Protective device for a high-voltage cable, high-voltage cable, high-voltage electrical system and motor vehicle

Abstract

Protective device (10) for integration into a high-voltage cable (4) of a high-voltage electrical system (1), comprising: - a fuse (11) for interrupting at least one electrical conductor (5) of the high-voltage cable (4) in the event of a fault, - a housing (16) for arrangement between two high-voltage cable sections (4a, 4b) of the high-voltage cable (4), in which the fuse (11) is arranged and which has terminals (17a, 17b) for connecting the fuse (11) to conductor sections (5a, 5b) of the at least one conductor (5), wherein at least a part of the housing (16) is detachable from the high-voltage cable sections (4a, 4b) without damage in order to enable replacement of at least the fuse (11) in the event of a defect of the fuse (11).characterized by a shielding element (14) for forming a cable shield (15) with a shielding conductor (7) of the high-voltage cable (4), which is arranged in the housing (16), wherein the terminals (17a, 17b) of the housing (16) are also designed for connecting the shielding element (14) to shielding conductor sections (7a, 7b) of the shielding conductor (7).

Description

[0001] The invention relates to a protective device for a high-voltage cable of a high-voltage electrical system, which includes a fuse for interrupting at least one electrical conductor of the high-voltage cable in the event of a fault. The invention also relates to a high-voltage cable, a high-voltage electrical system, and a motor vehicle.

[0002] The focus here is on high-voltage electrical systems for motor vehicles, particularly electrically powered vehicles. Such systems typically comprise numerous high-voltage components, for example, an electric motor, a traction battery, and power electronics. High-voltage cables or lines are used to electrically connect these components, often via connectors. To isolate the high-voltage components in the event of a fault, such as an overcurrent or overtemperature, protective devices with fuses are typically employed. These fuses can be, for example, cartridge fuses permanently integrated into the high-voltage cable and designed to interrupt an electrical conductor within the cable.If the fuse fails, for example after the fuse has tripped, the entire high-voltage cable usually has to be replaced, which is complex and expensive.

[0003] The object of the present invention is to provide a cost-effective and low-effort solution for replacing a defective fuse of a protective device of a high-voltage cable.

[0004] This problem is solved according to the invention by a protective device, a high-voltage cable, a high-voltage electrical system, and a motor vehicle with the features according to the respective independent claims. Advantageous embodiments of the invention are the subject of the dependent claims, the description, and the figures.

[0005] A protective device according to the invention for integration into a high-voltage cable of a high-voltage electrical system comprises a fuse for interrupting at least one electrical conductor of the high-voltage cable in the event of a fault and a shielding element for forming a cable shield with a shield conductor of the high-voltage cable. The protective device also comprises a housing for placement between two high-voltage cable sections. The fuse and the shielding element are arranged in the housing. The housing has connections for connecting the fuse to conductor sections of the at least one conductor and for connecting the shielding element to shield conductor sections of the shield conductor. At least part of the housing can be detached from the high-voltage cable sections without damage in order to allow replacement of at least the fuse in the event of a defect.

[0006] The invention also includes a high-voltage cable for a high-voltage electrical system with at least one electrical conductor, a shielding conductor, and at least one protective device according to the invention. The protective device is arranged between and connected to two high-voltage cable sections, each of which has a conductor section and a shielding conductor section. The fuse is arranged between two conductor sections of the at least one electrical conductor and is electrically connected to them. The shielding element is arranged between two shielding conductor sections of the shielding conductor and is electrically connected to them to form the cable shield. The high-voltage cable can have several conductors or cores, which are electrically insulated from one another and surrounded by an insulating cable sheath. The shielding conductor can, for example, be a metallic braid and surround the insulated conductors.The shielding serves to prevent the ingress and / or emission of electromagnetic fields. In particular, the high-voltage cable has at least one, preferably two, connectors by means of which the high-voltage cable can be electrically connected to at least one high-voltage component of the high-voltage electrical system. The at least one connector can, for example, be a high-voltage plug or a high-voltage socket.

[0007] A high-voltage electrical system according to the invention comprises at least two high-voltage components and at least one high-voltage cable according to the invention, which electrically connects the at least two high-voltage components. The high-voltage components can be, for example, a high-voltage battery, an electric drive motor, power electronics, or the like.

[0008] The high-voltage cable has an integrated protective device and is therefore designed as a ready-to-connect, pre-assembled high-voltage cable. The protective device housing is positioned between and connected to the two high-voltage cable sections. The housing contains a fuse, which is electrically connected to the two conductor sections of at least one electrical conductor. The housing provides terminals through which the conductor sections can be routed to and electrically connected to the fuse. In the event of a fault, such as an overcurrent and / or overtemperature, the fuse trips and disconnects the two conductor sections. This interrupts at least one electrical conductor and thus the high-voltage cable.The fuse can be reversible (resettable) or irreversible (non-resettable). For example, the fuse can include at least a temperature-controlled bimetallic switch and / or at least a fuse.

[0009] Furthermore, the protective device includes a shielding element. This shielding element, together with the shield conductor of the high-voltage cable, which is interrupted by the protective device and divided into two shield conductor sections, forms the cable shield. The shielding element can, for example, be a shielding plate. The shield conductor sections are also routed via the terminals to the shielding element located in the housing and electrically connected to it.

[0010] To allow for fuse replacement in case of a defect, at least part of the housing can be detached from the high-voltage line. In the case of an irreversibly tripping fuse, such as a cartridge fuse, the fuse may be defective due to its tripping. In this case, the entire housing, including the fuse and shielding, can be removed and replaced. For this purpose, the connections are designed as plug connectors that can be connected to corresponding connectors on the high-voltage cable sections. Alternatively, only part of the housing can be removed to open the housing and replace only the defective fuse. Therefore, if the fuse is defective, it is advantageous not to have to replace the entire high-voltage cable.

[0011] In particular, the housing comprises a lower housing section and an upper housing section. The fuse and the shielding element are located in the lower housing section. The lower housing section is attached to the high-voltage cable sections. The upper housing section is attached to the lower housing section in a way that allows for non-destructive removal, enabling the housing to be opened for fuse replacement. The upper housing section forms a cover for the lower housing section. When the lower and upper housing sections are assembled, they form an interior housing in which the fuse and the shielding element are located. If the fuse is defective, the upper housing section can be removed from the lower housing section, providing access to the defective fuse for replacement. The upper housing section is preferably attached to the lower housing section by means of a snap-fit ​​connection. Such a snap-fit ​​connection is particularly easy to open and close.

[0012] It is also possible for the housing upper and lower parts to have corresponding guide elements for joining them. Such guide elements can be pins or bolts, for example, arranged on the housing upper part and inserted into blind-hole guide elements in the housing lower part. This ensures that the housing closes securely and as intended after the safety device has been replaced.

[0013] Preferably, the connections are designed as grommet-like feedthroughs in a housing wall of the enclosure, wherein the shielding conductor sections and the conductor sections can be passed through the feedthroughs and electrically connected to the shielding element and the fuse. This embodiment is particularly advantageous if the enclosure can only be partially detached from the high-voltage cable sections. The feedthroughs are preferably formed in a housing wall associated with the lower part of the enclosure. The conductor sections and the shielding conductor sections can be inserted into the interior of the enclosure via the feedthroughs and connected there to the fuse or the shielding element.

[0014] It is advantageous if the protective device has plug-in connectors that are electrically connected to the fuse and can be electrically connected to corresponding plug-in connectors on the conductor sections. The defective fuse can therefore be easily removed from the housing by disconnecting the plug and replaced with a new one. In the case of a completely replaceable protective device, the plug-in connectors can be integrated into the terminals in the housing wall. Alternatively, the conductor sections with their corresponding plug-in connectors may be routed through the feedthroughs into the interior of the housing and connected to the fuse there by plugging them together. To replace the fuse, the housing cover is removed, the fuse is taken out by disconnecting the plug, and a new fuse is inserted.Then the housing cover is placed back onto the lower part of the housing to close the housing.

[0015] In a further development of the invention, the protective device has terminal block-like connecting elements, each comprising a terminal block electrically connected to the shielding element and a clamping screw for connecting the shielding conductor sections of the high-voltage cable to the terminal block. According to this embodiment, the shielding conductor sections are guided into the housing interior, particularly through the openings in the housing wall, and connected there to the terminal block via the clamping screws. This terminal block is electrically connected to the shielding element. The terminal block-like connecting elements and the shielding element are arranged, in particular, in the lower housing part, which is detachably connected to the upper housing part. Therefore, in the event of a fuse failure, only the fuse needs to be replaced without having to disconnect the terminal block-like connection.

[0016] The invention also includes a motor vehicle with a high-voltage electrical system according to the invention. The motor vehicle is specifically designed as an electrified motor vehicle, i.e., as an electric or hybrid vehicle.

[0017] The embodiments and advantages presented with reference to the protective device according to the invention apply accordingly to the high-voltage cable according to the invention, to the high-voltage on-board network according to the invention, and to the motor vehicle according to the invention.

[0018] Further features of the invention will become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures alone, are not only usable in the combinations specified, but also in other combinations or on their own.

[0019] The invention will now be explained in more detail with reference to a preferred embodiment and the drawings.

[0020] They show: Fig. 1 a schematic representation of an embodiment of a high-voltage electrical system; Fig. 2a, Fig. 2b Schematic representations of designs of fuses; Fig. 3 a schematic representation of an embodiment of a protective device; and Fig. 4 A schematic representation of an embodiment of a terminal block-like connecting element.

[0021] In the figures, identical and functionally equivalent elements are provided with the same reference symbols.

[0022] Fig. Figure 1 shows a high-voltage electrical system 1 for a motor vehicle. The high-voltage electrical system 1 comprises two high-voltage components 2 and 3 and a high-voltage cable 4. The high-voltage cable 4 allows the high-voltage components 2 and 3 to be electrically connected. The high-voltage cable 4 has two electrical conductors 5 and 6, as well as a shielding conductor 7. The shielding conductor 7 can, for example, be a metal braid that surrounds the insulated conductors 5 and 6 to improve electromagnetic compatibility and ensure interference-free signal transmission. The high-voltage cable 4 also has connectors 8 and 9 for connecting to the high-voltage components 2 and 3.

[0023] Furthermore, the high-voltage cable 4 has a protective device 10, which is designed to isolate the high-voltage components 2, 3 from each other in the event of a fault, in particular galvanically. The protective device 10 is arranged between two high-voltage cable sections 4a, 4b and connected to these high-voltage cable sections 4a, 4b to form a ready-to-connect, pre-assembled high-voltage cable 4. A fuse 11 is arranged in at least one of the conductors 5, 6, here in conductor 5. This fuse 11 is electrically connected to two conductor sections 5a, 5b of conductor 5 and is designed to disconnect the conductor sections 5a, 5b in the event of a fault, thereby interrupting conductor 5.

[0024] Fuse 11 can, for example, be an overcurrent protection device that interrupts conductor 5 in the event of an overcurrent, and / or a thermal fuse that interrupts conductor 5 in the event of an overtemperature. Fuse 11 can, for example, be, as shown in Fig. 2a shown, as a fuse 12 or, as in Fig. 2b shown, designed as a temperature-controlled bimetallic switch 13.

[0025] Furthermore, the protective device 10 has a shielding element 14, which is connected to shield conductor sections 7a, 7b of the shield conductor 7 to form a cable shield 15 of the high-voltage cable 4. The shielding element 14 and the fuse 11 are arranged in a housing 16, which is located on the high-voltage cable sections 4a, 4b. The housing 16 has terminals 17a, 17b, via which the fuse 11 can be electrically connected to the conductor sections 5a, 5b and via which the shielding element 14 can be electrically connected to the shield conductor sections 7a, 7b. At least part of the housing 16 can be detached from the high-voltage cable sections 4a, 4b without damage, so that in the event of a defect in the fuse 11, only the fuse 11, and not the entire high-voltage cable 4, needs to be replaced.

[0026] The protective device 10 is exemplary in Fig. Figure 3 shows that the housing 16 has an upper housing part 18 and a lower housing part 19, which enclose an interior housing space 20. The fuse 11 and the shielding element 14 are arranged in the interior housing space 20 in the area of ​​the lower housing part 19. The terminals 17a, 17b are designed as grommet-like feedthroughs 21 in a housing wall 22 of the lower housing part 19, through which the conductor sections 5a, 5b and the shielding conductor sections 7a, 7b are led into the interior housing space 20. In the interior housing space 20, the conductor sections 5a, 5b are electrically connected to the fuse 11. For this purpose, the fuse 11 and the conductor sections 5a, 5b can be connected, as shown by the temperature-controlled bimetallic switch 13 in Figure 3. Fig. Figure 2b shows corresponding plug-in connectors 23 and 24, so that the fuse 11 can be replaced in the event of a defect by disconnecting the plug connection 25 formed by the plug-in connectors 23 and 24. The plug connection 25 can also be thermally coupled to a heat sink 26. For this purpose, for example, the fuse-side plug-in connector 23 can be attached to a metal plate.

[0027] Fuse 11 can also be used, as shown by fuse 12 in Fig. As shown in 2a, this can be implemented via a plug connection 25 using a cable lug 27 arranged on the fuse 11. Of course, the plug connection 25 can also be configured according to Fig. 2b on the security according to Fig. 2a and vice versa.

[0028] For electrically connecting the shielding element 14 to the shield conductor sections 7a, 7b, the protective device 10 can use terminal block-like connecting elements 28, as shown in Fig. Figure 4 shows the following components, which are arranged in the housing 16. The terminal block-like connecting elements 28 have a terminal block 29, which is electrically and mechanically connected to the shielding element 14 and which has a tubular profile 30. The terminal block 29 consists at least partially of an electrically conductive material. The shielding conductor section 7a, 7b is inserted into the tubular profile 30 and fixed by means of a clamping screw 31 of the terminal block-like connecting element 28. By means of the clamping screw 31, the shielding conductor section 7a, 7b is electrically connected to the terminal block 29 and thus to the shielding element 14.

[0029] The upper part of the housing 18 can, as in Fig.As shown in Figure 3, the fuse 11 can be detached from the lower housing part 19 without damage. For this purpose, the housing 16 has, for example, a snap connection 32. The snap connection 32 is formed here by elastic snap hooks 33 on the upper housing part 18 and projections 34 on the lower housing part 19. To replace the defective fuse 11, the snap connection 32 is released by detaching the snap hooks 33 from the projections 34. After releasing the snap connection 32, the upper housing part 18 can be removed from the lower housing part 19 and the fuse 11 can be removed by disconnecting the plug connection 25, for example, by simply pulling out the fuse 11. A functioning fuse 11 can then be connected to the conductor sections 5a, 5b, for example, by plugging it in, and the upper housing part 18 can be placed back onto the lower housing part 19 to close the housing 16.For this purpose, the upper housing part 18 and the lower housing part 19 have corresponding guide elements 35, 36. The guide elements 35 on the upper housing part can, for example, be pins or bolts which can be inserted into the guide elements 36 on the lower housing part in the form of blind holes. As soon as the snap hooks 33 are engaged on the projections 34, the upper housing part 18 and the lower housing part 19 are mechanically connected again.

Claims

[1] Protective device (10) for integration into a high-voltage cable (4) of a high-voltage electrical system (1), comprising - a fuse (11) for interrupting at least one electrical conductor (5) of the high-voltage cable (4) in the event of a fault, characterized by - a shielding element (14) for forming a cable shield (15) with a shielding conductor (7) of the high-voltage cable (4), and - a housing (16) for arrangement between two high-voltage cable sections (4a, 4b) of the high-voltage cable (4), in which the fuse (11) and the shielding element (14) are arranged and which has connections (17a, 17b) for connecting the fuse (11) to conductor sections (5a, 5b) of the at least one conductor (5) and for connecting the shielding element (14) to shield conductor sections (7a, 7b) of the shield conductor (7), wherein at least a part of the housing (16) is detachable from the high-voltage cable sections (4a, 4b) without damage in order to allow replacement of at least the fuse (11) in the event of a defect of the fuse (11). [2] Protective device (10) according to claim 1, characterized by that the fuse (11) has at least a fuse element (12) and / or at least a temperature-controlled bimetallic switch (13). [3] Protective device (10) according to claim 1 or 2, characterized by, that the housing (16) has a lower housing part (19) and an upper housing part (18), wherein the lower housing part (19), in which the fuse (11) and the shielding element (14) are arranged, is attached to the high-voltage cable sections (4a, 4b) and the upper housing part (18) is attached to the lower housing part (19) in a way that allows the housing (19) to be opened for replacement of the fuse (11) without damage. [4] Protective device (10) according to claim 3, characterized by , that the upper part of the housing (18) is attached to the lower part of the housing (19) by means of a snap connection (32). [5] Protective device (10) according to claim 3 or 4, characterized by , that the upper housing part (18) and the lower housing part (19) have corresponding guide elements (35, 36) for joining the upper housing part (18) and the lower housing part (19). [6] Protective device (10) according to any of the preceding claims, characterized by, that the connections (17a, 17b) are designed as grommet-like feedthroughs (21) in a housing wall (22) of the housing (16), wherein the shielding conductor sections (7a, 7b) and the conductor sections (5a, 5b) can be passed through the feedthroughs (21) and can be electrically connected to the shielding element (14) and the fuse (11). [7] Protective device (10) according to any of the preceding claims, characterized by , that the protective device (10) has plug-in connectors (23, 27) which are electrically connected to the fuse (11) and can be electrically connected to corresponding plug-in connectors (24) of the conductor sections (5a, 5b). [8] Protective device (10) according to any of the preceding claims, characterized by, that the protective device (10) has terminal block-like connecting elements (28), each of which has a terminal block (29) that is electrically connected to the shielding element (14) and a clamping screw (31) for connecting the shield conductor sections (7a, 7b) of the high-voltage cable (4) to the terminal block (29). [9] High-voltage cable (4) for a high-voltage on-board network (1) comprising at least one electrical conductor (5), a shielding conductor (7) and at least one protective device (10) according to one of the preceding claims, wherein the protective device (10) is arranged between two high-voltage cable sections (4a, 4b), each comprising a conductor section (5a, 5b) and a shielding conductor section (7a, 7b). [10] High-voltage cable (4) according to claim 9, characterized by, that the high-voltage cable (4) is ready for connection and has at least one connector (8, 9) for electrically connecting the high-voltage cable (4) to at least one high-voltage component (2, 3) of the high-voltage on-board network (1). [11] High-voltage electrical system (1) for a motor vehicle comprising at least two high-voltage components (2, 3) and at least one high-voltage cable (4) according to claim 9 or 10, which electrically connects the at least two high-voltage components (2, 3). [12] Motor vehicle with a high-voltage electrical system (1) according to claim 11.

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