Inverter unit and inverter

Abstract

The present utility model provides an inverter unit, the inverter unit (100) comprising: a bus capacitor housing (1), the bus capacitor housing being made from a plastic material by injection molding; a bus capacitor module (2), the bus capacitor module being accommodated in the bus capacitor housing; a radiator (3), the radiator being fixedly connected to an outer side of the bus capacitor housing, and the radiator having a first surface that faces the bus capacitor housing (1) and an opposite second surface (30); a power module (4), the power module being fixedly connected to the second surface of the radiator and being electrically connected to the bus capacitor module; and an AC busbar assembly (5), the AC busbar assembly being integrally formed with the bus capacitor housing (1) by injection molding. The present utility model also provides an inverter that comprises the inverter unit described above.

Description

[0001] Inverter unit and inverter

[0002] Description

[0003] Technical Field

[0004] The present utility model relates to the field of electric drives of electric vehicles, in particular an inverter unit and an inverter used in an electric drive system.

[0005] Background Art

[0006] In an electric drive system of new energy vehicles / electric vehicles, an inverter is a core control unit. The reason why the inverter is so important is that a power battery outputs DC, which must be converted when supplying power to an electric motor that uses AC.

[0007] A power module realizes AC / DC conversion in the inverter and is a key electronic device, and a DC side is connected to a bus capacitor, and an AC side outputs AC power to an electric motor by means of a busbar; it is necessary to monitor AC power by means of measurement with a Hall current sensor. The bus capacitor mainly keeps voltage fluctuations in the DC bus within an allowed range in a controller, and prevents transient voltage and overvoltage from the DC bus from affecting a chip.

[0008] In an existing technical solution, the DC-side power module and the bus capacitor have a split design; that is, only the power module has an independent heat dissipation design, and the bus capacitor cannot share a cooling channel; moreover, the AC-side power module and a DC output busbar (which contains a Hall current sensor) have a split design, which requires a bolted connection.

[0009] In the existing design described above, the bus capacitor cannot achieve an ideal heat dissipation effect, and an AC output busbar (which contains a Hall current sensor, also known as a Hall magnetic ring) requires a bolted connection, increasing material and process costs; the power module connected and fitted to the bus capacitor is not sufficiently compact, resulting in a larger inverter volume, which affects performance such as the overall power density of the controller.

[0010] Summary of the Utility Model

[0011] To overcome at least one of the above problems, the purpose of the present utility model is to provide a low-cost and structurally compact inverter unit, wherein an AC output busbar and a Hall magnetic ring / Hal I current sensor are injection molded integrally with a bus capacitor housing, and a bus capacitor module and a power module jointly use the same radiator, which not only enables the bus capacitor module to sufficiently dissipate heat but also reduces the volume of the inverter unit.

[0012] For this purpose, the present utility model provides an inverter unit, the inverter unit comprising: a bus capacitor housing, the bus capacitor housing being made from a plastic material by injection molding; a bus capacitor module, the bus capacitor module being accommodated in the bus capacitor housing; a radiator, the radiator being fixedly connected to an outer side of the bus capacitor housing, and the radiator having a first surface that faces the bus capacitor housing and an opposite second surface; a power module, the power module being fixedly connected to the second surface of the radiator and being 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.

[0013] In the above solution, since the bus capacitor housing is made from a 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 compared with making the bus capacitor housing with metal such as aluminum, material costs are significantly reduced.

[0014] In a solution of the present utility model, the bus capacitor housing is constructed as a rectangular cuboid and has a top wall and a bottom wall that is opposite the top wall, the top wall having a recess, wherein the shape and size of the recess and the shape and size of the radiator are chosen so that the radiator can be hermetically connected to the top wall and covers the recess, and the radiator is arranged so that there is a gap space between the first surface and a bottom face of the recess. In one example, the first surface of the radiator has multiple heat dissipation fins that extend into the recess for more efficient heat dissipation.

[0015] According to a solution of the present utility model, the bus capacitor housing has a first sidewall in a length direction thereof and a second sidewall that is opposite the first sidewall, and has three receptacles that are near the first sidewall or the second sidewall and extend from the top wall; and the AC busbar assembly comprises three copper bar components and three Hall magnetic rings, wherein each of the receptacles receives one of the copper bar components and one of the Hall magnetic rings, and each of the copper bar components extends through a corresponding Hall magnetic ring and a corresponding receptacle and has a first end and a second end that extend beyond the receptacle, wherein the first end is electrically connected to the power module, and the second end forms an AC power output terminal of the inverter unit.

[0016] According to a preferred solution of the present utility model, the three receptacles extend outward from the top wall perpendicular to a plane of the top wall and are spaced apart equidistantly from each other, wherein each of the receptacles has an accommodating part in the form of an open ring, suitable for receiving the Hall magnetic ring.

[0017] In a solution, the bus capacitor module comprises multiple capacitor core members, and the multiple capacitor core members are sealed inside the bus capacitor housing by injection molding.

[0018] According to a solution of the present utility model, the inverter unit further comprises a DC busbar assembly, the DC busbar assembly being arranged on one side of the bus capacitor housing that is opposite the AC output busbar assembly, and the DC busbar assembly being electrically connected to the power module and comprising a positive copper bar that is electrically connected to a positive pole of the multiple capacitor core members, and a negative copper bar that is electrically connected to a negative pole of the multiple capacitor core members. According to a solution of the present utility model, the bus capacitor housing further comprises a third sidewall and a fourth sidewall in a width direction thereof; 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 that is 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 that is located in the bottom wall, so that the first fluid channel, the gap space and the second fluid channel form a cooling medium channel that extends between the first port and the second port. Preferably, the first and second sidewalls are opposite and parallel to each other, and the third and fourth sidewalls are opposite and parallel to each other. Here, the cooling medium can be 50% ethylene glycol + 50% water, for example. Providing such a cooling medium channel causes cooling medium to simultaneously flow through the radiator and the bus capacitor housing, which can more efficiently dissipate heat of the bus capacitor module and the power module simultaneously.

[0019] According to a preferred solution of the present utility model, the bus capacitor housing is made of a polyphenylene sulfide material for example, and the radiator is made of aluminum for example, the radiator being hermetically fixedly connected to the top wall of the bus capacitor housing. Since the bus capacitor housing is made of plastic material, costs may be significantly reduced, and the total assembly weight of the inverter unit can further be reduced.

[0020] According to a preferred embodiment of the present utility model, multiple nuts are embedded at intervals from each other around the recess in the top wall of the bus capacitor housing, and multiple threaded through holes are correspondingly provided on the radiator near a peripheral edge thereof, the radiator being fixedly connected to the bus capacitor housing by means of multiple threaded fasteners, such as bolts, cooperating with the multiple threaded through holes and the multiple nuts, and a sealing washer surrounding a sidewall of the recess between the top wall and the radiator. 2024P01017WC

[0021] The present utility model further provides an inverter, which comprises the inverter unit described above and a housing for encapsulating the inverter unit described above.

[0022] With the above technical solutions, the inverter unit / inverter of the present utility model can produce at least one of the following beneficial technical effects: low cost, the bus capacitor module and the radiator can be supplied from the same supplier, reducing assembly costs; the bus capacitor module and the power module share the radiator and the cooling medium channel, such that the bus capacitor module sufficiently dissipates heat; the bus capacitor housing is made from a plastic material, which not only is lightweight, reducing the total assembly weight of the inverter unit, but also further reduces costs; the radiator is integrated in the bus capacitor housing, such that the structure is compact, reducing the size of the inverter unit and further reducing the size and volume of the inverter; and the AC busbar and the Hall magnetic ring are integrated as a whole with the bus capacitor housing by injection molding, reducing the size and volume of the inverter unit and reducing the total assembly weight.

[0023] Brief Description of the Drawings

[0024] Referring to the accompanying drawings, by reading the detailed description below, further features and advantages of the present utility model will be understood more clearly:

[0025] Fig. 1 shows a three-dimensional drawing of an inverter unit according to an embodiment of the present utility model;

[0026] Fig. 2 is a three-dimensional drawing of a bus capacitor housing of the inverter unit in Fig. 1 , wherein an AC busbar assembly is integrated in the bus capacitor housing by injection molding;

[0027] Fig. 3 is an exploded view of the inverter unit shown in Fig. 1 ;

[0028] Fig. 4 is a bottom view of the inverter unit shown in Fig. 1 ; and

[0029] Fig. 5 is a sectional view of A-A of the inverter unit shown in Fig. 4.

[0030] Detailed Description of the Invention 2024P01017WC

[0031] The present utility model is explained in further detail below in conjunction with the accompanying drawings and specific embodiments. The explanations regarding orientations that may be used in the following description, such as “upper”, “lower”, “inner” and “outer”, are only for the convenience of description, and are not intended to form any limitation on the technical solutions of the present utility model, unless expressly stated. In addition, hereinafter, terms such as “first” and “second” are used to describe elements of the present application; these terms are only used for distinguishing various elements, rather than for imposing a restriction on the nature, sequence, order or number of these elements. In addition, it should be noted that, in the present description, identical or similar reference numerals are used for the same technical features.

[0032] The terms “top” and “bottom” are used for describing relational positioning of features of the present utility model. These terms should be understood to refer to the orientation of the product as shown in Figs. 1 and 2. In the present utility model, the “inverter unit” is a portion of an inverter and is a core unit module of the inverter. The inverter according to the present application is mainly used for new energy electric vehicles, but can also be used in the photovoltaic field and frequency converters, etc.

[0033] Fig. 1 shows an embodiment of an inverter unit 100 according to the present utility model. In this embodiment, the inverter unit 100 comprises a bus capacitor housing 1 , a bus capacitor module 2, a radiator 3, a power module 4 and an AC busbar assembly 5 (also known as an AC output busbar assembly). The advantages are that the bus capacitor housing 1 is made from a plastic material by injection molding, and the AC busbar assembly 5 is made integrally therewith; the radiator 3 is integrated on an outer side of the bus capacitor housing 1 , the power module 4 being fixedly connected to an upper surface of the radiator, the bus capacitor module 2 and the power module 4 jointly using the same radiator, and the power module 4 also being electrically connected to the bus capacitor module 2.

[0034] Fig. 2 shows a three-dimensional drawing of an embodiment of a bus capacitor housing 1 , the bus capacitor housing 1 being constructed as a rectangular cuboid, and having a top wall 11 , a bottom wall 12 that is opposite the top wall, a first 2024P01017WC

[0035] sidewall 13 and a second sidewall in a length direction thereof, a third sidewall 14 and a fourth sidewall 15 in a width direction thereof, and an accommodating chamber defined by these walls, the accommodating chamber being used for receiving the bus capacitor module 2. Advantageously, the top wall 11 has, for example, a rectangular recess 111 , the size of which is also selected to fit the size of the radiator. In this embodiment, the recess 111 is preferably a stepped recess that defines a peripheral edge / periphery 110. The bus capacitor housing 1 is typically made of polyphenylene sulfide (PPS); this type of material not only can satisfy process requirements, but also is low cost and lightweight. Specifically, polyphenylene sulfide is a new high-performance thermoplastic resin with high mechanical strength, high-temperature resistance, chemical resistance, flame resistance, good thermal stability, excellent electrical performance and other advantages. It is widely used in electronics, automotive, mechanical and chemical fields. However, a person skilled in the art should understand that the bus capacitor housing is not limited to the above plastic material, rather other plastic materials can also be used and are likewise covered by the scope of the present application.

[0036] In the above embodiment of the present utility model, the bus capacitor housing is injection molded using a plastic material, and compared to existing bus capacitor housings made of a metal material such as aluminum, the injection molded structure thereof is simple and the cost is low; moreover, the AC busbar assembly is integrated as a whole with the bus capacitor housing, such that the assembly process is simple compared to a fixed connection by means of cooperation between a threaded fastener and a threaded hole.

[0037] Further referring to Fig. 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 a plane of the top wall, and are preferably spaced apart equidistantly from each other in the length direction of the bus capacitor housing 1. Moreover, the AC busbar assembly 5 comprises three copper bar components 51 and three Hall magnetic rings 52. Each of the receptacles receives one copper bar component 51 and one Hall magnetic ring 52. Each of the copper bar components 51 has a first end 511 and a second end 512 that extend beyond the receptacle, and extends through the 2024P01017WC

[0038] corresponding Hall magnetic ring and corresponding receptacle 10. The first end 511 of each copper bar component 51 is electrically connected to the power module 4, and the second end 512 of each copper bar component 51 forms an AC power output terminal of the inverter unit; that is, the second ends of the three copper bar components form a three-phase AC power output end, and the output end, for example, is electrically connected to an electric motor. In one preferred embodiment, each receptacle 10 has an accommodating part 10a in the form of an open ring for receiving a Hall magnetic ring 52.

[0039] Fig. 3 is an exploded view of the inverter unit 100 shown in Fig. 1 , and for the purpose of matching the recess 111 , the radiator 3 is also correspondingly constructed as a rectangular plate, the radiator having a first surface (not shown) that faces the bus capacitor housing 1 and an opposite second surface 30, i.e. the upper surface of the radiator. In one preferred embodiment, the radiator 3 is made of aluminum. Multiple nuts 8a are embedded at intervals from each other, for example by injection molding, around the recess 111 in the top wall of the bus capacitor housing 1 , and multiple threaded through holes 3a are correspondingly provided on the radiator 3 near a peripheral edge thereof, the radiator 3 being fixedly connected to the bus capacitor housing 1 by means of multiple threaded fasteners 8b, such as bolts, extending through corresponding threaded through holes 3a and joining to corresponding nuts 8a. Preferably, a sealing washer 8c that surrounds the peripheral edge of the recess 11 is provided between the top wall and the radiator, thus hermetically fixedly connecting the radiator to the top wall 11 of the bus capacitor housing 1. After assembly, there is a gap space g between the first surface (not shown) of the radiator 3 and the bottom face 112 of the recess 111 , the gap space g being suitable for a cooling medium to flow. In addition, for better heat dissipation efficiency, the first surface of the radiator that faces the bus capacitor housing 1 has multiple heat dissipation fins that extend into the recess 11 , and the length of the heat dissipation fins can be selected for contact with the bottom face 112 or separation from the bottom face 112.

[0040] In the above embodiment, the inverter unit 100 further comprises a DC busbar assembly 6 that is electrically connected to the power module 4, the DC busbar assembly being arranged on one side of the bus capacitor housing that is opposite the AC busbar assembly, for example on the side where the second sidewall 14 is 2024P01017WC

[0041] located. For example, the DC busbar assembly 6 may comprise a positive copper bar 61 and a negative copper bar 62 that are fixedly connected to the bus capacitor housing 1 , the positive copper bar 61 being electrically connected to a positive pole of the bus capacitor module, and the negative copper bar 62 being electrically connected to a negative pole of the bus capacitor module.

[0042] Fig. 4 is a bottom view of the inverter unit 100 according to the present utility model; Fig. 5 is a sectional view of A-A of the inverter unit shown in Fig. 4. As can be seen from the figures, the inverter unit 100 has a cooling medium channel L, shown as a dotted line, the cooling medium channel L extending between a first port 142 and a second port 152 that are located in a bottom wall 12 of the bus capacitor housing 1 , and is formed by a first fluid channel 141 , a second fluid channel 151 and a gap space g that is located between the radiator 3 and the bottom face of the recess 111. For example, the first fluid channel 141 may comprise a first inclined section 1411 and a first vertical section 1412 that extend in the third sidewall 13, wherein the first inclined section 1411 passes into the gap space g, i.e. being in fluid communication therewith, and the first vertical section 1412 passes into the first port 142. The second fluid channel 151 may comprise a second inclined section 1511 and a second vertical section 1512 that extend in the fourth sidewall 15, wherein the second inclined section 1511 passes into the gap space g, i.e. being in fluid communication therewith, and the second vertical section 1512 extends to the second port 152. The above layout of the cooling medium channel L is only illustrative; provided that the fluid channel is formed in a sidewall of the bus capacitor housing 1 and is in fluid communication with the gap space, fluid channels of other layout forms are likewise covered by the scope of the present application. Due to the configuration of the inverter unit as described above, the power module 4 and the bus capacitor module 2 jointly use the same radiator 3 and the same cooling medium channel L, thereby enabling the power module and bus capacitor module to dissipate heat better.

[0043] As can be seen from Fig. 5, in one embodiment, the bus capacitor module 2 comprises multiple capacitor core members 20, and these capacitor core members 20 are sealed in the bus capacitor housing 1 by means of injection molding. During the operation of the inverter, DC high-voltage power from a storage battery can be delivered to the bus capacitor module 2 via the DC busbar 2024P01017WC

[0044] assembly 6, and then reaches the power module 4 and is converted into AC power, which is discharged from the AC busbar component 5 to an electrical apparatus, such as an electric motor.

[0045] The present utility model further provides an inverter, which comprises the inverter unit 100 described above.

[0046] Although the present utility model has been disclosed above through preferred embodiments, it is by no means limited to these. Any combinations, changes and amendments made by a person skilled in the art without departing from the spirit and scope of the present utility model shall be included in the scope of protection of the present utility model, and therefore the scope of protection of the present utility model shall be the scope defined by the claims.

Claims

Claims1. An inverter unit, characterized in that the inverter unit (100) comprises: a bus capacitor housing (1), the bus capacitor housing being made from a plastic material by injection molding;a bus capacitor module (2), the bus capacitor module being accommodated in the bus capacitor housing;a radiator (3), the radiator being fixedly connected to an outer side of the bus capacitor housing, and the radiator having a first surface that faces the bus capacitor housing (1) and an opposite second surface (30);a power module (4), the power module being fixedly connected to the second surface of the radiator and being electrically connected to the bus capacitor module; andan AC busbar assembly (5), the AC busbar assembly being integrally formed with the bus capacitor housing (1) by injection molding.

2. The inverter unit as claimed in claim 1, characterized in thatthe bus capacitor housing (1) is constructed as a rectangular cuboid and has a top wall (11) and a bottom wall (12) that is opposite the top wall, the top wall (11) having a recess (111), wherein the shape and size of the recess and the shape and size of the radiator are chosen so that the radiator can be hermetically connected to the top wall and covers the recess (111), and the radiator is arranged so that there is a gap space (g) between the first surface and a bottom face (112) of the recess.

3. The inverter unit as claimed in claim 2, characterized in thatthe bus capacitor housing (1) has a first sidewall (13) in a length direction thereof and a second sidewall (14) that is opposite the first sidewall, and has three receptacles (10) that are near the first sidewall or the second sidewall and extend from the top wall; andthe AC busbar assembly (5) comprises three copper bar components (51 ) and three Hall magnetic rings (52),wherein each of the receptacles receives one of the copper bar components (51 ) and one of the Hall magnetic rings (52), and each of the copper bar components extends through a corresponding Hall magnetic ring and acorresponding receptacle and has a first end (511) and a second end (512) that extend beyond the receptacle, wherein the first end is electrically connected to the power module, and the second end forms an AC power output terminal of the inverter unit.

4. The inverter unit as claimed in claim 3, characterized in that the three receptacles (10) extend outward from the top wall perpendicular to a plane of the top wall and are spaced apart equidistantly from each other in the length direction, wherein each of the receptacles has an accommodating part (10a) in the form of an open ring, suitable for receiving the Hall magnetic ring (52).

5. The inverter unit as claimed in any one of claims 1 to 4, characterized in thatthe bus capacitor module (2) comprises multiple capacitor core members (20), and the multiple capacitor core members (20) are sealed inside the bus capacitor housing (1) by injection molding.

6. The inverter unit as claimed in claim 5, characterized in thatthe inverter unit further comprises a DC busbar assembly (6), the DC busbar assembly being arranged on one side of the bus capacitor housing that is opposite the AC busbar assembly, the DC busbar assembly being electrically connected to the power module (4) and comprising a positive copper bar (61) that is electrically connected to a positive pole of the multiple capacitor core members, and a negative copper bar (62) that is electrically connected to a negative pole of the multiple capacitor core members.

7. The inverter unit as claimed in claim 3 or 4, characterized in thatthe bus capacitor housing further comprises a third sidewall (14) and a fourth sidewall (15) in a width direction thereof; andthe 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) that is 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) that is located in the bottom wall (12), so that the first fluidchannel, the gap space and the second fluid channel form a cooling medium channel (L) that extends between the first port and the second port.

8. The inverter unit as claimed in any one of claims 2 to 4, characterized in that the bus capacitor housing (1) is made of a polyphenylene sulfide material, and the radiator (3) is made of aluminum, the radiator (3) being hermetically fixedly connected to the top wall of the bus capacitor housing (1 ).

9. The inverter unit as claimed in claim 8, characterized in that multiple nuts (8a) are embedded at intervals from each other around the recess (111 ) in the top wall of the bus capacitor housing (1), and multiple threaded through holes (3a) are correspondingly provided on the radiator (3) near a peripheral edge thereof, the radiator being fixedly connected to the bus capacitor housing (1) by means of multiple threaded fasteners (8b) cooperating with the multiple threaded through holes (3a) and the multiple nuts (8a), and a sealing washer (8c) surrounding a sidewall of the recess between the top wall and the radiator.

10. An inverter, characterized in that the inverter comprises the inverter unit as claimed in any one of claims 1 to 9.

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