Contactor cooling device and contactor arrangement with contactor cooling device

Abstract

The present invention relates to a contactor cooling device (10) and a contactor arrangement (30) comprising a contactor cooling device (10) according to the invention. The contactor cooling device (10) according to the invention is designed to establish an electrical connection between an electrical contact (21, 22) of an electrical conductor, in particular of a HV network, and a contactor contact (31, 32) of a contactor (30). The contactor cooling device (10) has a connecting section (13) designed to establish a connection between the contactor cooling device (10) and the contactor contact (31, 32). The contactor cooling device (10) further has at least one cooling fluid inlet (11), at least one cooling fluid outlet (12), and at least one cooling fluid channel, wherein the cooling fluid channel (40) is designed to transport a cooling fluid (41) from the cooling fluid inlet (11) to the cooling fluid outlet (12).

Description

[0001] The present invention relates to a contactor cooling device and a contactor arrangement with a contactor cooling device according to the invention.

[0002] A contactor, also known as a high-voltage contactor (HV contactor), is an important safety element for the operation of an electric vehicle. It is designed to disconnect the HV circuit under certain conditions, such as a disconnection or failure of the control circuit, to ensure that the energy stored in the battery is not accidentally released. The HV contactor isolates the HV battery from the vehicle's high-voltage electrical system both electrically and galvanically.

[0003] For the purposes of this application, galvanic isolation in a contactor means that there is no conductive connection between the control circuit and the load circuit (HV on-board power supply), nor within the load circuit itself. This enables complete potential separation, which is not necessarily achieved with simple electrical isolation. Galvanic isolation prevents dangerous voltages or currents from passing from the load circuit into the control circuit. This is particularly important for applications involving high voltages or currents.

[0004] Typically, two main contactors are used—one for the positive terminal and one for the negative terminal of the battery. This allows for all-pole isolation from the vehicle electrical system. The contactors must be able to switch current flow in both directions to enable both propulsion and regenerative braking. As mentioned above, they must be able to open upon loss of the control signal. Furthermore, sufficient insulation resistance must be maintained in the open state to ensure galvanic isolation.

[0005] In a contactor, galvanic isolation is typically achieved through the use of an electromagnetic system. The control current activates a coil, which generates a magnetic field. This magnetic field then mechanically causes the contacts in the load circuit to close or open via a corresponding connecting element between the contacts, without a direct electrical connection between the circuits. The coil is also referred to as the contactor drive in the application.

[0006] Due to increasing demands on the HV electrical system in vehicles, the power demand is also rising. The entire current flows through the contactors in the HV battery. Due to the internal resistance of the contactor itself, a considerable amount of heat is generated in the center of the contactor, which must be dissipated as efficiently as possible to maintain the full performance of the HV system.

[0007] Document CN 116 053 081 A discloses a contactor for a high-voltage battery in a vehicle, wherein the contactor is connected to a cooling circuit of the electric vehicle drive motor and is temperature-controlled by means of a cooling medium. The contactor is temperature-controlled by an integrated coolant distribution system. Document DE 10 2021 128 966 A1 discloses a contactor for an HV battery in a vehicle, wherein the contactor is connected to a cooling circuit of the HV battery and is temperature-controlled by means of a cooling medium. The contactor is designed with internal cooling. Document US 2022 278 414 A1 discloses a contactor for an HV battery in a vehicle, wherein the contactor is indirectly cooled by means of a carrier. The carrier is temperature-controlled by means of a cooling medium.

[0008] Document US 2022 119 121 A1 discloses a contactor for an electric motor in an aircraft, wherein the contactor is connected to a cooling circuit and temperature-controlled by means of a cooling medium. The temperature of the contactor is controlled indirectly via a cooling plate. Document US 2018 062 226 A1 discloses a contactor for an HV battery in a vehicle. Document US 2022 077 699 A1 discloses a contactor for an HV battery in a vehicle. Document EP 3 972 114 A1 discloses a contactor for an HV battery in an aircraft, wherein the contactor is connected to a cooling circuit of an electric motor and temperature-controlled by means of a cooling medium.

[0009] Against the background of the prior art presented above, it is an object of the present invention to provide a contactor cooling device and a contactor arrangement with a contactor cooling device according to the invention, by means of which an efficient and practical possibility for cooling the contactor can be ensured.

[0010] This object is achieved by the subject matter of the independent claims. Advantageous embodiments of the invention are contained in the subclaims.

[0011] The contactor cooling device according to the invention is designed to establish an electrical connection between an electrical contact of an electrical conductor, in particular of a HV network, and a contactor contact of a contactor. For this purpose, either the entire protective cooling device is designed to be electrically conductive or it has at least one conductive section designed to electrically connect the corresponding contactor contact and electrical contact to one another. For the purposes of the application, a distinction is made between an electrical contact and a contactor contact. The electrical contact always describes the contact of the electrical line, while the contactor contact refers to the contact within the contactor. According to the prior art, the contactor contact and the electrical contact of the line are connected directly to one another.

[0012] The contactor cooling device has a connecting section designed to establish a connection between the contactor cooling device and the contactor contact. The term "establishing a connection" / "connected" is understood in the context of the application to mean that physical contact is / is established. This can involve fastening one component, here the contactor cooling device, to the other component, here the contactor contact. The contactor cooling device further has at least one cooling fluid inlet, at least one cooling fluid outlet, and at least one cooling fluid channel, wherein the cooling fluid channel is designed to transport a cooling fluid from the cooling fluid inlet to the cooling fluid outlet.

[0013] The contactor arrangement according to the invention comprises a contactor with a first contactor contact and a second contactor contact, which can be electrically connected and electrically and in particular galvanically separated by a connecting element movable by means of a contactor drive. Furthermore, at least one contactor cooling device according to the invention is provided, which is connected to at least one contactor contact and is designed to establish an electrical connection between an electrical contact of an electrical conductor and the contactor contact of the contactor to which it is connected. Furthermore, the contactor arrangement has a cooling fluid line designed to provide cooling fluid at the cooling fluid inlet of the contactor cooling device and to receive cooling fluid at the cooling fluid outlet of the contactor cooling device. The cooling fluid line has, in particular, different, separate sections.The section that provides the cooling fluid at the cooling fluid inlet is not the same section that receives the cooling fluid at the cooling fluid outlet.

[0014] The contactor cooling device is therefore designed to be placed between the electrical contact of the electrical line and a contactor contact. It is electrically conductive and capable of conducting a cooling fluid, thus cooling the contactor contact and dissipating heat. This prevents the electrical contact or contactor contact from coming into contact with cooling fluid, as the fluid is simply conducted through the contactor cooling device. The contactor cooling device is easily replaceable in the event of a defect. This eliminates the need to replace an electrical contact or contactor contact.

[0015] In an advantageous embodiment of the contactor cooling device, the connecting section is designed as a thread or has a thread in sections. This is designed to be screwed into a corresponding mating thread on the contactor contact. In an advantageous embodiment of the contactor arrangement, the connecting section is accordingly at least partially screwed into the contactor contact and thus fastened to it by the threaded connection. Preferably, the contactor cooling device therefore projects at least partially into the contactor contact. This ensures particularly efficient cooling of the contactor contact. The connection by means of a thread ensures simple assembly, disassembly and replacement of the contactor cooling device, whereby a secure connection can be ensured both mechanically and for establishing the electrical contact.

[0016] According to the invention, the cooling fluid channel is arranged spirally in the contactor cooling device, at least in sections. This allows the duration of the cooling fluid remaining within the contactor cooling device to be increased, thus increasing the heat transfer to the cooling fluid and thus enhancing the cooling performance.

[0017] A further advantageous embodiment of the invention is one in which the cooling fluid channel is designed as a cavity, in particular as a cavity supported by struts, within the interior of the contactor cooling device. In this embodiment, the channel is understood less as a conduit for the cooling fluid, but rather as a volume in the form of a chamber, with the preferably provided struts supporting the volume to ensure the structural integrity of the contactor cooling device. The volume is flooded with the cooling fluid, with the cooling channel inlet introducing cooling fluid into the volume, while it is discharged from the volume again via the cooling channel outlet.

[0018] In a further advantageous embodiment of the contactor cooling device according to the invention, it has a screw shape. For the purposes of this application, a screw-shaped body is understood to be composed of two individual bodies, one of which has a cylindrical or slightly conical shape, also referred to as a threaded section, and the other body adjoins the cylindrical or slightly conical body in the axial direction and protrudes radially beyond the cylindrical or conical body, also referred to as the screw head. The screw head of the screw shape does not necessarily have to be round.

[0019] Preferably, the threaded portion of the helical contactor cooling device is designed to protrude into the contactor contact to which the contactor cooling device is connected, and the screw head of the helical contactor cooling device is designed to contact the electrical contact. In particular, the cooling fluid inlet and / or the cooling fluid outlet are arranged in the screw head of the helical contactor cooling device. This geometric configuration of the contactor cooling device ensures efficient cooling while maintaining a space-saving design. Likewise, such an embodiment is easy to assemble and disassemble.

[0020] In an advantageous embodiment of the contactor arrangement, both a first contactor contact and a second contactor contact of the contactor are each connected to a contactor cooling device, and the two contactor cooling devices are further connected by the cooling fluid line such that the cooling fluid transported by the cooling fluid line is transported from the cooling channel outlet of one contactor cooling device to the cooling channel inlet of the other contactor cooling device. In other words, the contactor cooling devices are connected in series by the cooling fluid line. They are thus part of the same cooling system and are supplied with the same cooling fluid. This simplifies the complexity of the cooling system, since only one cooling circuit needs to be provided.

[0021] Preferably, the contactor cooling device extends at least partially into the contactor contact. This ensures the best possible heat transfer from the contactor contact to the cooling fluid, thus improving cooling performance.

[0022] Furthermore, in one embodiment of the contactor arrangement, the contactor cooling device has a helical shape. The contactor cooling device is arranged such that the threaded portion extends into the contactor contact to which the contactor cooling device is connected, and the screw head of the helical contactor cooling device is in contact with or connected to the electrical contact.

[0023] In the following, the invention is described with reference to the attached Fig. 1 is explained in more detail. Fig. 1 shows a schematic illustration of an embodiment of the contactor arrangement 1 according to the invention in a cross section.

[0024] The contactor arrangement 1 has a contactor 30. This, in turn, has a contactor housing 35, a contactor drive 34 in the form of a coil generating a magnetic field, two contactor contacts 31, 32 protruding from the contactor housing 35, and a connecting element 33. The connecting element 33 is designed such that, when the contactor drive 34 is energized, it connects the two contactor contacts 31, i.e., the first contactor contact 31 and the second contactor contact 32, to one another, so that a current can flow between the two contactor contacts 31, 32. If the contactor drive 34 is not energized, the connecting element 33 moves, so that there is no electrical connection between the contactor contacts 31, 32. The control current of the contactor drive 34 is separated from the power circuit to be separated by the contactor 30.

[0025] Furthermore, the contactor assembly 1 has two contactor cooling devices 10, each of which is connected to one of the contactor contacts 31, 32. The contactor cooling devices 10 have a screw shape, with a connecting section 13 corresponding to the threaded section of the screw shape. The connecting section 13 has a thread that is screwed into the corresponding contactor contact 31, 32 and thus protrudes into it. The contactor cooling devices 10 are thus firmly connected to the contactor contacts 31, 32.

[0026] The screw head of the contactor cooling devices 10 protrudes beyond the contactor contacts 31, 32 and is connected to an electrical contact 21, 22 of the power circuit. The electrical contacts 21, 22 lead to an HV electrical system, for example, of a vehicle, which can be separated from an HV battery (not shown) by the contactor 30. The electrical contacts 21, 22 can be electrically separated by the contactor 30.

[0027] The contactor cooling devices 10 are designed to be electrically conductive, so that in the Fig. 1, a current flow can be conducted from the first electrical contact 21 via one of the contactor cooling devices 10, the first contactor contact 31, the connecting element 33, the second contactor contact 32 and the other contactor cooling device 10 to the second electrical contact 22.

[0028] Furthermore, a cooling fluid line 40 is provided, which transports a cooling fluid 41. This reaches a cooling fluid inlet 11 in the screw head of the contactor cooling device 10 that is connected to the first contactor contact 31 via the cooling fluid line 40. From there, the cooling fluid 41 is guided in a cooling fluid channel within the contactor cooling device 10 so that it can absorb heat from the contactor cooling device 10 and thus from the first contactor contact 31. Once the cooling fluid 41 has passed through the cooling channel, it reaches a cooling fluid outlet 12 of the contactor cooling device 10, which is also located in the screw head. From there, it reaches a cooling fluid line intermediate section 42 and then to a cooling fluid inlet 11 of the other contactor cooling device 10, which is connected to the second contactor contact 32.There, it is again guided through this contactor cooling device 10 by means of a cooling fluid channel and reaches the cooling fluid line 40 again through a cooling fluid outlet 12. On its way, the cooling fluid 41 has absorbed heat from the contactor cooling devices 10 and in particular the contactor contacts 31, 32, whereby they are cooled.

[0029] The cooling fluid 41 and the cooling fluid line 40 can be designed as part of an existing cooling circuit, for example of the battery, or can be designed as a separate cooling circuit.

[0030] In the event of a defect in the cooling system or within one of the contactor cooling devices 10, these can be easily replaced without having to replace the contactor 30 itself or other components. LIST OF REFERENCE SYMBOLS 1 contactor arrangement 10 Contactor cooling device 11 Cooling fluid inlet 12 Cooling fluid outlet 13 connecting section 21 first electrical contact 22 second electrical contact 30 contactor 31 first contactor contact 32 second contactor contact 33 Connecting element 34 Contactor drive 35 contactor housings 40 Cooling fluid line 41 Cooling fluid 42 Cooling fluid line intermediate section

Claims

[1] Contactor cooling device (10) for establishing an electrical connection between an electrical contact (21, 22) of an electrical conductor and a contactor contact (31, 32) of a contactor (30), comprising a connecting section (13) designed to establish a connection between the contactor cooling device (10) and the contactor contact (31, 32), and a cooling fluid inlet (11), a cooling fluid outlet (12) and a cooling fluid channel (40), wherein the cooling fluid channel (40) is designed to transport a cooling fluid (41) from the cooling fluid inlet (11) to the cooling fluid outlet (12), wherein the cooling fluid channel (40) is arranged at least in sections in a spiral shape in the contactor cooling device (10). [2] Contactor cooling device (10) according to the preceding claim, wherein the connecting portion (13) is designed as a thread and is designed to be screwed into a corresponding counter thread on the contactor contact (31, 32). [3] Contactor cooling device (10) according to one of the preceding claims, wherein the cooling channel is formed as a cavity in the interior of the contactor cooling device (10), in particular supported by struts. [4] Contactor cooling device (10) according to one of the preceding claims, wherein the contactor cooling device (10) has a screw shape. [5] Contactor cooling device (10) according to the preceding claim, wherein the threaded portion of the screw shape is designed to protrude into the contactor contact (31, 32) to which the contactor cooling device (10) is connected, and the screw head of the screw shape is designed to be contacted with the electrical contact (21, 22). [6] Contactor cooling device (10) according to one of the two preceding claims, wherein the cooling fluid inlet (11) and / or the cooling fluid outlet (12) are arranged in the screw head of the screw shape. [7] Contactor arrangement (1), comprising a contactor (30) with a first contactor contact (31) and a second contactor contact (31, 32), which can be electrically connected and electrically and galvanically separated by a connecting element (33) movable by means of a contactor drive (34), at least one contactor cooling device (10) according to one of the preceding claims, which is connected to at least one contactor contact (31, 32) and is designed to establish an electrical connection between an electrical contact (21, 22) of an electrical conductor and the contactor contact (31, 32) of the contactor (30) to which it is connected, and a cooling fluid line (40) configured to provide cooling fluid (41) at the cooling fluid inlet (11) of the contactor cooling device (10) and to receive cooling fluid (41) at the cooling fluid outlet (11) of the contactor cooling device (10). [8] Contactor arrangement (1) according to the preceding claim, wherein the contactor cooling device (1) is attached to the contactor contact (31, 32) by means of a thread. [9] Contactor arrangement (1) according to one of the preceding claims 7 or 8, wherein both the first contactor contact (31) and the second contactor contact (32) of the contactor (10) are each connected to a contactor cooling device (10) and the two contactor cooling devices (10) are connected by the cooling fluid line (40) such that the cooling fluid (41) transported through the cooling fluid line (40) is transported from the cooling channel outlet (12) of one contactor cooling device (10) to the cooling channel inlet (11) of the other contactor cooling device (10). [10] Contactor arrangement (1) according to one of the preceding claims 7 to 9, wherein the contactor cooling device (10) projects at least partially into the contactor contact (31, 32).

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