Inverter unit and inverter

Abstract

The utility model provides an inverter unit, and the inverter unit (100) comprises a bus capacitor housing (1) which is made of a plastic material through injection molding; the bus capacitor module (2) is accommodated in the bus capacitor shell (1); the radiator (3) is fixedly connected to the outer side of the bus capacitor shell, and the radiator is provided with a first surface facing the bus capacitor shell (1) and a second surface (30) opposite to the first surface; a power module (4) fixedly connected to the second surface of the heat sink and electrically connected to the bus capacitor module; and the alternating current busbar assembly (5) and the bus capacitor shell (1) are manufactured into a whole through injection molding. The utility model also provides an inverter comprising the inverter unit.

Description

Technical Field

[0001] This utility model relates to the field of electric drive for electric vehicles, and more particularly to inverter units and inverters used in electric drive systems. Background Technology

[0002] In the electric drive system of new energy vehicles / electric vehicles, the inverter is the core control unit. The inverter is so important because the power battery outputs DC power, which must be converted when supplying AC power to the motor.

[0003] The power module plays a crucial role in the inverter, converting AC to DC power. It's a key electronic component; the DC terminal connects to the bus capacitor, while the AC terminal outputs AC power to the motor via the busbar. The AC power needs to be monitored and detected by a Hall effect current sensor. The bus capacitor primarily functions within the controller to keep DC bus voltage fluctuations within acceptable limits and to prevent overcharging and transient voltage from the DC bus from affecting the chips.

[0004] In existing technical solutions, the DC power module and the bus capacitor are designed separately, meaning that only the power module has an independent heat dissipation design, and the bus capacitor cannot share the cooling water channel; furthermore, the AC power module and the DC output bus (including the Hall current sensor) are designed separately and require bolt connection.

[0005] In the existing designs described above, the bus capacitor cannot achieve ideal heat dissipation, and the AC output busbar (containing the Hall current sensor, also known as the Hall magnetic ring) requires bolt connection, which increases material and process costs; the connection and assembly of the power module and the bus capacitor is not compact enough, resulting in a large inverter size, which in turn affects the overall power density and other performance of the controller. Utility Model Content

[0006] To overcome at least one of the above problems, the purpose of this utility model is to provide a low-cost and compact inverter unit, wherein the AC output busbar and Hall magnetic ring / Hall current sensor are integrally injection molded with the bus capacitor housing, and the bus capacitor module and the power module share the same heat sink, which not only enables the bus capacitor module to be fully cooled, but also reduces the size of the inverter unit.

[0007] Therefore, this utility model provides an inverter unit, the inverter unit comprising: a bus capacitor housing, the bus capacitor housing being made of plastic material by injection molding; a bus capacitor module, the bus capacitor module being housed within the bus capacitor housing; a heat sink, the heat sink being fixedly connected to the outside of the bus capacitor housing, and the heat sink having a first surface facing the bus capacitor housing and a second surface opposite to it; a power module, the power module being fixedly connected to the second surface of the heat sink and electrically connected to the bus capacitor module; and an AC busbar assembly, the AC busbar assembly being integrally formed with the bus capacitor housing by injection molding.

[0008] In the above solution, since the bus capacitor housing is made of plastic material by injection molding, and the AC busbar assembly is integrally formed with the bus capacitor housing by injection molding, the manufacturing process is simple, and the material cost is significantly reduced compared with the bus capacitor housing being made of metal such as aluminum.

[0009] In one embodiment of this invention, the bus capacitor housing is constructed in a cuboid shape with a top wall and a bottom wall opposite to the top wall. The top wall has a groove, the shape and size of which are selected to allow the heat sink to be sealed to the top wall and cover the groove, and the heat sink is arranged such that there is a gap between the first surface and the bottom surface of the groove. In one example, the first surface of the heat sink has multiple heat dissipation fins extending into the groove for more efficient heat dissipation.

[0010] According to one aspect of this utility model, the bus capacitor housing has a first sidewall along its length and a second sidewall opposite to the first sidewall, and has three housings extending from the top wall near the first or second sidewall; and the AC bus assembly includes three copper bus components and three Hall effect magnetic rings; wherein each housing receives one of the copper bus components and one of the Hall effect magnetic rings, and each copper bus component extends through the corresponding Hall effect magnetic ring and the corresponding housing and has a first end and a second end extending beyond the housing, wherein the first end is electrically connected to the power module, and the second end constitutes the AC output terminal of the inverter unit.

[0011] According to a preferred embodiment of the present invention, the three receptacles extend outward from the top wall perpendicular to the plane containing the top wall and are equidistant from each other, wherein each of the receptacles has a receiving portion in the form of an open ring to accommodate the Hall magnetic ring.

[0012] In one embodiment, the bus capacitor module includes multiple capacitor core components, which are encapsulated within the bus capacitor housing by injection molding.

[0013] According to one aspect of this utility model, the inverter unit further includes a DC busbar assembly, which is arranged on the side of the bus capacitor housing opposite to the AC output busbar assembly. The DC busbar assembly is electrically connected to the power module and includes a positive copper busbar electrically connected to the positive terminal of the plurality of capacitor cores and a negative copper busbar electrically connected to the negative terminal of the plurality of capacitor cores.

[0014] According to one embodiment of this invention, the bus capacitor housing further includes a third sidewall and a fourth sidewall along its width direction; and the bus capacitor housing also has a first fluid channel and a second fluid channel, wherein the first fluid channel is in fluid communication with the gap space and extends in the third sidewall to a first port located in the bottom wall, and the second fluid channel is in fluid communication with the gap space and extends in the fourth sidewall to a second port located in the bottom wall, thereby forming a cooling medium channel extending between the first port and the second port. Preferably, the first sidewall and the second sidewall are opposite and parallel, and the third sidewall and the fourth sidewall are opposite and parallel. Here, the cooling medium can be, for example, 50% ethylene glycol + 50% water. By setting such a cooling medium channel, the cooling medium flows through the heat sink and the bus capacitor housing simultaneously, enabling more efficient simultaneous heat dissipation of the bus capacitor module and the power module.

[0015] According to a preferred embodiment of the present invention, the bus capacitor housing is made of, for example, polyphenylene sulfide material, and the heat sink is made of, for example, aluminum, the heat sink being hermetically fixed to the top wall of the bus capacitor housing. Because the bus capacitor housing is made of plastic material, costs can be significantly reduced, and the overall assembly weight of the inverter unit can also be reduced.

[0016] According to a preferred embodiment of the present invention, a plurality of nuts are spaced apart and embedded in the top wall of the bus capacitor housing around the groove, and the heat sink is provided with a plurality of threaded through holes near its periphery. The heat sink is fixedly connected to the bus capacitor housing by a plurality of threaded fasteners, such as bolts, cooperating with the plurality of threaded through holes and the plurality of nuts, and a sealing gasket is provided between the top wall and the heat sink, surrounding the side wall of the groove.

[0017] This utility model also provides an inverter, which includes the above-mentioned inverter unit and a housing for encapsulating the inverter unit.

[0018] Due to the adoption of the above technical solutions, the inverter unit / inverter of this utility model can produce at least one of the following beneficial technical effects: low cost; the bus capacitor module and heat sink can be supplied by the same supplier, reducing assembly costs; the bus capacitor module and power module share the heat sink and cooling medium channel, allowing the bus capacitor module to be fully cooled; the bus capacitor housing is made of plastic material, which not only makes it lightweight, reducing the total assembly weight of the inverter unit, but also further reduces costs; the heat sink is integrated into the bus capacitor housing, making the structure compact, reducing the size of the inverter unit, and thus reducing the size and volume of the inverter; and the AC busbar and Hall magnetic ring are integrated with the bus capacitor housing by injection molding, reducing the size and volume of the inverter unit and lowering the total assembly weight. Attached Figure Description

[0019] Referring to the accompanying drawings and reading the following detailed description, further features and advantages of this utility model will become clearer:

[0020] Figure 1 A perspective view of an inverter unit according to an embodiment of the present invention is shown;

[0021] Figure 2 for Figure 1 A perspective view of the bus capacitor housing of the inverter unit, wherein the AC busbar assembly is integrated into the bus capacitor housing by injection molding;

[0022] Figure 3 for Figure 1 An exploded view of the inverter unit shown;

[0023] Figure 4 for Figure 1 The bottom view of the inverter unit shown; and

[0024] Figure 5 for Figure 4 The inverter unit shown is a cross-sectional view (AA). Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The descriptions of orientations used in the following description, such as "upper," "lower," "inner," and "outer," are for convenience only unless explicitly stated otherwise and are not intended to limit the technical solution of the present invention. Furthermore, terms such as "first" and "second" are used below to describe elements of this application; these terms are only used to distinguish individual elements and are not intended to limit the nature, sequence, order, or number of these elements. Additionally, it should be noted that in this specification, the same technical features are represented by the same or similar reference numerals.

[0026] The terms "top" and "bottom" are used to describe the relational positioning of the features of this utility model. These terms should be understood as referring to... Figure 1 and Figure 2 The product shown is positioned accordingly. In this utility model, the "inverter unit" is a part of the inverter and is the core unit module of the inverter. The inverter according to this application is mainly used in new energy electric vehicles, but it can also be used in photovoltaic fields and frequency converters, etc.

[0027] Figure 1 An embodiment of an inverter unit 100 according to the present invention is shown. In this embodiment, the inverter unit 100 includes a bus capacitor housing 1, a bus capacitor module 2, a heat sink 3, a power module 4, and an AC busbar assembly 5 (also referred to as an AC output busbar assembly). Advantageously, the bus capacitor housing 1 is made of plastic material by injection molding, and the AC busbar assembly 5 is integrally formed therewith; the heat sink 3 is integrated to the outside of the bus capacitor housing 1, the power module 4 is fixedly connected to the upper surface of the heat sink, the bus capacitor module 2 and the power module 4 share the same heat sink, and the power module 4 is also electrically connected to the bus capacitor module 2.

[0028] Figure 2 A perspective view of one embodiment of the bus capacitor housing 1 is shown. The bus capacitor housing 1 is constructed in a cuboid shape and has a top wall 11, a bottom wall 12 opposite to the top wall, a first side wall 13 and a second side wall along its length, a third side wall 14 and a fourth side wall 15 along its width, and a receiving cavity defined by these walls for receiving the bus capacitor module 2. Advantageously, the top wall 11 has a recess 111, for example, rectangular, the size of which is also selected to match the size of the heat sink. In this embodiment, the recess 111 is preferably a stepped groove defining a circumferential edge / side 110. The bus capacitor housing 1 is typically made of polyphenylene sulfide (PPS), a material that not only meets process requirements but is also low in cost and lightweight. Specifically, polyphenylene sulfide is a novel high-performance thermoplastic resin with advantages such as high mechanical strength, high temperature resistance, chemical resistance, flame retardancy, good thermal stability, and excellent electrical properties. It has wide applications in the electronics, automotive, machinery, and chemical industries. However, those skilled in the art should understand that the bus capacitor housing is not limited to the aforementioned plastic materials, and other plastic materials may also be used, which are also covered within the scope of this application.

[0029] In the above embodiments of this utility model, the bus capacitor housing is injection molded from plastic material. Compared with the existing bus capacitor housing made of metal materials such as aluminum, its injection mold structure is simple and the material cost is low. Furthermore, the AC busbar assembly and the bus capacitor housing are integrated into one unit, which is simpler to assemble than the fixed connection through threaded fasteners and threaded holes in the prior art.

[0030] See you again Figure 2 The bus capacitor housing 1 has three receptacles 10 extending from the top wall near the first sidewall 13. In this embodiment, the three receptacles 10 extend outward from the top wall perpendicular to the plane containing the top wall, and are preferably equidistant along the length of the bus capacitor housing 1. Furthermore, the AC busbar assembly 5 includes three copper busbar components 51 and three Hall effect magnetic rings 52. Each receptacle receives one copper busbar component 51 and one Hall effect magnetic ring 52. Each copper busbar component 51 has a first end 511 and a second end 512 extending beyond the receptacle, and extending through the corresponding Hall effect magnetic ring and the corresponding receptacle 10. The first end 511 of each copper busbar component 51 is electrically connected to the power module 4, and the second end 512 of each copper busbar component 51 constitutes the AC output terminal of the inverter unit; that is, the second ends of the three copper busbar components constitute the output terminal of a three-phase AC power supply, which is electrically connected, for example, to a motor. In a preferred embodiment, each receptacle 10 has a receiving portion 10a in the form of an open ring for receiving the Hall effect magnetic ring 52.

[0031] Figure 3 for Figure 1 The exploded view of the inverter unit 100 shown shows that, to fit the recess 111, the heat sink 3 is also constructed as a rectangular plate, having a first surface (not shown) facing the bus capacitor housing 1 and a second surface 30 facing away, i.e., the upper surface of the heat sink. In a preferred embodiment, the heat sink 3 is made of aluminum. A plurality of nuts 8a are spaced apart around the recess 111 in the top wall of the bus capacitor housing 1, for example by injection molding, and the heat sink 3 has a plurality of threaded through holes 3a near its periphery. The heat sink 3 is fixedly connected to the bus capacitor housing 1 by a plurality of threaded fasteners 8b, such as bolts, extending through the corresponding threaded through holes 3a and engaging with the corresponding nuts 8a. Preferably, a sealing gasket 8c is provided between the top wall and the heat sink, surrounding the circumferential edge of the recess 11, thereby sealingly fixing the heat sink to the top wall 11 of the bus capacitor housing 1. After assembly, a gap space g exists between the first surface (not shown) of the heat sink 3 and the bottom surface 112 of the recess 111, which is suitable for the flow of the cooling medium. In addition, in order to obtain better heat dissipation efficiency, the first surface of the heat sink facing the bus capacitor housing 1 is provided with multiple heat dissipation fins, which extend into the groove 11. The length of the heat dissipation fins can be selected to contact the bottom surface 112 or to be spaced apart from the bottom surface 112.

[0032] In the above embodiments, the inverter unit 100 further includes a DC busbar assembly 6 electrically connected to the power module 4. The DC busbar assembly is arranged on the side of the bus capacitor housing opposite to the AC busbar assembly, for example, on the side where the second sidewall 14 is located. For example, the DC busbar assembly 6 may include a positive copper busbar 61 and a negative copper busbar 62 fixedly connected to the bus capacitor housing 1. The positive copper busbar 61 is electrically connected to the positive terminal of the bus capacitor module, and the negative copper busbar 62 is electrically connected to the negative terminal of the bus capacitor module.

[0033] Figure 4 This is a bottom view of the inverter unit 100 according to the present invention. Figure 5 for Figure 4 A cross-sectional view AA of the inverter unit is shown in the figure. As can be seen, the inverter unit 100 has a cooling medium channel L, shown in dashed lines, extending between a first port 142 and a second port 152 located in the bottom wall 12 of the bus capacitor housing 1. The cooling medium channel L is formed by a first fluid channel 141, a second fluid channel 151, and a gap space g located between the bottom surfaces of the heat sink 3 and the recess 111. For example, the first fluid channel 141 may include a first inclined section 1411 and a first vertical section 1412 extending in the third sidewall 13, wherein the first inclined section 1411 opens to and is in fluid communication with the gap space g, and the first vertical section 1412 opens to the first port 142. The second flow channel 151 may include a second inclined section 1511 and a second vertical section 1512 extending in the fourth sidewall 15, wherein the second inclined section 1511 opens to and is in fluid communication with the gap space g, and the second vertical section 1512 extends to the second port 152. The above-described layout of the cooling medium channel L is merely exemplary. Other fluid channels with layouts formed in the sidewall of the bus capacitor housing 1 and capable of fluid communication with the gap space are also covered within the scope of this application. Because the inverter unit has the above configuration, the power module 4 and the bus capacitor module 2 share the same heat sink 3 and the same cooling medium channel L, thereby enabling better heat dissipation for both the power module and the bus capacitor module.

[0034] from Figure 5 As can be seen, in one embodiment, the bus capacitor module 2 includes multiple capacitor core components 20, and these capacitor core components 20 are encapsulated within the bus capacitor housing 1 by injection molding. During the operation of the inverter, the DC high-voltage electricity from the battery can be transmitted to the bus capacitor module 2 via the DC bus assembly 6, and then to the power module 4, where it is converted into AC electricity and discharged from the AC bus assembly 5 to the electrical device, such as a motor.

[0035] This utility model also provides an inverter, which includes the inverter unit 100 described above.

[0036] Although the present invention has been disclosed above with reference to preferred embodiments, it is not limited thereto. Any combinations, changes, and modifications made by those skilled in the art without departing from the spirit and scope of the present invention should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope defined in the claims.

Claims

1. An inverter unit, characterized in that, The inverter unit (100) includes: Bus capacitor housing (1), wherein the bus capacitor housing is made of plastic material by injection molding; Bus capacitor module (2), the bus capacitor module is housed in the bus capacitor housing; A heat sink (3) is fixedly connected to the outside of the bus capacitor housing, and the heat sink has a first surface facing the bus capacitor housing (1) and a second surface (30) opposite to it. Power module (4), which is fixedly connected to the second surface of the heat sink and electrically connected to the bus capacitor module; and AC busbar assembly (5), which is integrally formed with the busbar capacitor housing (1) by injection molding.

2. The inverter unit according to claim 1, characterized in that, The bus capacitor housing (1) is constructed in a cuboid shape and has a top wall (11) and a bottom wall (12) opposite to the top wall. The top wall (11) is provided with a groove (111), wherein the shape and size of the groove are selected with respect to the shape and size of the heat sink to allow the heat sink to be sealed to the top wall and to cover the groove (111). The heat sink is arranged such that there is a gap space (g) between the first surface and the bottom surface (112) of the groove.

3. The inverter unit according to claim 2, characterized in that, The bus capacitor housing (1) has a first sidewall (13) along its length and a second sidewall (14) opposite to the first sidewall, and has three receptacles (10) extending from the top wall near the first or second sidewall; and The AC busbar assembly (5) includes three copper busbar components (51) and three Hall effect magnetic rings (52); Each of the housings receives a copper busbar component (51) and a Hall effect magnetic ring (52), and each copper busbar component extends through the corresponding Hall effect magnetic ring and the corresponding housing and has a first end (511) and a second end (512) extending beyond the housing, wherein the first end is electrically connected to the power module and the second end constitutes the AC output terminal of the inverter unit.

4. The inverter unit according to claim 3, characterized in that, The three receptacles (10) extend outward from the top wall perpendicular to the plane of the top wall and are equidistant along the length direction, wherein each of the receptacles has a receiving portion (10a) in the form of an open ring to accommodate the Hall magnetic ring (52).

5. The inverter unit according to any one of claims 1 to 4, characterized in that, The bus capacitor module (2) includes multiple capacitor core components (20), and the multiple capacitor core components (20) are encapsulated in the bus capacitor housing (1) by injection molding.

6. The inverter unit according to claim 5, characterized in that, The inverter unit further includes a DC busbar assembly (6), which is arranged on the side of the bus capacitor housing opposite to the AC busbar assembly. The DC busbar assembly is electrically connected to the power module (4) and includes a positive copper busbar (61) electrically connected to the positive terminal of the plurality of capacitor cores and a negative copper busbar (62) electrically connected to the negative terminal of the plurality of capacitor cores.

7. The inverter unit according to claim 3 or 4, characterized in that, The bus capacitor housing also includes a third sidewall (14) and a fourth sidewall (15) along its width direction; and The bus capacitor housing (1) also has a first fluid channel (141) and a second fluid channel (151), wherein the first fluid channel (141) is in fluid communication with the gap space (g) and extends in the third sidewall (14) to a first port (142) located in the bottom wall (12), and the second fluid channel (151) is in fluid communication with the gap space and extends in the fourth sidewall (15) to a second port (152) located in the bottom wall (12), thereby the first fluid channel, the gap space and the second fluid channel form a cooling medium channel (L) extending between the first port and the second port.

8. The inverter unit according to any one of claims 2 to 4, characterized in that, The bus capacitor housing (1) is made of polyphenylene sulfide material, and the heat sink (3) is made of aluminum. The heat sink (3) is sealed and fixedly connected to the top wall of the bus capacitor housing (1).

9. The inverter unit according to claim 8, characterized in that, A plurality of nuts (8a) are spaced apart and embedded in the top wall of the bus capacitor housing (1) around the groove (111). The heat sink (3) is provided with a plurality of threaded through holes (3a) near its periphery. The heat sink is fixedly connected to the bus capacitor housing (1) by a plurality of threaded fasteners (8b) cooperating with the plurality of threaded through holes (3a) and the plurality of nuts (8a). A sealing gasket (8c) is provided between the top wall and the heat sink, surrounding the side wall of the groove.

10. An inverter, characterized in that, The inverter includes an inverter unit according to any one of claims 1 to 9.

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