High-voltage box of electric automobile

Abstract

The utility model discloses a high-voltage box of an electric automobile, the high-voltage box comprises a shell and a protection circuit arranged in the shell, the protection circuit comprises a main fuse, a pre-charging circuit and an intelligent fuse Pyrofuse, the first end of the main fuse is connected with the positive electrode of a power battery, and the second end of the main fuse is connected with the first end of the pre-charging circuit; the first end of the pre-charging circuit is connected with the positive output end of the power supply, the second end of the pre-charging circuit is connected with the first end of the intelligent fuse Pyrofuse, the second end of the intelligent fuse Pyrofuse is connected with the positive output end of the power supply, and the third end of the intelligent fuse Pyrofuse is connected with the battery management system, so that the battery management system controls the intelligent fuse Pyrofuse to be closed or opened. According to the utility model, the on-off of the intelligent fuse Pyrofuse can be accurately controlled through the battery management system, and when the current exceeds a certain value, a high-voltage loop can be instantaneously disconnected, so that the safety of the power battery and the whole vehicle is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric vehicles, in particular to a high-voltage box of an electric vehicle. Background Art

[0002] At present, as a technical option, it is usually necessary to insert a traditional fuse in series in the high-voltage circuit as a disconnect device in an emergency. However, the existing traditional fuse (main fuse) is a current protection type, and there are two situations in which it will blow. One is when the circuit is short-circuited and the short-circuit current reaches the breaking current of the traditional fuse, the traditional fuse will blow; the other is when the loop current exceeds a certain size but does not reach the breaking current of the traditional fuse, and after the current continues for a certain period of time, the fuse will continue to heat up and then blow. In other words, when the loop current exceeds a certain size but does not reach the breaking current of the traditional fuse, the traditional fuse will not blow immediately, but will take a certain amount of time to blow, and the length of the blowing time is affected by factors such as different usage scenarios and usage habits. At this time, the high-voltage system has a risk of burning due to excessive current, so the traditional fuse cannot play a protective role in this situation and cannot protect the power battery and high-voltage system well. Utility Model Content

[0003] The purpose of this utility model is to solve the problem that when the circuit current exceeds a certain value but does not reach the breaking current of traditional fuses, traditional fuses cannot instantly disconnect the high-voltage circuit, thus failing to effectively protect the battery and high-voltage system. This utility model provides a high-voltage box for electric vehicles. By installing a smart fuse Pyrofuse in the high-voltage circuit and accurately controlling the on and off of the smart fuse through the battery management system, the smart fuse Pyrofuse can be instantly disconnected when the current exceeds a certain value, thereby improving the safety of the power battery and the entire vehicle.

[0004] In order to solve the above technical problems, the embodiment of the present utility model discloses a high-voltage box of an electric vehicle, which includes a housing and a protection circuit arranged in the housing. The protection circuit includes: a main fuse, a pre-charge circuit and a smart fuse Pyrofuse, wherein:

[0005] A first end of the main fuse is connected to the positive electrode of the power battery, and a second end of the main fuse is connected to the first end of the pre-charging circuit;

[0006] The second end of the pre-charging circuit is connected to the first end of the smart fuse Pyrofuse, the second end of the smart fuse Pyrofuse is connected to the positive output end of the power supply, and the third end of the smart fuse Pyrofuse is also connected to the battery management system, so that the battery management system controls the smart fuse Pyrofuse to be closed or opened.

[0007] With the above technical solution, on the one hand, since the smart fuse Pyrofuse is connected to the battery management system, the battery management system can set the melting current of the smart fuse Pyrofuse. When the loop current exceeds the melting current, the battery management system can control the smart fuse Pyrofuse to disconnect immediately to quickly cut off the high-voltage circuit. Compared with only setting the main fuse (i.e., the traditional fuse) in the loop, the smart fuse Pyrofuse can eliminate the instability caused by the uncertainty of the main fuse disconnection time, thereby improving the safety of the power battery and the entire vehicle. On the other hand, by setting the main fuse and the smart fuse Pyrofuse in the loop at the same time, the main fuse can be disconnected when the loop current reaches the breaking current of the main fuse, and the smart fuse Pyrofuse can be disconnected when the loop current exceeds a certain size but does not reach the breaking current of the main fuse. This can achieve double insurance and improve the safety of the power battery and the entire vehicle.

[0008] In a preferred embodiment of the present application, the pre-charging circuit further includes a pre-charging resistor, a pre-charging relay and a main positive relay, wherein the pre-charging resistor and the pre-charging relay are connected in series and in parallel with the main positive relay to form a pre-charging circuit.

[0009] In a preferred embodiment of the present application, the battery management system is connected to the smart fuse Pyrofuse via a low-voltage plug-in.

[0010] In a preferred embodiment of the present application, the protection circuit further includes a slow-charging fuse, a first end of the slow-charging fuse is connected to the second end of the smart fuse Pyrofuse, and the second end of the slow-charging fuse is connected to a slow-charging positive interface.

[0011] In a preferred embodiment of the present application, the protection circuit further includes a liquid-cooled fuse, a first end of the liquid-cooled fuse is connected to the second end of the smart fuse Pyrofuse, and the second end of the liquid-cooled fuse is connected to the high-voltage plug-in.

[0012] In a preferred embodiment of the present application, the low-voltage plug-in is also connected to the pre-charge relay and the main positive relay respectively, and the battery management system controls the pre-charge relay and the main positive relay to be closed or opened through the low-voltage plug-in.

[0013] In a preferred embodiment of the present application, the battery management system is connected to the control system of the electric vehicle, and the control system of the electric vehicle is used to receive the collision signal sent by the detection unit of the electric vehicle to control the smart fuse Pyrofuse to close or open.

[0014] As can be seen from the above, traditional fuses are only current protection type. When the electric vehicle crashes or suffers insulation damage in the circuit, traditional fuses will not melt. Therefore, the above technical solution is adopted. The electric vehicle's detection unit detects whether the electric vehicle has crashed and whether the circuit has insulation damage. When a collision or insulation damage fault is detected, the electric vehicle control system controls the intelligent fuse Pyrofuse through the battery management system to instantly disconnect, thereby quickly disconnecting the high-voltage circuit and protecting the battery and high-voltage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Showing a schematic diagram of a protection circuit in an embodiment of the present utility model;

[0016] Figure 2 A schematic structural diagram of a high-voltage box in an embodiment of the present utility model is shown;

[0017] Figure 3 Show Figure 2 A top view of

[0018] Figure 4 Shown is an exploded schematic diagram of a high-voltage box in an embodiment of the present utility model.

[0019] Reference numerals:

[0020] 1. Main fuse, 2. Pre-charge circuit, 21. Pre-charge resistor, 22. Pre-charge relay, 23. Main positive relay, 3. Pyrofuse, 4. Low-voltage plug-in, 5. Slow-charge fuse, 6. Slow-charge positive port, 7. Liquid-cooled fuse, 8. High-voltage plug-in, 9. Battery positive input copper busbar, 10. Power supply positive output copper busbar, 11. First series copper busbar, 12. Second series copper busbar, 13. Buckle, 14. Lower case. DETAILED DESCRIPTION

[0021] The following is an explanation of the implementation of the present invention by means of specific specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this utility model are limited to this implementation. On the contrary, the purpose of introducing the utility model in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide an in-depth understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0022] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0023] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as a limitation on the utility model.

[0024] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0025] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this embodiment based on specific circumstances.

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0027] refer to Figures 1 to 4 The embodiment of the present utility model discloses a high-voltage box of an electric vehicle, which includes a lower shell 14 and a protection circuit arranged in the lower shell 14. An installation space is formed in the lower shell 14, and the electronic components in the protection circuit are arranged in the installation space. Figure 1As shown, the protection circuit includes a main fuse 1 (i.e., a traditional fuse), a pre-charging circuit 2, and an intelligent fuse Pyrofuse 3. The pre-charging circuit 2 is mainly used to charge the power battery, and the main fuse 1 and the intelligent fuse Pyrofuse 3 are both used to protect the high-voltage circuit. Among them, the first end of the main fuse 1 is connected to the positive pole of the electric vehicle power battery, and the second end of the main fuse 1 is connected to the first end of the pre-charging circuit 2. The second end of the pre-charging circuit 2 is connected to the first end of the intelligent fuse Pyrofuse 3, the second end of the intelligent fuse Pyrofuse 3 is connected to the positive output end of the power supply, and the third end of the intelligent fuse Pyrofuse is also connected to the battery management system, so that the battery management system controls the intelligent fuse Pyrofuse 3 to be closed or disconnected. Specifically, as Figure 3 and Figure 4 As shown, the first end of the main fuse 1 is connected to the positive electrode of the power battery via the battery positive input copper busbar 9. The second end of the main fuse 1 is connected to the first end of the pre-charging circuit 2 via a first series copper busbar 11. The second end of the pre-charging circuit 2 is connected to the first end of the smart fuse pyrofuse 3 via a second series copper busbar 12. The second end of the smart fuse pyrofuse 3 is connected to the power supply positive output copper busbar 10. The third end of the smart fuse pyrofuse 3 is connected to the battery management system via a low-voltage plug-in 4.

[0028] With the above technical solution, on the one hand, since the smart fuse Pyrofuse3 is connected to the battery management system, the battery management system can set the melting current of the smart fuse Pyrofuse3. When the loop current exceeds the melting current, the battery management system can control the smart fuse Pyrofuse3 to disconnect immediately to quickly cut off the high-voltage circuit. Compared with only setting a traditional fuse (i.e., the main fuse 1) in the loop, the smart fuse Pyrofuse3 can eliminate the instability caused by the uncertainty of the disconnection time of the main fuse 1, thereby improving the safety of the power battery and the entire vehicle. On the other hand, by setting the main fuse 1 and the smart fuse Pyrofuse3 in the loop at the same time, it is possible to achieve that when the loop current reaches the breaking current of the main fuse 1, the main fuse 1 is disconnected, and when the loop current exceeds a certain size but does not reach the breaking current of the main fuse 1, the smart fuse Pyrofuse3 is disconnected. This can achieve double insurance and improve the safety of the power battery and the entire vehicle.

[0029] In a preferred embodiment of the present application, the positive output terminal of the power supply can be connected to a load or to the positive fast-charge port of an electric vehicle. The load can be a motor or an air-conditioning compressor, for example. When the positive output terminal of the power supply is connected to the load, the power battery discharges; when the positive output terminal of the power supply is connected to the positive fast-charge port of an electric vehicle, the power battery charges.

[0030] In a preferred embodiment of the present application, Figure 1 、 Figure 3 and Figure 4 As shown, the protection circuit also includes a pre-charge resistor 21, a pre-charge relay 22 and a main positive relay 23. The pre-charge resistor 21 and the pre-charge relay 22 are connected in series and then connected in parallel with the main positive relay 23 to form a pre-charge circuit 2. Figure 3 and Figure 4 The front side of the pre-charging resistor 21 is set close to the side of the lower shell 14. The lower shell 14 is provided with three buckles 13, which are respectively located on the left side, right side and rear side of the pre-charging resistor 21. The pre-charging resistor 21 is fixed to the lower shell 14 by the three buckles 13, which can increase the connection stability between the pre-charging resistor 21 and the lower shell 14.

[0031] In a preferred embodiment of the present application, Figure 4 As shown, the low-voltage plug-in 4 is also connected to the pre-charge relay 22 and the main positive relay 23 respectively. The battery management system controls the pre-charge relay 22 and the main positive relay 23 to be closed or opened through the low-voltage plug-in 4. Specifically, the low-voltage plug-in 4 is connected to the pre-charge relay 22 and the main positive relay 23 through a low-voltage collection harness.

[0032] It will be understood by those skilled in the art that in some variations of the above embodiments, a fast charging fuse may be further provided in the protection circuit as needed, and the fast charging fuse and the fast charging positive interface constitute a fast charging circuit. The first end of the fast charging fuse is connected to the copper bus 10 at the positive output end of the power supply, and the second end of the fast charging fuse is connected to the fast charging positive interface. The fast charging fuse can protect the fast charging circuit and prevent accidents such as fire caused by excessive current during fast charging.

[0033] In a preferred embodiment of the present application, in order to increase the user's charging options, in addition to the fast charging circuit, the protection circuit is also provided with a slow charging circuit. Figure 1 and Figure 3 The slow charging circuit includes a slow charging fuse 5 and a slow charging positive interface 6. The first end of the slow charging fuse 5 is connected to the second end of the smart fuse Pyrofuse 3, and the second end of the slow charging fuse 5 is connected to the slow charging positive interface 6. Similarly, the slow charging fuse 5 can protect the slow charging circuit and prevent accidents such as fire caused by excessive current during the slow charging process.

[0034] In the preferred embodiment of the present application, in order to cool the power battery in a high temperature environment and further enable the high voltage box to be used in a high temperature environment, continue to refer to Figure 1The protection circuit also includes a liquid cooling circuit, which includes a liquid cooling fuse 7. The first end of liquid cooling fuse 7 is connected to the second end of smart fuse Pyrofuse 3, and the second end of liquid cooling fuse 7 is connected to high-voltage plug-in 8. The electric vehicle is also equipped with a liquid cooling relay, which is connected to liquid cooling fuse 7. When the battery management system detects that the temperature of the power battery exceeds the set temperature, the electric vehicle control system controls the liquid cooling relay to energize, energizing the liquid cooling circuit to cool the power battery and prevent damage due to excessive temperature. Liquid cooling fuse 7 protects the liquid cooling circuit.

[0035] Those skilled in the art will appreciate that the relays and fuses in the above embodiments may be deleted according to actual conditions.

[0036] refer to Figure 4 In this application, the low-voltage plug-in 4 and high-voltage plug-in 8 are independently arranged. The low-voltage plug-in 4 is arranged below the high-voltage plug-in 8. The low-voltage collection harness is connected to the low-voltage plug-in 4, and the high-voltage collection harness is connected to the high-voltage plug-in 8. This not only avoids interference between the high-voltage and low-voltage circuits, reducing the incidence of faults, but also prevents faults caused by misconnecting high and low voltage wires. At the same time, the separate high and low voltage wiring harness design also facilitates inspection and maintenance, saving time and labor costs.

[0037] In addition to the aforementioned embodiments, the applicant also considers that when an electric vehicle collides or a circuit suffers insulation damage or other faults, traditional fuses cannot detect the above faults. Therefore, traditional fuses will not blow, which will pose a safety hazard to the high-voltage system.

[0038] To solve the above problems, the electric vehicle of the present application is also provided with a detection unit, which is used to detect whether the electric vehicle has collided. The battery management system is connected to the control system of the electric vehicle. The control system of the electric vehicle is used to receive the signal sent by the detection unit of the electric vehicle and transmit it to the battery management system. The battery management system controls the smart fuse Pyrofuse3 to close or disconnect.

[0039] Specifically, the detection unit is a collision detection sensor. The collision detection sensor is used to send a collision signal to the electric vehicle's control system when the electric vehicle collides. Because the electric vehicle's control system is connected to the battery management system, which is connected to the smart fuse Pyrofuse 3 via the low-voltage plug-in 4, the battery management system can control the smart fuse Pyrofuse 3 to open when the electric vehicle collides, instantly disconnecting the high-voltage circuit. Similarly, if insulation damage occurs in the circuit, the battery management system can control the smart fuse Pyrofuse 3 to open, instantly disconnecting the high-voltage circuit.

[0040] With the above technical solution, when an electric vehicle collides or an insulation failure occurs in the circuit, the intelligent fuse Pyrofuse3 is controlled to disconnect instantly, thereby quickly cutting off the high-voltage circuit within a few milliseconds to protect the battery and high-voltage system.

[0041] In summary, the high-voltage box in this application adds a smart fuse Pyrofuse3 in the protection circuit, and accurately controls the on and off of the smart fuse Pyrofuse3 through the battery management system and the control system of the electric vehicle. On the one hand, when the loop current exceeds a certain value, the smart fuse Pyrofuse3 is disconnected, which can instantly disconnect the high-voltage circuit; on the other hand, when the electric vehicle collides or the circuit has insulation damage failure, the smart fuse Pyrofuse3 is instantly disconnected, thereby quickly cutting off the high-voltage circuit, thereby effectively protecting the battery and high-voltage system and improving the safety of the entire vehicle.

[0042] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above description is provided to further illustrate the present invention in conjunction with specific embodiments, and that the present invention should not be construed as being limited to these descriptions. Those skilled in the art may make various changes in form and detail, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A high-voltage box for an electric vehicle, characterized in that: The high voltage box includes a housing and a protection circuit arranged in the housing, wherein the protection circuit includes: a main fuse, a pre-charge circuit and a smart fuse Pyrofuse, wherein: The first end of the main fuse is connected to the positive electrode of the power battery, and the second end of the main fuse is connected to the first end of the pre-charging circuit; The second end of the pre-charging circuit is connected to the first end of the smart fuse Pyrofuse, the second end of the smart fuse Pyrofuse is connected to the positive output end of the power supply, and the third end of the smart fuse Pyrofuse is also connected to the battery management system, so that the battery management system controls the smart fuse Pyrofuse to be closed or opened.

2. The high-voltage box of an electric vehicle according to claim 1, characterized in that: The pre-charging circuit includes a pre-charging resistor, a pre-charging relay and a main positive relay, wherein the pre-charging resistor and the pre-charging relay are connected in series and then connected in parallel with the main positive relay to form the pre-charging circuit.

3. The high-voltage box of the electric vehicle according to claim 2, characterized in that: The battery management system is connected to the smart fuse Pyrofuse via a low-voltage plug-in.

4. The high-voltage box of the electric vehicle according to claim 1, characterized in that: The protection circuit further includes a slow-charging fuse, a first end of the slow-charging fuse is connected to the second end of the smart fuse Pyrofuse, and the second end of the slow-charging fuse is connected to a slow-charging positive interface.

5. The high-voltage box of the electric vehicle according to claim 1, characterized in that: The protection circuit further includes a liquid-cooled fuse, a first end of the liquid-cooled fuse is connected to the second end of the smart fuse Pyrofuse, and the second end of the liquid-cooled fuse is connected to the high-voltage plug-in.

6. The high-voltage box of the electric vehicle according to claim 3, characterized in that: The low-voltage plug-in is also connected to the pre-charge relay and the main positive relay respectively, and the battery management system controls the pre-charge relay and the main positive relay to be closed or opened through the low-voltage plug-in.

7. The high-voltage box of an electric vehicle according to claim 1, characterized in that: The battery management system is connected to the control system of the electric vehicle. The control system of the electric vehicle is used to receive the collision signal sent by the detection unit of the electric vehicle and transmit it to the battery management system. The battery management system controls the smart fuse Pyrofuse to close or open.

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