0016] As a further solution of the present invention: the isolation inductor includes group A inductor, group B inductor, group C inductor and group D inductor. The group A inductor, group B inductor, group C inductor and group D inductor are symmetrically distributed on both sides of the ceramic capacitor. The group A inductor, group B inductor, group C inductor and group D inductor each include a number of inductors. Each group of inductors is composed of multiple long inductors and short inductors connected alternately. The long inductor isolates the energy storage units with a level difference of 3 levels, and the short inductor isolates the adjacent-level energy storage units; both the long inductor and the short inductor are high-voltage isolation inductors, and an inductor connecting piece is connected to the contact part of the long inductor and the short inductor. The inductor connecting pieces are divided into two groups. One group of inductor connecting pieces is crimped between the ceramic capacitor and the row of switch electrode head connectors, and the other group of inductor connecting pieces is connected between the ceramic capacitor and the switch connecting piece of the independent switch.

[0017] As a further solution of the present invention: the high-voltage pulse generator further includes a trigger connecting piece, an output connecting piece and an output electrode. The trigger connecting piece is connected through the high-voltage end of the 1st-level ceramic capacitor, and the output connecting piece is connected through the grounding end of the last-level ceramic capacitor to guide the output voltage to the axis of the high-voltage pulse generator; the output electrode is installed at the center of the insulating cover plate at the output end of the high-voltage pulse generator through a nut, opposite to the lower end of the output connecting piece and maintaining a certain distance as the output sharp switch gap.

[0018] As a further solution of the present invention: The housing structure includes guide rails, a metal outer cylinder, a cover plate and an insulating cover plate. The guide rails are symmetrically welded on both sides of the inner wall of the metal outer cylinder. The insulating bracket enters the metal outer cylinder through the guide rails and is fixed thereto, which can meet the application requirements of convenient installation and reliable fixation. The cover plate and the insulating cover plate are fixed on the two open ends of the metal outer cylinder. A limiting plate is fixed on one side of the cover plate, and the limiting plate is used to limit the insulating bracket. The metal outer cylinder, the cover plate and the insulating cover plate are connected to form a closed cavity.

[0019] As a further solution of the present invention: One end of the inductor group A is connected to a first charging cable, and the other end of the charging cable passes through the first insulating seat; One end of the inductor group B is connected to a second charging cable, and the other end of the second charging cable passes through the second insulating seat; One end of the inductor group C is connected to a grounding inductor through a wire; One end of the inductor group D is electrically connected to the cover plate through a spring.

[0020] As a further solution of the present invention: A plurality of air nozzles are penetrated and connected on one side of the cover plate. A spring is connected to the other side of the cover plate. A trigger assembly is installed through the cover plate. There is a certain distance between the trigger assembly and the trigger connection piece to form a trigger switch gap.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. In the present invention, by providing an insulating bracket with a flat multi-wing structure integrated with the gas switch structure and fixedly connecting the energy storage unit and the isolation inductor, it is possible to avoid the problems of low switching overvoltage coefficient, long axial structure, and limited light miniaturization degree of the high-voltage pulse generator. By adopting the fixing method of the insulating bracket entering the metal outer cylinder through the guide rails, it can meet the application requirements of convenient installation and reliable fixation.

[0023] 2. In the present invention, by dividing all ceramic capacitors into 2 groups and using two specifications of inductors for cross-stage isolation, it meets the use requirements of parallel charging and cross-stage isolation discharge of ceramic capacitors, can effectively improve the overvoltage coefficient of the remaining switches after the first-stage switch is triggered and conducted, and realizes the reliability and stability of the high-voltage pulse generator in repetitive operation.

[0024] 3. In the present invention, by adopting an insulating bracket with a multi-wing structure, half of the switches are integrated with the insulating bracket, and the remaining switches are distributed up and down. At the same time, the two groups of ceramic capacitors are respectively arranged above and below the insulating bracket, and the Marx main discharge circuit forms a folded structure of the Marx generator circuit, which not only reduces the axial length but also saves the insulating inner cylinder, greatly improving the light miniaturization degree of the device.

[0025] 4. In the present invention, the relative air pressure inside the high-voltage pulse generator is 1 atmosphere with gas insulation, meeting the structural requirements of small size and light weight. At the same time, it is convenient for use and maintenance, works stably and reliably, can be used as the pulse drive source of a portable pulse X-ray machine, and meets the usage requirements such as high pulse voltage and light miniaturization.

[0026] 5. In the present invention, the circuit and structure of the high-voltage pulse generator are ingeniously designed with a high degree of light miniaturization, and the circuit parameters such as the number of capacitor stages have strong expansibility, which can be used for the development of light miniaturized high-voltage pulse drive sources for various purposes. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a sectional view of the integrated structure of the insulating bracket and the switch structure of the present invention;

[0028] Figure 2 It is a connection relationship diagram of the independent switch, the switch connecting piece, and the ceramic capacitor of the present invention;

[0029] Figure 3 It is a connection relationship diagram of the insulating bracket, the ceramic capacitor, and the inductor connecting piece of the present invention;

[0030] Figure 4 It is a connection relationship diagram of the inductor, the inductor connecting piece, and the ceramic capacitor of the present invention;

[0031] Figure 5 It is a connection relationship diagram of the four groups of inductors, the charging cable, and the cover plate of the present invention;

[0032] Figure 6 It is a connection relationship diagram of the insulating bracket and the metal outer cylinder of the present invention;

[0033] Figure 7 It is the connection relationship between the trigger assembly and the cover plate of the present invention;

[0034] Figure 8 It is a connection relationship diagram of the output end, the insulating cover plate, and the output electrode of the present invention;

[0035] Figure 9 It is the circuit diagram of the Marx main discharge circuit of the present invention.

[0036] Figure 10 It is the waveform diagram of the repetitive pulse voltage generated in the experiment of driving the X-ray tube in the embodiment of the present invention.

[0037] In the figure: 1. Switch electrode head; 2. Electrode head connecting piece; 3. Insulating bracket; 4. Inductance connecting piece; 5. Energy storage unit; 6. Switch connecting piece; 7. Independent switch; 8. Long inductance; 9. Short inductance; 10. Trigger connecting piece; 11. Output connecting piece; 12. Guide rail; 13. Metal outer cylinder; 14. Limit plate; 15. Group A inductance; 16. Group B inductance; 17. Insulating seat; 18. Charging cable; 19. Group C inductance; 20. Wire; 21. Cover plate; 22. Inductance; 23. Group D inductance; 24. Spring; 25. Trigger assembly; 26. Air nozzle; 27. Insulating cover plate; 28. Output electrode; 29. Nut. Detailed implementation manner

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Embodiment:

[0040] Please refer to Figures 1 - 10 , a light and small high-repetition-rate high-voltage pulse generator is provided, which includes an insulating bracket 3, a row of switches, an independent switch 7, an energy storage unit 5, an isolation inductance, and a housing structure. On both sides of the inner wall of the insulating bracket 3, a plurality of electrode structures of the row of switches are symmetrically installed. All the switch structures are used for conducting current. The insulating bracket 3 is made of an insulating material and can serve as the framework structure of the high-voltage pulse generator, which is beneficial to maintaining the stability and reliability of the physical structure of the high-voltage pulse generator;

[0041] The energy storage unit 5 is divided into two groups. The first group is distributed at the top of the insulating bracket 3 and is connected to the upper electrode head connecting piece of the row of switches; the second group is distributed at the bottom of the insulating bracket 3 and is connected to the lower electrode head connecting piece of the row of switches. The energy storage unit 5 is used for storing electric energy;

[0042] On both sides inside the insulating shell of the independent switch 7, two switch electrode heads 1 are symmetrically connected to form an independent self-breakdown switch. A switch connecting piece 6 is respectively connected to the upper end of the first group of energy storage units and the lower end of the second group of energy storage units. An independent switch 7 is connected between two adjacent ceramic capacitors with the same number of stages through the switch connecting piece 6.

[0043] The isolation inductor is connected between the energy storage units 5. The energy storage units 5, the row-connected switches, and the independent switches 7 form a folded-structured Marx main discharge circuit. The Marx main discharge circuit includes multiple stages of discharge units. Each stage of the discharge unit is composed of an energy storage unit 5 and a switch. All the energy storage units 5 are charged in parallel through the isolation inductor, discharge in isolation from each other, and the discharge units of each stage are connected in sequence to form a series discharge circuit. There are two specifications for the isolation inductor, one is for the energy storage units 5 with a 3-stage difference in isolation levels, and the other is for the energy storage units 5 with adjacent isolation levels. By grouping and isolating the design of the energy storage units 5 at each stage, the overvoltage coefficient of the remaining switches after the first-stage switch is triggered and turned on can be increased, thereby increasing the working voltage range of the switches and realizing reliable repetitive operation and stable output of the high-voltage pulse generator.

[0044] The insulating bracket 3 is clamped on the inner wall of the housing structure. The inside of the housing structure is filled with gas. By using gas insulation, it is possible to achieve an output voltage of several hundred kilovolts, which is beneficial to the light miniaturization of the high-voltage pulse generator.

[0045] Preferably, as Figure 1 shown is a cross-sectional view of the integrated structure of the insulating bracket and the switch structure of the present invention. The insulating bracket 3 is a symmetric flat bracket. A plurality of through holes are formed through the side surface of the insulating bracket 3, and a plurality of flanks perpendicular to the arrangement direction of the through holes are formed between adjacent through holes. The plurality of through holes can serve as heat dissipation channels of the insulating bracket 3, which can strengthen the gas flow inside the insulating bracket 3, and the through holes can provide installation space for the connection between the switch structure and the insulating bracket 3, which is beneficial to ensuring the normal operation of the switch structure.

[0046] Preferably, as Figure 1 shown is a cross-sectional view of the integrated structure of the insulating bracket and the switch structure of the present invention. The switch structure includes a switch electrode head 1 and an electrode head connecting piece 2 connected to the top of the switch electrode head 1. The switch electrode head 1 includes a first group of switch electrode heads and a second group of switch electrode heads. The first group of switch electrode heads is symmetrically integrated inside the insulating bracket 3 through the corresponding through holes to form row-connected switches, which can effectively conduct the current between the top and bottom of the insulating bracket 3 to the energy storage unit 5; the second group of switch electrode heads is installed in the Figure 2 housing of the multiple independent switches 7 shown. Each independent switch 7 constitutes a self-breakdown gas switch.

[0047] Preferably, as Figure 3The figure shows the connection relationship diagram of the insulating bracket of the present invention with the ceramic capacitor and the inductor connecting piece. There are 12 energy storage units 5 in total, and the energy storage unit 5 is a ceramic capacitor. All the ceramic capacitors are divided into two groups. The first group includes the 1st, 4th, 5th, 8th, 9th, and 12th levels, which are located at the top of the insulating bracket 3. The second group includes the 2nd, 3rd, 6th, 7th, 10th, and 11th levels, which are located at the bottom of the insulating bracket 3. When the 1st to 12th level ceramic capacitors are connected in series for discharging, an n-layer folded discharge path that travels up and down along the insulating bracket 3 is presented. The inductor connecting piece 4 is divided into two groups. One end of the first group of inductor connecting pieces 4 is respectively connected to the upper ends of the first group of ceramic capacitors and the lower ends of the second group of ceramic capacitors. One end of the second group of inductor connecting pieces 4 is respectively crimped between the first group and the second group of ceramic capacitors and the connecting piece 2 of the row switch electrode head.

[0048] Preferably, as Figure 4 The figure shows the connection relationship diagram of the inductor, the inductor connecting piece and the ceramic capacitor of the present invention. Each group of inductors in group A, group B, group C and group D inductors is alternately composed of a plurality of long inductors 8 and a plurality of short inductors 9. The long inductor 8 is used to isolate the ceramic capacitors with a stage difference of 3 levels, and the short inductor 9 is used to isolate the ceramic capacitors with adjacent stages. One end of the long inductor 8 at one end of the group A inductor 15 is connected to one end of an inductor connecting piece 4. The other end of this inductor connecting piece 4 is connected to the upper end of the 1st level ceramic capacitor. One end of another inductor connecting piece 4 is connected between the other end of this long inductor 8 and the short inductor 9. The other end of this inductor connecting piece 4 is crimped between the 4th level ceramic capacitor and the connecting piece of the upper electrode head of the row switch. One end of another inductor connecting piece 4 is connected between the other end of this short inductor 9 and another long inductor 8. The other end of this inductor connecting piece 4 is connected to the top of the 5th level ceramic capacitor. By analogy, the connection of the group A inductor 15, the inductor connecting piece 4 and the first group of ceramic capacitors is completed. Each group of inductors in group B, group C and group D inductors is connected to the inductor connecting piece 4 and the corresponding ceramic capacitor in the same way according to the Figure 4 connection relationship in the figure. After the connection is completed, the first group of ceramic capacitors is charged in parallel through the group A inductor 15 and the group C inductor 19. The second group of ceramic capacitors is charged in parallel through the group B inductor 16 and the group D inductor 23. The high voltage pulse generator further includes a trigger connecting piece 10 and an output connecting piece 11. The trigger connecting piece 10 is connected through the high voltage end of the 1st level ceramic capacitor, and the output connecting piece is connected through the grounding end of the last level ceramic capacitor.

[0049] Preferably, as Figure 5The figure shows the connection relationship diagram of the four groups of inductors, charging cables and the cover plate of the present invention. One end of the inductor group A 15 is connected to the first charging cable 18, and the other end of the charging cable 18 passes through the first insulating seat 17; one end of the inductor group B 16 is connected to the second charging cable 18, and the other end of the second charging cable 18 passes through the second insulating seat 17; one end of the inductor group C 19 is connected to a wire 20, one end of the wire 20 is connected to the inductor 22, and the other end of the inductor 22 is connected to the cover plate 21; the inductor group D 23 is electrically connected to the cover plate 21 through a spring 24; the inductor group A 15 and the inductor group C 19, the inductor group B 16 and the inductor group D 23 are symmetrically distributed on both sides of the ceramic capacitor in pairs, and each group of inductors is composed of multiple inductors;

[0050] Preferably, as Figure 2 The figure shows the connection relationship diagram of the independent switch, switch connecting piece 6 and ceramic capacitor of the present invention. The upper end of the first energy storage unit and the lower end of the second energy storage unit are respectively connected to the switch connecting piece 6, and two adjacent switch connecting pieces 6 are connected to the electrode head connecting piece 2 on the independent switch 7. The independent switch 7 is used to connect adjacent energy storage units 5 in series after being turned on.

[0051] Preferably, as Figure 6 The figure shows the connection relationship diagram of the insulating bracket and the metal outer cylinder of the present invention. The housing structure includes guide rails 12, a metal outer cylinder 13 and a cover plate 21. The guide rails 12 are symmetrically welded on both sides of the inner wall of the metal outer cylinder 13. The method of entering the metal outer cylinder 13 through the guide rails 12 and fixing it thereto can meet the application requirements of convenient installation and reliable fixation.

[0052] Preferably, as Figure 3 、 Figure 7 The figure shows the connection relationship diagram of the four groups of inductors, charging cables and the cover plate of the present invention. Two air nozzles 26 are connected through the outside of the cover plate 21, one side of the cover plate 21 is fixedly connected with a spring 24, and the inductor group D 23 is connected to the cover plate 21 through the spring 24.

[0053] Preferably, as Figure 7 The figure shows the connection relationship between the trigger assembly and the cover plate of the present invention. The trigger assembly 25 is installed through the cover plate 21, and a certain distance (typical value 5mm) is reserved between the trigger assembly 25 and the trigger connecting piece 10 as the trigger switch gap.

[0054] Preferably, as Figure 8The figure shows the connection diagram of the output end of the present invention with the insulating cover plate and the output electrode. The housing structure further includes an insulating cover plate 27. The screw end of the output electrode 28 is installed at the center of the insulating cover plate 27 through a nut 29, and a certain distance (typical value 5 mm - 10 mm) is reserved between its spherical head end and the output connecting piece 11 as the output sharpening switch gap. The cover plate 21 and the insulating cover plate 27 are fixed on the metal flanges at the two openings of the metal outer cylinder 13. A limiting plate 14 is fixed on one side of the cover plate 21, and the limiting plate 14 is used to limit the two ends of the insulating bracket 3. The metal outer cylinder 13, the cover plate 21 and the insulating cover plate 27 are connected to form a closed cavity. The interface forms of the output end flange of the metal outer cylinder 13, the insulating cover plate 27 and the output electrode 28 can be designed according to the specific structure of the load.

[0055] As Figure 9 The figure shows the circuit diagram of the Marx main discharge loop in the embodiment of the present invention. The upper end of the first-stage ceramic capacitor C_1 is connected to the high-voltage end of the trigger switch S_tr; the lower end of the first-stage ceramic capacitor C_1 is connected to the upper end of the second-stage ceramic capacitor C_2 through the self-breakdown switch S_L; the lower end of the second-stage ceramic capacitor C_2 is connected to the lower end of the third-stage ceramic capacitor C_3 through the self-breakdown switch S_d; the upper end of the third-stage ceramic capacitor C_3 is connected to the lower end of the fourth-stage ceramic capacitor C_4 through the self-breakdown switch S_L; and so on. The upper end of the last-stage ceramic capacitor C_n is connected to the load (Load) through the self-breakdown switch S_d.

[0056] In this embodiment, the high-voltage pulse generator is set to 12 stages, with an external dimension of 18 cm × 18 cm × 32 cm, a volume of 10 L, and a mass of 6 kg. In the X-ray tube load experiment, it achieved an output of a peak voltage of 350 kV, a pulse front edge less than 10 ns, and a pulse half-height width greater than 80 ns, and could operate stably continuously at a repetition frequency of 20 Hz for more than 10 seconds.

[0057] As Figure 10 The figure shows the waveform diagram of the repetitive pulse voltage generated in the experiment of driving the X-ray tube in the embodiment of the present invention. This high-voltage pulse generator has passed the experimental verification as the driving source of the pulsed X-ray machine. Compared with the traditional pulse generator that also serves as the driving source of the X-ray machine and has a comparable output voltage, it can effectively reduce the volume of the high-voltage pulse generator and greatly improve the light and miniaturized level of the driving source of the pulsed X-ray machine.

[0058] The high-voltage pulse generator designed by the present invention uses gas insulation with a relative air pressure of about 1 atmosphere inside. It has a small size, light weight, is convenient for use and maintenance, and works stably and reliably, and can meet the usage requirements such as pulsed high voltage and light miniaturization at the same time.

[0059] On the other hand, the high-voltage pulse generator has a clever circuit and structure design, a high degree of light miniaturization, and strong expansibility of circuit parameters such as the number of capacitor stages. It can be used for the development of a light and small high-voltage pulse drive source with different output voltages.

[0060] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A small and light-weight high-frequency high-voltage pulse generator, characterized in that: include: An insulating bracket, wherein a plurality of switch electrode heads are symmetrically mounted on both sides of the inner wall of the insulating bracket to form a row switch composed of a plurality of self-breakdown switches; An independent switch, wherein two switch electrode heads are symmetrically mounted on both sides of the insulating shell of the independent switch to form an independent self-breakdown switch; An energy storage unit, wherein the energy storage unit is connected to the gang switch and the independent switch, both ends of the energy storage unit can be used as a high voltage end and a ground end, and the energy storage unit is used to store electrical energy; An isolation inductor, wherein the isolation inductor is connected between the energy storage units, and the energy storage unit, the row switch, and the independent switch form a Marx main discharge circuit of a folded structure. The Marx main discharge circuit includes a multi-stage discharge unit, and each stage of the discharge unit is composed of an energy storage unit and a switch. All energy storage units are charged in parallel through the isolation inductor, and discharged in isolation from each other. The discharge units at each stage are connected in sequence to form a series discharge circuit; The outer shell structure, the insulating bracket is clamped and connected to the inner wall of the outer shell structure, and the interior of the outer shell structure is filled with insulating gas.

2. The light and small-sized repetition rate high voltage pulse generator according to claim 1 is characterized in that: The insulating bracket is a symmetrical flat bracket, a plurality of through-holes are formed through the side surface of the insulating bracket, and a plurality of side wings perpendicular to the arrangement direction of the through-holes are formed between adjacent through-holes.

3. The light and small-sized repetition rate high voltage pulse generator according to claim 2 is characterized in that: There are 2n levels of energy storage units in total, and the energy storage units are ceramic capacitors. All ceramic capacitors are divided into two groups. Level 1, level 4, level 5, level 8, level 9... are the first group, which are located on the top of the insulating bracket; level 2, level 3, level 6, level 7, level 10... are the second group, which are located at the bottom of the insulating bracket. When the 1st to 2n-level ceramic capacitors are discharged in series, they present an n-layer folded discharge path that goes back and forth along the insulating bracket.

4. The light and small-sized repetition rate high voltage pulse generator according to claim 3 is characterized in that: The upper end of the first group of ceramic capacitors and the lower end of the second group of ceramic capacitors are respectively connected to switch connecting pieces, and an independent switch is connected between two adjacent levels of ceramic capacitors through the switch connecting piece.

5. The light and small-sized repetition rate high voltage pulse generator according to claim 4 is characterized in that: The isolation inductor includes an inductor group A, an inductor group B, an inductor group C and an inductor group D, and the inductors group A, group B, group C and group D are symmetrically distributed on both sides of the ceramic capacitor. The inductors group A, group B, group C and group D each include a plurality of inductors, and each group of inductors is composed of a plurality of long inductors and short inductors alternately connected. The long inductors isolate energy storage units with a difference of 3 levels, and the short inductors isolate energy storage units with adjacent levels. The contact portion of the long inductor and the short inductor is connected with an inductor connecting piece, and the inductor connecting piece is divided into two groups, one group of inductor connecting pieces is crimped between the ceramic capacitor and the electrode head connector of the row switch, and the other group of inductor connecting pieces is connected between the ceramic capacitor and the switch connecting piece of the independent switch.

6. The light and small-sized repetition rate high voltage pulse generator according to claim 5 is characterized in that: The high voltage pulse generator further comprises a trigger connection piece, an output connection piece and an output electrode, wherein the trigger connection piece is connected through the high voltage end of the first-stage ceramic capacitor; The output connecting piece is connected through the ground terminal of the last-stage ceramic capacitor to guide the output voltage to the axis of the high-voltage pulse generator; the output electrode is installed at the center of the insulating cover plate at the output end of the high-voltage pulse generator through a nut, opposite to the lower end of the output connecting piece and retaining a certain size of spacing as the output sharpening switch gap.

7. The light and small-sized repetition rate high voltage pulse generator according to claim 6 is characterized in that: The shell structure includes a guide rail, a metal outer cylinder, a cover plate and an insulating cover plate. The guide rail is symmetrically welded on both sides of the inner wall of the metal outer cylinder. The insulating bracket enters the metal outer cylinder through the guide rail and is fixed to the metal outer cylinder, which can meet the application requirements of convenient installation and reliable fixation; the cover plate and the insulating cover plate are fixed to the openings at both ends of the metal outer cylinder, and the metal outer cylinder is connected with the cover plate and the insulating cover plate to form a closed cavity.

8. The light and small-sized repetition rate high voltage pulse generator according to claim 7 is characterized in that: One end of the inductor of group A is connected to the first charging cable, and the other end of the charging cable passes through the first insulating seat; one end of the inductor of group B is connected to the second charging cable, and the other end of the second charging cable passes through the second insulating seat; one end of the inductor of group C is connected to the grounding inductor through a wire; and one section of the inductor of group D is electrically connected to the cover plate through a spring.

9. The light and small-sized repetition rate high voltage pulse generator according to claim 8 is characterized in that: One side of the cover plate is connected with a plurality of air nozzles, the other side of the cover plate is connected with a spring, a trigger assembly is installed in the cover plate, and the trigger assembly is spaced a certain distance from the trigger connecting piece to form a trigger switch gap.

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