Power module with insulatively separated heat sinks and vehicle with power module

Abstract

The invention relates to a power module, in particular a drive module. The power module has a heat sink device, in particular a cooling body, which is configured to conduct a fluid, and at least two power components which differ from one another. The power components are each thermally conductively or additionally electrically conductively connected to the heat sink device, in particular to a component of the heat sink device. According to the invention, the power components are each configured to conduct different electrical potentials, in particular ground potentials, from one another. The heat sink device comprises at least or only two components, in particular a component and a further component, which each have a cavity for conducting a fluid flow and which are connected to one another by means of an electrical insulator in such a way that the components can each be flowed through by a fluid flow which cools the two components, wherein the components are electrically insulated from one another in such a way that the electrical potentials of the power components are separated from one another within the heat sink device.

Description

Technical Field

[0001] This invention relates to a power module, particularly a drive module. The power module includes a heat-absorbing device configured for fluid guidance, particularly a cooling body, and at least two distinct power components. The power components are respectively connected thermally or additionally electrically to components of the heat-absorbing device, particularly the heat-absorbing device. Background Technology

[0002] A self-guided rectifier for a voltage-applied converter is known from DE 197 56 250 C2. The converter has a high-power module, which is detachably connected to a phase cooler phase by phase and connected to a partition wall in such an overlapping manner that the cooling fins of the high-power module extend into a ventilation chamber through the gaps in the partition wall.

[0003] A housing for an electric motor is known from DE 10 2010 041 589 A1, which is capable of being hermetically coupled to a housing element for receiving power electronics of the motor. Summary of the Invention

[0004] According to the invention, the power components are configured to conduct different potentials, particularly ground potentials. The heat-absorbing device comprises at least two components, particularly one component and another component, each having a cavity for guiding fluid flow, and they are connected to each other by means of an electrical insulator such that the components can be traversed by fluid flows that cool each component, wherein the components are electrically insulated from each other such that the potentials of the power components are separated within the heat-absorbing device. Furthermore, it is advantageous that no current, particularly ground current, can flow through the components of the heat-absorbing device, for example, those made of aluminum. It is also advantageous that corrosion, particularly electrolytic corrosion caused by electrolysis, does not occur on the cooling body, especially the water-conducting cooling body.

[0005] Preferably, the power module is a drive module for motor vehicles, particularly electric or hybrid vehicles. Advantageously, the inverter ground wire can be electrically separated from or sufficiently insulated from the ground wire of the motor of the drive unit. Furthermore, it is advantageous that a grounding loop causing electrolytic corrosion is thus avoided, because the grounding path on the heat-absorbing device is interrupted by the mutually insulated components of the heat-absorbing device.

[0006] Preferably, the components of the heat-absorbing device are formed by housing parts, preferably aluminum housing parts, wherein the housing parts are particularly separable and connected to each other, and an insulating layer surrounds them. Advantageously, the heat-absorbing device can thus be configured to electrically insulate the power components from each other.

[0007] Preferably, one component of the heat-absorbing device is connected to the housing of a power component, particularly a motor, and another component of the heat-absorbing device is connected to the housing of another power component, particularly an inverter or another power component. Therefore, it is advantageous that the ground potentials of the power components can be separated from each other.

[0008] In an advantageous embodiment, another component of the heat-absorbing device is electrically separated from the motor housing by means of an insulating element serving as an intermediary. For this purpose, the coupling surface of the coupling portion on the motor housing can extend laterally to the motor shaft on the end side or be coupled to the housing side and thus arranged parallel to the motor shaft. Advantageously, the inverter can then be coupled to the vicinity of the motor in a manner insulated from the motor housing.

[0009] The heat-absorbing device is preferably made of metal, especially aluminum or copper.

[0010] Advantageously, the heat-absorbing device is thus able to have good thermal conductivity.

[0011] In a preferred embodiment of the power module, the insulator is formed by a particularly flat electrical insulating element or layer, which is in contact with the components and, particularly according to a sandwich arrangement, surrounds the components. Advantageously, the power module can be constructed so compactly that the power components are each thermally connected to the same heat-absorbing device, particularly to a cooling body.

[0012] In a preferred embodiment, the power components are thermally coupled to fluid channels, which are fluidly connected to each other, particularly inside the heat-absorbing device, preferably inside the housing surrounding the cavity formed by the heat-absorbing device. Advantageously, the cooling body can then be provided in a space-saving and cost-effective manner and can provide high insulation resistance between the voltage-conducting components.

[0013] In a preferred embodiment, one component of the cooling body has an inlet for fluid, and another component has an outlet for fluid. The fluid channels are connected, particularly in fluid communication, to each other by means of passages in an insulator, especially within the cooling body. Therefore, advantageously, the only electrical connection between the components of the cooling body can be formed by a particularly conductive fluid, such as cooling water. The remaining components, particularly the components of the cooling body and the other component, are electrically insulated from each other by means of an electrical insulator.

[0014] In a preferred embodiment, the passage has a passage opening whose cross-section, transverse to the flow direction of the fluid, is configured to be smaller than the contact surface of the component separated by the insulator. Advantageously, the insulation resistance can be limited to the small passage opening that guides the fluid, particularly cooling water.

[0015] In a preferred embodiment, the insulator is formed by an insulating element. Furthermore, it is preferred that at least one or only one journal surrounding the perforation is molded onto the electrical insulating element, the journal extending into a component of the heat-absorbing device, particularly into the motor housing of a motor or the cooling body of an inverter. Advantageously, the fluid channel section insulated within the perforation by the electrical insulating element can then be electrically insulated relative to one of the components. Furthermore, it is preferred that the insulating element has two journals molded onto the electrical insulating element, these journals extending respectively into a component of the heat-absorbing device, particularly into the cooling body of an inverter or the motor housing. Advantageously, the fluid channel section formed in the perforation can then be electrically insulated relative to the other component.

[0016] Advantageously, the insulating element can then be provided with an extended insulating section in the perforated area compared to the thickness extension of the insulating element, through which the components of the heat-absorbing device are electrically insulated from each other.

[0017] Preferably, the perforation is formed in a cylindrical shape. In this embodiment, the journal is formed in a hollow cylindrical shape. In another embodiment, the perforation can have a polygonal cross-section. Advantageously, the journal can be molded onto an insulator, especially an insulating element.

[0018] In a preferred embodiment, the insulator is formed by a plastic layer. In another preferred embodiment, the insulator is a thermoplastic that is particularly resistant to temperature. Advantageously, the insulator can then fit snugly against the contact surface of the component.

[0019] The plastic layer is, for example, a polyethylene layer, a polypropylene layer, a PEEK layer (PEEK = Poly-Ether-Ether-Keton, PES layer = (Poly-Ether-Sulfon) polyethersulfone), a PPS layer (PPS = (Poly-Phenylen-Sulfid) polyphenylene sulfide), or a polyimide layer. Therefore, it is advantageous that the insulator can be supplied as a solid at low cost.

[0020] In another embodiment, the insulator is formed of silicone rubber. Advantageously, the insulator thus possesses a sealing function for the passage in addition to its insulating function. In this embodiment, the insulator is arranged and constructed to surround the passage.

[0021] In a preferred embodiment, the fluid is configured to be polar. The fluid is preferably an aqueous fluid. Advantageously, the fluid can then be provided at low cost and has good heat capacity. The fluid preferably contains water and ethylene glycol, especially diethylene glycol. Therefore, the fluid can advantageously be made antifreeze.

[0022] In another embodiment, the fluid is electrically insulating. In this embodiment, the fluid is formed, for example, by oil or ester, especially pentaerythritol ester. Advantageously, there is no current flow between the components of the heat-absorbing device, especially the housing of the cooling body, in the perforated area.

[0023] Preferably, the power module has a conductivity sensor or a resistance sensor configured to detect the conductivity or transition resistance formed between the components by the fluid. Advantageously, leakage current flowing through the fluid from one component of the cooling body to another component of the cooling body can then be detected.

[0024] Preferably, the resistance sensor is configured to generate an output signal representing the resistance between components. Preferably, a fault signal can be generated based on the output signal, for example, by a motor control unit. The control unit can provide the fault signal, for example, on a data bus.

[0025] The present invention also relates to an electric vehicle or a hybrid vehicle having a power module of the aforementioned type. The vehicle includes a motor for driving the vehicle and an inverter. In the vehicle, one component of the cooling unit is electrically connected to the inverter, and another component is electrically connected to the motor.

[0026] The power components are preferably formed by an inverter, and other power components are preferably formed by a motor. Advantageously, this allows both the inverter and the motor to be cooled by the same cooling unit.

[0027] In a preferred embodiment, one component of the heat-absorbing device is connected to the inverter's ground potential, and another component of the heat-absorbing device is connected to the motor's ground potential. Advantageously, apart from the transition resistance formed by the cooling water, the inverter's ground potential can then be electrically insulated from the motor's ground potential by means of an insulating layer and the power module thus constructed. Attached Figure Description

[0028] The invention will now be described with reference to the accompanying drawings and other embodiments. Other advantageous embodiments are derived from combinations of features described in the drawings and dependent claims.

[0029] Figure 1 An embodiment of a drive module including a motor and an inverter for energizing the motor is shown, wherein the motor housing and the inverter are respectively fluid-coolable coupled to a heat-absorbing device. Detailed Implementation

[0030] Figure 1 An embodiment of the drive module 1 is schematically shown in cross-section. The drive module 1 includes a motor 2 and an inverter 3. The inverter 3 is configured to energize the motor 2, particularly for generating a rotating magnetic field. In this embodiment, the inverter 3 includes three semiconductor switching half-bridges 4, 5, and 6, each configured to generate pulse-modulated current for operating the motor 2. The semiconductor switching half-bridges 4, 5, and 6 are also configured to generate heat dissipation.

[0031] The drive module 1 further includes a heat absorption device 8, which in this embodiment is configured as a cooling body and configured to guide fluid. The heat absorption device 8 is thermally connected to the inverter 3, particularly the semiconductor switching half-bridges 4, 5, and 6, and is configured to absorb heat loss generated by the inverter 3. The heat absorption device 8 is also thermally connected to the motor 2 and is configured to absorb heat loss from the motor 2.

[0032] In this embodiment, the heat-absorbing device 8 includes two components that are combined into a single unit: a component 9 that is thermally and electrically connected to the inverter 3, and another component 10 that is thermally and electrically connected to the motor 2. Components 9 and 10 are made of aluminum or copper, respectively, and are therefore electrically conductive. Component 9 can guide the inverter's ground potential 21, and component 10 can guide the motor's ground potential 20.

[0033] The component 9 and another component 10 respectively surround the cavity, which is configured to guide the fluid flow 15. The cavities 16 and 17 respectively form fluid channels in which the fluid flow 15 can flow and absorb lost heat from the power components 2 and 3.

[0034] For this purpose, component 9 surrounds cavity 17. In this embodiment, components 9 and 10 are respectively formed by an aluminum housing surrounding cavity 17 or 16. The other component 10 can be part of the housing of motor 2. Cavities 16 and 17 respectively form fluid channels in which fluid flow 15 can flow and absorb lost heat from power components 2 and 3.

[0035] The other component 10 has a coupling surface 23 for mechanical and thermally conductive coupling to component 9. Component 9 has a coupling surface 22 for mechanical and thermally conductive coupling to the other component 10. The thermally contact surfaces 22 and 23 are electrically insulated from each other and thermally connected by an electrical insulator, in this embodiment by an electrical insulating element 11. The electrical insulating element 11 is thermally conductive in this embodiment. The electrical insulating element 11 is formed, for example, by a plastic layer, particularly a thermoplastic layer, or a plastic sheet.

[0036] The cavity 17 or 16 enclosed by the components of the heat-absorbing device, particularly component 9 and another component 10, is fluidly connected to each other by means of a perforation 14 forming a passage. For this purpose, component 9 has a perforation 24 opposite to the perforation 25 of the other component 10.

[0037] The electrical insulating element 11 has a through hole 26 surrounded between through hole openings 24 and 25. This forms a through hole 14, which in this embodiment has a through hole surface 15.

[0038] In this way, the perforation volume of the perforation 14 can guide the flow of cooling water, which can reduce the insulation resistance between component 9 of the heat absorption device 8 and another component 10. Advantageously, the perforation 14, especially the perforation surface 15 of the perforation 14, is constructed small enough that the transition resistance between components 9 and 10 can limit the leakage current flowing there to less than 200 mA.

[0039] Figure 1 A variant of the drive module is also shown, in which the journal 33 surrounded by the perforation 14 is molded onto the electrically insulating element 11, the journal extending into the component 10, particularly the motor housing, thereby electrically insulating the fluid passage section insulated in the perforation by the electrically insulating element relative to the component 10. In this variant, the insulating element also has a journal 32 molded onto the electrically insulating element 11, the journal extending into the component 9, particularly the cooling body of the inverter 3, thereby electrically insulating the fluid passage section formed in the perforation 14 relative to the component 9.

[0040] Advantageously, components 9 and 10 of the heat-absorbing device 8 are thus able to have a large insulation resistance relative to each other.

[0041] In this embodiment, component 10 is sealed relative to insulating element 11 by means of seal 34, particularly an O-ring. In this embodiment, component 9 is sealed relative to insulating element 11 by means of seal 35, particularly an O-ring. In another embodiment, seals 34 and 35 can be injection molded onto insulating element 11.

[0042] The component 9 has a connector 13, particularly a connecting sleeve, which is fluidly coupled to the cavity 17 and configured to guide the fluid flowing in the cavity 17 from the heat absorption device 8 and deliver it to the fluid pump 18. In this embodiment, the other component 10 has a fluid connector 12, particularly a connecting sleeve, which is connected to the fluid pump 18 by means of a fluid conduit 19 and is configured in this embodiment as the inlet of the heat absorption device 8. The fluid flow 15 can be generated in a manner driven by the fluid pump 18 through the cavity 17 and further through the perforation 14 into the cavity 16, thus absorbing lost heat not only from the inverter 2 but also from the motor 2.

[0043] With Figure 1 Unlike the example shown, the fluid flow can also be guided from the motor 2 to the inverter 3 by a fluid pump. In this embodiment, the transition resistance between component 9 of the heat absorption device and another component 10 is formed by the amount of fluid, particularly cooling water, held in the perforation 14. The cooling water in this embodiment is low-mineral cooling water, such as distilled water or a water-glycol mixture.

[0044] In this embodiment, the motor 2, and especially its housing, is electrically connected to the motor ground wire 20. The inverter 3, and especially its housing, is connected to the inverter ground wire 21. In this embodiment, the ground potentials of the ground wires 20 and 21 are insulated from each other by means of a heat-absorbing device 8 with an electrically insulating structure, and especially by thermally conductive and electrically insulated components 9 and 10 connected to each other. In this way, the ground potentials 21 and 20 of the power components, especially the inverter 3 or the motor 2, are separated from each other within the heat-absorbing device.

[0045] In this embodiment, the power module 1 further includes a conductivity sensor 27, which is connected to component 9 on the input side via connection line 28 and to component 10 via connection line 29. The conductivity sensor is configured to detect the transition conductivity formed between components 9 and 10 of the heat-absorbing device 8 and generates an output signal representing the conductivity.

[0046] The fluid is, for example, a water-ethylene glycol mixture conforming to standards SAE J1034 and ASTM D 4985, such as... or In addition to ethylene glycol, the fluid preferably contains corrosion inhibitors, especially silicates, and more preferably organic acid salts.

[0047] Figure 2 A power module is shown, especially Figure 1The power module 1 shown is used in vehicles, particularly electric vehicles. The electric vehicle 30 has a controller 31 configured to generate a fault signal based on the output signal of the conductivity sensor 27 when a predetermined conductivity value is exceeded. During vehicle maintenance, the conductivity of the fluid 15 can be checked and the fluid 15 replaced based on the fault signal.

Claims

1. A power module (1) having heat-absorbing devices (8, 9, 10) configured for fluid guidance (15) and at least two power components (2, 3) that are different from each other and are thermally and electrically connected to the heat-absorbing devices (8, 9, 10). Its features are, The power components (2, 3) are respectively configured to conduct different potentials (20, 21), and the heat absorption device (8) includes at least or only two components (9, 10), each having a fluid channel (16, 17) formed by a cavity for guiding a fluid flow (15) and being connected to each other by means of an electrical insulator (11) such that the components (9, 10) can be respectively circulated by a fluid flow (15) cooling the two components (9, 10) and are electrically insulated from each other, so that the potentials (20, 21) of the power components (2, 3) are separated from each other within the heat absorption device (8, 9, 10).

2. The power module (1) according to claim 1. Its features are, The insulator (11) is formed by an electrically insulating insulating element, which is in contact with and surrounded between the components (9, 10).

3. The power module (1) according to any one of claims 1 or 2. Its features are, The components (9, 10) of the heat-absorbing device (8) are formed by housing parts, wherein the housing parts are connected to each other and enclose the insulator (11) between each other.

4. The power module (1) according to any one of claims 1 or 2. Its features are, The power components (2, 3) are thermally coupled to the fluid channels (16, 17), which are fluidly connected to each other inside the heat absorption device.

5. The power module (1) according to claim 4. Its features are, Component (9) has an inlet (13) for fluid (15), and another component has an outlet for fluid (15), and the fluid channels (16, 17) are connected to each other by means of passages in the insulator (11).

6. The power module (1) according to claim 5. Its features are, The passage has a passage opening, the cross section (15) of which is transverse to the flow direction of the fluid flow (15) is constructed to be smaller than the contact surfaces (22, 23) of the components (9, 10) separated by the insulator (11).

7. The power module (1) according to any one of claims 1 or 2. Its features are, The insulator (11) is formed by a plastic layer.

8. The power module (1) according to any one of claims 1 or 2. Its features are, The insulator (11) is formed by an insulating element, at least one journal (32, 33) surrounding the perforation (14) is molded onto the insulating element, the journal extending into a component (9, 10) of the heat-absorbing device (8), or two journals are molded onto the insulating element, these journals extending into one of the two components (9, 10) of the heat-absorbing device (8).

9. The power module (1) according to any one of claims 1 or 2. Its features are, The fluid (15) is polarized, and the power module (1) has a conductivity sensor (27) configured to detect the conductivity formed between the components (9, 10) through the fluid (15).

10. The power module (1) according to claim 1. Its features are, The power module (1) is a drive module.

11. The power module (1) according to claim 1. Its features are, The potentials (20, 21) of the power components (2, 3) are ground potentials (20, 21).

12. The power module (1) according to claim 2. Its features are, The insulating element is configured to be flat.

13. The power module (1) according to claim 3. Its features are, The housing components can be separately connected to each other and an insulating layer is enclosed between them.

14. A vehicle having a power module (1) according to any one of claims 1 to 13. Its features are, The vehicle has a motor (2) for driving the vehicle and an inverter (3), wherein a component (9) of the heat absorption device (8) is electrically connected to the inverter (3), and another component (10) is electrically connected to the motor (2).

15. The vehicle according to claim 14, Its features are, The vehicle in question is an electric vehicle.

16. The vehicle according to claim 14, Its features are, The vehicle in question is a hybrid vehicle.

17. The vehicle according to claim 15, Its features are, Component (9) of the heat absorption device (8) is connected to the ground potential (21) of the inverter (3), and another component (10) of the heat absorption device (8) is connected to the ground potential (20) of the motor (2).

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