Device and method for early warning based on battery shell deformation detection

Abstract

The invention discloses an early warning device and method based on battery shell deformation detection. The device comprises a detection path and a vehicle-mounted battery control unit. The vehicle-mounted battery control unit comprises a battery management unit, a battery cluster management unit and a battery system management unit; and the detection path surrounds the battery, is provided with a dry contact output terminal, and is connected with a vehicle-mounted battery control unit through the dry contact output terminal. The vehicle-mounted battery control unit obtains the on-off condition of the detection access according to the dry contact output terminal, and early warning of the safety of the electrochemical battery is achieved through battery deformation.

Description

Technical Field

[0001] The present invention relates to the field of battery safety technology, and in particular to a device and method for early warning based on battery shell deformation detection. Background Art

[0002] With the vigorous development of the new energy industry, electrochemical batteries are widely used, among which new energy vehicles, electrochemical energy storage and other industries use a large number of ternary batteries and lithium iron phosphate batteries; but due to the electrochemical properties of electrochemical batteries, new energy vehicles and energy storage power stations have caught fire from time to time in recent years. Then how to effectively manage the thermal runaway of electrochemical batteries has become a top priority.

[0003] Through a large amount of data research, it was found that in the early stage of thermal runaway, the battery module shell is intact and the temperature does not rise significantly, and gases such as carbon dioxide, carbon monoxide, ethyl methyl carbonate, dimethyl carbonate, and methane will be produced; with the further development of thermal runaway, the battery module shell will bulge or even rupture, and then the temperature will rise sharply. The battery electrochemical reaction will produce a large amount of gas, and harmful gases such as dimethyl ether, methyl formate, and ethylene will also begin to be produced.

[0004] Based on the discovery of the thermal runaway process of electrochemical batteries, hydrogen and other flammable gases can be used as important detection targets. Currently, flammable gas detection devices are being developed and applied in electrochemical energy storage projects. However, this method cannot achieve early warning of battery safety. Summary of the invention

[0005] To solve the above problems, the present invention provides a device and method for early warning based on battery casing deformation detection, which uses a material that is sensitive to external deformation to wrap the shape of the electrochemical energy storage battery, performs detection and early warning based on the deformation of the battery shape, and uses loop control to manage electrochemical battery thermal runaway to avoid fires caused by electric sparks generated by energized or powered-off equipment.

[0006] The present invention provides a device for early warning based on battery shell deformation detection, and the specific technical solution is as follows:

[0007] The device includes a detection path and an on-board battery control unit;

[0008] The vehicle-mounted battery control unit includes a battery management unit, a battery cluster management unit and a battery system management unit;

[0009] The detection path surrounds the battery, and is provided with a dry contact output terminal, and is connected to the vehicle-mounted battery control unit via the dry contact output terminal.

[0010] Furthermore, the detection path uses copper wire to surround the battery to form an electrical signal path.

[0011] Furthermore, the copper wire constituting the detection path is wrapped with insulating material.

[0012] Furthermore, the detection path is buried in the battery aluminum shell.

[0013] Furthermore, the device also includes a fixing clamp, through which the dry contact output terminal is fixed to the battery.

[0014] Furthermore, the detection paths are provided in plurality, and the detection paths are connected in parallel and are respectively connected to the vehicle-mounted battery control unit via the dry contact output terminals.

[0015] Furthermore, the detection path is provided with a corresponding plurality of dry contact output terminals, all of which are connected to the vehicle-mounted battery control unit.

[0016] The present invention also provides a method for early warning based on battery housing deformation detection. Based on the above device, the method includes:

[0017] S1: The vehicle-mounted battery control unit obtains the loop electrical signal of each detection path in real time to determine the on / off state of the detection path;

[0018] S2: If the vehicle-mounted battery control unit can receive the loop electrical signal of the detection path, it is determined that the battery is normal, and each unit of the vehicle-mounted battery control unit outputs a normal signal;

[0019] S3: If the vehicle-mounted battery control unit fails to receive the loop electrical signal of the detection path, it determines that the battery is abnormal, the battery cluster management unit controls the disconnection of the high-voltage box contactor of the cluster, and the battery system management unit outputs an alarm signal.

[0020] Furthermore, after step S3, it also includes judging whether the temperature detection unit outputs an alarm signal. If the temperature detection unit and the battery system management unit output an alarm signal at the same time, the battery system management unit controls to disconnect the stack switch.

[0021] The beneficial effects of the present invention are as follows:

[0022] The present invention uses a material that is sensitive to external deformation to wrap the exterior of an electrochemical energy storage battery. When the battery exterior is deformed, the pressure-sensitive material will break, causing a circuit to be broken. This allows detection and early warning based on the deformation of the battery exterior. At the same time, the battery control system can control the execution of corresponding actions to ensure vehicle safety and reduce the possibility of thermal runaway of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the detection path and the battery of the present invention.

[0024] Figure 2 It is a logical flow chart of the method of the present invention.

[0025] Explanation of the reference numerals: 1-detection circuit, 2-fixing clamp, 3-dry contact output terminal. DETAILED DESCRIPTION

[0026] The following description clearly and completely describes the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the embodiments of the present invention, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the invention product is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship in which the invention product is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0028] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Example 1

[0030] Embodiment 1 of the present invention discloses a device for early warning based on battery shell deformation detection, such as Figure 1 As shown, the details are as follows:

[0031] The device includes a detection path and an on-board battery control unit;

[0032] The vehicle-mounted battery control unit includes a battery management unit BMU, a battery cluster management unit BCU and a battery system management unit BAU;

[0033] The detection path surrounds the battery, and is provided with a dry contact output terminal 3 , through which the detection path is connected to the vehicle-mounted battery control unit.

[0034] As a preferred embodiment, the detection path uses copper wire to surround the battery to form an electrical signal path;

[0035] Specifically, the cross-sectional area of ​​the copper wire can be designed according to the Young's modulus, as described below:

[0036] When an elastic material is subjected to normal stress, it will produce normal strain, which is defined as the ratio of normal stress to normal strain, as follows:

[0037] If F is different, the strain length ε=σ / E is different, that is, the elongation of the wire is different;

[0038] E represents Young's modulus. Metal wires of the same material have the same elastic modulus and E.

[0039] σ represents normal stress, which is the force per unit area (F / S);

[0040] ε represents the positive strain, which refers to the relative deformation (relative elongation DL / L) under the action of external force. It reflects the magnitude of the deformation of the object.

[0041] Based on the above Young's modulus theory, the allowable variable length of the copper wire can be calculated by the metal elongation: ε = (L-Lo) / Lo;

[0042] Lo is the original length, and L is the length after deformation;

[0043] Copper wire stress can be calculated based on stress σ = F / A;

[0044] F: external loading force;

[0045] A: cross-sectional area of ​​the wire;

[0046] It can be deduced that E = (F*Lo) / {A*(L-Lo)}, where E is a constant. It can be seen that when L, Lo, and A are constant, F will also be constant.

[0047] Through simulation and experimental data, the displacement distance of the battery pack during actual operation can be calculated, and the cross-sectional area of ​​the copper wire can be confirmed by the formula E=(F*Lo) / {A*(L-Lo)}.

[0048] As a preferred embodiment, the copper wire constituting the detection path may be wrapped with an insulating material or the detection path may be buried in the battery aluminum shell;

[0049] Specifically, the insulating material may be made of PC, rubber and the like.

[0050] As a preferred embodiment, the device further comprises a fixing clamp 2, through which the dry contact output terminal 3 is fixed to the battery.

[0051] As a preferred embodiment, in this embodiment, a plurality of detection paths are provided, and the detection paths are connected in parallel and are respectively connected to the vehicle-mounted battery control unit through the dry contact output terminal 3 .

[0052] Specifically, the number of dry contact output terminals 3 can be reserved according to demand, thereby reducing the possibility of false alarms.

[0053] By setting up multiple detection paths in parallel, the accuracy of battery deformation detection is ensured to avoid false alarms.

[0054] Based on the device described above, in daily operation, when the battery bulges due to aging or the battery deforms due to sudden thermal aging, the on-board battery control unit performs a logical judgment based on the uploaded dry contact on-off status. The operation and maintenance personnel then make a comprehensive judgment based on the battery operating temperature, current, voltage, etc. at the time, and replace the battery P pack that may have thermal failure and return it to the factory, thereby reducing the possibility of battery thermal failure at the source.

[0055] Example 2

[0056] Embodiment 1 of the present invention discloses a device for early warning based on battery shell deformation detection, such as Figure 1 As shown, the details are as follows:

[0057] The device includes a detection path and an on-board battery control unit;

[0058] The vehicle-mounted battery control unit includes a battery management unit BMU, a battery cluster management unit BCU and a battery system management unit BAU;

[0059] The detection path surrounds the battery, and is provided with a dry contact output terminal 3 , through which the detection path is connected to the vehicle-mounted battery control unit.

[0060] As a preferred embodiment, the detection path uses copper wire to surround the battery to form an electrical signal path;

[0061] Specifically, the cross-sectional area of ​​the copper wire can be designed according to the Young's modulus, as described below:

[0062] When an elastic material is subjected to normal stress, it will produce normal strain, which is defined as the ratio of normal stress to normal strain, as follows:

[0063] If F is different, the strain length ε=σ / E is different, that is, the elongation of the wire is different;

[0064] E represents Young's modulus. Metal wires of the same material have the same elastic modulus and E.

[0065] σ represents normal stress, which is the force per unit area (F / S);

[0066] ε represents the positive strain, which refers to the relative deformation (relative elongation DL / L) under the action of external force. It reflects the magnitude of the deformation of the object.

[0067] Based on the above Young's modulus theory, the allowable variable length of the copper wire can be calculated by the metal elongation: ε = (L-Lo) / Lo;

[0068] Lo is the original length, and L is the length after deformation;

[0069] Copper wire stress can be calculated based on stress σ = F / A;

[0070] F: external loading force;

[0071] A: cross-sectional area of ​​the wire;

[0072] It can be deduced that E = (F*Lo) / {A*(L-Lo)}, where E is a constant. It can be seen that when L, Lo, and A are constant, F will also be constant.

[0073] Through simulation and experimental data, the displacement distance of the battery pack during actual operation can be calculated, and the cross-sectional area of ​​the copper wire can be confirmed by the formula E=(F*Lo) / {A*(L-Lo)}.

[0074] As a preferred embodiment, the copper wire constituting the detection path may be wrapped with an insulating material or the detection path may be buried in the battery aluminum shell;

[0075] Specifically, the insulating material may be made of PC, rubber and the like.

[0076] As a preferred embodiment, the device further comprises a fixing clamp 2, through which the dry contact output terminal 3 is fixed to the battery.

[0077] As a preferred embodiment, the detection path is provided with a corresponding plurality of dry contact output terminals 3 , all of which are connected to the vehicle-mounted battery control unit.

[0078] Based on the device described above, in daily operation, when the battery bulges due to aging or the battery deforms due to sudden thermal aging, the on-board battery control unit performs a logical judgment based on the uploaded dry contact on-off status. The operation and maintenance personnel then make a comprehensive judgment based on the battery operating temperature, current, voltage, etc. at the time, and replace the battery P pack that may have thermal failure and return it to the factory, thereby reducing the possibility of battery thermal failure at the source.

[0079] Example 3

[0080] Embodiment 3 of the present invention discloses a method for early warning based on battery housing deformation detection based on the above-mentioned embodiment 1 or 2, such as Figure 2 As shown, the specific steps are as follows:

[0081] The vehicle-mounted battery control unit obtains the loop electrical signal of each detection path in real time to determine whether the detection path is on or off;

[0082] If the vehicle-mounted battery control unit can receive the loop electrical signal of the detection path, it is determined that the battery is normal, and each unit of the vehicle-mounted battery control unit outputs a normal signal;

[0083] Specifically, after the BMU receives the loop electrical signal of the detection path, it feeds back the on-board intelligent system to output the BMU normal signal and sends a normal signal to the BCU at the same time. After the BCU receives the normal signal, it feeds back the on-board intelligent system to output the BCU normal signal and sends a normal signal to the BAU at the same time. After the BAU receives the normal signal, it feeds back the on-board intelligent system to output the BAU normal signal.

[0084] If the vehicle-mounted battery control unit fails to receive the loop electrical signal of the detection path, it determines that the battery is abnormal, the battery cluster management unit controls the disconnection of the high-voltage box contactor of the cluster, and the battery system management unit outputs an alarm signal.

[0085] Specifically, the BMU does not receive the loop electrical signal of the detection path, and feeds back the on-board intelligent system to output the BMU abnormal signal, and sends an abnormal signal to the BCU at the same time. After receiving the abnormal signal, the BCU controls the disconnection of the high-voltage box contactor of this cluster, and feeds back the on-board intelligent system to output the BCU abnormal signal, and sends an abnormal signal to the BAU at the same time. After receiving the abnormal signal, the BAU feeds back the on-board intelligent system to output the BAU abnormal signal, and monitors whether the temperature detection unit of the on-board intelligent system outputs an alarm signal.

[0086] Specifically, according to actual needs, only one set of detection paths or multiple sets of detection paths can be disconnected at the same time to determine that the battery is abnormal.

[0087] When a battery abnormality is detected, it also includes determining whether the temperature detection unit of the on-board intelligent system outputs an alarm signal. If the temperature detection unit and the battery system management unit output alarm signals at the same time, the battery system management unit controls the disconnection of the stack switch and drives the on-board intelligent system to perform corresponding emergency actions through different control strategies, such as cutting off the power supply circuit, which can reduce the possibility of fire. Abnormal batteries can be inspected and replaced by operation and maintenance personnel.

[0088] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A device for early warning based on battery shell deformation detection, characterized in that: Including detection pathway and on-board battery control unit; The vehicle-mounted battery control unit includes a battery management unit, a battery cluster management unit and a battery system management unit; The detection path surrounds the battery, and is provided with a dry contact output terminal, and is connected to the vehicle-mounted battery control unit via the dry contact output terminal.

2. The device for early warning based on battery casing deformation detection according to claim 1 is characterized in that: The detection path uses copper wire to surround the battery to form an electrical signal path.

3. The device for early warning based on battery shell deformation detection according to claim 2 is characterized in that: The copper wire constituting the detection path is wrapped with insulating material.

4. The device for early warning based on battery shell deformation detection according to claim 2 is characterized in that: The detection path is buried in the battery aluminum shell.

5. The device for early warning based on battery shell deformation detection according to claim 1 is characterized in that: The device also includes a fixing clamp, through which the dry contact output terminal is fixed on the battery.

6. The device for early warning based on battery shell deformation detection according to claim 1 is characterized in that: There are multiple detection paths, each detection path is connected in parallel and is connected to the vehicle-mounted battery control unit through the dry contact output terminal.

7. The device for early warning based on battery shell deformation detection according to claim 1 is characterized in that: The detection path is provided with a plurality of corresponding dry contact output terminals, all of which are connected to the vehicle-mounted battery control unit.

8. A method for early warning based on battery shell deformation detection, characterized in that: Based on the device for early warning based on battery casing deformation detection according to any one of claims 1 to 7, the method comprises: S1: The vehicle-mounted battery control unit obtains the loop electrical signal of each detection path in real time to determine the on / off state of the detection path; S2: If the vehicle-mounted battery control unit can receive the loop electrical signal of the detection path, it is determined that the battery is normal, and each unit of the vehicle-mounted battery control unit outputs a normal signal; S3: If the vehicle-mounted battery control unit fails to receive the loop electrical signal of the detection path, it determines that the battery is abnormal, the battery cluster management unit controls the disconnection of the high-voltage box contactor of the cluster, and the battery system management unit outputs an alarm signal.

9. The method for early warning based on battery casing deformation detection according to claim 8 is characterized in that: After step S3, the method further includes determining whether the temperature detection unit outputs an alarm signal. If the temperature detection unit and the battery system management unit output an alarm signal at the same time, the battery system management unit controls the stack switch to be disconnected.

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