Composite busbar structure and single-turn coil magnet system with same

Abstract

The application belongs to the field of pulse magnets, and specifically discloses a composite busbar structure and a single-turn coil magnet system with the same. The composite busbar structure comprises N groups of busbars. Each group of busbars comprises a positive busbar and a negative busbar. The N groups of busbars are distributed in the internal and external parts of a magnetic disconnector. One end of the positive busbar is connected to the positive electrode of a capacitor, and the other end of the positive busbar is insulated and passes through the internal part of the magnetic disconnector. One end of the negative busbar is connected to the negative electrode of the capacitor, and the other end of the negative busbar is insulated and closely attached to the external part of the magnetic disconnector. The positive busbar and the negative busbar are both connected by a plurality of sub-busbars. Sub-busbars of the same type are parallel to each other. The first type of sub-busbar is parallel to the radial direction of the magnetic disconnector, the second type of sub-busbar is a straight plate type sub-busbar parallel to the axial direction of the magnetic disconnector, and the third type of sub-busbar is a circular arc type sub-busbar parallel to the axial direction of the magnetic disconnector. The application realizes a low-inductance composite busbar structure of a single-turn coil magnet, thereby significantly improving the magnetic field strength.

Description

Technical Field

[0001] The present application belongs to the field of pulse magnets, and more specifically, relates to a composite busbar structure and a single-turn coil magnet system having the same. Background Art

[0002] With the development of emerging frontier scientific research such as condensed matter physics and materials science, strong magnetic fields, as a key tool for conducting experiments in these disciplines, have become a key scientific research focus for researchers at home and abroad. As scientific research continues to deepen, the requirements for magnetic fields in many fields are becoming increasingly stringent. For example, in the field of materials science, ultra-strong magnetic fields can be used to control the synthesis process and microstructure of materials, thereby preparing new materials with special properties or significantly improving the performance of existing materials.

[0003] The single-turn coil is a destructive pulse magnet used to generate ultra-high magnetic fields exceeding 100 T. The peak current of the single-turn coil magnet during discharge is as high as 1MA-3MA, and the discharge current rise rate is as high as 0.5 MA / -2MA / This makes the selection of switches used in its discharge circuit face huge challenges. The traditional single-turn coil discharge circuit uses a special gas switch. Although it can meet the requirements of the current rise rate, the limiting current of this type of switch is only 100kA-200kA, and the life is short. The single-turn coil magnet system using a gas switch requires at least 5 switches in parallel. However, the domestic gas switch has a long opening jitter time, which almost occupies half of the discharge rising edge, and multiple switches cannot be used in parallel. The foreign gas switch has a short opening jitter time, but a technical blockade is imposed on my country, making it impossible to purchase. For single-turn coil magnet systems using traditional semiconductor switches (such as thyristors and insulated-gate bipolar transistors (IGBT)), since the limiting current rise rate of such switches does not exceed 3kA / If such switches are used, a large number of switches need to be connected in series and parallel, and all switches must be turned on simultaneously, making voltage and current balancing extremely difficult and almost impossible to achieve. A single-turn coil magnet system using a new type of semiconductor switch (Reversely Switched Dynistor, RSD) can avoid the above problems. A single 3-inch RSD has a withstand voltage of up to 3kV and a current rise rate of up to 100kA / A single RSD can handle pulse currents up to 100kA with a turn-on time of less than 5ns, a jitter time of less than 1ns, and a stray inductance of only 10nH. Crucially, the RSD is a bipolar device with no gate. Multiple switches connected in series or parallel can be turned on instantly and synchronously, eliminating the need to consider voltage and current balancing in large series and parallel configurations. However, while the RSD's switching performance is excellent, it also presents a new problem: excessive inductance in the discharge circuit.

[0004] The discharge circuit of a single-turn coil magnet system using a semiconductor switch RSD is approximately a second-order RLC circuit. The inductance of the power supply circuit directly determines the time constant. To ensure that the discharge current rises quickly enough, the inductance of the discharge circuit is usually between 20nH and 50nH. However, the inductance of a classic RSD discharge circuit is not less than For a single-turn coil magnet, such a current rise rate would significantly weaken the generated magnetic field strength. Summary of the Invention

[0005] In view of the defects of the prior art, the purpose of this application is to provide a composite busbar structure and a single-turn coil magnet system having the same, aiming to solve the problem of excessive inductance of the discharge circuit of the traditional magnet system using semiconductor switches RSD.

[0006] To achieve the above objectives, in a first aspect, the present application provides a composite busbar structure, wherein the composite busbar structure is used to connect multiple capacitors to a magnetic isolating switch, and the composite busbar structure includes: N groups of busbars; each group of busbars includes: a positive busbar and a negative busbar, where N is an integer greater than 1;

[0007] The N groups of busbars are dispersedly arranged inside and outside the magnetic isolating switch, one end of the positive busbar in each group of busbars is connected to the positive pole of a capacitor, and the other end is insulated and passes through the inside of the magnetic isolating switch, and one end of the negative busbar is connected to the negative pole of the capacitor, and the other end is insulated and tightly attached to the outside of the magnetic isolating switch; the positive busbar and the negative busbar are both composed of a plurality of sub-busbars connected, and the plurality of sub-busbars include at least one of at least two of a first sub-busbar, a second sub-busbar and a third sub-busbar, and the sub-busbars of the same type in the positive busbar and / or negative busbar are aligned parallel to each other; the first sub-busbar is a sub-busbar parallel to the radial direction of the magnetic isolating switch, the second sub-busbar is a straight-plate sub-busbar parallel to the axial direction of the magnetic isolating switch, and the third sub-busbar is an arc-shaped sub-busbar parallel to the axial direction of the magnetic isolating switch;

[0008] Multiple groups of the N busbars are combined and divided into M busbar combinations. The other ends of all positive busbars in each busbar combination are connected to each other after passing through the interior of the magnetic isolating switch, and the other ends of all negative busbars are connected to each other after being closely attached to the outside of the magnetic isolating switch, so as to connect the corresponding multiple capacitors in parallel through the magnetic isolating switch; M is an integer greater than 0, M is less than or equal to N, and each busbar combination includes at least one group of busbars.

[0009] In some embodiments, the N groups of busbars are distributed inside and outside the magnetic isolator according to the shape of the magnetic isolator.

[0010] In some embodiments, the plurality of capacitors connected by the composite busbar structure are arranged in one plane, and the magnetic disconnector is arranged in a different plane.

[0011] In some embodiments, the positive busbar comprises a first sub-busbar and a second sub-busbar.

[0012] The negative busbar comprises three first sub-busbars and three second sub-busbars; a first first sub-busbar in the negative busbar is connected to a first second sub-busbar, a second first sub-busbar, a second second sub-busbar and a third first sub-busbar are sequentially connected to form an opening, one side of the opening is connected to the first second sub-busbar, and the other side of the opening is connected to a third second sub-busbar.

[0013] The first sub-busbar of the positive busbar is parallelly aligned with the first first sub-busbar of the negative busbar, the second first sub-busbar and the third first sub-busbar of the negative busbar are parallelly aligned with each other, and the three second sub-busbars of the negative busbar are parallelly aligned with different segments of the second sub-busbar of the positive busbar.

[0014] In some embodiments, the positive busbar comprises a first sub-busbar and a third sub-busbar.

[0015] The negative busbar comprises three first sub-busbars and three third sub-busbars; a first first sub-busbar in the negative busbar is connected to a first third sub-busbar, a second first sub-busbar, a second third sub-busbar and a third first sub-busbar are sequentially connected to form an opening, one side of the opening is connected to the first third sub-busbar, and the other side of the opening is connected to a third third sub-busbar.

[0016] The first sub-busbar of the positive busbar is parallelly aligned with the first first sub-busbar of the negative busbar, the second first sub-busbar and the third first sub-busbar of the negative busbar are parallelly aligned with each other, and the three third sub-busbars of the negative busbar are parallelly aligned with different segments of the third sub-busbar of the positive busbar.

[0017] In some embodiments, the first sub-busbar is used to connect the positive and negative poles of the capacitors around the magnetic disconnector, and to fit the surface of the magnetic disconnector radially outside the magnetic disconnector; the second sub-busbar or the third sub-busbar is used to pass through the inside of the magnetic disconnector, and to fit the surface of the magnetic disconnector axially or circumferentially outside the magnetic disconnector.

[0018] In some embodiments, the positive busbar and the negative busbar have the same width and thickness.

[0019] In a second aspect, the present application provides a single-turn coil magnet system, comprising: the composite busbar structure described in the first aspect or any embodiment of the first aspect, N capacitors, a magnetic isolation switch, M semiconductor switches RSD, and a single-turn coil;

[0020] The N capacitors are connected to the magnetic isolating switch through the composite busbar structure, and then connected to the single-turn coil through the M RSDs; the M busbar combinations respectively connect the corresponding multiple capacitors in parallel through the magnetic isolating switch, and then connect them one by one to the single-turn coil through an RSD.

[0021] It should be noted that the above-mentioned magnetic system also includes: reliable insulating materials and RSD corresponding trigger circuits to achieve ideal insulation between the positive and negative busbars, and between the positive and negative busbars and the magnetic isolation switch; the trigger circuit is used to control the on and off of the RSD.

[0022] In some embodiments, the N capacitors are dispersed around the magnetic isolation switch, and the multiple capacitors are arranged in one plane and are arranged in a different plane from the magnetic isolation switch.

[0023] In some embodiments, when the magnetic isolating switch is circular, the N groups of busbars and N capacitors are arranged along the circumference; when the isolating switch is rectangular, the N groups of busbars and N capacitors are arranged along the rectangle.

[0024] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies:

[0025] The present application proposes a composite busbar structure and a single-turn coil magnet system having the same, which consists of a planar wrap-around power busbar structure and a through-type positive busbar structure. When the semiconductor switch RSD is used as a switch in the discharge circuit of the single-turn coil magnet system, when the pulse capacitor group power supply is discharged, the structure can provide a very high current rise rate for the single-turn coil magnet with an extremely small inductance value, thereby significantly improving the magnetic field strength. The present application can effectively improve the current rise rate and effectively enhance the magnetic field strength compared to the traditional RSD discharge circuit without changing the power supply capacity, power supply voltage, RSD number and connection method. In addition, the manufacturing and assembly process of the present application is relatively simple, and the low inductance goal of the power supply circuit can be achieved with a relatively simple process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 1 is a schematic top view of a composite busbar structure and a schematic cross-sectional view of a busbar group provided in an embodiment of the present application;

[0027] Figure 2 This is an architectural diagram of a single-turn coil magnet system provided in an embodiment of the present application;

[0028] Figure 3 This is a schematic diagram of the connection between the composite busbar structure and the capacitor bank provided in an embodiment of the present application;

[0029] Figure 4 This is a schematic diagram of the connection between the positive busbar and the capacitor bank provided in an embodiment of the present application;

[0030] Figure 5 This is a schematic diagram of the positive busbar structure provided in an embodiment of the present application;

[0031] Figure 6 This is a schematic diagram of the negative busbar structure provided in an embodiment of the present application;

[0032] Figure 7 This is a schematic diagram of the corresponding position relationship of the positive and negative busbars and the parallel connection of the negative busbars provided in the embodiment of the present application;

[0033] Figure 8 This is a schematic diagram of positive and negative busbar currents provided in an embodiment of the present application;

[0034] Figure 9 This is a power supply equivalent circuit diagram of a single-turn coil magnet system provided in an embodiment of the present application.

[0035] In all the drawings, the same figure marks are used to represent the same elements or structures, where: 11 is the first first sub-busbar of the negative busbar; 12 is the second first sub-busbar of the negative busbar; 13 is the third first sub-busbar of the negative busbar; 21 is the first third sub-busbar of the negative busbar; 22 is the second third sub-busbar of the negative busbar; 23 is the third third sub-busbar of the negative busbar. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0037] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0038] like Figure 1 As shown, the present application provides an overall low-inductance structure of a single-turn coil destructive pulsed high magnetic field system, comprising: a planar surround-type power busbar structure and a through-type positive busbar structure.

[0039] The above-mentioned planar wraparound power busbar structure and through-hole positive busbar structure constitute a low-inductance composite busbar structure, such as Figure 2 As shown, the composite busbar structure is used to connect multiple capacitors to the magnetic isolating switch, and the composite busbar structure includes: N groups of busbars; each group of busbars includes: a positive busbar and a negative busbar, and N is an integer greater than 1;

[0040] The N groups of busbars are distributed inside and outside the magnetic isolating switch. One end of the positive busbar in each group of busbars is connected to the positive pole of a capacitor, and the other end is insulated and passes through the inside of the magnetic isolating switch. One end of the negative busbar is connected to the negative pole of the capacitor, and the other end is insulated and closely attached to the outside of the magnetic isolating switch.

[0041] Specifically, for ease of understanding, Figure 3 and Figure 4 The magnetic isolating switch is hidden in the figure. The negative busbar structure can be seen in Figure 3 As shown, the positive busbar structure can be found in Figure 4 shown.

[0042] The positive busbar and the negative busbar are both connected by a plurality of sub-busbars, and the plurality of sub-busbars include a first sub-busbar, a second sub-busbar and a third sub-busbar (see Figure 5 and Figure 6 At least one of at least two types of the positive busbar and / or negative busbar, the sub-busbars of the same type are aligned parallel to each other; the first sub-busbar is a sub-busbar parallel to the radial direction of the magnetic isolator, the second sub-busbar is a straight-plate sub-busbar parallel to the axial direction of the magnetic isolator, and the third sub-busbar is an arc-shaped sub-busbar parallel to the axial direction of the magnetic isolator.

[0043] In some embodiments, as Figure 5 As shown in (a), the positive busbar includes: a first sub-busbar and a second sub-busbar;

[0044] like Figure 6 As shown in (a), the negative busbar includes: three first sub-busbars and three second sub-busbars; the first first sub-busbar in the negative busbar is connected to the first second sub-busbar, the second first sub-busbar, the second second sub-busbar and the third first sub-busbar are sequentially connected to form an opening, one side of the opening is connected to the first second sub-busbar, and the other side is connected to the third second sub-busbar;

[0045] The first sub-busbar of the positive busbar is aligned parallel to the first first sub-busbar of the negative busbar, the second first sub-busbar and the third first sub-busbar of the negative busbar are aligned parallel to each other, and the three second sub-busbars of the negative busbar are respectively aligned parallel to different sections of the second sub-busbar of the positive busbar.

[0046] In some embodiments, as Figure 5 As shown in (b), the positive busbar includes: a first sub-busbar and a third sub-busbar;

[0047] like Figure 6As shown in (b), the negative busbar includes: three first sub-busbars and three third sub-busbars; the first first sub-busbar 11 of the negative busbar is connected to the first third sub-busbar 21, the second first sub-busbar 12, the second third sub-busbar 22 and the third first sub-busbar 13 are sequentially connected to form an opening, one side of the opening is connected to the first third sub-busbar 21, and the other side is connected to the third third sub-busbar 23;

[0048] The first sub-busbar of the positive busbar is aligned parallel to the first first sub-busbar of the negative busbar, the second first sub-busbar and the third first sub-busbar of the negative busbar are aligned parallel to each other, and the three third sub-busbars of the negative busbar are respectively aligned parallel to different sections of the third sub-busbar of the positive busbar.

[0049] Further preferably, multiple groups of the N busbars are combined and divided into M busbar combinations, the other ends of all positive busbars in each busbar combination are connected to each other after respectively passing through the interior of the magnetic isolating switch, and the other ends of all negative busbars are connected to each other after respectively clinging to the outside of the magnetic isolating switch, so as to connect the corresponding multiple capacitors in parallel through the magnetic isolating switch; M is an integer greater than 0, M is less than or equal to N, and each busbar combination includes at least one group of busbars.

[0050] It should be noted that the other ends of the multiple positive busbars in the N groups of busbars are respectively connected after passing through the interior of the magnetic isolating switch, and the connection method depends on the number of subsequent semiconductor switches RSD, that is, M is the number of RSDs; similarly, the other ends of the multiple negative busbars in the N groups of busbars are closely attached to the outside of the magnetic isolating switch and then connected, and the connection method also depends on the number of subsequent semiconductor switches RSD.

[0051] Specifically, Figure 2 The RSD shown is an example. The other ends of multiple negative busbars are connected to each other after being attached to the outside of the magnetic isolating switch. Figure 7 shown.

[0052] It can be further understood that when M=N, N groups of busbars pass through the inside and outside of the magnetic isolating switch respectively and are each connected to an RSD. That is, N groups of busbars are connected in parallel through N RSDs to power a single-turn coil. At this time, after the N groups of busbars are connected in parallel, the inductance of the corresponding composite busbar can still be kept low.

[0053] In some embodiments, the N groups of busbars are distributed inside and outside the magnetic isolator according to the shape of the magnetic isolator.

[0054] In some embodiments, the plurality of capacitors connected to the composite busbar structure are arranged in one plane and are arranged in a different plane from the magnetic isolation switch.

[0055] In some embodiments, see Figures 2 to 7 As shown, the first sub-busbar is used to connect the positive and negative poles of the capacitor to the periphery of the magnetic isolator, and is used to fit with the surface of the magnetic isolator in the radial direction outside the magnetic isolator, and the second sub-busbar or the third sub-busbar is used to pass through the interior of the magnetic isolator, and is used to fit with the surface of the magnetic isolator in the axial direction or circumferential direction outside the magnetic isolator.

[0056] It should be noted that, see Figure 8 The positive and negative busbars are closely aligned and placed in the figure. When current flows through the two busbars, the current directions are opposite. According to the law of electromagnetic induction, the magnetic fields they generate cancel each other out, thus achieving the effect of reducing inductance. However, if Figure 8 As shown in the figure, the two busbars are not closely aligned where the magnetic switch is wrapped, so the busbar group still has a certain inductance. Then, by using N groups of busbars in parallel, the total inductance is about 1 / N of the inductance of a single group of busbars. This structure can significantly reduce the inductance; the corresponding equivalent circuit can be seen in Figure 9 In summary, the present application can achieve the low inductance effect of the composite busbar structure.

[0057] It is understandable that in the embodiment of the present application, N groups of busbars are arranged in a dispersed manner inside and outside the magnetic isolator according to the shape of the magnetic isolator. Figures 1 to 7 It can be seen that in the embodiment of the present application, N capacitors are also dispersedly distributed around the magnetic isolator according to the shape of the magnetic isolator, and multiple capacitors are arranged in one plane and in a different plane from the magnetic isolator; the above arrangement enables each capacitor to be connected to the magnetic isolator through positive and negative busbars of as similar length as possible, without the need for additional adapters in the middle, and without introducing other inductances, further ensuring the low inductance of the composite busbar structure.

[0058] In a more specific embodiment, the present application provides a single-turn coil magnet system, comprising: the composite busbar structure described above, N capacitors, a magnetic isolation switch, M semiconductor switches RSD, and a single-turn coil;

[0059] The N capacitors are connected to a magnetic isolating switch via the composite busbar structure, and then to a single-turn coil via the M RSDs. The M busbars connect the corresponding multiple capacitors in parallel via the magnetic isolating switch, and then each capacitor is connected to the single-turn coil via an RSD. In other words, the N capacitors are divided into multiple groups connected in parallel, then connected to the RSD switch, and then connected in parallel to power the single-turn coil.

[0060] Furthermore, the composite busbar and capacitor bank are connected in parallel before the RSD switch. After the N capacitors and their corresponding composite busbars are connected in parallel, they are divided into M groups of capacitors and their corresponding composite busbars. Each group of composite busbars is interconnected after passing through a magnetic switch to connect to the subsequent RSD switch. The M RSD switches are connected in parallel to the single-turn coil to power it. The specific design of N and M, and the method of parallel power supply, are determined by the peak current and current rise rate required by the single-turn coil.

[0061] It should be noted that the single-turn coil magnets described above are typically destructive pulse magnets. Destructive pulse magnets place particularly high demands on the inductance of the discharge circuit, requiring the inductance of the discharge circuit to be extremely low. Accordingly, the low-inductance composite busbar structure provided in the embodiments of this application can also be applied to other non-destructive pulse magnets, and this embodiment of the application does not impose any further limitations on this.

[0062] In some embodiments, the N capacitors are dispersed around the magnetic isolation switch, and the multiple capacitors are arranged in one plane and are arranged in a different plane from the magnetic isolation switch.

[0063] In some embodiments, when the magnetic isolating switch is circular, the N groups of busbars and the N capacitors are arranged along the circumference; when the isolating switch is rectangular, the N groups of busbars and the N capacitors are arranged along the rectangle.

[0064] In one possible embodiment, taking N as 8, the above capacitors may have 8 ( Figures 2 to 4 Taking N as 8 as an example for illustration), the corresponding composite busbar structure includes 8 groups of busbars; the planar wraparound power busbar structure includes 8 groups of metal copper buses arranged along a circle, which are parallel to the top surfaces of the corresponding power capacitors. Each group of metal copper buses includes a positive busbar and a negative busbar, which are parallel to each other and arranged in layers above and below.

[0065] The through-type positive busbar structure includes 8 groups of metal copper bars arranged in a circle, each group of metal copper bars includes two busbars, positive and negative. The positive busbar passes through the inside of the magnetic isolating switch, and the negative busbar is placed outside the magnetic isolating switch.

[0066] It should be noted that the present application is preferably designed as a circular array arrangement, so as to minimize the length of the metal copper busbar to achieve the purpose of reducing the total inductance.

[0067] Preferably, tabs are provided at the ends of the positive and negative busbars, and the tabs are connected to the power capacitors via terminals.

[0068] Preferably, the optimal angle between adjacent metal copper busbars and the optimal size of the copper busbars need to be calculated using a low-inductance structure electromagnetic thermal simulation algorithm. The determination of the optimal value must take into account three requirements: first, reducing the inductance of the overall structure as much as possible; second, minimizing the heat generation and deformation of the copper busbars; and third, ensuring that there is sufficient space between adjacent capacitors.

[0069] It should be noted that in order to ensure that the busbar can pass currents above megaamperes, the busbar needs to be made of copper alloy materials with high conductivity, high strength and high melting point. The high conductivity is used to increase the discharge current, the high strength is used to prevent the busbar from excessive deformation, and the high melting point is used to prevent the busbar from melting due to excessive current.

[0070] Preferably, the positive and negative busbars of the metal copper busbar group have the same width and thickness excluding the tabs, and the positive busbar is 2 mm to 5 mm longer than the negative busbar.

[0071] It should be noted that the positive busbar is longer than the negative busbar in order to press-fit insulation material into it to ensure safety.

[0072] Preferably, the interval between the two busbars in each group of metal copper bars is mm-level, and an insulating material is pressed in between. The length and width of the insulating material are both 5mm to 20mm larger than the busbars.

[0073] It should be noted that the size of the insulating material is larger than that of the busbar in order to prevent the busbar from being broken down due to creepage.

[0074] Preferably, all the positive busbars arranged along the circumference pass through the interior of the magnetic isolating switch via the inner insulation structure, and all the special-shaped negative busbars arranged along the circumference are closely attached to the outside of the magnetic isolating switch and opposite to the positive busbars via the outer insulation structure.

[0075] Preferably, the angle between adjacent metal copper busbar groups is the same as the angle in the aforementioned composite busbar structure.

[0076] Preferably, the internal insulation structure includes an insulating component and a limiting component, which are connected by epoxy glue. The outer diameter of the insulating component is equal to the inner diameter of the magnetic isolating switch, the thin wall thickness is 1mm to 2mm, and the height is 20mm to 40mm larger than the height of the through-core positive busbar. A plurality of limiting grooves are provided on the limiting component, the groove width is consistent with the busbar width in the composite busbar structure described above, and the angle between adjacent grooves is the same as the angle in the composite busbar structure described above.

[0077] It should be noted that if the thin wall thickness is too small, the insulation performance cannot be guaranteed, and if the thin wall thickness is too large, the inductance cannot be effectively reduced. Therefore, the present application prefers the thickness of the above values.

[0078] Preferably, the inner diameter of the outer insulation structure is equal to the outer diameter of the magnetic isolating switch, is 4mm to 5mm thicker than the magnetic isolating switch, and has a thin wall thickness of 4mm to 6mm. A plurality of limit grooves are provided on the structure, and the groove width is consistent with the busbar width in the aforementioned composite busbar structure, and the angle between adjacent grooves is the same as the angle in the aforementioned composite busbar structure.

[0079] It should be noted that if the thin-wall thickness is too small, the insulation performance cannot be guaranteed, and if the thin-wall thickness is too large, the inductance cannot be effectively reduced and the device is slightly bulky. Therefore, the present application prefers the thickness of the above values.

[0080] Preferably, the copper negative busbar is in the shape of an open rectangular frame.

[0081] It should be noted that the present application is preferably designed in the shape of an open rectangular frame, and this shape depends on the shape of the magnetic isolating switch.

[0082] Preferably, the metal copper busbar group of the planar surround-type power busbar structure and the metal copper busbar group of the through-type positive busbar structure have a one-to-one correspondence in positive and negative directions and are welded at the ends.

[0083] Preferably, multiple groups of positive and negative busbars at the other end of the through-type positive busbar structure away from the welding point are connected through a copper plate, and then the RSD switch is connected using a copper busbar or cable.

[0084] It should be noted that the preferred design of this application is to use copper busbars for connection to minimize inductance, heat generation and deformation.

[0085] Preferably, a ring-shaped insulating material is pressed between the positive and negative busbars of the metal copper busbar group at the welding point. The outer diameter of the ring material is calculated based on the insulation breakdown simulation algorithm of the maximum discharge voltage. The outer diameter value needs to ensure the insulation performance between the positive and negative busbars of adjacent metal copper busbar groups at the welding point.

[0086] Example

[0087] In this embodiment, taking N=8 as an example, the capacitor has 8, the inner diameter of the magnetic isolation switch is 100 mm, the outer diameter is 300 mm, and the thickness is 45 mm. The 8 groups of metal copper bars are arranged in a circular shape, and the plane is parallel to the top surface of the capacitor. The angle between adjacent metal copper bar groups is 38°, so as to reserve a certain space in the plane of the 8 capacitors for placing other required devices, such as reserving the position of the demagnetizing coil, the bus bar width is 26 mm, the thickness is 2 mm, the positive bus bar length is 610 mm, and the negative bus bar length is 605 mm. Each group of metal copper bars includes two positive and negative bus bars arranged in parallel and layered, with a spacing of 2 mm, and an epoxy resin insulating material is arranged in the middle, the width of the insulating material is 40 mm, and the length is 610 mm. The positive and negative bus bars are provided with tabs at the ends, and the tabs are connected to the power supply capacitor through the terminal post. The 8 groups of metal copper bars are arranged in a circular shape, each group of metal copper bars includes two positive and negative bus bars, the angle between adjacent metal copper bar groups is 38°, the bus bar width is 26 mm, and the thickness is 2 mm. The positive bus bar passes through the inner insulation structure inside the magnetic isolation switch, and the negative bus bar is placed outside the magnetic isolation switch through the outer insulation structure. The thin wall thickness of the insulating part in the inner insulation structure is 1 mm, and the outer diameter is equal to the inner diameter of the magnetic isolation switch. The thin wall thickness of the outer insulation structure is 5 mm, and the inner diameter is equal to the outer diameter of the magnetic isolation switch. The copper-shaped negative bus bar is an open rectangular frame. The other end away from the welding position is connected to the positive and negative bus bars respectively by using an octagonal copper plate, and then connected to the RSD switch through a cable.

[0088] Through experiments, it is obtained that the overall low inductance structure has a direct current inductance value of 32.85 nH, and an inductance value of 6.52 nH under 1 MHz alternating current. When the discharge current peak value is 500 kA, the maximum deformation within 10 us is 0.336 nm, and the heat release is less than 1 K. It can be seen that when the semiconductor switch RSD is used as the switch of the single-turn coil magnet system discharge circuit, the structure can provide a very high current rise rate for the single-turn coil magnet with a very small inductance value when the pulse capacitor group power supply discharges, thereby significantly improving the magnetic field strength. The application can effectively improve the current rise rate and effectively enhance the magnetic field strength compared with the traditional RSD discharge circuit without changing the power supply capacity, power supply voltage and RSD quantity and connection mode. Moreover, the manufacturing and assembly process of the application is relatively simple, and the low inductance target of the power supply circuit can be realized by a relatively simple process.

[0089] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0090] In addition, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0091] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the two are connected to each other and the relative position relationship after the connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after the connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after the connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0092] In addition, in the embodiments of the present application, the mathematical concepts mentioned include symmetry, equality, parallelism, and perpendicularity. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense. A small amount of deviation is allowed, and it is possible to be approximately symmetric, approximately equal, approximately parallel, or approximately perpendicular. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0093] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A composite busbar structure for connecting multiple capacitors to magnetic isolating switches, characterized in that: The composite busbar structure includes: N groups of busbars; each group of busbars includes: a positive busbar and a negative busbar, where N is an integer greater than 1; The N groups of busbars are dispersedly arranged inside and outside the magnetic isolating switch, one end of the positive busbar in each group of busbars is connected to the positive pole of a capacitor, and the other end is insulated and passes through the inside of the magnetic isolating switch, and one end of the negative busbar is connected to the negative pole of the capacitor, and the other end is insulated and tightly attached to the outside of the magnetic isolating switch; the positive busbar and the negative busbar are both composed of a plurality of sub-busbars connected, and the plurality of sub-busbars include at least one of at least two of a first sub-busbar, a second sub-busbar and a third sub-busbar, and the sub-busbars of the same type in the positive busbar and / or negative busbar are aligned parallel to each other; the first sub-busbar is a sub-busbar parallel to the radial direction of the magnetic isolating switch, the second sub-busbar is a straight-plate sub-busbar parallel to the axial direction of the magnetic isolating switch, and the third sub-busbar is an arc-shaped sub-busbar parallel to the axial direction of the magnetic isolating switch; Multiple groups of the N busbars are combined and divided into M busbar combinations. The other ends of all positive busbars in each busbar combination are connected to each other after passing through the interior of the magnetic isolating switch, and the other ends of all negative busbars are connected to each other after being closely attached to the outside of the magnetic isolating switch, so as to connect the corresponding multiple capacitors in parallel through the magnetic isolating switch; M is an integer greater than 0, M is less than or equal to N, and each busbar combination includes at least one group of busbars.

2. The composite busbar structure according to claim 1, characterized in that: The N groups of busbars are distributed inside and outside the magnetic isolating switch according to the shape of the magnetic isolating switch.

3. The composite busbar structure according to claim 1, characterized in that: The multiple capacitors connected to the composite busbar structure are arranged in one plane and are arranged in a different plane from the magnetic isolating switch.

4. The composite busbar structure according to claim 1, characterized in that: The positive busbar includes: a first sub-busbar and a second sub-busbar; The negative busbar comprises: three first sub-busbars and three second sub-busbars; the first first sub-busbar in the negative busbar is connected to the first second sub-busbar, the second first sub-busbar, the second second sub-busbar and the third first sub-busbar are sequentially connected to form an opening, one side of the opening is connected to the first second sub-busbar, and the other side is connected to the third second sub-busbar; The first sub-busbar of the positive busbar is aligned parallel to the first first sub-busbar of the negative busbar, the second first sub-busbar and the third first sub-busbar of the negative busbar are aligned parallel to each other, and the three second sub-busbars of the negative busbar are respectively aligned parallel to different sections of the second sub-busbar of the positive busbar.

5. The composite busbar structure according to claim 1, characterized in that: The positive busbar includes: a first sub-busbar and a third sub-busbar; The negative busbar comprises: three first sub-busbars and three third sub-busbars; the first first sub-busbar in the negative busbar is connected to the first third sub-busbar, the second first sub-busbar, the second third sub-busbar and the third first sub-busbar are sequentially connected to form an opening, one side of the opening is connected to the first third sub-busbar, and the other side is connected to the third third sub-busbar; The first sub-busbar of the positive busbar is aligned parallel to the first first sub-busbar of the negative busbar, the second first sub-busbar and the third first sub-busbar of the negative busbar are aligned parallel to each other, and the three third sub-busbars of the negative busbar are respectively aligned parallel to different sections of the third sub-busbar of the positive busbar.

6. The composite busbar structure according to any one of claims 1 to 5, characterized in that: The first sub-busbar is used to connect the positive and negative poles of the capacitor to the periphery of the magnetic isolator, and is used to fit with the surface of the magnetic isolator in the radial direction outside the magnetic isolator. The second sub-busbar or the third sub-busbar is used to pass through the interior of the magnetic isolator, and is used to fit with the surface of the magnetic isolator in the axial direction or circumferential direction outside the magnetic isolator.

7. The composite busbar structure according to claim 3, characterized in that: The positive busbar and the negative busbar have the same width and thickness.

8. A single-turn coil magnet system, characterized in that: include: The composite busbar structure according to any one of claims 1 to 7, N capacitors, a magnetic isolating switch, M semiconductor switches RSD, and a single-turn coil; The N capacitors are connected to the magnetic isolating switch through the composite busbar structure, and then connected to the single-turn coil through the M RSDs; the M busbar combinations respectively connect the corresponding multiple capacitors in parallel through the magnetic isolating switch, and then connect them one by one to the single-turn coil through an RSD.

9. The single-turn coil magnet system according to claim 8, characterized in that: The N capacitors are dispersed around the magnetic isolation switch, and the multiple capacitors are arranged in one plane and are arranged in a different plane from the magnetic isolation switch.

10. The single-turn coil magnet system according to claim 9, characterized in that: When the magnetic isolating switch is circular, the N groups of busbars and the N capacitors are arranged along the circumference; when the isolating switch is rectangular, the N groups of busbars and the N capacitors are arranged along the rectangle.

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