Laminated busbar of SVG product based on SIC
By adopting the stacked busbar design of SIC-based SVG products in high-frequency power electronic equipment, and using copper foil copper clad and absorbing capacitor pads, the existing stacked busbars have been solved, and the efficient conductive and compact design is achieved, which significantly improves the operating performance of power electronic equipment.
Patent Information
- Application Number
- CN202411973090.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-03-07
AI Technical Summary
The existing stacked busbars are inefficient in high-frequency power electronic equipment and have a bloated structure, which cannot meet the compact design requirements.
The stacked busbar design of SIC-based SVG products includes upper and lower circuit boards and epoxy board insulation layers. It realizes efficient conductive and compact design through copper foil and copper-coated copper and absorbing capacitor pads.
It improves the conductivity efficiency of high-frequency current, reduces the cost, significantly reduces the coupling inductance, and increases the coupling capacitor, which can better suppress the instantaneous disturbance of DC bus voltage and low-potential high-frequency disturbance.
Smart Images
Figure CN119584414A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of power electronics technology, and in particular to a laminated busbar of a SIC-based SVG product. Background Art
[0002] In the field of power electronics, laminated busbars are commonly used to solve the current transmission problem of power switching components. Common laminated busbars use high-voltage thermal insulation layers to isolate and encapsulate copper plates of different shapes, and press them into a flat-plate integrated structure to form a laminated busbar. Threaded copper columns are reserved on the laminated busbar for connecting different conductive positions. The advantage of the laminated busbar is that it can complete the transmission of large currents and isolation of high voltages in a narrow space, and because of the laminated structure of the laminated busbar, it helps to reduce the coupling inductance of the busbar system, increase the coupling capacitance of the busbar system, and improve the operating environment of the power switching components. Therefore, it is widely used in the field of power electronics.
[0003] The existing laminated busbar technology also has some significant disadvantages. First of all, the thickness of the busbar is usually thick (to ensure the physical strength required), which has better applicability in high current and low frequency situations, but for the increasing number of high-frequency power electronic equipment in recent years, such as power electronic equipment using SIC high-frequency switching elements, such as APF or SVG, the disadvantages are more significant. First of all, due to the skin effect of high-frequency current, the copper busbar of traditional laminated busbars is not very efficient in conducting electricity, but it is expensive. Secondly, for small and medium power power electronic equipment, the structure of traditional laminated busbars has become bloated and does not meet the requirements of compact design. For this application scenario, the present application improves it.
[0004] Application Contents
[0005] The purpose of the present application is to provide a laminated busbar of an SVG product based on SIC in view of the defects and shortcomings of the prior art.
[0006] To achieve the above-mentioned purpose, the technical solution adopted in this application is: a laminated busbar of an SVG product based on SIC, the innovation of which is that it includes an upper circuit board and a lower circuit board, and the thickness and width of the copper foil of the upper circuit board and the lower circuit board are determined according to the current design requirements, and a high-voltage insulation layer is naturally formed by an epoxy board between the upper circuit board and the lower circuit board, and hardness support is achieved by the epoxy board.
[0007] Furthermore, the outer dimensions of the upper circuit board and the lower circuit board are completely consistent, and the opposite surfaces of the two circuit boards adopt a symmetrical design that is a mirror image of each other, that is, the two circuit boards are pressed together, the outer dimensions and openings of the copper foil of the contact layer are completely consistent, and after superposition, the conductive layer formed by the adjacent surfaces pressed together is the same equipotential surface.
[0008] Furthermore, the upper circuit board is provided with an absorption capacitor pad for mounting an absorption capacitor, and a mounting through hole is provided inside the absorption capacitor pad. A mounting through hole is also provided on the lower circuit board, and the upper and lower mounting through holes correspond to each other one by one.
[0009] Furthermore, the upper circuit board and the lower circuit board are both provided with positioning holes, and are positioned through the positioning holes, and then the absorption capacitor pads, the absorption capacitors on the circuit board and the supporting capacitors are formed into a whole by welding through them.
[0010] Furthermore, the absorption capacitor is installed between the busbar and the reference zero level.
[0011] Furthermore, the laminated busbar is mounted on the terminal of the SIC power element by means of screw crimping to form a complete electronic system.
[0012] After adopting the above structure, the beneficial effects of this application are:
[0013] 1. Compared with the laminated busbar pressed by multiple layers of copper plates, the laminated busbar required by the present application utilizes the mature technology of existing circuit board processing, and the design and processing are simple and efficient, and the cost of the laminated busbar can be greatly reduced;
[0014] 2. The laminated busbar of the present application can better utilize the high-frequency current skin effect to improve the current transmission efficiency, and because the middle layer adopts a double copper foil parallel conductive method, the related current carrying capacity can be doubled;
[0015] 3. The laminated busbar of the present application is more compact and can significantly reduce the coupling inductance between conductive layers, increase the coupling capacitance between conductive layers, and better suppress the DC bus voltage transient disturbance, especially suppress the bus voltage jump caused by zero point offset, to ensure the reliable operation of power devices;
[0016] 4. The laminated busbar of the present application adopts a bidirectional absorption capacitor solution for the busbar to the reference level, which can effectively suppress low-potential high-frequency disturbances and the impact on the busbar voltage. It is more suitable for harsh working conditions. The traditional laminated busbar solution is not suitable for such a design. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the structure of this application.
[0018] Description of reference numerals:
[0019] 1 upper circuit board, 2 lower circuit board, 3 absorption capacitor pad, 4 mounting through hole, 5 positioning hole. DETAILED DESCRIPTION
[0020] The present application is further described below in conjunction with the accompanying drawings.
[0021] In order to make the purpose, technical solution and advantages of this application more clear, the following further describes this application in detail in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described here are only used to explain this application and are not used to limit this application.
[0022] See also Figure 1 , a laminated busbar of an SVG product based on SIC, including an upper circuit board 1 and a lower circuit board 2, and the copper foil thickness and width of the upper circuit board 1 and the lower circuit board 2 are determined according to the current design requirements, and the upper circuit board 1 and the lower circuit board 2 are naturally formed by an epoxy board (not shown in the figure) to form a high-voltage insulation layer, and the epoxy board is used to achieve hardness support. Specifically, taking the 60KHZ SIC switching frequency as an example, the skin depth is about 0.27mm, and the copper foil thickness below 4OZ is selected, which will not be affected by the skin effect; in addition to adopting the intermediate stacking solution, the improvement of the current carrying capacity can also be achieved by expanding the conductive area, which fully meets the current carrying requirements of small and medium power (below 100KVA) high-frequency power electronic equipment; from the perspective of industry development, the switching frequency of power electronic equipment is gradually increasing, and the laminated busbar needs to take into account the requirements of large current and high frequency. The technical solution provided in this application can better solve this problem.
[0023] In this embodiment, the outer dimensions of the upper circuit board 1 and the lower circuit board 2 are exactly the same, and the opposite surfaces of the two circuit boards adopt a symmetrical design that is a mirror image of each other, that is, the two circuit boards are pressed together, the outer dimensions and openings of the copper foil of the contact layer are exactly the same, and after superposition, the conductive layer formed by the adjacent surfaces pressed together is the same equipotential surface.
[0024] In this embodiment, the upper circuit board 1 is provided with an absorption capacitor pad 3 for mounting an absorption capacitor, and a mounting through hole 4 is opened inside the absorption capacitor pad 3. The lower circuit board 2 also has a mounting through hole 4, and the upper and lower mounting through holes correspond to each other.
[0025] In this embodiment, the upper circuit board 1 and the lower circuit board 2 are both provided with positioning holes 5, and the positioning holes 5 are used to position the absorption capacitor pads 3, which are welded through, and the absorption capacitors and the supporting capacitors on the circuit board form a whole.
[0026] In this embodiment, the absorption capacitor is installed between the busbar and the reference zero level.
[0027] In this embodiment, the laminated busbar is mounted on the terminals of the SIC power element by means of screw crimping to form a complete electronic system.
[0028] In summary:
[0029] 1. The laminated busbar involved in the present application is composed of a double-layer circuit board with a symmetrical inner layer design, and can be welded into a whole through multiple groups of corresponding absorption capacitor pads 3, mounting through holes 4 and positioning holes 5;
[0030] 2. The copper cladding thickness and width of the laminated busbar involved in this application are designed based on the high-frequency long-term current and instantaneous maximum current requirements.
[0031] The above description is only used to illustrate the technical solution of the present application rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present application by ordinary technicians in this field should be included in the scope of the claims of the present application as long as they do not depart from the spirit and scope of the technical solution of the present application.
Claims
1. A laminated busbar of a SIC-based SVG product, characterized in that: It includes an upper circuit board and a lower circuit board, and the thickness and width of the copper foil of the upper circuit board and the lower circuit board are determined according to the current design requirements. A high-voltage insulation layer is naturally formed by an epoxy board between the upper circuit board and the lower circuit board, and hardness support is achieved by the epoxy board.
2. The laminated busbar of a SIC-based SVG product according to claim 1, characterized in that: The outer dimensions of the upper circuit board and the lower circuit board are completely consistent, and the opposite surfaces of the two circuit boards are designed to be symmetrical and mirror images of each other, that is, the two circuit boards are pressed together, the outer dimensions and openings of the copper foil of the contact layer are completely consistent, and after superposition, the conductive layers formed by the adjacent surfaces pressed together are the same equipotential surface.
3. The laminated busbar of a SIC-based SVG product according to claim 1, characterized in that: The upper circuit board is provided with an absorption capacitor pad for mounting an absorption capacitor, and a mounting through hole is provided inside the absorption capacitor pad. The lower circuit board also has a mounting through hole, and the upper and lower mounting through holes correspond to each other.
4. The laminated busbar of a SIC-based SVG product according to claim 2, characterized in that: The upper circuit board and the lower circuit board are both provided with positioning holes, and are positioned through the positioning holes, and then the absorption capacitor pads, the absorption capacitors on the circuit board and the supporting capacitors are formed into a whole through welding.
5. A laminated busbar of a SIC-based SVG product according to claim 3 or 4, characterized in that: The absorption capacitor is installed between the busbar and the reference zero level.
6. The laminated busbar of a SIC-based SVG product according to claim 1, characterized in that: The laminated busbar is mounted on the terminal of the SIC power element by means of screw crimping to form a complete electronic system.