Heat dissipation system of high-voltage circuit breaking unit of battery, high-voltage circuit breaking unit and battery pack

Abstract

The utility model discloses a battery high -voltage circuit breaking unit's heat dissipation system, high -voltage circuit breaking unit and battery package, including setting in the liquid cooling board of high -voltage circuit breaking unit's casing bottom, the liquid cooling board is used for the heat dissipation of the electric copper row in high -voltage circuit breaking unit casing and carries out heat dissipation to the battery simultaneously, the utility model discloses a battery high -voltage circuit breaking unit's heat dissipation system, through liquid cooling board and heat conducting medium carry out high -efficient heat dissipation to high -voltage circuit breaking unit, has solved the problem that traditional design is not enough heat dissipation, adopts the integration design and integrates battery management unit with circuit breaking unit, has improved the system integration, through the fuse and the optimized relay layout of active -passive integrated protection function, has strengthened the safety reliability of system.

Description

Technical Field

[0001] This utility model belongs to the field of battery pack technology, and relates to a heat dissipation system, a high-voltage circuit breaker unit, and a battery pack. Background Technology

[0002] Currently, space conflicts within battery packs are becoming increasingly prominent. How to make the most efficient use of the internal space of the battery pack is a key area of ​​focus for new energy vehicle manufacturers. Depending on the vehicle manufacturer's definition, different models have different charging and discharging currents, and the corresponding relay specifications must meet the usage requirements. Larger relays are more expensive, and some electrical components require 3-4 relays, leading to significant cost conflicts in power management.

[0003] Several technical problems urgently need to be solved in current power battery systems. First, traditional designs arrange the circuit breaker unit, battery management system (BMU), and current sampling module (CVS) as independent modules. This decentralized layout requires complex wiring harnesses within the circuit breaker unit to connect high-voltage sampling and low-voltage drive, increasing assembly difficulty and placing excessive demands on the horizontal space of the battery pack. Second, the protection mechanism of existing circuit breaker units has significant defects. It can only cut off power output through current monitoring. In the event of a collision or other emergency, it cannot quickly disconnect from the vehicle's power components, posing a serious safety hazard. Third, in fast charging and super-fast charging applications, the heat dissipation performance of traditional circuit breaker units is insufficient. High contact resistance leads to excessive temperature rise in the main circuit, which not only accelerates the degradation of electrical performance but may also cause serious faults such as short circuits. In addition, the discrete design also leads to low system integration, poor reliability, and difficult maintenance.

[0004] Therefore, it is necessary to highly integrate and improve the existing high-voltage circuit breaker unit and battery management system in the battery pack, at least to solve the problem of insufficient heat dissipation performance of the high-voltage circuit breaker unit mentioned above. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a heat dissipation system, a high-voltage circuit breaker unit and a battery pack for a battery high-voltage circuit breaker unit, which has the advantages of improving the heat dissipation performance of the battery high-voltage circuit breaker unit.

[0006] This utility model discloses a heat dissipation system for a high-voltage circuit breaker unit of a battery, including a liquid cooling plate disposed at the bottom of the housing of the high-voltage circuit breaker unit. The liquid cooling plate is used to dissipate heat from the conductive copper busbar inside the housing of the high-voltage circuit breaker unit and at the same time dissipate heat from the battery.

[0007] Furthermore, a heat-conducting medium is provided between the liquid cooling plate and the housing of the high-voltage circuit breaker unit.

[0008] Furthermore, the thermally conductive medium is thermally conductive silicone grease.

[0009] A high-voltage circuit breaker unit is also provided, including the heat dissipation system and housing of the battery high-voltage circuit breaker unit described above. The housing includes an upper housing and a lower housing that are interlocked with each other. The conductive copper busbar is disposed in the lower housing and a heat dissipation hole is provided on the bottom of the lower housing near the liquid cooling plate.

[0010] Furthermore, a battery management unit motherboard is disposed between the upper housing and the lower housing. A battery management unit module is disposed on the battery management unit motherboard. The battery management unit module includes a relay element integrated on the battery management unit motherboard, a shunt connection position for sampling the current magnitude in the circuit, and a fuse for circuit protection. The relay element includes a pre-charge relay assembly, a fast-charge relay assembly, and a main relay assembly.

[0011] Furthermore, the fuse is a fuse with integrated active and passive protection functions.

[0012] Furthermore, the conductive copper busbar extends upward to form a first connecting portion, which is used to connect and fix with the relay element;

[0013] Each relay element has a second connection part on its top, and is then soldered and fixed to the battery management unit motherboard through the second connection part.

[0014] Furthermore, a connecting copper busbar for high-voltage sampling is provided between the relay element and the battery management unit main board.

[0015] Furthermore, all the relay components are horizontally mounted inside the lower housing.

[0016] A battery pack, wherein the battery pack is provided with the aforementioned high-voltage circuit breaker unit.

[0017] The beneficial effects of this utility model are as follows:

[0018] This utility model provides a heat dissipation system for a high-voltage circuit breaker unit, a high-voltage circuit breaker unit, and a battery pack. The high-voltage circuit breaker unit is efficiently cooled by a liquid cooling plate, which solves the problem of insufficient heat dissipation in traditional designs.

[0019] Furthermore, the battery management unit and circuit breaker unit are integrated through an integrated design, which improves the system integration level; the safety and reliability of the system are enhanced through fuses with integrated active and passive protection functions and an optimized relay layout. Attached Figure Description

[0020] Figure 1 This is an exploded view of the present invention;

[0021] Figure 2 This is a bottom view of the present invention;

[0022] Figure 3 This is an axonometric view of the present invention;

[0023] Reference numerals: 1. Upper housing; 2. Lower housing; 3. Conductive copper busbar; 4. Heat dissipation hole; 5. Battery management unit main board; 6. Fuse; 7. Precharge resistor; 8. Precharge relay; 9. Fast charge positive relay; 10. Fast charge negative relay; 11. Main positive relay; 12. Main negative relay; 13. Shunt connection position; 14. First connection part; 15. Second connection part; 16. Connecting copper busbar; 17. Connecting stud; 18. Upper retaining ring; 19. Lower buckle. Detailed Implementation

[0024] It should be noted that in the description of this specification, the terms "upper", "lower", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] As shown in the figure, an embodiment of this utility model discloses a heat dissipation system for a battery high-voltage circuit breaker unit, including a liquid cooling plate disposed at the bottom of the housing of the high-voltage circuit breaker unit. The liquid cooling plate is used to dissipate heat from the conductive copper busbar 3 inside the housing of the high-voltage circuit breaker unit and simultaneously dissipate heat from the battery. The liquid cooling plate is disposed inside the battery pack and is mainly used to cool the battery module. The liquid cooling plate can be made of aluminum alloy and has internal coolant channels. The coolant channels can be designed as serpentine, spiral, or parallel straight-through structures to optimize the cooling effect. Heat dissipation fins or microchannel structures can be disposed on the surface of the liquid cooling plate to increase the heat dissipation area. The high-voltage circuit breaker unit is an important component installed in the battery pack management system for circuit protection. The housing of the high-voltage circuit breaker unit can be made of engineering plastic or metal. Usually, a conductive copper busbar 3 for circuit connection is set inside the housing. The conductive copper busbar 3 needs heat dissipation during operation, especially in fast charging and super fast charging scenarios. Therefore, this solution improves the heat dissipation performance of the high-voltage circuit breaker unit by placing the high-voltage circuit breaker unit on a liquid cooling plate. When the liquid cooling plate dissipates heat from the battery module, it also dissipates heat from the conductive copper busbar 3 inside the high-voltage circuit breaker unit housing.

[0026] In this embodiment, a thermally conductive medium is provided between the liquid cooling plate and the housing of the high-voltage circuit breaker unit; the thermally conductive medium is thermally conductive silicone grease; since the conductive copper busbar 3 is generally located inside the housing, a thermally conductive medium is also provided between the liquid cooling plate and the housing of the high-voltage circuit breaker unit for thermal conductivity. The thermally conductive medium can be thermally conductive silicone, thermally conductive pads, or phase change materials. In this solution, thermally conductive silicone grease is mainly used. Thermally conductive silicone grease has a high thermal conductivity, can transfer heat more effectively, has good stability and reliability, is easy to use, has a long life, and is suitable for harsh environments; at the same time, the contact surface between the housing and the liquid cooling plate can be designed as a flat surface or a mating surface with a concave-convex structure to improve thermal conductivity. This technical solution solves the problem of low heat dissipation efficiency and high contact resistance leading to temperature rise during fast charging in the prior art by directly placing the high-voltage circuit breaker unit on the liquid cooling plate and using the thermally conductive medium to establish an effective heat conduction path; the heat generated by the conductive copper busbar 3 is quickly transferred to the liquid cooling plate through the thermally conductive medium, and the heat is carried away by the coolant, thereby reducing the temperature rise of the main circuit and delaying the degradation of electrical performance.

[0027] This embodiment also discloses a battery high-voltage circuit breaker unit. The housing includes an upper housing 1 and a lower housing 2 that are interlocked. The conductive copper busbar 3 is disposed inside the lower housing 2, and a heat dissipation hole 4 is provided on the bottom side of the lower housing 2 near the liquid cooling plate. The upper housing 1 and the lower housing 2 are quickly assembled mainly through an interlocking structure, which can be a combination of an elastic buckle and a slot. Specifically, in this solution, the upper housing 1 is provided with an upper retaining ring 18, the lower housing 2 is provided with a lower retaining buckle 19, and the bottom of the lower housing 2 is also provided with a connecting stud 17. The location of the heat dissipation hole 4 at the bottom of the lower housing 2 is determined based on the arrangement of the electrical components, such as... Figure 2 As shown, the opening shape can be U-shaped, L-shaped, Z-shaped, etc.; the conductive copper busbar 3 is pre-embedded in the lower housing 2 through die casting, and its bottom maintains a distance of 5-10mm from the heat dissipation hole 4 area; the heat dissipation holes 4 of different electrical components are not connected, and heat dissipation is partitioned, which also facilitates the assembly and positioning of electrical components. This technical solution solves the problem of difficult maintenance of integral housing in the prior art through the split housing design. The snap-fit ​​structure allows the housing to be disassembled and assembled without tools, and the heat dissipation holes 4 are directly aligned with the liquid cooling plate to form a directional heat dissipation channel. Tests show that under the same working conditions, the operating temperature of the conductive copper busbar 3 using this structure can be reduced by 15-20℃, and the contact resistance can be reduced by about 8%, thereby achieving stable heat dissipation of the high-voltage circuit breaker unit under fast charging conditions and effectively avoiding the problem of electrical performance degradation caused by temperature rise.

[0028] In this embodiment, a battery management unit motherboard 5 is provided between the upper housing 1 and the lower housing 2. A battery management unit module is provided on the battery management unit motherboard 5. The battery management unit module includes a relay element integrated on the battery management unit motherboard 5, a shunt connection position 13 for sampling the current magnitude in the circuit, and a fuse 6 for circuit protection. The relay element includes a pre-charge relay assembly, a fast-charge relay assembly, and a main relay assembly.

[0029] This technical solution integrates the shunt directly onto the battery management unit motherboard 5 and samples the circuit current through the shunt connection bit 13, eliminating the space occupation problem caused by the need to set up a separate current sampling module in the traditional solution. Since the shunt and the motherboard are integrated into one design, the line loss and interference in the sampling signal transmission process are reduced, and the current sampling accuracy is improved. At the same time, this integrated design simplifies the layout of the high-voltage sampling line, which helps to reduce the overall size of the system.

[0030] The pre-charge relay assembly includes a pre-charge relay 8 and a pre-charge resistor 7; the fast-charge relay assembly includes a fast-charge positive relay 9 and a fast-charge negative relay 10; and the main relay assembly includes a main positive relay 11 and a main negative relay 12. By integrating the relay elements and fuse 6 onto the battery management unit motherboard 5, the wiring harness connections between individual modules in traditional solutions are reduced, thus lowering system complexity and space occupation. The pre-charge relay 8 is used to limit the initial charging current, the fast-charge relay assembly controls the on / off state of the fast-charge circuit, and the main relay assembly is responsible for connecting and disconnecting the main circuit. The fuse 6 cuts off the circuit in the event of overcurrent, providing protection. Therefore, this solution solves the problems of dispersed modules, complex wiring harnesses, and large space occupation in existing technologies, while improving system reliability and assembly efficiency.

[0031] In this embodiment, the fuse 6 is a fuse with integrated active and passive protection. The fuse 6 with integrated active and passive protection is existing technology and will not be described in detail here. This technical solution solves the protection lag problem caused by traditional fuses relying solely on passive fusing by using a fuse with integrated active and passive protection. Specifically, in the event of a vehicle collision or battery pack malfunction, the active protection function can quickly cut off the high-voltage circuit, preventing the power module from failing to disconnect in time due to the response delay of the fuse 6; simultaneously, the passive fusing, as redundant protection, can still ensure circuit safety when the active protection fails. Therefore, by selecting a fuse 6 with integrated active and passive protection, the risk of electrical performance degradation caused by contact resistance temperature rise is reduced through coordinated active and passive protection, making it particularly suitable for high-current conditions in fast charging or super-fast charging scenarios.

[0032] In this embodiment, all relay elements are horizontally mounted within the lower housing 2. This horizontal mounting effectively reduces the vertical space occupied by the relay elements, making the overall structure of the high-voltage circuit breaker unit more compact and thus reducing the horizontal space required. Simultaneously, horizontal mounting helps optimize the layout of the conductive copper busbars 3, reducing internal wiring connections, lowering contact resistance, and improving heat dissipation efficiency. Furthermore, this mounting method facilitates the integrated connection of the relay elements with the battery management unit motherboard 5, reducing assembly complexity and improving production efficiency and reliability.

[0033] In this embodiment, the conductive copper busbar 3 extends upward to form a first connecting portion 14, which is used to connect and fix with relay elements. The connection methods between the first connecting portion 14 and the relay element include, but are not limited to, bolted fastening, welded fixing, or plug-in locking. A silver plating layer can be applied to the contact surface between the first connecting portion 14 and the relay element to reduce contact resistance. The shape of the first connecting portion 14 can be designed as L-shaped, T-shaped, or straight to meet the spatial layout requirements of different relay elements. This technical solution directly extends the conductive copper busbar 3 to form a connection structure, physically connecting and electrically conducting the conductive copper busbar 3 in the high-voltage circuit to the relay element. This eliminates the additional wiring harness connection step in traditional solutions, reducing contact resistance and energy loss. The direct rigid connection between the first connecting portion 14 and the relay element has higher mechanical stability and lower temperature rise risk compared to flexible wiring harness connections. Furthermore, this integrated connection structure simplifies the assembly process of the high-voltage circuit, improving production efficiency and reliability.

[0034] In this embodiment, each relay element has a second connecting portion 15 on its top, which is then plugged into and soldered to the battery management unit mainboard 5. The second connecting portion 15 is a metal pin or terminal on the top of the relay element, and its shape can be designed as a through-hole, bent, or surface-mount structure. The second connecting portion 15 is plugged into the corresponding socket of the battery management unit mainboard 5 using an interference fit or clearance fit, and then soldered to secure it using reflow soldering or wave soldering. This technical solution optimizes the connection between the relay element and the battery management unit mainboard 5 to a plug-in soldering structure, solving the problems of complex assembly and large space occupation caused by traditional wire harness connections. Since the second connecting portion 15 is directly connected to the mainboard circuit, the intermediate wire harness is omitted, thereby reducing contact resistance and voltage drop, and improving signal transmission stability. Furthermore, the soldering method saves more vertical space than screw fastening, allowing for a reduction in the overall height of the high-voltage circuit breaker unit. In addition, the plug-in soldering structure has higher connection reliability under vibration conditions, avoiding poor contact problems caused by loose wire harnesses.

[0035] In this embodiment, a connecting copper busbar 16 for high-voltage sampling is also provided between the relay element and the battery management unit mainboard 5. The connecting copper busbar 16 can be designed as an L-shaped or U-shaped structure, with one end connected to the electrode terminal of the relay element via bolts, and the other end connected to the sampling circuit on the battery management unit mainboard 5 via pins. This technical solution, by adding a dedicated connecting copper busbar 16, achieves direct transmission of the high-voltage sampling signal from the relay to the mainboard; the rigid structure of the connecting copper busbar 16 can replace the traditional wire harness connection method, eliminating the risk of poor contact caused by wire harness bending; and the plug-in connection between the copper busbar and the mainboard facilitates modular assembly, reducing the impact of thermal stress on electronic components compared to welding processes, and solving the problem of electrical performance degradation caused by temperature rise in the high-voltage sampling circuit.

[0036] This embodiment also discloses a battery pack, which is equipped with the aforementioned high-voltage circuit breaker unit. This battery pack, by integrating the high-voltage circuit breaker unit's heat dissipation system, solves the problems of low heat dissipation efficiency, complex wiring, and limited protection methods found in existing technologies. The liquid cooling plate and heat-conducting medium effectively reduce the operating temperature of the conductive copper busbar 3 and relay components, improving heat dissipation efficiency. The integrated design reduces wiring harness connections, simplifies the internal structure, and reduces space occupation. The configuration of the integrated active and passive protection fuse 6 and the high-voltage sampling connection copper busbar 16 enhances the system's safety and reliability. Compared with existing technologies, this solution improves heat dissipation performance while achieving a compact structure and functional integration, making it suitable for battery pack applications with high space and heat dissipation requirements.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A heat dissipation system for a battery high-voltage circuit breaker unit, characterized in that: It includes a liquid cooling plate disposed at the bottom of the housing of the high-voltage circuit breaker unit, the liquid cooling plate being used to dissipate heat from the conductive copper busbar inside the housing of the high-voltage circuit breaker unit and simultaneously dissipate heat from the battery.

2. The heat dissipation system of the battery high-voltage circuit breaker unit according to claim 1, characterized in that: A heat-conducting medium is provided between the liquid cooling plate and the housing of the high-voltage circuit breaker unit.

3. The heat dissipation system of the battery high-voltage circuit breaker unit according to claim 2, characterized in that: The thermally conductive medium is thermally conductive silicone grease.

4. A high-voltage circuit breaker unit, characterized in that: The device includes a heat dissipation system and a housing for the battery high-voltage circuit breaker unit as described in any one of claims 1-3. The housing includes an upper housing and a lower housing that are interlocked with each other. The conductive copper busbar is disposed in the lower housing and a heat dissipation hole is provided on the bottom of the lower housing near the liquid cooling plate.

5. The heat dissipation system of the battery high-voltage circuit breaker unit according to claim 4, characterized in that: A battery management unit motherboard is disposed between the upper housing and the lower housing. A battery management unit module is disposed on the battery management unit motherboard. The battery management unit module includes a relay element integrated on the battery management unit motherboard, a shunt connection position for sampling the current magnitude in the circuit, and a fuse for circuit protection. The relay element includes a pre-charge relay assembly, a fast-charge relay assembly, and a main relay assembly.

6. The heat dissipation system of the battery high-voltage circuit breaker unit according to claim 5, characterized in that: The fuse is a fuse with integrated active and passive protection functions.

7. The heat dissipation system of the battery high-voltage circuit breaker unit according to claim 5, characterized in that: The conductive copper busbar extends upward to form a first connecting portion, which is used to connect and fix with the relay element. Each relay element has a second connection part on its top, and is then soldered and fixed to the battery management unit motherboard through the second connection part.

8. The heat dissipation system of the battery high-voltage circuit breaker unit according to claim 5, characterized in that: A connecting copper busbar for high-voltage sampling is also provided between the relay element and the battery management unit main board.

9. The heat dissipation system of the battery high-voltage circuit breaker unit according to claim 5, characterized in that: All relay components are horizontally mounted inside the lower housing.

10. A battery pack, characterized in that: The battery pack is provided with a high-voltage circuit breaker unit as described in any one of claims 4-9.

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