High voltage nanosecond pulse coaxial line with cable connection between inner and outer cylinders

Abstract

The application provides a high-voltage nanosecond pulse coaxial line capable of realizing cable connection between inner and outer tubes, and can solve the problems of the cable connection mode between the inner and outer tubes of the existing coaxial line, which cannot meet the needs of various signal introduction, has weak anti-interference ability and poor reliability. The coaxial line comprises an outer tube, an inner tube, an insulating support body, a vortex-shaped hollow inductor and a multi-core cable arranged in the vortex-shaped hollow inductor. The insulating support body is sleeved outside the inner tube and located between the outer tube and the inner tube. The vortex-shaped hollow inductor is arranged on the outer wall of the insulating support body, and the two ends of the vortex-shaped hollow inductor are arranged in the outer tube and the inner tube and are in sealed connection with the outer tube and the inner tube. The outer diameter d L of the vortex-shaped hollow inductor, the inner diameter a of the outer tube and the outer diameter b of the inner tube satisfy the following relationship: (a-b) / [N×(d L +d)]≥sinθ, d is 0.5-2 times of d L , the average inter-turn electric field E is lower than the direct current breakdown field strength of the medium between the outer tube and the inner tube, and the corresponding inductive reactance value of the vortex-shaped hollow inductor under the nanosecond pulse

Description

Technical Field

[0001] This invention relates to a high-voltage nanosecond pulse coaxial cable, specifically a high-voltage nanosecond pulse coaxial cable that enables cable connection between inner and outer cylinders. Background Technology

[0002] In pulsed power technology, to transmit pulsed voltage or current with high power capacity, pulse drive sources and transmission lines typically employ coaxial cable structures, generating nanosecond-level, kilovolt-level high-voltage pulses between the inner and outer cylinders of the coaxial cable. With the development of technologies such as gas switches and high-power microwaves, scenarios have emerged requiring the laying of cables between the inner and outer cylinders of nanosecond pulse coaxial cables. These include power supply and control of the main switch trigger of a built-in pulse drive source, and optical signal transmission in an omnidirectional rotating antenna signal acquisition device, necessitating the laying of various types of cables such as power lines, signal lines, and optical fibers. Because transmitting high-voltage nanosecond pulses via coaxial cable generates a transient strong electromagnetic field between the inner and outer cylinders, it is crucial to prevent insulation failure between the inner and outer cylinders during cable laying to avoid introducing the transient strong electromagnetic field into the cable and interfering with the equipment, while also preventing nanosecond pulse attenuation.

[0003] There are three main cable connection methods between the inner and outer cylinders of existing high-voltage nanosecond pulse coaxial cables: (1) using an externally insulated metal wire to wind a conical spiral inductor between the inner and outer cylinders of the coaxial cable to ground or boost the voltage of the inner cylinder; (2) using a special high-voltage cable and an insulated sealing structure to introduce the electrical signal from the outer cylinder into the inner cylinder; (3) setting a coil on the inner cylinder and coupling it with the primary coil on the outer cylinder through a magnetic field to boost the voltage of the triggering device in the inner cylinder. However, the common problem with the above-mentioned cable connection methods between the inner and outer cylinders of high-voltage nanosecond pulse coaxial cables is that they cannot meet the requirements for introducing multiple types of signals, have weak anti-interference ability, and poor reliability. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problems of existing high-voltage nanosecond pulse coaxial cables, which have the inability to meet the requirements of various types of signal introduction, weak anti-interference ability, and poor reliability. The invention provides a high-voltage nanosecond pulse coaxial cable that can realize cable connection between inner and outer cylinders.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-voltage nanosecond pulse coaxial cable that enables cable connection between inner and outer cylinders is unique in that:

[0007] Includes outer cylinder, inner cylinder, insulating support, spiral hollow inductor, and multi-core cable;

[0008] The insulating support is a hollow frustum-shaped structure, which is fitted onto the outside of the inner cylinder and located between the outer cylinder and the inner cylinder.

[0009] The vortex-shaped hollow inductor is formed by winding a metal circular tube into a vortex shape. The vortex-shaped hollow inductor is mounted on the outer wall of an insulating support. Its two ends pass through the outer and inner cylinders respectively, and are sealed to both cylinders. The outer diameter d of the vortex-shaped hollow inductor... L The inner diameter 'a' of the outer cylinder and the outer diameter 'b' of the inner cylinder satisfy the following relationship: (ab) / [N×(d)] L +d)]≥sinθ, where N is the total number of turns of the vortex hollow inductor, d is the inter-turn distance of the vortex hollow inductor, and θ is the angle between the inner wall of the insulating support and the inner cylinder; the inter-turn distance d of the vortex hollow inductor is its outer diameter d L The average electric field E between turns is 0.5 to 2 times that of the outer cylinder and the inner cylinder, and is lower than the DC breakdown field strength of the dielectric between the outer and inner cylinders; the inductive reactance of the vortex hollow inductor under a nanosecond pulse is... Where, ε r2 The relative permittivity of the medium between the outer and inner cylinders;

[0010] The multi-core cable is run through and insulated from the vortex hollow inductor. One end of the cable near the outer cylinder is connected to a device for power supply and signal control, and the other end near the inner cylinder is connected to a device for switch triggering and signal monitoring.

[0011] Furthermore, a first base is provided on the outer wall of the outer cylinder;

[0012] A second base is provided on the inner wall of the inner cylinder;

[0013] The two ends of the vortex hollow inductor are respectively mounted on the first base and the second base; both the first base and the second base are equipped with sealing components to achieve sealing of the medium between the inner cylinder and the outer cylinder, and to achieve good electrical contact between the vortex hollow inductor and the inner cylinder and the outer cylinder.

[0014] Furthermore, the sealing assembly includes a screw-on sealing cap and a sealing gasket;

[0015] Both of the aforementioned spun sealing caps are fitted onto the outside of the vortex hollow inductor and are threaded onto the first base and the second base, respectively;

[0016] Both sealing gaskets are fitted around the outside of the spiral hollow inductor and are respectively positioned between the end of the spun sealing cap and the end of the first base, and between the end of the spun sealing cap and the end of the second base.

[0017] Furthermore, to improve reliability, the surface roughness Ra of the outer surface of the vortex hollow inductor is ≤6.3.

[0018] Furthermore, a vortex-shaped semi-cylindrical groove is formed along the axial direction on the outer wall of the insulating support; the vortex-shaped hollow inductor is disposed in the semi-cylindrical groove.

[0019] The relative permittivity ε of the insulating support r1 The relative permittivity ε of the medium between the outer and inner cylinders r2 The following relationship should be satisfied: |ε r1 -ε r2 | / ε r2 ≤0.5, which can reduce the electric field in the coaxial medium at the semi-cylindrical groove.

[0020] Furthermore, in order to further improve the installation stability of the vortex hollow inductor and the insulating support, the groove width of the semi-cylindrical groove is adapted to the outer diameter of the vortex hollow inductor, and the groove depth of the semi-cylindrical groove is not less than 1 / 2 of the outer diameter of the vortex hollow inductor.

[0021] The inner diameter of the small end of the insulating support is adapted to the outer diameter of the inner cylinder, and the outer diameter of the large end of the insulating support is adapted to the inner diameter of the outer cylinder.

[0022] Furthermore, the wall thickness h and the outer diameter d of the vortex hollow inductor are... L and the outer diameter d of the multi-core cable s The following relationship is satisfied between them: 2h+d s <d L .

[0023] Furthermore, the multi-core cable includes a dual-core DC power supply line and a dual-core trigger control line. The ends of the dual-core DC power supply line and the dual-core trigger control line near the outer cylinder are respectively connected to devices for power supply and signal control, and the ends near the inner cylinder are respectively connected to devices for switch triggering and signal monitoring.

[0024] Furthermore, both the spun sealing cap and the sealing gasket are made of metal.

[0025] Furthermore, the first base is integrally formed with the outer cylinder, or the first base is welded to the outer wall of the outer cylinder;

[0026] The second base is integrally formed with the inner cylinder, or the second base is welded to the inner wall of the inner cylinder.

[0027] The beneficial effects of this invention are:

[0028] 1. This invention provides a high-voltage nanosecond pulse coaxial cable that enables cable connection between inner and outer cylinders. By incorporating a vortex hollow inductor, multi-core cables are threaded through the vortex hollow inductor, enabling connection between the external coaxial cable and various types of cables within the inner cylinder. This satisfies the need to introduce various types of signals from the outside into the inner cylinder, and improves the flexibility of the deployment of triggering, control, and signal acquisition devices in the pulse power system.

[0029] 2. The present invention uses a vortex hollow inductor to achieve high-resistance isolation between the inner and outer cylinders under nanosecond pulses. The cable is sealed between the inner and outer cylinders with a vortex hollow inductor, which can completely shield the interference caused by high voltage nanosecond pulses to the internal cable and has strong anti-interference ability.

[0030] 3. This invention, through reasonable design of the inductive reactance value, does not affect the transmission of nanosecond pulses in the coaxial line. By controlling the inter-turn distance and average electric field between turns of the vortex hollow inductor, the introduction of this structure will not cause inter-turn breakdown or insulation failure between the inner and outer cylinders, thus ensuring reliable insulation under high voltage nanosecond pulses.

[0031] 4. This invention has the advantages of high voltage resistance and a simple and reliable sealing structure. The surface roughness Ra of the outer surface of the vortex hollow inductor in this invention is ≤6.3, which can avoid local electric field enhancement under high voltage, thereby improving reliability. In addition, the relative permittivity of the insulating support is similar to that of the medium between the outer and inner cylinders, which can reduce the electric field in the coaxial medium at the semi-cylindrical groove. Attached Figure Description

[0032] Figure 1 This is a three-dimensional structural schematic diagram of an embodiment of the high-voltage nanosecond pulse coaxial cable of the present invention that enables cable connection between inner and outer cylinders;

[0033] Figure 2 yes Figure 1 View from direction B;

[0034] Figure 3 yes Figure 2 AA-direction cross section;

[0035] Figure 4 yes Figure 3 A magnified view of a section at point I;

[0036] Figure 5 yes Figure 3 Enlarged view of a section at point II;

[0037] Figure 6 This refers to the voltage waveforms of the nanosecond pulse transmitted in this embodiment of the invention before and after passing through the vortex hollow inductor;

[0038] Figure 7These are the trigger signal waveforms before and after entering the vortex hollow inductor during high-voltage nanosecond pulse transmission in this embodiment of the invention.

[0039] Figure 8 This refers to the DC voltage waveforms before and after entering the vortex hollow inductor during high-voltage nanosecond pulse transmission in this embodiment of the invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1-Spinning sealing cap, 2-Whirlpool hollow inductor, 3-Multi-core cable, 31-Dual-core DC power cable, 32-Dual-core trigger control cable, 4-Insulating support body, 41-Semi-cylindrical groove, 5-Outer cylinder, 51-First base, 6-Inner cylinder, 61-Second base, 7-Sealing assembly, 8-Sealing gasket. Detailed Implementation

[0042] like Figures 1-5 As shown, a high-voltage nanosecond pulse coaxial cable capable of connecting cables between inner and outer cylinders includes an outer cylinder 5, an inner cylinder 6, an insulating support 4, a spiral hollow inductor 2, and a multi-core cable 3. Specifically, a first base 51 is welded to the outer wall of the outer cylinder 5, and a second base 61 is welded to the inner wall of the inner cylinder 6. In other embodiments, the first base 51 is integrally formed with the outer cylinder 5, and the second base 61 is integrally formed with the inner cylinder 6. The insulating support 4 has a hollow frustum-shaped structure and is fitted onto the outside of the inner cylinder 6, located between the outer cylinder 5 and the inner cylinder 6. The inner diameter of the small end of the insulating support 4 matches the outer diameter of the inner cylinder 6, and the outer diameter of the large end of the insulating support 4 matches the inner diameter of the outer cylinder 5. A vortex-shaped semi-cylindrical groove 41 is formed along the axial direction on the outer wall of the insulating support 4. The vortex-shaped hollow inductor 2 is formed by winding a round copper tube in a vortex pattern. The vortex-shaped hollow inductor 2 is placed in the semi-cylindrical groove 41. The groove width of the semi-cylindrical groove 41 is adapted to the outer diameter of the vortex-shaped hollow inductor 2, and the groove depth of the semi-cylindrical groove 41 is not less than 1 / 2 of the outer diameter of the vortex-shaped hollow inductor 2. The two ends of the vortex-shaped hollow inductor 2 are respectively mounted on the first base 51 and the second base 61. A sealing assembly 7 is installed on both the first base 51 and the second base 61. Each sealing assembly 7 includes a spiral... The sealing cap 1 and sealing gasket 8 are made of metal. Both sealing caps 1 are fitted onto the outside of the spiral hollow inductor 2 and are threaded onto the first base 51 and the second base 61, respectively. The two sealing gaskets 8 are fitted onto the outside of the spiral hollow inductor 2 and are respectively positioned between the ends of the sealing cap 1 and the first base 51, and between the ends of the sealing cap 1 and the second base 61. This is used to seal the medium between the inner cylinder 6 and the outer cylinder 5, and to ensure good electrical contact between the spiral hollow inductor 2 and the inner and outer cylinders 6 and 5. The surface roughness Ra of the outer surface of the spiral hollow inductor 2 is 6.3. The outer diameter d of the spiral hollow inductor 2 is... LThe inner diameter a of outer cylinder 5 and the outer diameter b of inner cylinder 6 satisfy the following relationship: (ab) / [N×(d L +d)]≥sinθ, where N is the total number of turns of the vortex hollow inductor 2, d is the inter-turn distance of the vortex hollow inductor 2, and θ is the angle between the inner wall of the insulating support 4 and the inner cylinder 6. The inter-turn distance d of the vortex hollow inductor 2 is its outer diameter d L The average electric field E between turns is 0.5 to 2 times that of the inner cylinder 6, which is lower than the DC breakdown field strength of the dielectric between the outer cylinder 5 and the inner cylinder 6. E = U / (N×d), where U is the peak voltage of the pulse. The inductive reactance of the vortex hollow inductor 2 under a nanosecond pulse is... Where, ε r2 ε represents the relative permittivity of the medium between the outer cylinder 5 and the inner cylinder 6. The relative permittivity ε of the insulating support 4 is also given. r1 The relative permittivity ε of the medium between the outer cylinder 5 and the inner cylinder 6 r2 The following relationship should be satisfied: |ε r1 -ε r2 | / ε r2 ≤0.5.

[0043] A multi-core cable 3 is threaded inside a spiral hollow inductor 2. Its outer diameter is smaller than the inner diameter of the spiral hollow inductor 2, and the outer sheath of the multi-core cable 3 is insulated from the spiral hollow inductor 2. The wall thickness h and outer diameter d of the spiral hollow inductor 2 are specified. L And the outer diameter d of the multi-core cable 3 s The following relationship is satisfied between them: 2h+d s <d L In this embodiment, the multi-core cable 3 includes a 700V dual-core DC power supply line 31 and a dual-core trigger control line 32. The ends of the 700V dual-core DC power supply line 31 and the dual-core trigger control line 32 near the outer cylinder 5 are respectively connected to devices for power supply and signal control, and the ends near the inner cylinder 6 are respectively connected to devices for switch triggering and signal monitoring.

[0044] In this embodiment, the impedance of the coaxial line The coaxial cable has a resistance of 45Ω and is used to transmit pulses with a voltage of 400kV and a pulse width of 20ns. The inner diameter a of the outer cylinder 5 is 280mm, the outer diameter b of the inner cylinder 6 is 90mm, the dielectric is No. 45 transformer oil, and the relative permittivity ε is 45. r2 The dielectric constant is 2.3, and the material of the insulating support 4 is MC nylon with a relative permittivity ε. r1 The groove depth of the semi-cylindrical groove 41 of the insulating support 4 is 4mm, and the groove spacing is the same as the turn spacing. The outer diameter d of the vortex hollow inductor 2 is... LThe diameter is 7mm, the wall thickness h is 1mm, the total number of turns N is 10, the inter-turn distance d is 6mm, and the angle θ between the inner wall of the insulating support 4 and the inner cylinder 6 is 40°. Based on the inductance formula, the inductance of the vortex hollow inductor 2 is approximately 30μH. Under a pulse with a pulse width of 20ns, the inductive reactance X of the vortex hollow inductor 2 is... L It is approximately 4.7kΩ, about 105 times the impedance of a 45Ω coaxial line. The average electric field E between turns is 67kV / cm, which is less than the DC breakdown field strength of No. 45 transformer oil.

[0045] Figure 6 The figure shows the voltage waveforms of the nanosecond pulse transmitted in this embodiment before and after passing through the vortex hollow inductor 2. As can be seen from the figure, the pulse waveforms before and after passing through the vortex hollow inductor 2 are consistent, and the vortex hollow inductor 2 does not affect the transmission of the nanosecond pulse.

[0046] Figure 7 This is the trigger signal waveform before and after entering the vortex hollow inductor 2 during high-voltage nanosecond pulse transmission in this embodiment. Figure 8 This is the DC voltage waveform before and after entering the vortex hollow inductor 2 during high-voltage nanosecond pulse transmission in this embodiment. Figure 7 and Figure 8 It can be seen that the vortex hollow inductor 2 realizes the transmission of both trigger and DC voltage signals between the inner cylinder 6 and the outer cylinder 5, and these two signals are not affected by the high voltage nanosecond pulse in the coaxial line.

[0047] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-voltage nanosecond pulse coaxial cable capable of connecting cables between inner and outer cylinders, characterized in that: It includes an outer cylinder (5), an inner cylinder (6), an insulating support (4), a spiral hollow inductor (2), and a multi-core cable (3); The insulating support (4) is a hollow frustum structure. The insulating support (4) is fitted on the outside of the inner cylinder (6) and is located between the outer cylinder (5) and the inner cylinder (6). The vortex hollow inductor (2) is formed by winding a metal tube in a vortex pattern. The vortex hollow inductor (2) is disposed on the outer wall of the insulating support (4). The two ends of the vortex hollow inductor (2) are respectively inserted into the outer cylinder (5) and the inner cylinder (6) and are sealed to the outer cylinder (5) and the inner cylinder (6); the outer diameter d of the vortex hollow inductor (2) L The inner diameter a of the outer cylinder (5) and the outer diameter b of the inner cylinder (6) satisfy the following relationship: (ab) / [N×(d L +d)]≥sinθ, where N is the total number of turns of the vortex hollow inductor (2), d is the inter-turn distance of the vortex hollow inductor (2), and θ is the angle between the inner wall of the insulating support (4) and the inner cylinder (6); the inter-turn distance d of the vortex hollow inductor (2) is its outer diameter d L The average electric field E between turns is 0.5 to 2 times that of the outer cylinder (5) and inner cylinder (6), which is lower than the DC breakdown field strength of the medium between the outer cylinder (5) and inner cylinder (6); the inductive reactance value of the vortex hollow inductor (2) under nanosecond pulse is 0.5 to 2 times that of the inner cylinder (6). Where, ε r2 The relative permittivity of the medium between the outer cylinder (5) and the inner cylinder (6); The multi-core cable (3) is run through the vortex hollow inductor (2) and is insulated from the vortex hollow inductor (2). One end of the cable near the outer cylinder (5) is connected to a device for power supply and signal control, and the other end near the inner cylinder (6) is connected to a device for switch triggering and signal monitoring. A first base (51) is provided on the outer wall of the outer cylinder (5); A second base (61) is provided on the inner wall of the inner cylinder (6); The two ends of the vortex hollow inductor (2) are respectively mounted on the first base (51) and the second base (61); both the first base (51) and the second base (61) are equipped with sealing components (7) to achieve sealing of the medium between the inner cylinder (6) and the outer cylinder (5), and to achieve good electrical contact between the vortex hollow inductor (2) and the inner cylinder (6) and the outer cylinder (5); The sealing assembly (7) includes a spun sealing cap (1) and a sealing gasket (8); Both of the aforementioned spun sealing caps (1) are sleeved on the outside of the vortex hollow inductor (2) and are respectively threaded onto the first base (51) and the second base (61); Both sealing gaskets (8) are fitted on the outside of the vortex hollow inductor (2) and are respectively located between the ends of the spun sealing cap (1) and the first base (51) and between the ends of the spun sealing cap (1) and the second base (61).

2. The high-voltage nanosecond pulse coaxial cable for connecting inner and outer cylinders according to claim 1, characterized in that: The surface roughness Ra of the outer surface of the vortex hollow inductor (2) is ≤6.

3.

3. The high-voltage nanosecond pulse coaxial cable for connecting inner and outer cylinders according to claim 2, characterized in that: The outer wall of the insulating support (4) is provided with a vortex-shaped semi-cylindrical groove (41) along the axial direction; the vortex-shaped hollow inductor (2) is disposed in the semi-cylindrical groove (41); The relative permittivity ε of the insulating support (4) r1 The relative permittivity ε of the medium between the outer cylinder (5) and the inner cylinder (6) r2 The following relationship should be satisfied: |ε r1 -ε r2 | / ε r2 ≤0.

5.

4. The high-voltage nanosecond pulse coaxial cable for connecting inner and outer cylinders according to claim 3, characterized in that: The width of the semi-cylindrical groove (41) is adapted to the outer diameter of the vortex hollow inductor (2), and the depth of the semi-cylindrical groove (41) is not less than 1 / 2 of the outer diameter of the vortex hollow inductor (2). The inner diameter of the small end of the insulating support (4) is adapted to the outer diameter of the inner cylinder (6), and the outer diameter of the large end of the insulating support (4) is adapted to the inner diameter of the outer cylinder (5).

5. The high-voltage nanosecond pulse coaxial cable for connecting inner and outer cylinders according to claim 4, characterized in that: The wall thickness h and outer diameter d of the vortex hollow inductor (2) are... L and the outer diameter d of the multi-core cable (3) s The following relationship is satisfied between them: 2h+d s <d L .

6. The high-voltage nanosecond pulse coaxial cable for connecting inner and outer cylinders according to claim 5, characterized in that: The multi-core cable (3) includes a dual-core DC power supply line (31) and a dual-core trigger control line (32). The ends of the dual-core DC power supply line (31) and the dual-core trigger control line (32) near the outer cylinder (5) are respectively connected to devices for power supply and signal control, and the ends near the inner cylinder (6) are respectively connected to devices for switch triggering and signal monitoring.

7. The high-voltage nanosecond pulse coaxial cable for connecting inner and outer cylinders according to claim 1, characterized in that: Both the spun sealing cap (1) and the sealing gasket (8) are made of metal.

8. The high-voltage nanosecond pulse coaxial cable for connecting inner and outer cylinders according to claim 7, characterized in that: The first base (51) is integrally formed with the outer cylinder (5), or the first base (51) is welded to the outer wall of the outer cylinder (5); The second base (61) is integrally formed with the inner cylinder (6), or the second base (61) is welded to the inner wall of the inner cylinder (6).

Images