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

Abstract

The invention belongs to the field of pulse magnets, and particularly discloses a composite busbar structure and a single-turn coil magnet system with the composite busbar structure. Each group of busbars comprises a positive busbar and a negative busbar; the N groups of busbars are dispersedly distributed inside and outside the magnetic isolation switch, one end of the positive busbar is connected with a positive electrode of a capacitor, the other end of the positive busbar penetrates through the magnetic isolation switch in an insulated manner, one end of the negative busbar is connected with a negative electrode of the capacitor, and the other end of the negative busbar is tightly attached outside the magnetic isolation switch in an insulated manner; each of the positive busbar and the negative busbar is formed by connecting a plurality of sub-busbars, and the sub-busbars of the same type are parallel and aligned with each other; the first sub-busbar is a sub-busbar parallel to the radial direction of the magnetic isolation switch, the second sub-busbar is a straight plate type sub-busbar parallel to the axial direction of the magnetic isolation switch, and the third sub-busbar is an arc-shaped sub-busbar parallel to the axial direction of the magnetic isolation switch. According to the invention, the low-inductance composite busbar structure of the single-turn coil magnet is realized, so that the magnetic field intensity is remarkably improved.

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 the focus of scientific and technological research by researchers at home and abroad. For example, in 1998, American scientists Robert Betts Laughlin, Horst Ludwig Störmer and Daniel Chee Tsui discovered the fractional quantum Hall effect under the combined extreme conditions of 28T strong magnetic field and 0.085K ultra-low temperature, and won the Nobel Prize for this. With the continuous deepening of scientific research, the requirements for magnetic fields in many fields are increasing. 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 / , which 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. 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 this type of switch is 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. The single-turn coil magnet system using a new 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 pass a pulse current of 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. Most importantly, RSD is a bipolar device without a gate. Multiple switches in series and parallel can be turned on instantly and synchronously, and large-scale series and parallel connections do not need to consider voltage and current balancing. However, although the RSD switch has excellent performance, a new problem has arisen - the inductance of the discharge circuit is too large.

[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 20nH-50nH. However, the inductance of the classic RSD discharge circuit is no less than For a single-turn coil magnet, such a current rise rate will greatly weaken the generated magnetic field strength. Summary of the invention

[0005] In view of the defects of the prior art, the purpose of the present 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 switch RSD.

[0006] To achieve the above objectives, in a first aspect, the present application provides a composite busbar structure, which 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, and 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 closely 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 the first sub-busbar, the second sub-busbar and the third sub-busbar, and the sub-busbars of the same type in the positive busbar and / or the 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; The N groups of 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 inside of the magnetic isolation switch respectively, and the other ends of all negative busbars are connected to each other after being closely attached to the outside of the magnetic isolation switch respectively, so as to connect the corresponding multiple capacitors in parallel through the magnetic isolation 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.

[0007] In some embodiments, the N groups of busbars are dispersedly distributed inside and outside the magnetic isolating switch according to the shape of the magnetic isolating switch.

[0008] 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.

[0009] In some embodiments, 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 in parallel 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 aligned in parallel with each other, and the three second sub-busbars of the negative busbar are respectively aligned in parallel with different sections of the second sub-busbar of the positive busbar.

[0010] In some embodiments, 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 in parallel 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 aligned in parallel with each other, and the three third sub-busbars of the negative busbar are respectively aligned in parallel with different sections of the third sub-busbar of the positive busbar.

[0011] In some embodiments, the first sub-busbar is used to connect the positive and negative poles of the capacitor to the periphery of the magnetic isolation switch, and to fit with the surface of the magnetic isolation switch in the radial direction on the outside of the magnetic isolation switch, and the second sub-busbar or the third sub-busbar is used to pass through the inside of the magnetic isolation switch, and to fit with the surface of the magnetic isolation switch in the axial direction or circumferential direction on the outside of the magnetic isolation switch.

[0012] In some embodiments, the positive busbar and the negative busbar have the same width and thickness.

[0013] 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 of the embodiments of the first aspect, N capacitors, a magnetic isolation 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 to the single-turn coil one by one through an RSD.

[0014] It should be noted that the above-mentioned magnetic system also includes: reliable insulating materials and a trigger circuit corresponding to the RSD 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.

[0015] In some embodiments, the N capacitors are dispersed around the magnetic isolation switch, and the plurality of capacitors are arranged in one plane and are arranged in a different plane from the magnetic isolation switch.

[0016] 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. In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art: The present application proposes a composite busbar structure and a single-turn coil magnet system having the same, which is composed 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 of the discharge circuit of the single-turn coil magnet system, when the pulse capacitor group power supply is discharged, the structure can provide a single-turn coil magnet with an extremely high current rise rate 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

[0017] Figure 1 is a top view schematic diagram of a composite busbar structure and a cross-sectional schematic diagram of a busbar group provided in an embodiment of the present application; Figure 2 It is a structural diagram of a single-turn coil magnet system provided in an embodiment of the present application; Figure 3 is a schematic diagram of the connection between the composite busbar structure and the capacitor bank provided in an embodiment of the present application; Figure 4is a schematic diagram of the connection between the positive busbar and the capacitor bank provided in an embodiment of the present application; Figure 5 is a schematic diagram of the positive busbar structure provided in an embodiment of the present application; Figure 6 is a schematic diagram of the negative busbar structure provided in an embodiment of the present application; Figure 7 It is the corresponding position relationship of the positive and negative busbars provided in the embodiment of the present application, and the schematic diagram of the parallel connection of the negative busbars; Figure 8 is a schematic diagram of positive and negative busbar currents provided in an embodiment of the present application; Fig. 9 This is a power supply equivalent circuit diagram of a single-turn coil magnet system provided in an embodiment of the present application.

[0018] In all the drawings, the same figure marks are used to represent the same elements or structures, among which: 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

[0019] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0020] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0021] like Figure 1 As shown, the present application provides an overall low inductance structure of a single-turn coil destructive pulsed strong magnetic field system, including: a planar surround power busbar structure and a through-hole positive busbar structure.

[0022] The above-mentioned planar wraparound power busbar structure and through-type 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; 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 electrode 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 electrode of the capacitor, and the other end is insulated and tightly attached to the outside of the magnetic isolating switch.

[0023] 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.

[0024] The positive busbar and the negative busbar are both formed by connecting 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 above (as shown), the same type of sub-busbars 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.

[0025] In some embodiments, Figure 5 As shown in (a), the positive busbar includes: a first sub-busbar and a second sub-busbar; 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; The first sub-busbar of the positive busbar is aligned in parallel 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 aligned in parallel with each other, and the three second sub-busbars of the negative busbar are respectively aligned in parallel with different sections of the second sub-busbar of the positive busbar.

[0026] In some embodiments, Figure 5 As shown in (b), the positive busbar includes: a first sub-busbar and a third sub-busbar; like Figure 6 As shown in (b), the negative busbar includes: three first sub-busbars and three third sub-busbars; the first first sub-busbar 11 in 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; The first sub-busbar of the positive busbar is aligned in parallel 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 aligned in parallel with each other, and the three third sub-busbars of the negative busbar are respectively aligned in parallel with different sections of the third sub-busbar of the positive busbar.

[0027] 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 passing through the inside of the magnetic isolating switch respectively, 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 respectively, 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.

[0028] It should be noted that the other ends of the multiple positive busbars in the N groups of busbars are connected after passing through the inside 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 RSD; similarly, the other ends of the multiple negative busbars in the N groups of busbars are connected after being closely attached to the outside of the magnetic isolating switch, and the connection method also depends on the number of subsequent semiconductor switches RSD.

[0029] 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.

[0030] It can be further understood that when M=N, after N groups of busbars pass through the inside and outside of the magnetic isolating switch respectively, each is connected to an RSD, that is, N groups of busbars are connected in parallel through N RSDs to power the 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.

[0031] In some embodiments, the N groups of busbars are dispersedly distributed inside and outside the magnetic isolating switch according to the shape of the magnetic isolating switch.

[0032] 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.

[0033] 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 isolating switch, and is used to fit with the surface of the magnetic isolating switch in the radial direction outside the magnetic isolating switch, and the second sub-busbar or the third sub-busbar is used to pass through the inside of the magnetic isolating switch, and is used to fit with the surface of the magnetic isolating switch in the axial direction or circumferential direction outside the magnetic isolating switch.

[0034] It should be noted that see Figure 8The positive and negative busbars are closely aligned and placed. 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 to achieve the effect of reducing inductance. However, if Figure 8 As shown in the figure, the two busbars are not closely aligned at the place 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 greatly reduce the inductance; the corresponding equivalent circuit can be seen in Fig. 9 In summary, the present application can achieve the low inductance effect of the composite busbar structure.

[0035] It can be understood that in the embodiment of the present application, N groups of busbars are arranged in a dispersed manner inside and outside the magnetic isolating switch according to the shape of the magnetic isolating switch. 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 isolating switch according to the shape of the magnetic isolating switch, and multiple capacitors are arranged in one plane, and are arranged in a different plane from the magnetic isolating switch; the above-mentioned arrangement enables each capacitor to be connected to the magnetic isolating switch through positive and negative busbars of as similar length as possible, and no additional adapter is required in the middle, and no other inductance will be introduced, further ensuring the low inductance of the composite busbar structure.

[0036] In a more specific embodiment, the present application provides a single-turn coil magnet system, comprising: the above-mentioned composite busbar structure, N capacitors, a magnetic isolation 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 to the single-turn coil one by one through an RSD. That is, the N capacitors are divided into multiple groups and connected in parallel, and then connected to the RSD switch and then connected in parallel to supply power to the single-turn coil.

[0037] Furthermore, the above-mentioned composite busbar and the capacitor group before the RSD switch are connected in parallel. After the N capacitors and the corresponding composite busbars are connected in parallel, they are divided into M groups of capacitors and corresponding composite busbars. After passing through the magnetic switch, each group of composite busbars is connected to each other to connect to the subsequent RSD switch. The M RSD switches are connected in parallel to the single-turn coil to power the single-turn coil. How to design N and M specifically and how to perform parallel power supply needs to be determined by the current peak value and current rise rate required by the single-turn coil.

[0038] It should be noted that the above-mentioned single-turn coil magnet is usually a destructive pulse magnet. Destructive pulse magnets have particularly prominent requirements on the inductance of the discharge circuit, and the inductance of the discharge circuit needs to be extremely low. Accordingly, the low-inductance composite busbar structure provided in the embodiment of the present application can also be applied to other non-destructive pulse magnets, and the embodiment of the present application does not make further limitations on this.

[0039] In some embodiments, the N capacitors are dispersed around the magnetic isolation switch, and the plurality of capacitors are arranged in one plane and are arranged in a different plane from the magnetic isolation switch.

[0040] 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.

[0041] In a possible embodiment, taking N as 8 as an example, 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 bars arranged along a circle, which are parallel to the top surfaces of the correspondingly arranged power capacitors, and each group of metal copper bars includes positive and negative busbars, which are parallel to each other and arranged in layers up and down; 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.

[0042] 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.

[0043] Preferably, tabs are provided at the ends of the positive and negative busbars, and the tabs are connected to the power supply capacitors via terminals.

[0044] Preferably, the optimal angle between adjacent metal copper busbars and the optimal size of the copper busbars need to be calculated by a low-inductance structure electromagnetic thermal simulation algorithm. The determination of the optimal value needs to take into account three requirements: first, to reduce the inductance value of the overall structure as much as possible; second, to minimize the heat generation and deformation of the copper busbar; and third, to ensure that there is enough space between adjacent capacitors.

[0045] 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 excessive deformation of the busbar, and the high melting point is used to prevent the busbar from melting due to excessive current.

[0046] 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.

[0047] It should be noted that the positive busbar is longer than the negative busbar in order to press-fit insulating materials therein to ensure safety.

[0048] Preferably, the interval between two busbars in each group of metal copper bars is mm-level, and an insulating material is pressed in between, and the length and width of the insulating material are both 5 mm to 20 mm larger than the busbars.

[0049] 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.

[0050] Preferably, all the positive busbars arranged along the circumference pass through the interior of the magnetic isolating switch via an inner insulating structure, and all the special-shaped negative busbars arranged along the circumference are closely attached to the exterior of the magnetic isolating switch and opposite to the positive busbars via an outer insulating structure.

[0051] Preferably, the angle between adjacent metal copper bar groups is the same as the angle in claim 3.

[0052] 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-hole positive busbar. A plurality of limiting grooves are provided on the limiting component, the groove width is consistent with the busbar width in claim 3, and the angle between adjacent grooves is the same as the angle in claim 3.

[0053] It should be noted that if the thickness of the thin wall is too small, the insulation performance cannot be guaranteed, and if the thickness of the thin wall is too large, the inductance cannot be effectively reduced. Therefore, the present application prefers the thickness of the above value.

[0054] Preferably, the inner diameter of the external 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, the groove width is consistent with the busbar width in claim 3, and the angle between adjacent grooves is the same as the angle in claim 3.

[0055] It should be noted that if the thickness of the thin wall is too small, the insulation performance cannot be guaranteed, and if the thickness of the thin wall is too large, the inductance cannot be effectively reduced and it is slightly bulky. Therefore, the present application prefers the thickness of the above value.

[0056] Preferably, the copper negative busbar is in the shape of an open rectangular frame.

[0057] It should be noted that the present application is preferably designed as an open rectangular frame shape, and this shape depends on the shape of the magnetic isolating switch.

[0058] Preferably, the metal copper bar group of the planar wraparound power busbar structure corresponds to the metal copper bar group of the through-type positive busbar structure in positive and negative directions and are welded at the ends.

[0059] 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 a cable.

[0060] It should be noted that the preferred design of the present application is to use copper busbars for connection to minimize inductance, heat generation and deformation.

[0061] 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.

[0062] Example In this embodiment, taking N as 8 as an example, there are 8 capacitors, the inner diameter of the magnetic isolating switch is 100mm, the outer diameter is 300mm, and the thickness is 45mm. The 8 groups of metal copper bars of the planar surround power busbar structure are arranged in a circle, 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 on the plane where the 8 capacitors are located to place other required devices, such as reserving the position of the demagnetization coil. The busbar width is 26mm, the thickness is 2mm, the positive busbar is 610mm long, and the negative busbar is 605mm long. Each group of metal copper bars includes positive and negative busbars that are parallel to each other and placed in layers up and down, with an interval of 2mm, and epoxy resin insulating material is pressed in the middle. The insulating material is 40mm wide and 610mm long. Ears are set at the ends of the positive and negative busbars, and the ears are connected to the power capacitors through the terminals. The through-type positive busbar structure has 8 groups of metal copper bars arranged in a circle. Each group of metal copper bars contains two positive and negative busbars. The angle between adjacent metal copper bar groups is 38°. The busbar width is 26mm and the thickness is 2mm. The positive busbar passes through the inside of the magnetic isolating switch through the inner insulation structure, and the negative busbar is placed outside the magnetic isolating switch through the outer insulation structure. The thin wall thickness of the insulating component in the inner insulation structure is 1mm, and the outer diameter is equal to the inner diameter of the magnetic isolating switch. The thin wall thickness of the outer insulation structure is 5mm, and the inner diameter is equal to the outer diameter of the magnetic isolating switch. The copper special-shaped negative busbar is an open rectangular frame. An octagonal copper plate is used at the other end away from the welding point to connect the positive and negative busbars respectively, and then connect the RSD switch through a cable.

[0063] The test results show that the DC inductance of the overall low inductance structure is 32.85nH, and the inductance under 1MHz AC is 6.52nH. The maximum internal deformation is 0.336nm, and the heat generation is less than 1K. It can be seen that 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. Compared with the traditional RSD discharge circuit, the present application can effectively increase the current rise rate and effectively enhance the magnetic field strength without changing the power supply capacity, power supply voltage, RSD quantity 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.

[0064] It should be understood that expressions such as "including" and "may include" that may be used in the present 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 the present application, terms such as "including" and / or "having" 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.

[0065] In addition, in the present 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.

[0066] 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 relative position relationship after connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference 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.

[0067] In addition, in the embodiments of the present application, the mathematical concepts mentioned are symmetry, equality, parallelism, verticality, etc. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense, and allow a small amount of deviation, approximation to symmetry, approximation to equality, approximation to parallelism, approximation to verticality, etc. are all possible. 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.

[0068] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A composite busbar structure, which is used to connect multiple capacitors with 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, and 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 closely 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 the first sub-busbar, the second sub-busbar and the third sub-busbar, and the sub-busbars of the same type in the positive busbar and / or the 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; The N groups of 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 inside of the magnetic isolation switch respectively, and the other ends of all negative busbars are connected to each other after being closely attached to the outside of the magnetic isolation switch respectively, so as to connect the corresponding multiple capacitors in parallel through the magnetic isolation 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 dispersedly 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 comprises: 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 in parallel 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 aligned in parallel with each other, and the three second sub-busbars of the negative busbar are respectively aligned in parallel with 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 comprises: 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 in parallel 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 aligned in parallel with each other, and the three third sub-busbars of the negative busbar are respectively aligned in parallel with 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 isolating switch, and is used to fit with the surface of the magnetic isolating switch in the radial direction outside the magnetic isolating switch. The second sub-busbar or the third sub-busbar is used to pass through the interior of the magnetic isolating switch, and is used to fit with the surface of the magnetic isolating switch in the axial direction or circumferential direction outside the magnetic isolating switch.

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 to the single-turn coil one by one 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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