Multi-group series ultrahigh frequency non-inductive capacitor bank

Abstract

The utility model relates to a multi-group series connection ultrahigh frequency non-inductive capacitor group, which is characterized by comprising N groups of series connection capacitor group bodies and a common busbar assembly, each capacitor bank body comprises an independent busbar and 2M columns of capacitors, all the busbars are connected in series through a common busbar assembly to form a busbar assembly, and the 2M columns of capacitors in the same capacitor bank body are symmetrically arranged on the busbar assembly left and right. According to the ultrahigh frequency non-inductive capacitor bank with multiple groups connected in series, the leakage inductance of the capacitor bank can be greatly reduced, and the current on each capacitor is more uniform. The technical scheme disclosed by the utility model can be directly used in the design of a resonant capacitor bank of a high-frequency or ultrahigh-frequency induction heating power supply, and can also be directly used in the structural design of a direct-current bus filter capacitor bank of the high-frequency or ultrahigh-frequency induction heating power supply.

Description

Technical Field

[0001] The utility model relates to a plurality of groups of ultra-high frequency non-inductive capacitors connected in series, belonging to the application field of power electronic products, and mainly used in the design structure of resonant capacitor groups and inverter filter capacitor groups of high-frequency and ultra-high frequency induction heating power supplies. Background Art

[0002] At present, the commonly used filter capacitor group and resonant capacitor group adopts the method of sandwiching multiple capacitors between two parallel large copper plates. When multiple groups of capacitors are connected in series, multiple parallel large copper plates are arranged in a row, and multiple capacitors are sandwiched between two adjacent parallel copper plates, forming a matrix array. This structure has no major problems when used in medium-frequency applications, but when applied to high frequencies, the voltage drop caused by the leakage inductance inside the capacitor group will be relatively large, and the current of each capacitor in the capacitor group is uneven, resulting in uneven heat generation. Because the capacitor group forms a large circle when connected to the outside, the induction power to the external metal chassis is also very large, causing problems such as chassis heating. Utility Model Content

[0003] The technical problem to be solved by the utility model is: for high-frequency and ultra-high-frequency induction heating power supplies, the inductance (also called leakage inductance) generated in the structure of the capacitor group has a great influence on the operation of the equipment. When used as a filter capacitor group, the capacitor in the capacitor group and its own leakage inductance have an internal resonant frequency. If the operating frequency of the equipment is close to the resonant frequency of the capacitor group itself, high-frequency resonance is likely to occur inside the capacitor group, resulting in excessive oscillation current inside the capacitor group and heat. When used as a resonant capacitor group, when a high-frequency alternating current is passed through the capacitor group, the inductance of the capacitor group itself will produce a large voltage drop, and will reduce the resonant frequency of the resonant circuit, causing the operating frequency to deviate greatly from the design value.

[0004] In order to solve the above technical problems, the technical solution of the utility model is to provide a plurality of groups of ultra-high frequency non-inductive capacitor groups connected in series, characterized in that the groups include N groups of capacitor groups connected in series and a common busbar assembly, N≥2; each group of capacitor groups includes an independent busbar and 2M columns of capacitors, M≥1, and all the busbars are connected in series through the common busbar assembly to form a busbar assembly, and the 2M columns of capacitors in the same group of capacitor groups are arranged symmetrically on the left and right on the busbar assembly, with M columns of capacitors on each side, and each column of capacitors is connected between an L-type capacitor group copper bar and a U-type capacitor group copper bar, or between two U-type capacitor group copper bars, all L-type capacitor group copper bars and all U-type capacitor group copper bars are fixed on the busbar assembly, and the L-type capacitor group copper bar and the U-type capacitor group copper bar are insulated from the busbar assembly by an insulating plate.

[0005] Preferably, the copper bars of all the L-shaped capacitor groups are consistent in size, and the copper bars of all the U-shaped capacitor groups are consistent in size.

[0006] Preferably, all the L-shaped capacitor group copper bars and the U-shaped capacitor group copper bars are individually connected to the water / air duct, and each water / air duct is connected to a water / air joint.

[0007] Preferably, the two L-shaped capacitor group copper bars located at the same position in the left and right directions are electrically connected together through a plurality of capacitor group copper bar connecting bolts and capacitor group copper bar connecting nuts; the two U-shaped capacitor group copper bars located at the same position in the left and right directions are electrically connected together through a plurality of capacitor group copper bar connecting bolts and capacitor group copper bar connecting nuts.

[0008] Preferably, one of the two L-shaped capacitor group copper bars or the U-shaped capacitor group copper bars located at the same position in the left and right directions is connected to the busbar assembly, and the other L-shaped capacitor group copper bar or the U-shaped capacitor group copper bar that is not connected to the busbar assembly is insulated from the busbar assembly by the insulating plate.

[0009] Preferably, the capacitor group copper bar connecting bolts are insulated from the busbar assembly by an insulating gasket.

[0010] The utility model designs a plurality of sets of ultra-high frequency non-inductive capacitors connected in series, which can greatly reduce the leakage inductance itself, and the current flowing through each capacitor is more uniform. The technical solution disclosed in the utility model can be directly used in the design of the resonant capacitor group of a high frequency or ultra-high frequency induction heating power supply, and the utility model can also be directly used in the structural design of the DC bus filter capacitor group of a high frequency or ultra-high frequency induction heating power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a top view of multiple groups of ultra-high frequency non-inductive capacitors connected in series according to the utility model;

[0012] Figure 2 It is a front view of a plurality of sets of ultra-high frequency non-inductive capacitors connected in series according to the utility model;

[0013] Figure 3 It is a left view of a plurality of sets of ultra-high frequency non-inductive capacitors connected in series according to the utility model;

[0014] Figure 4 This is a cross-sectional view of a plurality of sets of ultra-high frequency non-inductive capacitors connected in series according to the utility model;

[0015] Figure 5 It is a partial enlarged view of multiple groups of ultra-high frequency non-inductive capacitor groups D connected in series according to the utility model.

[0016] Description of reference numerals:

[0017] 1——busbar one; 2——busbar two; 3——busbar three; 4——busbar insulation board; 5——L-type capacitor group copper busbar; 6——capacitor group copper busbar connecting bolts; 7——cooling copper tube; 8——capacitor connecting bolts; 9——capacitor; 10——U-type capacitor group copper busbar insulation board; 11——U-type capacitor group copper busbar; 12——L-type capacitor group copper busbar insulation board; 13——water joint; 14——capacitor group copper busbar connecting nut; 15——busbar large-hole insulation gasket. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

[0019] In the capacitor group designed by the utility model, there is a busbar assembly composed of busbar 1, busbar 2 2 and busbar 3 3, wherein busbar 1 and busbar 2 2 are symmetrically arranged and are both fixedly connected to U-shaped busbar 3 3, busbar 1 is connected to the left side of busbar 3 3, and busbar 2 2 is connected to the right side of busbar 3 3. Two large groups of large capacitor groups connected in series are arranged on the busbar assembly, and each group of large capacitor groups is composed of six columns of capacitors connected in parallel. One group of large capacitor groups is located on the left side of the busbar assembly, fixed on the left side of busbar 1 and busbar 3 3, and another group of large capacitor groups is located on the right side of the busbar assembly, fixed on the right side of busbar 2 2 and busbar 3 3. The large capacitor group located on one side of the busbar assembly is arranged symmetrically with three columns as a group, with three columns on each side. Each column of capacitors is connected between the L-type capacitor group copper bar 5 and the U-type capacitor group copper bar 11, or is connected between two groups of U-type capacitor group copper bars 11. In this embodiment, all L-type capacitor group copper bars 5 are of the same size, and all U-type capacitor group copper bars 11 are of the same size. All L-type capacitor group copper bars 5 and U-type capacitor group copper bars 11 are welded with water copper tubes 7, and a water joint 13 is welded at each end of the water copper tube 7. The water joint 13 connects the water copper tube 7 to cool all L-type capacitor group copper bars 5 and U-type capacitor group copper bars 11 through water, and indirectly cools the capacitor 9. All L-type capacitor group copper bars 5 and U-type capacitor group copper bars 11 are respectively connected to the left side of busbar 1, busbar 2, busbar 3, or the right side of busbar 3. Two L-type capacitor group copper bars 5 at the same position are electrically connected together through multiple capacitor group copper bar connecting bolts 6 and capacitor group copper bar connecting nuts 14. Two U-type capacitor group copper bars 11 at the same position are electrically connected together through multiple capacitor group copper bar connecting bolts 6 and capacitor group copper bar connecting nuts 14. The two L-type capacitor group copper bars 5 and the U-type capacitor group copper bars 11 at the same position are only connected to one of the left sides of busbar 1, busbar 2, busbar 3 or the right side of busbar 3, and are not connected to other parts. Therefore, the L-type capacitor group copper bar 5 or the U-type capacitor group copper bar 11 is insulated from the left side of the unconnected busbar 1, busbar 2, busbar 3 or the right side of busbar 3 by the insulating plate 4, insulating plate 12, and insulating plate 10. When the capacitor group connecting copper bar bolt 6 passes through the left side of busbar 1, busbar 2, busbar 3 or the right side of busbar 3 that is not connected to the L-type capacitor group copper bar or the U-type capacitor group copper bar, a large hole is opened on the left side of busbar 1, busbar 2, busbar 3 or the right side of busbar 3, and then an insulating gasket 15 is embedded in the large hole to prevent the capacitor group connecting copper bar bolt 6 from short-circuiting with the busbar assembly. All capacitors are connected between the L-shaped capacitor group copper bar 5 and the U-shaped capacitor group copper bar 11 , or between two groups of U-shaped capacitor group copper bars 11 , using two capacitor connecting bolts 8 .

[0020] like Figure 1As shown, it is a series structure of two large groups of capacitor groups. One capacitor group is composed of busbar 1 and busbar 3 3, and all capacitors connected between busbar 1 1 and busbar 3 3 are connected in parallel. One capacitor group is composed of busbar 2 2 and busbar 3 3, and all capacitors connected between busbar 2 2 and busbar 3 3 are connected in parallel. According to similar structural expansion, multiple groups of capacitors can be designed in series, and the structure of each large group of capacitors is exactly the same. The gap between busbar 1 and busbar 3 3, and busbar 2 2 and busbar 3 3 in the capacitor group designed by the utility model can be very small. It only needs to be padded with a 1-2 mm thick polytetrafluoroethylene insulating plate to play a role in high-voltage insulation, which greatly reduces the leakage inductance between the busbars. Generally, the larger the gap, the greater the leakage inductance.

[0021] This embodiment discloses a capacitor bank copper bar structure that can be installed on both sides. Figure 1 As shown in the figure, all the L-shaped capacitor copper bars 14 and U-shaped capacitor copper bars 11 are installed on both sides of busbar 1, busbar 2, and busbar 3, and are isolated by insulating plates. The current directions of two adjacent columns of capacitors on the same side of busbar 1, busbar 2, or busbar 3 are opposite, and no larger current loop will be formed.

[0022] The capacitor groups in the above embodiment can be connected in series in multiple groups, such as Figure 1 As shown, the structure exemplified in the above embodiment is a mode of connecting two groups of capacitors in series. The structures of the two groups of capacitors are exactly the same. They are connected in series through busbar 3, and can also be designed as many groups connected in series.

[0023] The above embodiment is a structure with a cooling copper tube, wherein when water flows through the water-passing copper tube 7, it can be used for full water cooling, a water cooling structure, or water and air are passed through at the same time, and it can be used for air cooling + water cooling. The technical solution can also be designed as an air cooling structure. For example: when water is not passed through the water-passing copper tube 7, it can also be used for full air cooling, only air cooling. It can also be designed to not weld the water-passing copper tube 7, and only air is blown directly, and it can be used as a full air cooling structure, that is, all water-passing copper tubes 7 and water joints 13 are removed to use the air cooling structure.

Claims

1. A plurality of sets of ultra-high frequency non-inductive capacitors connected in series, characterized in that: It includes N groups of capacitor group bodies connected in series and a common busbar assembly, N≥2; each group of capacitor group bodies includes an independent busbar and 2M columns of capacitors, M≥1, and all the busbars are connected in series through the common busbar assembly to form a busbar assembly. The 2M columns of capacitors in the same group of capacitor group bodies are symmetrically arranged on the left and right of the busbar assembly, with M columns of capacitors on each side, and each column of capacitors is connected between an L-type capacitor group copper bar and a U-type capacitor group copper bar, or between two U-type capacitor group copper bars. All L-type capacitor group copper bars and all U-type capacitor group copper bars are fixed on the busbar assembly, and the L-type capacitor group copper bar and the U-type capacitor group copper bar are insulated from the busbar assembly by an insulating plate.

2. A plurality of sets of ultra-high frequency non-inductive capacitors connected in series as claimed in claim 1, characterized in that: The copper bars of all L-shaped capacitor groups are consistent in size, and the copper bars of all U-shaped capacitor groups are consistent in size.

3. A plurality of sets of ultra-high frequency non-inductive capacitors connected in series as claimed in claim 1, characterized in that: All the L-shaped capacitor group copper bars and the U-shaped capacitor group copper bars are individually connected to the water / air ducts, and each water / air duct is connected to the water / air joint.

4. A plurality of sets of ultra-high frequency non-inductive capacitors connected in series as claimed in claim 1, characterized in that: The two L-shaped capacitor group copper bars located at the same position in the left and right directions are electrically connected together through a plurality of capacitor group copper bar connecting bolts and capacitor group copper bar connecting nuts; the two U-shaped capacitor group copper bars located at the same position in the left and right directions are electrically connected together through a plurality of capacitor group copper bar connecting bolts and capacitor group copper bar connecting nuts.

5. A plurality of sets of ultra-high frequency non-inductive capacitors connected in series as claimed in claim 1, characterized in that: One of the two L-shaped capacitor group copper bars or the U-shaped capacitor group copper bars located at the same position in the left and right directions is connected to the busbar assembly, and the other L-shaped capacitor group copper bar or the U-shaped capacitor group copper bar not connected to the busbar assembly is insulated from the busbar assembly by the insulating plate.

6. A plurality of sets of ultra-high frequency non-inductive capacitors connected in series as claimed in claim 1, characterized in that: The capacitor group copper bar connecting bolts are insulated from the busbar assembly by insulating gaskets.

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