Controllable shock wave fast pulse high-voltage cable and preparation method thereof

Abstract

The invention provides a controllable shock wave fast pulse high-voltage cable and a preparation method thereof, and the cable comprises a conductor which is a solid copper conductor; the conductor shielding layer and the insulating layer are tightly coated on the conductor by adopting a double-layer co-extrusion process; the eccentricity of the insulating layer is less than or equal to 3%; the semi-conductive tape wrapping layer is tightly wrapped outside the insulating layer by adopting a semi-conductive nylon tape; the braided shielding layer is braided outside the semi-conductive tape wrapping layer by adopting tinned copper wires; and the sheath layer is extruded outside the braided shielding layer by adopting a polyurethane elastomer material and is shaped by a sectional cooling process. A conductor solid structure and ultralow insulation eccentricity control are adopted to form a synergistic effect, interface defects and electric field distortion are effectively inhibited, the tolerance limit of a conventional cable is broken through, meanwhile, the polyurethane elastomer outer sheath is combined with a segmented cooling process, the mechanical strength and toughness of the sheath are improved, and the service life of the cable is prolonged. And a key guarantee is provided for reliable operation of shock wave equipment under limiting conditions.

Description

Technical Field

[0001] This invention relates to the field of special cable technology, specifically to a controllable shock wave fast pulse high voltage cable and its preparation method, which is specifically designed for transmitting nanosecond to microsecond level fast pulses, high voltage (peak value ≥ 500kV) and large current. It is particularly suitable for connecting high voltage pulse power supplies and shock wave generating devices (such as geological exploration, underground crushing equipment, shock wave medical equipment, etc.) to transmit electrical energy. Background Technology

[0002] Controlled shock wave technology plays an irreplaceable role in resource exploration, hard rock fracturing, and medical lithotripsy. Its core relies on high-voltage cables capable of efficiently and reliably transmitting fast pulse currents with extremely fast rise times (wavefront time ≤ 1.5 μs) and extremely high peak values ​​(voltage ≥ 500 kV). In this fast-pulse scenario, the cable must simultaneously meet the performance requirements of high pulse transmission efficiency, low signal distortion, high withstand voltage reliability, and good mechanical stability to adapt to complex operating conditions.

[0003] However, current cable structures and manufacturing methods struggle to simultaneously meet the aforementioned synergistic performance requirements, and generally suffer from the following drawbacks:

[0004] 1. Low pulse transmission efficiency due to high-frequency skin effect and eddy current loss: Traditional stranded copper conductors have gaps between the strands, which generate significant eddy currents under high-frequency pulses, resulting in a significant decrease in pulse transmission efficiency. In addition, conductor oxidation at high temperatures increases resistance.

[0005] 2. Strong electric field distortion and poor insulation reliability: Micro-gaps, impurities or process defects (eccentricity > 5%) inside or at the interface of the insulation layer can easily cause partial discharge. Under repeated fast pulse high voltage impacts, the insulation material will deteriorate rapidly, seriously threatening the pulse voltage withstand life of the cable.

[0006] 3. Insufficient shielding effectiveness and mechanical protection: Traditional copper strip wrapping shields are prone to cracking and failure under dynamic bending conditions; when the braided shielding density is less than 80%, it cannot meet the high requirements of electromagnetic shielding in fast pulse scenarios. Conventional rubber sheaths are prone to hardening and cracking in harsh environments such as oil stains and vibrations, resulting in loss of sealing and protective functions.

[0007] Given the limitations of existing technologies, it is urgent to develop a new type of cable and its manufacturing method to fill the technological gap in high-voltage cables for controllable shock waves. Summary of the Invention

[0008] The purpose of this invention is to overcome the defects of the prior art and provide a controllable shock wave fast pulse high voltage cable and its preparation method, which can solve the problems in the prior art.

[0009] To achieve the above and other objectives, the present invention is implemented through the following technical solutions: As a first aspect, the present invention proposes a controllable shock wave fast pulse high-voltage cable, comprising a conductor, which is a solid copper conductor; a conductor shielding layer and an insulation layer, which are tightly wrapped on the conductor using a one-time molding double-layer co-extrusion process; the eccentricity of the insulation layer is ≤3%; a semi-conductive tape wrapping layer, which is made of semi-conductive nylon tape tightly wrapped around the insulation layer, with a wrapping overlap rate ≥20%; a braided shielding layer, which is made of tin-plated copper wire braided around the semi-conductive tape wrapping layer, with a braiding density ≥85%; and a sheath layer, which is made of polyurethane elastomer material extruded outside the braided shielding layer and shaped by a segmented cooling process.

[0010] In one embodiment, the conductor cross-sectional area of ​​the conductor is determined according to the adiabatic calculation formula and operating conditions.

[0011] In one embodiment, the conductor shielding layer is made of a cross-linked semiconducting material; the insulating layer is made of ultra-pure cross-linked polyethylene material.

[0012] In one embodiment, the nominal thickness and the thinnest point insulation thickness of the insulation layer are calculated using a formula. Calculate, where: U BIL K'1 is the reference impact strength; K'2 is the repeated impact aging coefficient; K'3 is the insulation temperature coefficient; E is the safety margin. L(imp) The electric field strength of the material under impact.

[0013] In one embodiment, the braiding angle of each tin-plated copper wire is controlled between 40° and 50°.

[0014] As a first aspect, the present invention proposes a method for preparing a controllable shock wave fast pulse high-voltage cable, comprising:

[0015] Step 1: Select conductor material according to operating conditions, and determine the required conductor cross-sectional area according to the thermal insulation method calculation formula; calculate and determine the nominal thickness and the thinnest point insulation thickness of the insulation layer;

[0016] Step 2: Prepare a solid conductor with a corresponding conductor diameter based on the cross-sectional area of ​​the conductor;

[0017] Step 3: Co-extrude a conductor shielding layer and an insulation layer on the outside of the conductor; during the extrusion process, use an online diameter measuring instrument to monitor the outer diameter of the insulation layer in real time, and adjust the process parameters based on the real-time feedback system to ensure that the eccentricity of the insulation layer is ≤3%;

[0018] Step 4: Wrap a semi-conductive nylon tape around the outside of the insulation layer to form a semi-conductive tape wrapping layer, and control the wrapping overlap rate to be ≥20%.

[0019] Step 5: A shielding layer is woven using tin-plated copper wire outside the semiconductive strip wrapping layer, with a weaving density ≥ 85%.

[0020] Step 6: Extruding a sheath layer using polyurethane elastomer material outside the braided shielding layer; the extrusion process uses a semi-extrusion mold and is simultaneously vacuumed, and the extruded sheath material is shaped using a segmented cooling process.

[0021] In one embodiment, the nominal thickness and the thinnest point insulation thickness of the insulation layer are calculated according to the formula. Calculate, where: U BIL K'1 is the reference impact strength; K'2 is the repeated impact aging coefficient; K'3 is the insulation temperature coefficient; E is the safety margin. L(imp) The electric field strength of the material under impact.

[0022] In one embodiment, in step three, the double-layer co-extrusion is followed by vulcanization in a vulcanization pipeline for cross-linking and curing of the conductor shielding layer and the insulation layer.

[0023] In one embodiment, in step five, each tin-plated copper wire entering the braiding machine is subjected to independent and precise tension control, while the braiding angle is controlled between 40° and 50°; welding of the entire strand of tin-plated copper wire is prohibited.

[0024] In one embodiment, in step six, the segmented cooling process involves first slow cooling with hot water at 45°C to 60°C for 1 to 3 minutes, followed by rapid cooling with cold water at 15°C to 30°C for shaping.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. The controllable shock wave fast pulse high voltage cable provided by this invention has excellent and reliable pulse withstand voltage performance: the solid conductor and the ultra-low insulation layer eccentricity (≤3%) work synergistically to significantly reduce conductor loss and effectively suppress interface defects and electric field distortion; under extremely harsh over-temperature conditions (5-10℃ above the rated limit), it breaks through the withstand limit of conventional cables and can continuously withstand 500 negative polarity 500kV lightning impulses of specific waveforms (wavefront 1.0-1.4μs, half peak 40-60μs) without breakdown;

[0027] 2. The controllable shock wave fast pulse high voltage cable provided by this invention has excellent mechanical and dynamic properties: the optimized polyurethane elastic outer sheath combined with the segmented cooling process gives the sheath extremely high mechanical strength (≥33MPa) and toughness (elongation at break ≥590%), effectively resisting wear, hardening and cracking under harsh working conditions such as oil stains, vibration, and repeated bending, ensuring long-term sealed protection.

[0028] 3. The controllable shock wave fast pulse high voltage cable provided by this invention has high-precision structural consistency and stability: the double-layer co-extrusion process of the conductor shielding layer and the insulation layer and the real-time online diameter measurement feedback control achieve an eccentricity of ≤3% for the thick insulation layer (outer diameter 25mm), which fundamentally reduces the risk of partial discharge caused by geometric inhomogeneity and ensures the long-term reliability of the insulation system; at the same time, the precise tension and angle control (40°-50°) of the braided shielding layer ensures high braiding density (≥85%) and a flat surface, providing stable and efficient electromagnetic shielding. Attached Figure Description

[0029] Figure 1 The diagram shown is a structural schematic of a controllable shock wave fast pulse high-voltage cable according to the present invention.

[0030] Figure 2 The diagram shows a process flow diagram of a controllable shock wave fast pulse high voltage cable according to the present invention. Detailed Implementation

[0031] This invention provides a controllable shock wave fast pulse high voltage cable and its preparation method, which solves the problems of low pulse transmission efficiency, poor pulse voltage tolerance, insufficient shielding effectiveness and mechanical protection in existing cables, making them unsuitable for complex working conditions of controllable shock waves.

[0032] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. It should be understood that the present invention is not limited to the exemplary embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. It should also be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0033] The overall concept of the technical solution provided by this invention is as follows: A controllable shock wave fast pulse high-voltage cable includes a conductor, which is a solid copper conductor; a conductor shielding layer and an insulation layer, which are tightly wrapped on the conductor by a one-time molding double-layer co-extrusion process; the eccentricity of the insulation layer is ≤3%; a semi-conductive tape wrapping layer, which is made of semi-conductive nylon tape tightly wrapped around the insulation layer, with a wrapping overlap rate ≥20%; a braided shielding layer, which is made of tin-plated copper wire braided around the semi-conductive tape wrapping layer, with a braiding density ≥85%; and a sheath layer, which is made of polyurethane elastomer material extruded outside the braided shielding layer and shaped by a segmented cooling process.

[0034] Its main concept is that the use of a solid conductor structure and ultra-low insulation eccentricity control creates a synergistic effect, effectively suppressing interface defects and electric field distortion, breaking through the tolerance limit of conventional cables. At the same time, the polyurethane elastic outer sheath combined with segmented cooling process improves the mechanical strength and toughness of the sheath, providing a key guarantee for the reliable operation of shock wave equipment under extreme conditions.

[0035] After introducing the basic principles of the present invention, various non-limiting embodiments of the present invention will be described in detail below.

[0036] like Figure 1 As shown, the present invention provides a controllable shock wave fast pulse high voltage cable, the structure of which, from the inside out, consists of a conductor 1, a conductor shielding layer 2, an insulation layer 3, a semi-conductive tape wrapping layer 4, a braided shielding layer 5, and a sheath layer 6.

[0037] Conductor 1 is a high-purity (purity ≥ 99.99%) solid copper conductor. The copper conductor is selected and its cross-sectional area is determined according to the adiabatic method calculation formula recommended by IEC 60986 and the operating conditions. For example, considering harsh operating conditions: peak pulse current 25kA, half-life 350μs, energy dissipation time 5ms, pulse interval 30min, ambient temperature 30℃; the copper conductor parameter is taken as: K = 226As. 1 / 2 / mm 2 β=234.5K, σ c ×10 6 = 3.45 J / K·m3, ρ 20 ×10 -8 = 1.7241 Ω·m; the cross-sectional area of ​​the conductor required to ensure that the temperature rise does not exceed 90℃ is calculated to be 16 mm². 2 To ensure both conductor compactness and airtightness at the interface with insulation, a solid 16mm conductor was selected. 2 Copper conductor (corresponding to a diameter of 4.5±0.1mm). This structure completely eliminates the strand gaps in the stranded conductor, significantly reducing high-frequency eddy current losses and skin effect, and improving pulse transmission efficiency.

[0038] The conductor shielding layer 2 and the insulation layer 3 are tightly coated onto the conductor 1 using a one-time double-layer co-extrusion process. The conductor shielding layer 2 is a cross-linked semi-conductive material; the insulation layer 3 is made of ultra-pure cross-linked polyethylene material, as calculated by the formula: (where: U) BIL K'1 is the reference impact strength; K'2 is the repeated impact aging coefficient; K'3 is the insulation temperature coefficient; E is the safety margin. L(imp) The nominal thickness and thinnest point insulation thickness of the insulation layer are determined based on the material selection (to determine the impact electric field strength). For example, in a design with a 500kV impulse voltage, at U... BIL=500kV; K'1=1.05; K'2=1.00; K'3=1.05, E L(imp) To determine the impact electric field strength of the ultra-pure cross-linked polyethylene material, and considering production margins, the nominal thickness of insulation layer 3 was determined to be 9.3 mm, with a minimum thickness of 8.36 mm. Simultaneously, through precise process control using an online diameter gauge and a real-time feedback system, the eccentricity of insulation layer 3 was ensured to be ≤3% (corresponding to a nominal outer diameter of approximately 25 mm). This ultra-low eccentricity insulation layer 3 effectively eliminated air gaps at the insulation interface, significantly suppressing local electric field distortion.

[0039] The semi-conductive tape wrapping layer 4 is made of semi-conductive nylon tape tightly wrapped around the insulation layer 3 with a wrapping overlap rate of ≥20%, ensuring that there is no air gap between it and the surface of the insulation layer 3, and providing a uniform transition electric field.

[0040] The braided shielding layer 5 is made of tin-plated copper wire woven around the semi-conductive strip wrapping layer 4. By precisely controlling the braiding angle (40°~50°) and the tension uniformity of each copper wire, and prohibiting the welding of whole strands, the surface of the braided shielding layer 5 is ensured to be flat and the braiding density is ≥85%, so as to provide excellent electromagnetic shielding performance and flexibility.

[0041] The sheath layer 6 is made of polyurethane elastomer material extruded and molded outside the braided shielding layer. Combining a semi-extrusion die and a synchronous vacuum process to reduce the stretch ratio, as well as a segmented cooling and shaping process, the sheath is endowed with high density, excellent mechanical strength and elongation, as well as excellent resistance to oil stains, wear and dynamic fatigue.

[0042] like Figure 2 As shown, this invention provides a method for preparing a controllable shock wave fast pulse high-voltage cable, comprising the following steps:

[0043] Step 1: Select the conductor material according to the operating conditions, and determine the required conductor cross-sectional area according to the thermal insulation method calculation formula. Calculate the nominal thickness and the thinnest point insulation thickness of the insulation layer, where: U BIL K'1 is the reference impact strength; K'2 is the repeated impact aging coefficient; K'3 is the insulation temperature coefficient; E is the safety margin. L(imp) The impact electric field strength of the material;

[0044] Step 2: Prepare a solid conductor 1 with a corresponding conductor diameter based on the conductor cross-sectional area;

[0045] Step 3: Co-extrude conductor shielding layer 2 and insulation layer 3 on the outside of conductor 1; during the extrusion process, use an online diameter measuring instrument to monitor the outer diameter of insulation layer 3 in real time, and adjust the process parameters based on the real-time feedback system to ensure that the eccentricity of insulation layer 3 is ≤3%;

[0046] Step 4: Wrap a semi-conductive nylon tape around the outside of the insulation layer 3 to form a semi-conductive tape wrapping layer 4. Strictly control the wrapping overlap rate to ≥20%, and precisely adjust the wrapping angle and tension to ensure that the semi-conductive nylon tape is tightly attached to the surface of the insulation layer 3, avoid introducing air gaps, form a uniform electric field transition layer, and avoid the risk of partial discharge.

[0047] Step 5: Braid the shielding layer 5 using tin-plated copper wire outside the semiconductive strip wrapping layer 4;

[0048] Specifically, during the braiding process of the shielding layer 5, precise tension control of the strands is implemented to ensure uniform stress on each copper wire, and the braiding angle is strictly controlled between 40° and 50°; this angle range optimizes the flexibility and uniformity of the shielding layer. Soldering of entire strands of copper wire is prohibited. Through these controls, the final braided shielding layer 5 has a smooth surface and a braiding density of over 85%, providing excellent electromagnetic shielding effectiveness and structural stability.

[0049] Step 6: Polyurethane elastomer material is extruded and coated onto the sheath layer 6 outside the braided shielding layer 5. A semi-extrusion mold is used during the extrusion process and vacuuming is performed simultaneously to effectively reduce the stretch ratio of the molten polyurethane during the extrusion molding process, improve the density of the sheath layer 6 and the adhesion between the sheath layer 6 and the braided shielding layer 5, and reduce internal voids. The extruded sheath material is shaped using a segmented cooling process, which first slow-cools it with hot water at 45℃~60℃ and then rapidly cools it with cold water at 15℃~30℃, to obtain a controllable shock wave fast pulse high voltage cable.

[0050] Example 1:

[0051] The following section uses a harsh operating condition (reference impact strength 500kV, peak pulse current 25kA, half-life 350μs, energy dissipation time 5ms, pulse interval 30min, ambient temperature 30℃) as an example to detail the manufacturing process of a controllable shock wave fast pulse high-voltage cable adapted to the operating conditions:

[0052] Step 1: Select a high-quality, oxygen-free round copper rod with a purity ≥ 99.99% as the conductor material, based on the operating conditions. The initial diameter is 9.5mm. The copper conductor parameter is: K = 226As. 1 / 2 / mm 2 β=234.5K, σ c ×10 6 = 3.45 J / K·m3, ρ 20 ×10 -8 = 1.7241 Ω·m. Based on the adiabatic calculation formula, the conductor cross-sectional area required to ensure a temperature rise of no more than 90℃ is 16 mm². 2 According to the calculation formula: (where: U) BIL=500kV; K'1=1.05; K'2=1.00; K'3=1.05) The nominal thickness of insulation layer 3 is calculated to be 9.3mm, and the thinnest point is not less than 8.36mm.

[0053] Step 2: Feed the 9.5mm diameter round copper rod into a precision copper extrusion machine for one-time extrusion molding. Precisely control the extrusion die and process parameters to ensure that the diameter of the solid copper conductor 1 after molding is 4.5±0.1mm (corresponding to a cross-sectional area of ​​approximately 16mm²). 2 Use a high-precision micrometer or laser diameter gauge for online or offline inspection to ensure that the diameter tolerance meets the requirements. At the same time, adjust the mold size according to the DC resistance test results of the copper wire to ensure that the resistance is qualified. Regularly check the cooling system to prevent the copper wire from oxidizing at high temperature.

[0054] Step 3: Simultaneously extrude the conductor shielding layer 2 and the insulation layer 3 using a double-layer co-extrusion unit equipped with a precision temperature control system and an independent screw. The conductor shielding layer 2 is a cross-linked internal semi-conductive shielding material (nominal thickness 1.0 mm). The temperature settings for each zone (8 zones in total) of the extruder are: 62℃, 102℃, 105℃, 112℃, 111℃, 44℃, 112℃, and 89℃, with the deviation of each zone strictly controlled within ±2℃. The screw speed is 6.61±1 rpm. The insulation layer 3 uses ultra-pure cross-linked polyethylene insulation material (nominal thickness 9.3 mm, nominal outer diameter approximately 25 mm). The temperature settings for each zone (10 zones in total) of the extruder are: 86℃, 125℃, 124℃, 121℃, 120℃, 125℃, 118℃, 106℃, 118℃, and 119℃, with the deviation of each zone strictly controlled within ±2℃. The screw speed is 14.83±1 rpm. After double-layer co-extrusion, the material enters a vulcanization pipeline for cross-linking and curing. The temperatures of each zone (a total of 8 zones) in the vulcanization pipeline are set as follows: 252℃, 252℃, 253℃, 216℃, 251℃, 252℃, 254℃, and 246℃, with temperature deviations strictly controlled within ±2℃; the pipeline pressure is set at 7.6 ± 0.3 Bar. This vulcanization process is carried out under precisely controllable high temperature (approximately 250℃) and pressure (7.6 Bar) conditions to ensure strict control of the cross-linking degree of the two layers, thereby achieving good interfacial fusion and eliminating air gaps.

[0055] The above-mentioned start-up process parameters (including extrusion and vulcanization parameters) are determined in advance by special process control software based on material characteristics and production line speed, and are monitored and adjusted in real time during production to ensure that the eccentricity of the insulation layer 3 is controlled within ≤3%.

[0056] Step 4: Tightly wrap the outer surface of the insulation layer 3 with semi-conductive nylon tape to form a semi-conductive tape wrapping layer 4. The wrapping overlap rate should be strictly controlled to ≥20% to ensure complete coverage without any exposed areas.

[0057] Step 5: Braid the shielding layer 5 using tin-plated copper wire outside the semi-conductive strip wrapping layer 4. Implement independent and precise tension control for each tin-plated copper wire entering the braiding machine, while strictly controlling the braiding angle between 40° and 50°. Soldering the tin-plated copper wire in whole strands is prohibited. Single wire joints are allowed, but they must be firm and reliable, and the joint length and position must be strictly controlled to avoid affecting surface flatness and electrical continuity. Ensure that the final braided shielding layer 5 has a smooth and flat surface, without protrusions or depressions, and that the braiding density reaches at least 85%.

[0058] Step Six: Polyurethane elastomer material is extruded from the braided shielding layer 5 using a semi-extrusion die. Simultaneously, the vacuum system is activated to apply negative pressure to the sheath at the die opening. The extruded sheath is then shaped using a segmented cooling process.

[0059] First stage (slow cooling): The extruded sheath is immediately placed in a hot water bath at 45℃~60℃ for slow cooling for 1min~3min. This stage effectively releases the internal stress of processing through slow cooling, avoids surface stress cracking or uneven local shrinkage caused by rapid cooling, and at the same time inhibits the tendency of material embrittlement caused by excessively high crystallization rate;

[0060] The second stage (rapid cooling): After cooling in a hot water bath, the sheath is immediately immersed in a cold water bath at 15℃~30℃ for rapid cooling and shaping. This stage rapidly locks in the molecular structure, giving the sheath excellent surface finish, dimensional stability, and final mechanical properties.

[0061] Test results: 1. The tensile strength of sheath layer 6 was measured to be 33 N / mm² according to the test method provided in GB / T 12706.3-2020. 2 The elongation at break reached 590%, far exceeding the performance of conventional rubber sheaths. 2. Under test conditions where the conductor temperature was set 5℃~10℃ higher than its rated maximum operating temperature, the cable underwent a negative polarity lightning impulse test. The test system consisted of a pulse generator, the cable under test, a terminal connector, a simulated load device / electrode, and an insulating oil tank. The pulse generator was responsible for generating a negative polarity lightning wave with an effective wavefront time of 1.0μs to 1.4μs, a half-peak time of 40μs to 60μs, and a peak voltage of 500kV. The insulating oil tank contained mineral insulating oil, immersing the cable terminal connector and the device electrode in it. Test results: After 500 impacts, the cable did not experience any breakdown, and no obvious bubbles were observed in the insulating oil tank, fully verifying its ultra-high reliability under extreme conditions.

[0062] Comparative Example 1:

[0063] The difference between this comparative example and Example 1 is that a 7-strand stranded copper conductor is used instead of a solid copper conductor, while maintaining a cross-sectional area of ​​16 mm². 2The diameter of the single wire is 1.7 mm, and the stranding ratio is 12±1. The eccentricity of the insulation layer is also controlled within ≤3%, but due to the uneven surface of the stranded conductor, the measured insulation eccentricity will fluctuate by about 4%, and there is a significant gap between the stranded conductor and the insulation layer.

[0064] Under the same lightning impulse test conditions as in Example 1, the test results showed that obvious bubbles were generated in the insulation layer during the test, and the cable broke down on the 97th impulse.

[0065] Comparative Example 2:

[0066] The difference between this comparative example and Example 1 is that the eccentricity of the insulation layer was adjusted from ≤3% to 5%. The relatively large insulation eccentricity control resulted in a smaller thickness at the thinnest point of the insulation.

[0067] Under the same lightning impulse test conditions as in Example 1, the test results showed that the cable broke down during the 322nd impulse.

[0068] In summary, the solid copper conductor structure of this invention completely eliminates the strand gaps and surface unevenness of stranded conductors, laying the foundation for uniform insulation layer coverage and avoiding local electric field distortion caused by uneven conductor surfaces. The insulation layer eccentricity is strictly controlled within 3%, which, combined with the flat surface of the solid conductor, ensures uniform radial thickness of the insulation layer, preventing electric field concentration points caused by local thinning. Therefore, the solid conductor structure and ultra-low insulation eccentricity (≤3%) control create a synergistic effect, significantly reducing conductor loss and effectively suppressing interface defects and electric field distortion. This surpasses the tolerance limits of conventional cables, allowing it to withstand 500 consecutive negative polarity 500kV lightning strikes of specific waveforms (wavefront 1.0μs~1.4μs, half-peak 40μs~60μs) without breakdown. This provides a crucial guarantee for the reliable operation of shock wave equipment under extreme conditions.

[0069] Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial applicability. The above embodiments are merely illustrative of the principles and effects of this invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of this invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A controllable shock wave fast pulse high-voltage cable, characterized in that, include The conductor is made of solid copper. The conductor shielding layer and the insulation layer are tightly wrapped on the conductor using a one-time molding double-layer co-extrusion process; the eccentricity of the insulation layer is ≤3%; A semi-conductive tape wrapping layer is made by tightly wrapping a semi-conductive nylon tape around the outside of the insulating layer, with a wrapping overlap rate of ≥20%. The braided shielding layer is made of tin-plated copper wire braided outside the semiconductive strip wrapping layer, with a braiding density of ≥85%. The sheath layer is made of polyurethane elastomer material extruded outside the braided shielding layer and shaped by a segmented cooling process.

2. The controllable shock wave fast pulse high-voltage cable according to claim 1, characterized in that, The conductor cross-sectional area is determined based on the adiabatic calculation formula and operating conditions.

3. The controllable shock wave fast pulse high-voltage cable according to claim 1, characterized in that, The conductor shielding layer is made of cross-linked semi-conductive material; the insulating layer is made of ultra-pure cross-linked polyethylene material.

4. The controllable shock wave fast pulse high-voltage cable according to claim 3, characterized in that, The nominal thickness and the thinnest point insulation thickness of the insulation layer are calculated using the formula... Calculate, where: U BIL K'1 is the reference impact strength; K'2 is the repeated impact aging coefficient; K'3 is the insulation temperature coefficient; E is the safety margin. L(imp) The electric field strength of the material under impact.

5. The controllable shock wave fast pulse high-voltage cable according to claim 4, characterized in that, The braiding angle of each tin-plated copper wire is controlled between 40° and 50°.

6. A method for preparing a controllable shock wave fast pulse high-voltage cable, characterized in that, include Step 1: Select conductor material according to operating conditions, and determine the required conductor cross-sectional area according to the thermal insulation method calculation formula; calculate and determine the nominal thickness and the thinnest point insulation thickness of the insulation layer; Step 2: Prepare a solid conductor with a corresponding conductor diameter based on the cross-sectional area of ​​the conductor; Step 3: Co-extrude a conductor shielding layer and an insulation layer on the outside of the conductor; during the extrusion process, use an online diameter measuring instrument to monitor the outer diameter of the insulation layer in real time, and adjust the process parameters based on the real-time feedback system to ensure that the eccentricity of the insulation layer is ≤3%; Step 4: Wrap a semi-conductive nylon tape around the outside of the insulation layer to form a semi-conductive tape wrapping layer, and control the wrapping overlap rate to be ≥20%. Step 5: A shielding layer is woven using tin-plated copper wire outside the semiconductive strip wrapping layer, with a weaving density ≥ 85%. Step 6: Extruding a sheath layer using polyurethane elastomer material outside the braided shielding layer; the extrusion process uses a semi-extrusion mold and is simultaneously vacuumed, and the extruded sheath material is shaped using a segmented cooling process.

7. The preparation method according to claim 6, characterized in that, The nominal thickness and the thinnest point insulation thickness of the insulation layer are calculated according to the formula. Calculate, where: U BIL K'1 is the baseline impact strength; K'1 is the repeated impact aging coefficient. K'2 is the insulation temperature coefficient; K'3 is the safety margin; E L(imp) The electric field strength of the material under impact.

8. The preparation method according to claim 6, characterized in that, In step three, the double-layer co-extrusion process proceeds into a vulcanization pipeline for cross-linking and curing of the conductor shielding layer and the insulation layer.

9. The preparation method according to claim 6, characterized in that, In step five, each tin-plated copper wire entering the braiding machine is subjected to independent and precise tension control, while the braiding angle is controlled between 40° and 50°; welding of the entire strand of tin-plated copper wire is prohibited.

10. The preparation method according to claim 6, characterized in that, In step six, the segmented cooling process involves first slow cooling with hot water at 45℃ to 60℃ for 1 to 3 minutes, followed by rapid cooling with cold water at 15℃ to 30℃ for shaping.

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