A compact Marx generator based on thin-film capacitors

Abstract

The application provides a compact Marx generator based on a thin film capacitor, and relates to the technical field of pulse power. The compact Marx generator based on the thin film capacitor comprises a capacitor body, the capacitor body is provided with an insulating shell and symmetrically arranged electrode one for a charging electrode and electrode two for a discharging electrode, the electrode one and the electrode two constitute a gas spark switch, and are directly screwed on the charging electrode of the thin film capacitor and the discharging electrode of an adjacent unit, the insulating shell is provided with mounting boss one and mounting boss two on both sides, and a switch integrated with the capacitor electrode comprises the electrode one screwed on the charging electrode of the capacitor body and the electrode two mounted on the discharging electrode. Through the cooperation of various structures, the response speed of the system is improved, the mechanical stress of the electrode is reduced, the overall material cost is reduced, the assembly efficiency is improved, and the industrial scale production demand is met.

Description

Technical Field

[0001] This invention relates to the field of pulse power technology, specifically to a compact Marx generator based on a thin-film capacitor. Background Technology

[0002] The Marx generator, a classic pulse power device, consists of a core structure of multiple capacitors connected in series with switches. It generates high-voltage pulses through parallel charging and series discharging. The Marx generator comprises an inner core, an insulating support structure, and a housing. The inner core is the core component of the Marx generator, a key device for energy storage and pulse compression. It typically consists of multiple units, each containing an energy storage capacitor, a charging inductor, a discharging inductor, and a gas spark switch. The insulating support material provides a fixed support structure for the inner core and also provides insulation protection. The housing is the protective structure for mounting the Marx generator.

[0003] Early Marx generators mostly used film capacitors and spark gas switches with independent chambers, resulting in a relatively large size and weight. In recent years, to meet the demands for miniaturization and high stability, Marx generators have evolved towards more compact, modular, and solid-state designs. Capacitors are now made of smaller, lighter solid-state ceramic capacitors, and switches are either IGBT solid-state switches or spark gas switches directly connected to ceramic capacitors without chambers. This has led to a more compact overall structure and significantly reduced size and weight. Compared to earlier Marx generators, the reduced loop inductance results in a shorter leading edge and a steeper output pulse.

[0004] Solid-state Marx uses IGBT solid-state switches to replace traditional gas spark switches, which has the advantage of higher repetition rate. However, because the operating voltage of a single IGBT solid-state switch is low, in order to meet the operating voltage requirements of tens or even hundreds of kilovolts of Marx generators, multiple IGBT switches are often connected in series and parallel, which further brings problems such as series and parallel voltage equalization protection. This not only results in low reliability but also greatly increases the cost.

[0005] Existing small Marx generators using ceramic capacitors employ a Z-shaped stacking structure, with the gas spark switch spatially separated from the ceramic capacitor. This results in a longer connection inductance. Furthermore, the inductance of ceramic capacitors is slightly larger than that of film capacitors. Consequently, the discharge inductance of the Marx generator is relatively large, leading to a slower output pulse speed and a larger pulse leading edge. Additionally, ceramic capacitors have a shorter lifespan compared to film capacitors. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a compact Marx generator based on thin-film capacitors, which solves the problems of large inductance, large pulse width, and short lifespan caused by Z-shaped stacking of ceramic capacitors.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a compact Marx generator based on a thin-film capacitor, comprising: The capacitor body has an insulating shell and symmetrically arranged electrode one for charging and electrode two for discharging. Electrode one and electrode two form a gas spark switch and are directly threaded to the charging electrode of the film capacitor and the discharging electrode of the adjacent unit. The insulating shell of the capacitor body is provided with mounting boss one and mounting boss two on both sides. A switch integrated into the capacitor electrodes includes an electrode one that is directly mounted on the charging electrode of the capacitor body via threads, and an electrode two that is mounted on the discharging electrode. An open discharge gap is formed between adjacent stages by the front electrode and the rear electrode facing each other. The capacitor body is provided with an insulating side plate 1 and an insulating side plate 2 on its upper and lower sides, respectively. The inner sides of the insulating side plate 1 and the insulating side plate 2 are provided with positioning slots to engage the mounting bosses 1 and 2 of each stage to fix the linear stacked structure.

[0008] Preferably, the distance between electrode one and electrode two is 1-3 mm, and the depth of insertion is continuously adjustable.

[0009] Preferably, the axes of electrode one and electrode two are perpendicular to the electrode surface of the capacitor body, and the threads of the two electrodes are M6-M10 metric threads.

[0010] Preferably, adjacent stages are connected by a T-shaped inductor connecting strip, the two ends of which are pressed into the base of the first spark electrode of the preceding stage and the base of the second spark electrode of the following stage.

[0011] Preferably, the first mounting boss and the second mounting boss are integrally molded structures of glass fiber reinforced polyimide, with stainless steel hexagonal nuts pre-embedded inside.

[0012] Preferably, the positioning groove spacing tolerance of the first insulating side plate and the second insulating side plate is ≤0.1mm, and the groove depth is two-thirds of the height of the first mounting boss and the second mounting boss.

[0013] Preferably, the capacitor body has external dimensions of 93mm×81mm×36mm, and the distance from the center point of the charging electrode to the center point of the discharging electrode is 72±0.5mm.

[0014] Preferably, the open discharge gap is exposed to the atmospheric environment and has no independent sealed cavity structure.

[0015] Preferably, the inductor connecting strip is a multilayer laminated structure of 0.2mm thick copper foil, and the contact surface with the electrode base is coated with conductive silver paste.

[0016] Preferably, the six capacitor bodies form a multi-level energy storage unit, and the lengths of the first insulating side plate and the second insulating side plate are matched with the six-level overall assembly dimensions, with an outer dimension of less than 450mm×300mm×150mm.

[0017] Working principle: The high-voltage power supply charges all capacitor bodies in parallel through the inductive connecting strip to the first electrode. When the capacitor voltage reaches the breakdown threshold of the gas spark switch, the open discharge gap formed between the second electrode of the preceding capacitor body and the first electrode of the adjacent subsequent stage breaks down and conducts in the air. At this time, the Marx generator changes from parallel charging to series discharge: the current flows directly to the first electrode through the second electrode across the open gap, and then is transmitted to the next stage through the T-shaped inductive connecting strip. The two ends of the connecting strip are pressed into the electrode base, and finally, the multi-stage series output high-voltage pulses are sent to the load. This process minimizes loop inductance through two core designs: Electrode 1 and Electrode 2 are directly screwed into the metal electrode surface of the capacitor body via threads, eliminating the independent connection harness between the switch and the capacitor and reducing loop inductance. The six-electrode capacitor body is precisely engaged with the positioning slots of insulating side plate one and insulating side plate two via mounting boss one and mounting boss two, ensuring that adjacent electrodes maintain a co-facing center distance. Compared to Z-shaped stacking, this shortens the discharge path, optimizing the gas switch discharge channel to a millimeter-level linear topology. Ultimately, under 300kV / Level 6 operating conditions, the capacitor body provides low-inductance energy storage support, the copper foil laminated inductor connecting strip is coated with conductive silver paste to further reduce contact resistance, the output pulse leading edge is reduced, and the cycle life of the thin film capacitor is improved.

[0018] This invention provides a compact Marx generator based on a thin-film capacitor. It offers the following advantages: 1. This invention integrates electrode one and electrode two directly into the charging and discharging electrodes of the capacitor body through a threaded direct connection, eliminating independent leads. The shortest loop path is formed between adjacent stages by a T-shaped inductor connecting the electrode base, which significantly reduces the pulse loop area. The compact structure shortens the high-voltage pulse transmission path and compresses the pulse leading edge to within 20ns, thereby improving the system response speed.

[0019] 2. This invention utilizes an open discharge gap, where the front electrode and the rear electrode face each other, combined with a sealless cavity design, to utilize natural heat dissipation from the atmospheric environment, avoiding local overheating losses. The thin-film capacitor body, together with the flexible vibration-absorbing structure of the copper foil stacked connecting strip, reduces the mechanical stress of the electrodes. The synergistic effect enables the switch to achieve a lifespan exceeding 10^6 cycles at a peak current of 10kA, with a failure rate of less than 0.3‰.

[0020] 3. This invention uses standardized threaded installation of electrodes, eliminating the need for welding or additional fasteners; the connecting strip and electrode base are bonded and cured by pre-coated conductive silver paste, replacing the traditional brazing process, eliminating the need for protection circuits and vacuum packaging, reducing overall material costs, increasing assembly efficiency by 3 times, and meeting the needs of industrial-scale production. Attached Figure Description

[0021] Figure 1 This is a capacitor assembly diagram of a compact Marx generator based on a thin-film capacitor according to the present invention; Figure 2 This is a diagram of the capacitor body and gas spark switch electrode assembly of a compact Marx generator based on a thin-film capacitor according to the present invention. Figure 3 This is a schematic diagram of the gas spark switch electrode structure of a compact Marx generator based on a thin-film capacitor according to the present invention. Figure 4 This is a circuit diagram of a compact Marx generator based on a thin-film capacitor according to the present invention.

[0022] The components are: 1. Capacitor body; 2. Electrode 1; 3. Inductor connecting strip; 4. Mounting boss 1; 5. Electrode 2; 6. Mounting boss 2; 7. Insulating side plate 1; 8. Insulating side plate 2. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: like Figure 1-3 As shown, an embodiment of the present invention provides a compact Marx generator based on a thin-film capacitor, comprising: The capacitor body 1 has an insulating shell and symmetrically arranged electrodes 2 for charging and 5 for discharging. Electrodes 2 and 5 form a gas spark switch and are directly threaded to the charging electrode of the film capacitor and the discharging electrode of the adjacent unit. The insulating shell has mounting bosses 4 and 6 on both sides. The distance between electrodes 2 and 5 is 1-3mm and can be continuously adjusted by screwing in. The axes of electrodes 2 and 5 are perpendicular to the electrode surface of the capacitor body 1, and the screw threads are M6-M10 metric threads. The external dimensions of the capacitor body 1 are 93mm×81mm×36mm, and the distance from the center point of the charging electrode to the center point of the discharging electrode is 72±0.5mm. Specifically: The insulating shell of capacitor body 1 is made of flame-retardant polycarbonate injection molding, with its external dimensions strictly controlled at 93mm×81mm×36mm. Symmetrically arranged on both sides of the shell, electrode 12 is embedded at the center point of the charging electrode surface, and electrode 25 is embedded at the center point of the discharging electrode surface with the same specification threaded hole. The center distance between the two electrodes is 72±0.5mm. Electrode 12 and electrode 25 are directly screwed into the corresponding electrode surface using M10×1 metric threads, with a screwing depth that is continuously adjustable from 0-5mm. The axes of both are perpendicular to the electrode mounting plane of capacitor body 1, with a perpendicularity of <0.1°. By adjusting the screwing depth, the distance between the top of electrode 12 and the top of electrode 25 can be precisely controlled at 1-3mm, forming an adjustable gas spark switch gap reference surface. Mounting boss 14 and mounting boss 26 are integrally formed on both sides of the insulating shell, symmetrically distributed on both sides of the 81mm width direction of the shell. The boss size is 15mm×10mm×6mm, and contains M4 stainless steel pre-embedded nuts for subsequent snap-fit ​​fixing.

[0025] Example 2: Figure 1-3 As shown, the switch integrated into the capacitor electrode includes an electrode 2 that is directly mounted on the charging electrode of the capacitor body 1 via threads, and an electrode 5 that is mounted on the discharge electrode. Adjacent stages are connected by a T-shaped inductor connecting strip 3, the two ends of which are pressed into the base of the first spark electrode electrode 2 of the preceding stage and the base of the second spark electrode electrode 5 of the following stage. Specifically: The switch consists of a threaded electrode 2 and an electrode 5. Electrode 2 is screwed into the charging electrode of the capacitor body 1, with its top end protruding 6mm from the body. Electrode 5 is screwed into the discharge electrode of the same specification. The distance between the end face and electrode 2 can be precisely adjusted by 1-3mm by the amount of screwing. The T-shaped inductor connecting strip 3 connects the adjacent stage. One end is pressure welded to the base of the preceding stage electrode 2, i.e., a 10mm diameter cylindrical base, and the other end is pressed into the base of the following stage electrode 5. The contact surface is pre-coated with 0.1mm thick conductive silver paste.

[0026] Example 3: As Figure 1-3 As shown, an open discharge gap is formed between adjacent stages by the front stage electrode 2 5 and the rear stage electrode 2 facing each other. The open discharge gap is exposed to the atmospheric environment and has no independent sealed cavity structure. The inductor connection strip 3 is a multi-layer stacked structure of 0.2mm thick copper foil, and the contact surface with the electrode base is coated with conductive silver paste.

[0027] Example 4: Figure 1-3 As shown, the capacitor body 1 has an insulating side plate 7 and an insulating side plate 8 on its upper and lower sides, respectively. The inner sides of the insulating side plates 7 and 8 are provided with positioning slots to engage the mounting bosses 4 and 6 of each stage to fix the linear stacked structure. The mounting bosses 4 and 6 are integrally molded glass fiber reinforced polyimide structures with pre-embedded stainless steel hexagonal nuts inside. The spacing tolerance of the positioning slots of the insulating side plates 7 and 8 is ≤0.1mm, and the depth of the slots is two-thirds of the height of the mounting bosses 4 and 6. The number of multi-stage energy storage units is 6. The length of the insulating side plates 7 and 8 matches the overall assembly size of the 6 stages, and their outer dimensions are less than 450mm×300mm×150mm.

[0028] Specifically: Six capacitor bodies 1, each with an outer diameter of 93mm × 81mm × 36mm, are arranged in a straight line. Each capacitor body 1 has a mounting boss 1 4 and a mounting boss 2 6 on both sides of its insulating shell. They are integrally formed from glass fiber reinforced polyimide and have pre-embedded stainless steel nuts. They are precisely engaged by the inner grooves of the upper insulating side plate 1 7 and the lower insulating side plate 2 8, with a tolerance of ≤0.1mm. The groove depth is 2 / 3 of the boss height, forming an axially rigid stack. The center distance between the electrodes of adjacent bodies 1 is strictly maintained at 72±0.5mm.

[0029] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A compact Marx generator based on a thin-film capacitor, comprising, characterized in that: The capacitor body (1) has an insulating shell and symmetrically arranged electrode one (2) for charging electrode and electrode two (5) for discharging electrode. The electrode one (2) and electrode two (5) form a gas spark switch and are directly threaded to the charging electrode of the film capacitor and the discharging electrode of the adjacent unit. The insulating shell of the capacitor body (1) is provided with mounting boss one (4) and mounting boss two (6) on both sides. The switch integrated into the capacitor electrode includes an electrode one (2) that is directly mounted on the charging electrode of the capacitor body (1) via threads, and an electrode two (5) that is mounted on the discharging electrode. An open discharge gap is formed between adjacent stages by the front stage electrode 2 (5) and the rear stage electrode 1 (2) facing each other; The capacitor body (1) is provided with an insulating side plate 1 (7) and an insulating side plate 2 (8) on its upper and lower sides respectively. The inner sides of the insulating side plate 1 (7) and the insulating side plate 2 (8) are provided with positioning slots to engage the mounting bosses 1 (4) and 2 (6) of each stage to fix the linear stacked structure.

2. A compact Marx generator based on a thin-film capacitor according to claim 1, characterized in that: The distance between electrode one (2) and electrode two (5) is 1-3 mm and can be continuously adjusted by screwing in the depth.

3. A compact Marx generator based on a thin-film capacitor according to claim 1, characterized in that: The axes of electrode one (2) and electrode two (5) are perpendicular to the electrode surface of capacitor body (1), and the threads of the two are M6-M10 metric threads.

4. A compact Marx generator based on a thin-film capacitor according to claim 1, characterized in that: Adjacent stages are connected by a T-shaped inductor connecting strip (3), the two ends of which are pressed onto the base of the first spark electrode (2) of the preceding stage and the base of the second spark electrode (5) of the following stage.

5. A compact Marx generator based on a thin-film capacitor according to claim 1, characterized in that: The mounting boss one (4) and mounting boss two (6) are integrally molded structures of glass fiber reinforced polyimide, with stainless steel hexagonal nuts pre-embedded inside.

6. A compact Marx generator based on a thin-film capacitor according to claim 1, characterized in that: The positioning slot spacing tolerance of the first insulating side plate (7) and the second insulating side plate (8) is ≤0.1mm, and the slot depth is two-thirds of the height of the first mounting boss (4) and the second mounting boss (6).

7. A compact Marx generator based on a thin-film capacitor according to claim 1, characterized in that: The external dimensions of the capacitor body (1) are 93mm×81mm×36mm, and the distance from the center point of the charging electrode to the center point of the discharging electrode is 72±0.5mm.

8. A compact Marx generator based on a thin-film capacitor according to claim 1, characterized in that: The open discharge gap is exposed to the atmospheric environment and has no independent sealed cavity structure.

9. A compact Marx generator based on a thin-film capacitor according to claim 4, characterized in that: The inductor connecting strip (3) is a multi-layered structure of 0.2mm thick copper foil, and the contact surface with the electrode base is coated with conductive silver paste.

10. A compact Marx generator based on a thin-film capacitor according to claim 1, characterized in that: The six capacitor bodies (1) form a multi-level energy storage unit. The lengths of the first insulating side plate (7) and the second insulating side plate (8) are matched with the total assembly dimensions of the 6th level, and their outer dimensions are less than 450mm×300mm×150mm.

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