Three-phase bridge topology laminated busbar structure suitable for 62mm silicon carbide module

Abstract

The invention discloses a three-phase bridge topology laminated busbar structure suitable for a 62mm silicon carbide module. The three-phase bridge topology laminated busbar structure comprises a laminated busbar, three 62mm silicon carbide modules are arranged on the back surface of the laminated busbar; each 62mm silicon carbide module is connected with a driving circuit board, one side of each driving circuit board is hollowed out and is fixedly arranged on one side of the laminated busbar, and the other side of each driving circuit board is suspended relative to the laminated busbar; a plurality of absorption capacitors are arranged on the front surface of the laminated busbar; the back surface of the laminated busbar is also provided with a plurality of decoupling capacitors. The absorption capacitor and the decoupling capacitor are connected in parallel on the laminated busbar; each phase of the 62mm silicon carbide module is connected in parallel with an absorption capacitor, and a main power loop of the three-phase bridge is connected in parallel with a decoupling capacitor. The novel three-phase bridge topology laminated busbar structure matched with the 62mm silicon carbide module for use is realized by connecting the 62mm silicon carbide module, the fixed capacitor and the laminated busbar and connecting the laminated busbar and the 62mm silicon carbide module by plugging the driving circuit board.

Description

Technical Field

[0001] This invention relates to the field of power electronic device technology, and in particular to a three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules. Background Technology

[0002] In the field of power electronics, power modules require main circuit conductors to function. Traditional conductors are mainly cables and copper busbars. Cables are insulated by their sheaths, but have large current loop cross-sections and high parasitic inductance. Copper busbars are insulated by air and have low withstand voltage. Due to the fast switching speed of SiC MOSFET devices, large current changes di / dt occur in the circuit. If the parasitic inductance L in the circuit is large, the SiC MOSFET device will experience a large voltage overshoot L*di / dt, which can seriously damage the SiC MOSFET device. The parasitic inductance within power modules has been optimized by packaging engineers, and the voltage levels of power modules are becoming increasingly higher. To reduce the overall parasitic inductance of the circuit, it is necessary to reduce the stray inductance of the main circuit conductors and improve their insulation. Laminated busbars, composed of copper conductors and insulating materials, are a new type of electrical connection method that is increasingly favored by power electronics engineers. Compared to cables and copper busbars, laminated busbars have lower stray inductance, better heat dissipation, and higher insulation levels.

[0003] In power modules, the 62mm package is a common packaging form used in welding machines and photovoltaic fields. For example, in the photovoltaic field, existing technologies have disclosed multilayer busbars adapted to the ANPC topology three-level inverter circuit of 62mm modules, but the busbar structure for silicon carbide modules has not been disclosed, thus hindering the construction of a module power testing platform. The main difficulties are: first, there is no driver circuit board adapted to the module product, and the corresponding suitable driver parameters have not been accumulated; second, there is no power testing platform, lacking both the busbar for circuit construction and suitable high-power loads, as well as heat dissipation channels and circulating water systems. Summary of the Invention

[0004] Technical Objective: To address the drawback of high stray inductance in existing 62mm module three-phase bridge circuits, this invention provides a three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules. The 62mm silicon carbide module is connected via a plug-in drive circuit board, and capacitors are fixed to the stacked busbar with screws. The stacked busbar is then connected to the 62mm silicon carbide module with screws, thus achieving the assembly of the structure and realizing a novel three-phase bridge topology stacked busbar structure for use with 62mm silicon carbide modules.

[0005] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution.

[0006] A three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules includes a stacked busbar; three 62mm silicon carbide modules are arranged on the back of the stacked busbar; each 62mm silicon carbide module is connected to a drive circuit board, each drive circuit board has a hollowed-out side and is fixedly mounted on one side of the stacked busbar, and the other side of the drive circuit board is suspended relative to the stacked busbar; several absorption capacitors are provided on the front of the stacked busbar; several decoupling capacitors are also provided on the back of the stacked busbar; the absorption capacitors and decoupling capacitors are connected in parallel on the stacked busbar; each phase of the 62mm silicon carbide module is connected in parallel with an absorption capacitor, and a decoupling capacitor is connected in parallel in the main power circuit of the three-phase bridge.

[0007] Preferably, the 62mm silicon carbide module includes a control terminal, an intermediate phase output power terminal, a power terminal N, and a power terminal P; the control terminal is plugged into the drive circuit board; the intermediate phase output power terminal, power terminal N, and power terminal P are located in the cutout position of the drive circuit board, and the power terminal N and power terminal P are fixed to the stacked busbar by screws, and the intermediate phase output power terminal is connected out with a wire with a copper lug.

[0008] Preferably, the stacked busbar consists of a first insulating layer, a first copper layer, a second insulating layer, a third insulating layer, a second copper layer, and a fourth insulating layer from top to bottom; a hollow copper pillar is embedded between the first copper layer and the second copper layer to achieve conductive connection between the devices on the front and back sides of the stacked busbar.

[0009] Preferably, the side where the third insulating layer, the second copper layer, and the fourth insulating layer are aligned extends beyond the width of at least one power terminal P on the side where the first insulating layer, the first copper layer, and the second insulating layer are aligned.

[0010] Preferably, the first copper layer and the second copper layer are made of copper.

[0011] Preferably, the insulation performance of the second and third insulating layers is higher than that of the first and fourth insulating layers.

[0012] Preferably, the exposed portions of the first and second copper layers in the stacked busbar that are not covered by the insulating layer are connected by wires with copper lugs, and the connection ends are located on the side of the stacked busbar away from the drive circuit board.

[0013] Preferably, a plurality of decoupling capacitors are disposed on the back side of the stacked busbar, the decoupling capacitors are arranged in a 3*3 array, and the decoupling capacitors are located on the side of the stacked busbar away from the drive circuit board.

[0014] Preferably, the front side of the stacked busbar is provided with 6 absorption capacitors, and a 62mm silicon carbide module is connected to 2 absorption capacitors.

[0015] Preferably, one end of the absorption capacitor is a two-hole connection terminal; the connection terminals of the two absorption capacitors overlap and are fixedly connected to the stacked busbar by screws; the absorption capacitor is connected to the power terminal P and power terminal N of the 62mm silicon carbide module.

[0016] Beneficial effects: 1. This invention connects a 62mm module via a plug-in driver circuit board, fixes the capacitor and the multilayer busbar with screws, and connects the busbar and the 62mm module with screws to achieve the assembly of the structure of this invention, realizing a novel three-phase bridge topology multilayer busbar structure for use with 62mm silicon carbide power modules. 2. The structure of this invention can solve the problem of large stray inductance in the 62mm module three-phase bridge circuit. The structure is clear, the manufacturing method is simple, the production cost is low, and it can be mass-produced. 3. By connecting a decoupling capacitor and an absorption capacitor in parallel on the busbar, this invention can suppress oscillation spikes near the high frequency and switching frequency, thereby enhancing the stability of the circuit. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a three-phase bridge topology stacked busbar structure suitable for a 62mm silicon carbide module according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the front and back layout of a three-phase bridge topology stacked busbar structure suitable for a 62mm silicon carbide module according to an embodiment of the present invention; Figure 3 for Figure 1 Diagram of the mid-layer busbar structure; Figure 4 for Figure 1 Diagram of the absorption capacitor structure; Figure 5 for Figure 1 Middle drive circuit board structure diagram; Figure 6 for Figure 1 62mm silicon carbide module structure diagram; Figure 7 for Figure 1 Diagram of the decoupling capacitor structure; Figure 8 This is a comparative schematic diagram of the connection between the 62mm silicon carbide module and the drive circuit board in the present invention and the prior art; Figure 9 for Figure 1 An exploded view showing the connection between a single 62mm silicon carbide module and the stacked busbar and drive circuit board; Figure 10 This is a side view of a three-phase bridge topology stacked busbar suitable for a 62mm silicon carbide module according to an embodiment of the present invention; Among them, 1. Stacked busbar, 11. First insulating layer, 12. First copper layer, 13. Second insulating layer, 14. Third insulating layer, 15. Second copper layer, 16. Fourth insulating layer; 2. Absorption capacitor; 3. Driver circuit board; 4. 62mm silicon carbide module, 41. Intermediate phase output power terminal, 42. Power terminal N, 43. Power terminal P; 44. Gate connector of lower bridge arm; 45. Kelvin source connector of lower bridge arm; 46. Kelvin source connector of upper bridge arm; 47. Gate connector of upper bridge arm; 5. Decoupling capacitor. Detailed Implementation

[0018] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments.

[0019] The embodiments are for illustrative purposes only and do not constitute a limitation on the scope of the claims. Other alternative means that can be conceived by those skilled in the art are all within the scope of the claims of this invention.

[0020] Furthermore, in the description of this invention, it should be noted that the terms "central," "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] Example: As attached Figure 1 To be continued Figure 7 As shown, the present invention discloses a three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules, comprising a stacked busbar 1; three 62mm silicon carbide modules 4 are disposed on the back side of the stacked busbar 1; each 62mm silicon carbide module 4 is connected to a drive circuit board 3, each drive circuit board 3 is hollowed out on one side and fixedly disposed on one side of the stacked busbar 1, and the other side of the drive circuit board 3 is suspended relative to the stacked busbar 1; a plurality of absorption capacitors 2 are disposed on the front side of the stacked busbar 1; a plurality of decoupling capacitors 5 are disposed on the back side of the stacked busbar 1; the absorption capacitors 2 and the decoupling capacitors 5 are connected in parallel on the stacked busbar 1. Each phase of the 62mm silicon carbide module 4 is connected in parallel with a low-inductance absorption capacitor, and a decoupling capacitor is connected in parallel in the main power circuit of the three-phase bridge, which can suppress oscillation spikes near high frequency and switching frequency, and maintain the stability of system operation.

[0022] The 62mm silicon carbide module 4 is a three-phase bridge topology circuit, model WMH003M120F1A. Other 62mm modules implemented in existing technologies are also applicable as long as they conform to a general shape. The 62mm silicon carbide module 4 includes control terminals, intermediate phase output power terminals 41, power terminals N42 and P43. The control terminals are plugged into the drive circuit board 3. The control terminals include the gate connector 44 of the lower bridge arm, the Kelvin source connector 45 of the lower bridge arm, the Kelvin source connector 46 of the upper bridge arm, and the gate connector 47 of the upper bridge arm. The control terminals are plug-in type and are plugged into the drive circuit board. The intermediate phase output power terminals 41, N42 and P43 are located in the cutout position of the drive circuit board 3. The power terminals N42 and P43 are fixed to the stacked busbar 1 with screws. The intermediate phase output power terminal 41 is connected out with a wire with a copper lug. Through this position and structural design, the 62mm silicon carbide module 4 in this invention fits more closely to the drive circuit board 3.

[0023] As attached Figure 3 As shown, attached Figure 3 The left side shows a diagram of the explosion. Figure 3 The right side shows a schematic diagram after assembly. The stacked busbar 1 consists of, from top to bottom, a first insulating layer 11, a first copper layer 12, a second insulating layer 13, a third insulating layer 14, a second copper layer 15, and a fourth insulating layer 16. A hollow copper pillar is embedded between the first copper layer 12 and the second copper layer 15 to achieve conductive connection between the devices on the front and back sides of the stacked busbar 1. Holes for connecting the decoupling capacitor 5 are formed on the first insulating layer 11, the first copper layer 12, the second insulating layer 13, the third insulating layer 14, the second copper layer 15, and the fourth insulating layer 16, and the connection is achieved through the hollow copper pillar embedded between the first copper layer 12 and the second copper layer 15. The side where the third insulating layer 14, the second copper layer 15, and the fourth insulating layer 16 are aligned extends beyond the width of at least one power terminal P43 on the side where the first insulating layer 11, the first copper layer 12, and the second insulating layer 13 are aligned; a hole is provided on one side of the first insulating layer 11, the first copper layer 12, and the second insulating layer 13 to accommodate the power terminal N42 and the intermediate phase output power terminal 41 on the 62mm silicon carbide module 4; a hole is provided on the third insulating layer 14, the second copper layer 15, and the fourth insulating layer 16 to accommodate the power terminal P43, the power terminal N42, and the intermediate phase output power terminal 41 on the 62mm silicon carbide module 4.

[0024] In this embodiment, the first copper layer 12 and the second copper layer 15 are made of copper. Each insulating layer can be the same or different, but the insulation performance of the second insulating layer 13 and the third insulating layer 14 is required to be higher than that of the first insulating layer 11 and the fourth insulating layer 16, selected according to actual conditions. In this embodiment, the first insulating layer 11 and the fourth insulating layer 16 are made of FR4 epoxy pads; the second insulating layer 13 and the third insulating layer 14 are made of PET. In other embodiments of the invention, all insulating layers can be made of materials with the same insulation performance, as long as the actual needs are met. The exposed portions of the first and second copper layers in the stacked busbar 1 that are not covered by the insulating layers are connected with wires with copper lugs, and the connection ends are located on the side of the stacked busbar away from the drive circuit board 3. This positional arrangement prevents the stacked busbar from becoming irregularly shaped, reduces costs, and also increases the mechanical strength of the stacked busbar.

[0025] Several decoupling capacitors 5 are arranged on the back of the stacked busbar 1. The decoupling capacitors 5 are arranged in a 3*3 array, and the decoupling capacitors are located on the side of the stacked busbar away from the drive circuit board 3. Several through holes are provided at the positions of the decoupling capacitors 5. Each decoupling capacitor 5 corresponds to 2 holes. The decoupling capacitors 5 are fixedly connected to the stacked busbar 1 in the holes by screws. The three-phase bridge topology circuit corresponds to three 62mm silicon carbide modules 4. Each 62mm silicon carbide module 4 corresponds to two absorption capacitors 2. The capacitance value of the decoupling capacitors 5 must meet the requirements of the three-phase bridge topology circuit, that is, meet the requirements of the main power circuit of the three-phase bridge. The specific data is determined according to the actual situation. For example, the number of decoupling capacitors 5 required is determined according to the capacitance value of each decoupling capacitor 5. Generally, 6 or 9 are the optimal choices. In this embodiment, a 3*3 array is used, and the size of each decoupling capacitor 5 does not exceed 70*84.5*84.5mm. The decoupling capacitor 5 is a 1500V 56uF film capacitor. Nine decoupling capacitors 5 are arranged in a 3*3 array and connected to the laminated busbar 1 by M6 screws.

[0026] The front side of the stacked busbar 1 has six absorption capacitors 2, one end of which is a two-hole connection terminal. A 62mm silicon carbide module 4 is connected to two absorption capacitors 2, with the connection ends of the two absorption capacitors 2 overlapping and fixedly connected to the stacked busbar 1 by screws. The absorption capacitors 2 are connected to the 62mm silicon carbide module 4, specifically to the power terminals P43 and N42 of the 62mm silicon carbide module 4. In this embodiment, the size of the absorption capacitors 2 must not exceed 40*44*44mm. The absorption capacitors 2 are 1uF±5% 1250V buffer absorption capacitors, connected to the stacked busbar 1 and the 62mm silicon carbide module 4 by M6 screws. The drive circuit board 3 is an FHD0220 dual-channel drive board, one end of which is directly plugged into the control terminal of the 62mm silicon carbide module, and the other end uses a standardized horn connector. As attached Figure 10 As shown, a heat dissipation channel is set on the back side of the stacked busbar 1 and under the 62mm silicon carbide module 4. The 62mm silicon carbide module 4 needs to be placed on the heat dissipation channel at a suitable height to balance the height difference between the 62mm silicon carbide module 4 and the decoupling capacitor 5.

[0027] As attached Figure 8 and attached Figure 9 As shown, attached Figure 8 The right side shows a schematic diagram of the connection between a 62mm silicon carbide module and a drive circuit board in the prior art, while the left side shows a schematic diagram of the connection between a 62mm silicon carbide module and a drive circuit board in this invention; from Figure 8 and Figure 9 As can be seen from the present invention, in the prior art, when the 62mm silicon carbide module is connected to the drive circuit board, it is necessary to additionally lead out the connection terminals of the 62mm silicon carbide module through leads and connect them to the stacked busbar. This results in a height difference between the 62mm silicon carbide module and the drive circuit board, which is not conducive to modular integration. In the present invention, one side of the drive circuit board 3 is hollowed out, and the intermediate phase output power terminals 41, N42 and P43 of the 62mm silicon carbide module are located in the hollowed-out position of the drive circuit board 3, so that the 62mm silicon carbide module, the drive circuit board and the stacked busbar can fit tightly together, reducing the space size.

[0028] This invention designs a stacked busbar structure with a driver board and capacitor pairs to realize the construction of a three-phase bridge topology circuit for 62mm modules. The power terminal layout of the 62mm module differs from that of HPD and Economial3 modules, making busbar connection inconvenient: firstly, the intermediate phase output terminals are too close to the P and N terminals, making it difficult to connect the intermediate phase output terminals with wires; secondly, the control terminals and power terminals of the 62mm silicon carbide module are too close together, and the control terminals are plugged into the driver circuit board and screwed to the stacked busbar, causing spatial conflicts between the driver circuit board and the stacked busbar. This invention perfectly solves the problem of difficult layout of the three-phase bridge topology circuit for 62mm silicon carbide modules. While other designs can solve the above two problems, they result in an irregular busbar structure, which is not conducive to actual production and has weaker structural strength. This invention, by connecting decoupling capacitors and absorption capacitors in parallel on the busbar, can suppress oscillation spikes near high frequencies and switching frequencies, enhancing circuit stability. This invention aims to design a main circuit conductor device suitable for 62mm silicon carbide modules, providing a solution for building a module power testing platform.

[0029] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules, characterized in that, The system includes a multilayer busbar; three 62mm silicon carbide modules are mounted on the back of the multilayer busbar; each 62mm silicon carbide module is connected to a drive circuit board, with one side of each drive circuit board being hollowed out and fixedly mounted on one side of the multilayer busbar, and the other side of the drive circuit board being suspended relative to the multilayer busbar; several absorption capacitors are mounted on the front of the multilayer busbar; several decoupling capacitors are also mounted on the back of the multilayer busbar; the absorption capacitors and decoupling capacitors are connected in parallel on the multilayer busbar; each phase of the 62mm silicon carbide module is connected in parallel with an absorption capacitor, and a decoupling capacitor is connected in parallel in the main power circuit of the three-phase bridge.

2. The three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules according to claim 1, characterized in that: The 62mm silicon carbide module includes control terminals, intermediate phase output power terminals, power terminal N, and power terminal P. The control terminals are plugged into the drive circuit board. The intermediate phase output power terminals, power terminal N, and power terminal P are located in the cutout position of the drive circuit board. Power terminal N and power terminal P are fixed to the stacked busbar with screws. The intermediate phase output power terminals are connected out with wires with copper lugs.

3. The three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules according to claim 1, characterized in that: The stacked busbar consists of a first insulating layer, a first copper layer, a second insulating layer, a third insulating layer, a second copper layer, and a fourth insulating layer, from top to bottom. A hollow copper pillar is embedded between the first copper layer and the second copper layer to achieve conductive connection between the devices on the front and back sides of the stacked busbar.

4. A three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules according to claim 3, characterized in that: The side where the third insulating layer, the second copper layer, and the fourth insulating layer are aligned extends beyond the side where the first insulating layer, the first copper layer, and the second insulating layer are aligned by at least one power terminal P.

5. A three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules according to claim 2, characterized in that: The first and second copper layers are made of copper.

6. A three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules according to claim 2, characterized in that: The insulation performance of the second and third insulating layers is higher than that of the first and fourth insulating layers.

7. A three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules according to claim 2, characterized in that: The exposed portions of the first and second copper layers in the stacked busbar that are not covered by the insulation layer are connected by wires with copper lugs, and the connection ends are located on the side of the stacked busbar away from the drive circuit board.

8. A three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules according to claim 1, characterized in that: Several decoupling capacitors are arranged on the back of the stacked busbar. The decoupling capacitors are arranged in a 3*3 array and are located on the side of the stacked busbar away from the drive circuit board.

9. A three-phase bridge topology stacked busbar structure suitable for 62mm silicon carbide modules according to claim 1, characterized in that: The front side of the stacked busbar has 6 absorption capacitors, and a 62mm silicon carbide module is connected to 2 absorption capacitors.

10. A three-phase bridge topology stacked busbar structure suitable for a 62mm silicon carbide module according to claim 1, characterized in that: One end of the absorption capacitor is a two-hole connection terminal; the connection terminals of the two absorption capacitors overlap and are fixedly connected to the stacked busbar by screws; the absorption capacitors are connected to the power terminals P and N of the 62mm silicon carbide module.

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