阅读说明：本技术 一种组合绝缘型卷绕带状脉冲形成线 (Combined insulation type winding ribbon pulse forming line ) 是由 李嵩 刘啸 高景明 杨汉武 张自成 闵亚飞 刘照华 晏龙波 蔡浩 陈冬群 钱宝良 于 2020-06-23 设计创作，主要内容包括：本发明公开了一种组合绝缘型卷绕带状脉冲形成线,目的是提高脉冲形成线耐压等级及能量密度峰值。本发明由金属带和绝缘介质带组成,金属带由上金属带,中金属带和下金属带构成,绝缘介质带由上储能介质带,下储能介质带和隔离介质带构成；上储能介质带和下储能介质带均由n2层聚酰亚胺膜和n1层聚丙烯膜叠加而成；隔离介质带由n3层聚丙烯膜沿垂直于上金属带方向叠加而成；金属带和绝缘介质带按照上金属带-上储能介质带-中金属带-下储能介质带-下金属带-隔离介质带的顺序依次叠加,并卷绕成阿基米德螺旋线状。本发明通过组合绝缘方式优化高压电极边缘电场分布,提高了高功率脉冲形成线耐压等级及能量密度峰值。(The invention discloses a combined insulated winding ribbon pulse forming line, and aims to improve the withstand voltage grade and the energy density peak value of the pulse forming line. The invention comprises a metal belt and an insulating medium belt, wherein the metal belt comprises an upper metal belt, a middle metal belt and a lower metal belt, and the insulating medium belt comprises an upper energy storage medium belt, a lower energy storage medium belt and an isolation medium belt; the upper energy storage medium belt and the lower energy storage medium belt are formed by overlapping n2 layers of polyimide films and n1 layers of polypropylene films; the isolation medium belt is formed by stacking n3 polypropylene films along the direction vertical to the upper metal belt; the metal belt and the insulating medium belt are sequentially overlapped according to the sequence of the upper metal belt, the upper energy storage medium belt, the middle metal belt, the lower energy storage medium belt, the lower metal belt and the isolating medium belt, and are wound into an Archimedes spiral line shape. According to the invention, the distribution of the electric field at the edge of the high-voltage electrode is optimized in a combined insulation mode, and the voltage withstand level and the energy density peak value of a high-power pulse forming line are improved.)

1. A combined insulation type winding strip pulse forming line comprises a metal belt (1), wherein the metal belt (1) is composed of an upper metal belt (1-3), a middle metal belt (1-4) and a lower metal belt (1-5), the length of the middle metal belt (1-4) and the length of the lower metal belt (1-5) are both L4, the length of L4 is 22000mm, the width of the upper metal belt (1-3) is D3, and the width of the middle metal belt (1-4) and the width of the lower metal belt (1-5) are both D3; the upper metal belt (1-3) is a7 thick, the middle metal belt (1-4) is a9 thick, the lower metal belt (1-5) is a11 thick, a 7-a 9-a 11 thick, and the upper metal belt and the lower metal belt are made of copper belts; the combined insulation type winding belt-shaped pulse forming line is characterized by further comprising an insulation medium belt (3), wherein the insulation medium belt (3) is composed of an upper energy storage medium belt (3-6), a lower energy storage medium belt (3-7) and an isolation medium belt (3-8); the metal belt (1) and the insulating medium belt (3) are sequentially overlapped according to the sequence of the upper metal belt (1-3) -the upper energy storage medium belt (3-6) -the metal belt (1-4) -the lower energy storage medium belt (3-7) -the lower metal belt (1-5) -the isolating medium belt (3-8), and are wound into an Archimedes spiral line shape;

the lengths of the upper energy storage medium belt (3-6) and the lower energy storage medium belt (3-7) are both L3; the width of the upper energy storage medium belt (3-6) and the width of the lower energy storage medium belt (3-7) are both D4; the upper energy storage medium belt (3-6) and the lower energy storage medium belt (3-7) are formed by overlapping n2 layers of polyimide films and n1 layers of polypropylene films and play a role in storing electric field energy; the thickness of the upper energy storage medium belt (3-6) is a8, the thickness of the lower energy storage medium belt (3-7) is a10, a8 is a10, n1 × h1+ n2 × h2, a8 is more than or equal to 0.8mm and less than or equal to 1.5mm, h2 is the thickness of a single-layer polyimide film, and h1 is the thickness of a single-layer polypropylene film; in the direction perpendicular to the surface of the upper metal belt (1-3), the polyimide film and the polypropylene film in the upper energy storage medium belt (3-6) are distributed in a sandwich structure, namely the energy storage medium belt (3-6) in the direction is formed by overlapping a first upper polyimide film (3-6-1), a first middle polypropylene film (3-6-2) and a first lower polyimide film (3-6-3), wherein the total thickness of the first middle polypropylene film (3-6-2) is a (n) 1 multiplied by h1, the distance between the first middle polypropylene film (3-6-2) and the upper metal belt (1-3) is h, namely the thickness of the first upper polyimide film (3-6-1) is h, and h is more than 0mm and less than or equal to 0.05 mm; the lower energy storage medium belt (3-7) is formed by overlapping a second upper polyimide film (3-7-1), a second middle polypropylene film (3-7-2) and a second lower polyimide film (3-7-3), the lower energy storage medium belt (3-7) and the upper energy storage medium belt (3-6) are symmetrical about the middle metal belt (1-4) in the direction vertical to the surface of the upper metal belt (1-3), the thickness b of the second middle polypropylene film (3-7-2) is a, and the thickness c of the second lower polyimide film (3-7-3) is h;

the length of the isolation medium belt (3-8) is L3, the width is D4, the thickness is a12, and the isolation medium belt is formed by stacking n3 layers of polypropylene films along the direction vertical to the upper metal belt (1-3); n3 is a positive integer.

2. A composite insulated coiled ribbon pulse forming wire as claimed in claim 1, wherein the archimedes' spiral has an inner radius R1 of 80mm and an axial length L2 of 250 mm.

3. A composite insulated coiled ribbon pulse forming wire as claimed in claim 1, characterised in that said metal ribbon (1) has D3-34 mm, said a 7-a 9-a 11-0.2 mm.

4. A composite insulated coiled ribbon pulse forming line as claimed in claim 1, wherein said insulating dielectric ribbon (3) has L3-23000 mm and D4-50 mm.

5. The composite insulated wound ribbon pulse forming wire of claim 1, wherein said single polyimide film has a thickness h2 of 0.025mm, a relative dielectric constant of 3.5, and a breakdown field strength of 275 kV/mm; the thickness h1 of the single-layer polypropylene film is 0.01mm, the relative dielectric constant is 2.5, and the breakdown field strength is 375 kV/mm.

6. A composite insulated coiled ribbon pulse forming line as claimed in claim 1, wherein the thickness a 12-50 mm and n 3-50 mm of the insulating dielectric tape (3-8).

7. A composite insulated coiled ribbon pulse forming line as claimed in claim 1, wherein the thickness a8 of the upper energy storage media ribbon (3-6) is 1mm, the thickness a of the first middle polypropylene film (3-6-2) is 0.4mm, the thickness h of the first upper polyimide film (3-6-1) is 0.025mm, and the thickness of the first lower polyimide film (3-6-3) is 0.575 mm.

Technical Field

The invention relates to a winding belt-shaped pulse forming line in the technical field of high-power pulse driving sources, in particular to a combined insulation type winding belt-shaped pulse forming line.

Background

Pulsed power technology (Pulsed power technology) is an electro-physical technology that stores energy at a relatively low power, converts the energy at a much higher power to Pulsed electromagnetic energy and discharges it into a specific load, and the device for generating high-power electrical pulses is called a high-power Pulsed drive source. Since the 60 s of the 20 th century, with the development of nuclear physics, electron beam modulator physics, laser and plasma physics research, the pulse power technology has been rapidly developed as a high-tech emerging subject, is one of the leading-edge high-tech which is very active internationally, and has wide application prospects in the military field and the civil field. The pulse forming device is one of the core parts of a high-power pulse driving source and is mainly used for modulating pulse waveforms. The winding strip pulse forming line is one kind of pulse forming device, and is produced by using solid insulating film as energy storing medium, amplifying and winding strip line widely used in microwave engineering, i.e. one kind of device for forming square wave pulse with plate conductor and insulating medium laid in certain proportion and order and wound into Archimedes spiral line shape. Plum fleshy, Qian baohu, yan han wu, et al, academic paper "An improved rolled strip pulse forming line" [ Song Li, bailiang Qian, Hanwu Yang, et al, "An improved rolled pulse forming line (Li Song, Qian bao Li, yan Hanwu, a modified rolled strip pulse forming line, Scientific Instruments Review, volume 84,064704, page number 1-6)", Review of Scientific Instruments, vol.84,064704, pp:1-6 ], a wound strip pulse forming line based on solid insulating film (DMD film) whose structure is shown in fig. 1, mainly consists of metal strip 1 and film 2. Wherein the metal belt 1 is composed of an upper metal belt 1-3, a middle metal belt 1-4 and a lower metal belt 1-5. FIG. 2 is a three-dimensional view of the pulse forming wire unwinding configuration, and FIG. 2(a) is a front view of a coiled ribbon pulse forming wire; FIG. 2(b) is a side view of a coiled ribbon pulse forming line; FIG. 2(c) is a top view of a coiled ribbon pulse forming line; the upper metal strips 1-3 are made of copper strips with a length L4 of 22000mm, a width D3 of 80mm and a thickness a7 of 0.15 mm. The metal strips 1 to 4 are made of copper strips, with a length L4, a width D3 and a thickness a9 of 0.15 mm. Lower metal belts 1 to 5 are made of copper belts with a length L4, a width D3 and a thickness a11 of 0.15 mm. The DMD membrane 2 is composed of upper DMD membranes 2-6, middle DMD membranes 2-7, and lower DMD membranes 2-8. Wherein the upper DMD film 2-6 is made of polyester film and polyester fiber paper composite material, the length L1 is 23000mm, the width D1 is 250mm, and the thickness a2 is 1.2mm (considering the requirements of pulse forming line intrinsic impedance and insulation design, six DMD films are stacked to form the upper DMD film 2-6, each thickness is 0.2 mm). The middle DMD membrane 2-7 is made of a polyester film, polyester fiber paper composite material, as in the upper DMD membrane 2-6, and has a length L1, a width D1, and a thickness a4 of 1.2mm (in consideration of requirements such as pulse-forming line intrinsic impedance and insulation design, six DMD membranes are stacked to form the middle DMD membrane 2-7, each having a thickness of 0.2 mm). The lower DMD membrane 2-8 is made of a mylar-paper composite material, as in the upper DMD membrane 2-6, and has a length L, a width D1, and a thickness a6 of 0.4mm (two DMD membranes are stacked, each having a thickness of 0.2mm, in consideration of the requirements of pulse-forming line intrinsic impedance and insulation design). The metal strip 1 and the DMD membrane 2 are wound together in accordance with an archimedes spiral. The high-power pulse forming line after winding is generally cylindrical, sequentially comprises a lower DMD film 2-8, a lower metal belt 1-5, a middle DMD film 2-7, a metal belt 1-4, an upper DMD film 2-6 and an upper metal belt 1-3 from inside to outside, the inner radius R1 of the wound cylinder is 55mm, the axial length L2 is 250mm, the outer radius of the wound cylinder is determined by the inner diameter and the length of the metal belt, and the longer the length is, the larger the number of turns is, and the larger the outer radius is.

In the working state of the high-power pulse forming line, the metal belt 1-4 is at a high potential, the upper metal belt 1-3 and the lower metal belt 1-5 are at a ground potential, and the field enhancement effect easily causes the breakdown of the insulating dielectric film at the edge of the metal belt 1-4, so that the charging voltage peak value of the metal belt is limited and a higher withstand voltage level (c) cannot be met>100kV) and the peak energy density of the high-power pulse forming line can only reach 1.8552 × 10⁵J/m³There is room to be lifted. At present, the research on the winding belt-shaped pulse forming line mainly focuses on the improvement of the output characteristic of the high-power pulse driving source, and no report is found on the research on the energy density peak value improvement of the winding belt-shaped pulse forming line.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a combined insulated winding strip pulse forming line aiming at the defects that the existing winding strip pulse forming line can not meet the application requirement of higher voltage-withstanding grade by using a single material as an energy storage medium and has low energy density peak value, and the like.

The technical scheme of the invention is as follows:

the combined insulated winding belt-shaped pulse forming line consists of a metal belt and an insulating medium belt. The metal belt consists of an upper metal belt, a middle metal belt and a lower metal belt, and the insulating medium belt consists of an upper energy storage medium belt, a lower energy storage medium belt and an isolation medium belt.

The length of the upper metal belt and the length of the lower metal belt are both L4, L4 is 22000mm, the width of the upper metal belt and the width of the lower metal belt are both D3, D3 is 34mm, the thickness of the upper metal belt is a7, the thickness of the middle metal belt is a9, the thickness of the lower metal belt is a11, the requirement that a7 is a9 is that a11 is 0.2mm is met, and the upper metal belt and the lower metal belt are both made of copper belts. The length of the upper energy storage medium belt and the length of the lower energy storage medium belt are both L3, and L3 is 23000 mm. The width of the upper energy storage medium belt and the width of the lower energy storage medium belt are both D4, and D4 is 50 mm. The upper energy storage medium belt has the thickness of a8, and the lower energy storage medium belt has the thickness of a10, and the requirement that a8 is equal to a10 is met. The upper energy storage dielectric tape and the lower energy storage dielectric tape are formed by overlapping n2 layers of polyimide films and n1 layers of polypropylene films and play a role in storing electric field energy, wherein the thickness h2 of a single-layer polyimide film is 0.025mm, the relative dielectric constant is 3.5, and the breakdown field intensity is 275 kV/mm; the thickness h1 of the single-layer polypropylene film is 0.01mm, the relative dielectric constant is 2.5, and the breakdown field strength is 375 kV/mm.

The number of the polyimide film layers n2, the number of the polypropylene film layers n1, the thickness of the single-layer polyimide film h2 and the thickness of the single-layer polypropylene film h1 meet the requirements that a8 is a10 is n1 x h1+ n2 x h2, and a8 is more than or equal to 0.8mm and less than or equal to 1.5 mm. In the direction perpendicular to the surface of the upper metal belt, the polyimide film and the polypropylene film in the upper energy storage medium belt are distributed in a sandwich structure, namely the energy storage medium belt in the direction is formed by overlapping a first upper polyimide film, a first middle polypropylene film and a first lower polyimide film, wherein the total thickness of the first middle polypropylene film is a (n) 1 x h1, the distance from the first middle polypropylene film to the upper metal belt is h, namely the thickness of the first upper polyimide film is h, and the thickness of 0mm < h is less than or equal to 0.05 mm. The lower energy storage medium belt is formed by overlapping a second upper polyimide film, a second middle polypropylene film and a second lower polyimide film, the thickness b of the second middle polypropylene film in the lower energy storage medium belt is a, and the thickness c of the second lower polyimide film is h, namely the lower energy storage medium belt and the upper energy storage medium belt are symmetrical relative to the middle metal belt in the direction perpendicular to the surface of the upper metal belt.

The length of the isolation medium strip is L3, the width is D4, the thickness is a12, the a12 is 0.5mm, the isolation medium strip is formed by stacking n3(n3 is a positive integer, preferably 50) polypropylene films in the direction perpendicular to the upper metal strip, and the thickness h1 of the single-layer polypropylene film is 0.01 mm. The metal belt and the insulating medium belt are sequentially overlapped according to the sequence of the upper metal belt, the upper energy storage medium belt, the metal belt, the lower energy storage medium belt, the lower metal belt and the isolating medium belt, and are wound into an Archimedes spiral line shape, wherein the inner radius R1 of the Archimedes spiral line is 80 mm.

When the charging of the combined insulated winding strip pulse forming line is finished, the upper metal belt and the lower metal belt are at low potential, and the metal belt is at high potential. The electric field intensity of the edges of the metal strip at high potential is far larger than that of other parts of the pulse forming line due to the field enhancement effect, so that the breakdown probability of the edges of the metal strip is obviously increased.

The structures and materials of the isolation medium belt, the upper energy storage medium belt and the lower energy storage medium belt influence the electric field distribution of the pulse forming line, the surfaces of the two sides of the isolation medium belt are respectively contacted with the upper metal belt and the lower metal belt in the adjacent period after the pulse forming line is wound, the function of storing energy is not born, and the energy storage capacity of the pulse forming line is not influenced theoretically, so the invention does not carry out research on the isolation medium belt. According to the invention, the distribution of the polyimide film and the polypropylene film in the upper energy storage medium belt and the lower energy storage medium belt is changed, so that the distribution of the field intensity at the edge of the metal belt is optimized, and the energy density peak value of the high-power pulse forming line is improved.

Through simulation of finite element simulation software, the thickness a8 of the upper energy storage medium strip of the combined insulation type winding strip pulse forming line is preferably 1mm, namely a8-a 10-n 1 × h1+ n2 × h 2-1 mm, the thickness a of the first middle polypropylene film is preferably 0.4mm, the thickness h of the first upper polyimide film of the upper energy storage medium strip is preferably 0.025mm, and the thickness a8-a-h of the first lower polyimide film is preferably 1mm-0.4mm-0.025 mm-0.575 mm. Namely, the composition of the sandwich-type upper energy storage medium belt in the direction vertical to the upper metal belt (from the upper metal belt to the middle metal belt) is a first upper polyimide film (with the thickness of 0.025mm), a first middle polypropylene film (with the thickness of 0.4mm) and a first lower polyimide film (with the thickness of 0.575 mm).

The invention can achieve the following technical effects:

1. according to the invention, the distribution of the high-voltage electrode fringe electric field is optimized in a combined insulation mode, the influence of the field enhancement effect on the electrode fringe electric field is reduced, and the high-power pulse forming line voltage withstand level and the energy density peak value are improved.

2. The invention has simple principle, convenient use and wide application range.

Drawings

FIG. 1 is a diagram of a solid insulating film (DMD film) -based winding tape pulse forming line reported in academic paper "An improved winding tape pulse forming line" by Li Song Li, Qianbaoliang, Bailiang Qian, Hanwu Yang et al (An improved winding tape pulse forming line), Review of scientific instruments, Vol.84,064704, pp:1-6 by Yanchu Wu et al;

FIG. 2 is an expanded three-view of a solid insulating film (DMD film) based coiled ribbon pulse forming line of FIG. 1; FIG. 2(a) is a coiled ribbon pulse formation line elevation view; FIG. 2(b) is a side view of a coiled ribbon pulse forming line;

FIG. 2(c) is a top view of a coiled ribbon pulse forming line;

FIG. 3 is a view showing a structure of a combined insulated type winding ribbon pulse forming line according to the present invention;

FIG. 4 is a three-view drawing of the combined insulated coiled strip pulse forming line deployment structure of FIG. 3; FIG. 4(a) is a front view of a composite insulated coiled ribbon pulse forming line of the present invention; FIG. 4(b) is a side view of the combined insulated coiled strip pulse forming line of the present invention; FIG. 4(c) is a top view of the composite insulation type coiled strip pulse forming line of the present invention;

FIG. 5 is an enlarged view of a circled portion at Q in FIG. 4 (b);

FIG. 6 is a graph showing the variation of the electric field intensity at the edge of the metal tape 1-4 in the combined insulated coiled strip pulse forming line according to the parameters a and h, wherein a is the thickness of the polypropylene film, and h is the distance between the polypropylene film and the upper metal tape 1-3;

FIG. 7 is a graph showing the variation of the equivalent capacitance C per unit length of the combined insulated winding strip pulse forming line and the potential of the metal strip 1-4 with a when h is 0.025 mm;

fig. 8 is a graph showing the variation of the peak value of the energy density per unit length of the combined insulated winding ribbon pulse forming line with a when h is 0.025 mm.

Detailed Description

Fig. 3 is a schematic view of a combined insulated wound strip pulse forming line of the present invention, which is composed of a metal tape 1 and an insulating dielectric tape 3. The metal belt 1 is composed of an upper metal belt 1-3, a middle metal belt 1-4 and a lower metal belt 1-5, and the insulating dielectric belt 3 is composed of an upper energy storage dielectric belt 3-6, a lower energy storage dielectric belt 3-7 and an isolation dielectric belt 3-8.

FIG. 4 is a developed three-view of the combined insulated coiled strip pulse forming line of the present invention, and FIG. 4(a) is a front view of the combined insulated coiled strip pulse forming line of the present invention; FIG. 4(b) is a side view of the combined insulated coiled strip pulse forming line of the present invention; FIG. 4(c) is a plan view of the composite insulation type wound strip pulse forming line according to the present invention. The upper metal belt 1-3, the metal belt 1-4 and the lower metal belt 1-5 are L4, L4 is 22000mm, the upper metal belt 1-3, the metal belt 1-4 and the lower metal belt 1-5 are D3, D3 is 34mm, the upper metal belt 1-3 is a7 in thickness, the metal belt 1-4 is a9 in thickness, the lower metal belt 1-5 is a11 in thickness, a7 is a9 is a11 is 0.2mm, and the upper metal belt 1-3, the lower metal belt 1-5 and the lower metal belt are all made of copper belts. The lengths of the upper energy storage medium belt 3-6 and the lower energy storage medium belt 3-7 are both L3, and L3 is 23000 mm. The width of the upper energy storage medium belt 3-6 and the width of the lower energy storage medium belt 3-7 are both D4, and D4 is 50 mm. The thickness of the upper energy storage dielectric strip 3-6 is a8, the thickness of the lower energy storage dielectric strip 3-7 is a10, a8 is equal to a10, the upper energy storage dielectric strip 3-6 and the lower energy storage dielectric strip 3-7 are formed by overlapping n2 layers of polyimide films and n1 layers of polypropylene films, and the electric field energy storage function is achieved, wherein the thickness h2 of the single-layer polyimide film is 0.025mm, the relative dielectric constant is 3.5, and the breakdown field intensity is 275 kV/mm; the thickness h1 of the single-layer polypropylene film is 0.01mm, the relative dielectric constant is 2.5, and the breakdown field strength is 375 kV/mm.

Fig. 5 is an enlarged view of a circled portion at Q in fig. 4(b), wherein the number of polyimide film layers n2, the number of polypropylene film layers n1, the thickness of single-layer polyimide film h2 and the thickness of single-layer polypropylene film h1 satisfy the requirement that a8 is n 10 which is n1 × h1+ n2 × h 2. In the direction perpendicular to the surface of the upper metal belt 1-3, the polyimide film and the polypropylene film in the upper energy storage medium belt 3-6 are distributed in a sandwich structure, namely the energy storage medium belt 3-6 in the direction is formed by overlapping a first upper polyimide film 3-6-1, a first middle polypropylene film 3-6-2 and a first lower polyimide film 3-6-3, wherein the total thickness of the first middle polypropylene film 3-6-2 is a, n1 x h1, the distance from the upper metal belt 1-3 is h, and the thickness of the first upper polyimide film 3-6-1 is h. The lower energy storage dielectric strip 3-7 is formed by overlapping a second upper polyimide film 3-7-1, a second middle polypropylene film 3-7-2 and a second lower polyimide film 3-7-3, wherein the thickness b of the second middle polypropylene film 3-7-2 in the lower energy storage dielectric strip 3-7 is n1 × h1, and the thickness c of the second lower polyimide film 3-7-3 is h, that is, the lower energy storage dielectric strip 3-7 and the upper energy storage dielectric strip 3-6 are symmetrical with respect to the middle metal strip 1-4 in the direction perpendicular to the surface of the upper metal strip 1-3.

As shown in fig. 4, the length of the insulating medium belt 3-8 is L3, the width is D4, the thickness is a12, a12 is 0.5mm, the insulating medium belt is formed by stacking n3 (50) polypropylene films along the direction perpendicular to the upper metal belt 1-3, and the thickness of the single polypropylene film h1 is 0.01 mm. The metal belt 1 and the insulating medium belt 3 are sequentially overlapped according to the sequence of the upper metal belt 1-3, the upper energy storage medium belt 3-6, the metal belt 1-4, the lower energy storage medium belt 3-7, the lower metal belt 1-5 and the isolating medium belt 3-8, and are wound into an Archimedes spiral shape. The inner radius R1 of the wound cylinder was 80mm, and the axial length L2 was 250 mm.

When the charging of the combined insulated winding strip pulse forming line is finished, the upper metal belt 1-3 and the lower metal belt 1-5 are at low potential, and the metal belt 1-4 is at high potential. The electric field intensity of the edges of the metal strips 1-4 at high potential is far larger than that of other parts of the pulse forming line due to the field enhancement effect, so that the breakdown probability of the edges of the metal strips 1-4, namely the circle parts at the positions of figures 5-M, is remarkably increased.

The structures and materials of the isolation medium belts 3-8, the upper energy storage medium belts 3-6 and the lower energy storage medium belts 3-7 affect the electric field distribution of the pulse forming lines, the surfaces of the two sides of the isolation medium belts 3-8 are respectively contacted with the upper metal belts 1-3 and the lower metal belts 1-5 in the adjacent period after the pulse forming lines are wound, the function of storing energy is not born, and the energy storage capacity of the pulse forming lines is not affected theoretically, so the isolation medium belts 3-8 are not researched. According to the invention, the distribution of the polyimide film and the polypropylene film in the upper energy storage medium belt 3-6 and the lower energy storage medium belt 3-7 is changed, so that the field intensity distribution of the edge of the metal belt 1-4 is optimized, and the energy density peak value of the high-power pulse forming line is improved.

The energy density peak value of the winding strip-shaped pulse forming line is determined by the equivalent capacitance value of the pulse forming line and the voltage between the high and low potential electrodes, and the energy density peak value of the winding strip-shaped pulse forming line per unit length isC is an equivalent capacitance formed by the metal strips 1-3 and the metal strips 1-4 on the pulse forming line with unit length, and U is a peak potential value of the metal strips 1-4. Equivalent capacitanceWherein C is₂Total capacitance of polyimide film per unit length for pulse formation, C₁The total capacitance of the polypropylene film per unit length of wire is formed for the pulse. Keeping the potential of the metal strips 1-4 at 60kV, changing the thickness and position of the polypropylene film, and obtaining the magnitude of the field intensity of the edges of the metal strips 1-4 through finite element simulation software simulation as shown in FIG. 6. Curve a shows that the magnitude of the fringe field strength of the metal strips 1-4 is 138.8kV/mm when a is 0, i.e. the upper energy storage medium strips 3-6 are composed of polyimide films only. Curves D to J show the results of the variation of the field intensity at the edges of the metal strips 1 to 4 with h, when a is 0.1mm to 0.7 mm. When the total thickness a of the middle polypropylene film 3-6-2 of the upper energy storage medium belt 3-6 is unchanged, the field intensity of the middle metal belt 1-4 at the edge position is increased along with the increase of the thickness h of the first polyimide film 3-6-1 of the upper energy storage medium belt 3-6. When h is constant and the value is small (h)<0.05mm), the field strength at the edge position of the metal strip 1-4 is reduced along with the increase of the total thickness a of the middle polypropylene film of the upper energy storage medium strip 3-6. therefore, the combined insulated strip-shaped winding pulse forming line of the invention takes a polyimide film with the thickness h2 × 1 being 0.025mm, namely, only 1 layer of the thickness h2 is 0.025mm between the first middle polypropylene film 3-6-2 and the upper metal strip 1-3 of the upper energy storage medium strip 3-6. fixed h2 × 1 is 0.025mm, the potential of the metal strip 1-4 is gradually increased, so that the field strength at the edge position of the metal strip 1-4 reaches the peak of the compressive strength of the polyimide film (the peak of the compressive strength is determined by the material, the peak of the compressive strength of the polyimide film is 275kV), the curve of the equivalent capacitance per unit length C of the pulse forming line and the potential U of the metal strip 1-4 along with the change of the potential a of the polypropylene strip 1-4 are obtained as shown in fig. 7. L is the graph of the equivalent capacitance along with the change of the a, the equivalent capacitance of the metal strip 3-4 is known from the graph L, the change of the metal strip 3-6, the change of the thickness K2 along with the change of the energy storage medium strip 3-6, the change of the thickness K2 along with the change of the equivalent capacitance of the medium strip 3-6, the mediumWhen h is h2 × 1 is 0.025mm, the variation curve of the energy density peak value per unit length of the combined insulated strip pulse forming line with a is shown in fig. 8, and the simulation result shows that when a is 0.4mm, the energy per unit length is 15.963J at maximum, and the energy density peak value per unit volume in this case is 2.3485 × 10 by conversion⁵J/m³Energy density 1.8552 × 10 compared with background art⁵J/m³The improvement effect is obvious. Therefore, the thickness a8 of the upper energy storage medium band 3-6 of the combined insulation type winding band-shaped pulse forming line is preferably 1mm, the thickness a of the first middle polypropylene film 3-6-2 is preferably 0.4mm, the thickness h of the first upper polyimide film 3-6-1 of the upper energy storage medium band 3-6 is preferably 0.025mm, and the thickness a8-a-h of the first lower polyimide film 3-6-3 is preferably 1mm-0.4mm-0.025 mm-0.575 mm. Namely, the composition of the sandwich-type upper energy storage medium belt 3-6 in the direction vertical to the upper metal belt 1-3 (the upper metal belt 1-3 points to the middle metal belt 1-4) is that a first upper polyimide film 3-6-1 (with the thickness of 0.025mm), a first middle polypropylene film 3-6-2 (with the thickness of 0.4mm) and a first lower polyimide film 3-6-3 (with the thickness of 0.575 mm).