Short-circuit protection circuit of battery pack, battery pack, management system of battery pack and electric equipment

Abstract

The utility model discloses a short-circuit protection circuit of a battery pack, the battery pack, a management system of the battery pack and electric equipment. The protection circuit comprises at least one of a first short-circuit protection module, a second short-circuit protection module, a third short-circuit protection module and a fourth short-circuit protection module, wherein the first short-circuit protection module, the second short-circuit protection module, the third short-circuit protection module and the fourth short-circuit protection module are respectively used for being connected with a battery pack in series to form a charging and discharging loop; the first short-circuit protection module is used for cutting off the charging and discharging loop when the battery pack is short-circuited; at least one of the first short-circuit protection module, the second short-circuit protection module, the third short-circuit protection module and the fourth short-circuit protection module is used for cutting off a charging and discharging loop when the whole battery pack is short-circuited; and the third short-circuit protection module or / and the fourth short-circuit protection module is / are used for cutting off the charging and discharging loop when the electric equipment corresponding to the battery pack or the battery pack management system fails. And the short-circuit protection reliability of the battery pack can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and in particular relates to a short-circuit protection circuit of a battery pack, a battery pack and a management system thereof, and electrical equipment. Background Art

[0002] Existing battery pack short-circuit protection circuits generally use MOS tubes (Metal-Oxide Semiconductor Field-Effect Transistors, Metal-Oxide Semiconductor FET, MOSFET). The upper limit of the short-circuit protection current of MOS tubes is small, within 1500A. When the short-circuit current exceeds 1500A, it cannot provide protection. The MOS tube fails by breakdown, that is, the high-voltage circuit is the pathway, which poses the risk of insulation electric shock to the battery system and makes the battery unrepairable and unusable. In addition, when the battery pack itself short-circuits, the existing protection circuit cannot provide protection. Finally, the existing protection circuit has a single protection method and a low functional safety level. Utility Model Content

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a short-circuit protection circuit for a battery pack, a battery pack and its management system, and an electrical device.

[0004] In a first aspect of the present invention, a short-circuit protection circuit for a battery pack is provided, comprising: at least one short-circuit protection module among a first short-circuit protection module, a second short-circuit protection module, a third short-circuit protection module, and a fourth short-circuit protection module, wherein the first short-circuit protection module, the second short-circuit protection module, the third short-circuit protection module, and the fourth short-circuit protection module are respectively configured to be connected in series with a battery pack to form a charge-discharge circuit;

[0005] Among them, the first short-circuit protection module is used to cut off the charge and discharge circuit when a short circuit occurs in the battery pack itself; at least one short-circuit protection module among the first short-circuit protection module, the second short-circuit protection module, the third short-circuit protection module and the fourth short-circuit protection module is used to cut off the charge and discharge circuit when a short circuit occurs in the battery pack as a whole, and the third short-circuit protection module and / or the fourth short-circuit protection module are also used to cut off the charge and discharge circuit when the electrical equipment corresponding to the battery pack or the battery pack management system fails.

[0006] In addition, the short-circuit protection circuit of the battery pack of the present invention may also have the following additional technical features:

[0007] Preferably, the first short-circuit protection module comprises a first narrow-diameter metal member and a second narrow-diameter metal member, wherein the first narrow-diameter metal member and the second narrow-diameter metal member are electrically connected to the positive electrode and the negative electrode of the battery pack and / or the battery modules constituting the battery pack, respectively;

[0008] The first narrow-diameter metal piece and the second narrow-diameter metal piece each include a first metal segment and a second metal segment connected, and a flow area at the connection between the first metal segment and the second metal segment is smaller than a flow area of ​​the first metal segment and smaller than a flow area of ​​the second metal segment.

[0009] Preferably, the width of the first metal segment and the second metal segment at the connection point is smaller than the width of the first metal segment, and smaller than the width of the second metal segment.

[0010] Preferably, the first metal segment is provided with a tab welding hole extending in the length direction, and a plurality of via holes are provided in the width direction at the connection between the first metal segment and the second metal segment.

[0011] Preferably, the second short-circuit protection module includes a fuse, and the fuse is connected in series with the positive electrode or the negative electrode of the battery pack.

[0012] Preferably, the third short-circuit protection module includes a first charge and discharge unit, which is connected in series with the positive electrode or the negative electrode of the battery pack, and includes a discharge switch tube and a charge switch tube connected in series.

[0013] Preferably, the discharge switch tube is a first N-type MOS tube, and the charge switch tube is a second N-type MOS tube. The source of the first N-type MOS tube is connected to the positive electrode of the battery pack, the drain of the first N-type MOS tube is connected to the drain of the second N-type MOS tube, and a first body diode is connected between the source and drain of the first N-type MOS tube.

[0014] The source of the second N-type MOS transistor is connected to the load, the gate of the second N-type MOS transistor and the gate of the first N-type MOS transistor are both connected to the controller, and a second body diode is connected between the source and drain of the second N-type MOS transistor.

[0015] Preferably, the third short-circuit protection module also includes a second charge and discharge unit, which is connected in parallel with the first charge and discharge unit. The second charge and discharge unit includes a first resistor and a P-type MOS tube connected in series, wherein a third body diode is connected between the source and drain of the P-type MOS tube.

[0016] Preferably, the second charge and discharge unit further includes an anti-reverse diode, the positive terminal of the anti-reverse diode is connected to the P-type MOS tube, and the negative terminal of the anti-reverse diode is connected to the load.

[0017] Preferably, the fourth short-circuit protection module includes a first fuse and / or a second fuse, wherein the first fuse and the second fuse are connected in parallel to form a first parallel circuit, and the first parallel circuit is connected in series with the positive electrode or the negative electrode of the battery pack.

[0018] Preferably, the first fuse is a two-terminal fuse, and the second fuse is a three-terminal fuse.

[0019] Preferably, the short-circuit protection circuit also includes a current detection module and a controller, the current detection module is used to detect the current information of the charging and discharging circuit, the signal output end of the current detection module is electrically connected to the signal input end of the controller, and the signal output end of the controller is electrically connected to the third short-circuit protection module and the fourth short-circuit protection module respectively.

[0020] Preferably, the current detection module includes a first current acquisition unit and / or a second current acquisition unit, wherein the first current acquisition unit and the second current acquisition unit are connected in series;

[0021] The first current acquisition unit includes a first sampling resistor and an AFE chip connected in parallel; the second current acquisition unit includes a second sampling resistor and an OPA chip connected in parallel.

[0022] A second aspect of the present invention provides a battery pack, comprising the short-circuit protection circuit of the battery pack described in any embodiment of the present application.

[0023] A third aspect of the present invention provides a battery pack management system, comprising the battery pack and a load as described in any embodiment of the present application, wherein the short-circuit protection circuit is connected in series with the load to form a charge and discharge loop.

[0024] The fourth aspect of the present invention provides an electrical device, which includes the short-circuit protection circuit of the battery pack described in any embodiment of the present application, or includes the battery pack of any embodiment of the present application, or includes the battery pack management system of any embodiment of the present application.

[0025] According to the short-circuit protection circuit of the battery pack, the battery pack and its management system, and the electrical equipment provided by the utility model, the short-circuit protection circuit of the battery pack, the first short-circuit protection module, the second short-circuit protection module, the third short-circuit protection module and the fourth short-circuit protection module serve as independent short-circuit protection modes or multiple combined short-circuit protection modes, which improve the safety level of the battery pack short-circuit protection and further improve the safety of the battery pack; and can achieve full current protection, from the minimum fault current to the maximum short-circuit current (500A~10KA), all can be protected, with the characteristics of good stability, strong reliability, comprehensiveness, and a wide range of protection current, and can be used for short-circuit protection of electrical equipment such as electric motorcycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 A schematic diagram of a short-circuit protection circuit for a battery pack provided in an embodiment of the present application;

[0028] Figure 2 A structural diagram of a battery pack in which a short-circuit protection circuit provided in an embodiment of the present application is applied;

[0029] Figure 3 for Figure 2 Installation position diagram of the first narrow diameter metal member and the second narrow diameter metal member;

[0030] Figure 4 for Figure 3 The first narrow diameter metal part structure diagram;

[0031] Figure 5 for Figure 4 Schematic diagram of the fusing principle of the first narrow diameter metal part;

[0032] Figure 6 A structural diagram of a fuse provided in an embodiment of the present application;

[0033] Figure 7 A schematic diagram of a short-circuit protection circuit for a battery pack provided in an embodiment of the present application;

[0034] Figure 8 for Figure 7 A parallel circuit diagram of the first charge and discharge unit and the second charge and discharge unit;

[0035] Figure 9 A diagram showing the installation positions of the first N-type MOS transistor and the second N-type MOS transistor on the protection board provided in an embodiment of the present application;

[0036] Figure 10 A diagram showing the installation position of a three-terminal fuse on a protection board provided in an embodiment of the present application;

[0037] Figure 11 for Figure 10 The three-terminal fuse structure diagram in Figure 1;

[0038] Figure 12 A flowchart of a short-circuit protection method for a battery pack provided in an embodiment of the present application.

[0039] In the above picture:

[0040] 10 battery pack; 11 battery group; 111 battery module; 12 connecting copper busbar;

[0041] 20 first short-circuit protection module; 21 first narrow-diameter metal member; 210 first metal segment; 211 tab welding hole; 220 second metal segment; 221 via; 22 second narrow-diameter metal member;

[0042] 30 fuses;

[0043] 40 third short-circuit protection module; 41 first charge and discharge unit; 410 discharge switch tube; 4101 first N-type MOS tube; 4102 first body diode; 420 charge switch tube; 4201 second N-type MOS tube; 4202 second body diode;

[0044] 42 second charge and discharge unit; 421 first resistor; 422 P-type MOS tube; 423 third body diode; 424 anti-reverse diode;

[0045] 50 fourth short circuit protection module; 51 first fuse; 52 second fuse;

[0046] 60 current detection module; 61 first current acquisition unit; 611 first sampling resistor; 612 AFE chip; 62 second current acquisition unit; 621 second sampling resistor; 622 OPA chip;

[0047] 70 controller; 80 positive high-voltage connector; 81 negative high-voltage connector; 90 load; 100 protection board; 110 heating control module. DETAILED DESCRIPTION

[0048] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant utility model and are not intended to limit the utility model. It should also be noted that, for ease of description, only portions relevant to the utility model are shown in the accompanying drawings.

[0049] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0050] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a," "the," and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

[0051] Unless the context requires otherwise, throughout the specification and claims, the term "comprising" is to be construed in an open, inclusive sense, that is, meaning "including, but not limited to."

[0052] Throughout the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the present disclosure. Schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be included in any one or more embodiments or examples in any appropriate manner.

[0053] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0054] Currently, electric vehicles, such as electric motorcycles, are increasingly being accepted by users and the public. Electric motorcycle owners are increasingly demanding long-range driving and high-rate charging and discharging. This has put forward design requirements for high voltage, large capacity, and high-current charging and discharging for the core power source of electric motorcycles, such as battery packs. Compared with conventional current charging and discharging on traditional voltage platforms, the safety requirements for electric motorcycle battery packs have increased exponentially, mainly in four categories: electrical safety, short-circuit protection safety, mechanical safety, and thermal safety. Among them, short-circuit protection safety is particularly important. Due to the increase in charging and discharging capacity, large currents are used for charging and discharging, so the internal resistance of the battery cell needs to be reduced proportionally. At the same time, as the voltage platform increases, according to Ohm's law, when high voltage and low resistance are present, the short-circuit current increases exponentially. Therefore, studying how to increase the short-circuit protection capability of the battery pack is an important topic. It needs to have the characteristics of high efficiency, strong reliability, and full current protection to comprehensively guarantee the short-circuit protection safety of electric motorcycles.

[0055] The existing solution uses the hardware tolerance of the MOS tube on the battery management system protection board to provide protection. The main disadvantages of this solution are: first, the current upper limit of the short-circuit protection is small, usually within 1500A, and it cannot protect against currents above 1500A. That is, when the short-circuit current is greater than 1500A, the existing protection board cannot provide protection, and the MOS tube fails by breakdown, that is, the high-voltage circuit is the pathway, which puts the battery system at risk of insulation electric shock and the battery cannot be repaired and used; second, when the battery pack 11 itself is short-circuited, the existing protection board cannot provide protection; third, the protection method of the existing protection board is single and the functional safety level is low.

[0056] To solve the above problems, refer to Figure 1 According to a first aspect of an embodiment of the present application, a short-circuit protection circuit for a battery pack is provided, comprising:

[0057] At least one short-circuit protection module among the first short-circuit protection module 20, the second short-circuit protection module, the third short-circuit protection module 40 and the fourth short-circuit protection module 50, wherein the first short-circuit protection module 20, the second short-circuit protection module, the third short-circuit protection module 40 and the fourth short-circuit protection module 50 are respectively used to be connected in series with the battery pack 11 to form a charge and discharge circuit;

[0058] Among them, the first short-circuit protection module 20 is used to cut off the charging and discharging circuit when a short circuit occurs in the battery pack 11 itself; at least one short-circuit protection module among the first short-circuit protection module 20, the second short-circuit protection module, the third short-circuit protection module 40 and the fourth short-circuit protection module 50 is used to cut off the charging and discharging circuit when a short circuit occurs in the battery pack as a whole, and the third short-circuit protection module 40 and / or the fourth short-circuit protection module 50 are also used to cut off the charging and discharging circuit when the electrical equipment corresponding to the battery pack or the battery pack management system fails.

[0059] Specifically, the battery pack 10 generally includes one or more battery packs 11 and related electrical components. The battery pack 11 includes one or more battery membrane blocks, which can be formed by connecting different types of battery modules 111 through connecting copper bars 12. The battery module 111 is formed by connecting multiple battery cells in series or in parallel. For example, Figure 2 As shown, the battery pack 10 includes a plurality of battery packs 11 of different shapes, two of which are identical in size, while the other two differ in size. Each battery pack 11 has a positive electrode and a negative electrode, and the battery modules 111 comprising each battery pack 11 also have positive and negative electrodes, enabling both charging and discharging. At least one of the first short-circuit protection module 20, the second short-circuit protection module, the third short-circuit protection module 40, and the fourth short-circuit protection module 50 is connected in series with the positive or negative electrode of the battery pack 11 to form a charge-discharge circuit.

[0060] In one example, the charge and discharge circuit refers to a positive high-voltage connector connected to the positive pole of the battery pack 11, and a negative high-voltage connector connected to the negative pole of the battery pack 11, thereby forming a charge and discharge circuit. The charge and discharge circuit is connected in series with a first short-circuit protection module, which can be used for automatic triggering protection when the battery pack 11 itself is short-circuited.

[0061] In another example, a charge-discharge circuit is formed by connecting the positive electrode of the battery pack 11 to a positive high-voltage connector, which is connected to a load, and the negative electrode of the battery pack 11 to a negative high-voltage connector, which is connected to a load. In this charge-discharge circuit, the first short-circuit protection module 20, the second short-circuit protection module, the third short-circuit protection module 40, and the fourth short-circuit protection module 50 are connected in series. The load 90 refers to an electronic device or equipment connected to the output terminal of the battery pack 10, which consumes the power provided by the battery pack 10.

[0062] A short circuit in the battery pack 11 itself usually refers to a short circuit caused by problems with the battery module 111 or the battery cell inside the battery pack 11, affecting a local area inside the battery pack 11. For example, damage to the diaphragm between the battery cells, electrolyte leakage, contact between the positive and negative electrodes, etc. can cause a short circuit in the battery module itself. In addition, overcharging, over-discharging, high temperature or improper use may also cause a short circuit in the battery pack 11 itself.

[0063] A short circuit in the battery pack as a whole refers to a short circuit caused by a failure of any device in the charge and discharge circuit formed by the battery pack 11, which affects the performance and safety of the entire battery pack 10. It is usually caused by a failure in the circuit design, connection or external system of the battery pack. For example, a power supply failure, line overload, short circuit or incorrect device connection may cause a short circuit in the battery pack as a whole.

[0064] The main causes of battery management system (BMS) failures include hardware failure, software failure, and external factors. Hardware failure is the most common type of BMS failure, and includes sensor failure, controller failure, and communication failure. Sensor failure can prevent the BMS from accurately acquiring battery status, controller failure can affect the battery's charge and discharge process, and communication failure can prevent the BMS from receiving or sending correct information. Software failures include program errors, improper parameter settings, and data loss. Program errors can cause abnormal system operation, improper parameter settings can cause battery overcharging, over-discharging, or overheating, and data loss can affect fault diagnosis and life prediction. External factors such as ambient temperature, humidity, and electromagnetic interference can also affect BMS performance.

[0065] The failure of the electric equipment corresponding to the battery pack refers to a collision of the electric equipment, for example, if the vehicle corresponding to the battery pack 10 collides, the displacement sensor on the vehicle is used to detect whether the vehicle has collided.

[0066] The short circuit protection circuit of the battery pack provided in the embodiment of the present application includes at least one short circuit protection module among a first short circuit protection module 20 , a second short circuit protection module, a third short circuit protection module 40 and a fourth short circuit protection module 50 .

[0067] Exemplarily, if only one short-circuit protection module is included, the first short-circuit protection module 20, the second short-circuit protection module, the third short-circuit protection module 40 and the fourth short-circuit protection module 50 are respectively connected in series with the battery pack 11 as independent short-circuit protection modules to form a charge and discharge circuit. The first short-circuit protection module 20, the second short-circuit protection module, the third short-circuit protection module 40 and the fourth short-circuit protection module 50 are respectively used as four basic battery pack short-circuit protection modes, which together constitute the short-circuit protection strategy of the battery pack of the present application. Among them, each short-circuit protection module can be connected in series with the positive or negative pole of the battery pack 11. Being connected in series with the positive pole of the battery pack 11 means that each short-circuit protection module is connected in series between the positive pole of the battery pack 11 and the load 90. Being connected in series with the negative pole of the battery pack 11 means that each short-circuit protection module is connected in series between the negative pole of the battery pack 11 and the load 90. The principle of subsequent connection with the positive or negative pole of the battery pack 11 is the same as this, and the embodiments of the present application will not be repeated.

[0068] Exemplarily, if two short-circuit protection modules are included, the two short-circuit protection modules are connected in series and are respectively connected in series with the battery pack 11 and the load 90 to form a charge and discharge loop, wherein the two short-circuit protection modules can be both connected in series with the positive electrode of the battery pack 11, or both connected in series with the negative electrode of the battery pack 11, or one is connected in series with the positive electrode of the battery pack 11 and the other is connected in series with the negative electrode of the battery pack 11. For example, the two short-circuit protection modules are: the first short-circuit protection module 20 and the second short-circuit protection module, the first short-circuit protection module 20 and the third short-circuit protection module 40, the first short-circuit protection module 20 and the fourth short-circuit protection module 50, the second short-circuit protection module and the third short-circuit protection module 40, the second short-circuit protection module and the fourth short-circuit protection module 50, and the third short-circuit protection module 40 and the fourth short-circuit protection module 50. In this example, the protection can be completed by triggering any one of the two short-circuit protection modules, thereby improving the efficiency, safety and reliability of the short-circuit protection of the battery pack 10.

[0069] For example, if three short-circuit protection modules are included, the three short-circuit protection modules are connected in series and are respectively connected in series with the battery pack 11 and the load 90 to form a charge and discharge circuit. The three short-circuit protection modules can all be connected in series with the positive electrode of the battery pack 11, or all be connected in series with the negative electrode of the battery pack 11, or some are connected in series with the positive electrode of the battery pack 11 and the remaining parts are connected in series with the negative electrode of the battery pack 11. For example, the three short-circuit protection modules are: the first short-circuit protection module 20, the second short-circuit protection module and the third short-circuit protection module 40, the first short-circuit protection module 20, the second short-circuit protection module and the fourth short-circuit protection module 50, the first short-circuit protection module 20, the third short-circuit protection module 40 and the fourth short-circuit protection module 50, the second short-circuit protection module, the third short-circuit protection module 40 and the fourth short-circuit protection module 50. In this example, the protection can be completed by triggering any one of the three short-circuit protection modules, thereby improving the efficiency, safety and reliability of the short-circuit protection of the battery pack 10.

[0070] For example, if four short-circuit protection modules are included, the four short-circuit protection modules are connected in series and are respectively connected in series with the battery pack 11 and the load 90 to form a charge and discharge loop. The four short-circuit protection modules can all be connected in series with the positive electrode of the battery pack 11, or all be connected in series with the negative electrode of the battery pack 11, or some are connected in series with the positive electrode of the battery pack 11 and the remaining parts are connected in series with the negative electrode of the battery pack 11. The four short-circuit protection modules are respectively a first short-circuit protection module 20, a second short-circuit protection module, a third short-circuit protection module 40 and a fourth short-circuit protection module 50. In this example, the protection can be completed by triggering any one of the four short-circuit protection modules, thereby improving the efficiency, safety and reliability of the short-circuit protection of the battery pack 10.

[0071] In the embodiment of the present application, the first short-circuit protection module 20, the second short-circuit protection module, the third short-circuit protection module 40 and the fourth short-circuit protection module 50 serve as independent short-circuit protection modes or multiple combined short-circuit protection modes, thereby improving the safety level of the short-circuit protection of the battery pack 10 and further improving the safety of the battery pack 10.

[0072] In some embodiments, reference Figures 2 to 4 The first short circuit protection module 20 includes a first narrow diameter metal member 21 and a second narrow diameter metal member 22, and the first narrow diameter metal member 21 and the second narrow diameter metal member 22 are electrically connected to the positive electrode and the negative electrode of the battery pack 11 and / or the battery module 111 constituting the battery pack 11 respectively; it should be understood that, if Figure 4 As shown, the battery modules 111 constituting the battery pack 11 may also have a positive electrode and a negative electrode, so that the first narrow-diameter metal member 21 and the second narrow-diameter metal member 22 are electrically connected to the positive electrode and the negative electrode of the battery module 111, respectively. That is, a plurality of first narrow-diameter metal members 21 and second narrow-diameter metal members 22 may be provided in the battery pack 11, so as to form a corresponding first short-circuit protection module 20 at the positive electrode and the negative electrode of each battery module 111, that is, the number of the first short-circuit protection modules 20 is less than or equal to the number of the battery modules 111 included in the battery pack 11;

[0073] The first narrow-diameter metal member 21 and the second narrow-diameter metal member 22 both include a first metal segment 210 and a second metal segment 220 that are bent and connected. The width of the first metal segment 210 and the second metal segment 220 at the connection is smaller than the width of the first metal segment 210 and smaller than the width of the second metal segment 220. The purpose of this setting is to ensure that the flow area at the connection between the first metal segment 210 and the second metal segment 220 is smaller than the width of the first metal segment 210 and smaller than the flow area of ​​the second metal segment 220.

[0074] Specifically, the first narrow-diameter metal member 21 is electrically connected to the positive electrode of the battery pack 11, and the second narrow-diameter metal member 22 is electrically connected to the negative electrode of the battery pack 11. The first narrow-diameter metal member 21 and the second narrow-diameter metal member 22 have the same structure. Exemplarily, the first narrow-diameter metal member 21 and the second narrow-diameter metal member 22 can be narrow-diameter copper bars or narrow-diameter aluminum bars, preferably narrow-diameter copper bars. The narrow-diameter copper bar includes a first metal segment 210 and a second metal segment 220 connected by a bend. The first metal segment 210 and the second metal segment 220 can be integrally formed. The width of the first metal segment 210 and the second metal segment 220 at the connection is smaller than the width of the first metal segment 210 and smaller than the width of the second metal segment 220, so that the narrow-diameter copper bar forms a narrow diameter at the connection between the first metal segment 210 and the second metal segment 220. When the current is overloaded, the narrow diameter of the narrow-diameter copper bar will be deformed by high temperature and melted. At this time, the fuse is the position where the narrow-diameter copper bar terminates the current. The first metal segment 210 serves as the current overcurrent zone, and the connection between the first metal segment 210 and the second metal segment 220 serves as the fuse zone. A stud is further provided at the end of the second metal segment 220 away from the first metal segment 210. The stud can pass through the connecting copper busbar 12 on the battery pack 11 and be screwed together with bolts. In other words, the first narrow-diameter metal member 21 and the second narrow-diameter metal member 22 are both detachably connected to the connecting copper busbar 12 via the stud and bolts. The battery cells in the battery pack 11 have positive and negative tabs. The positive tab can pass through the tab welding hole 211 on the first narrow-diameter metal member 21 and be welded to the first narrow-diameter metal member 21. The negative tab can pass through the tab welding hole 211 on the second narrow-diameter metal member 22 and be welded to the second narrow-diameter metal member 22, acting as a busbar.

[0075] In this example, by providing narrow copper busbars at the positive and negative poles of the battery pack 11, a protective effect can be provided when a short circuit occurs in the battery pack 11 itself. When the short-circuit current of the battery pack 11 itself reaches 8000A, the narrow copper busbar is automatically triggered to fuse to cut off the charge and discharge circuit, thereby completing the short-circuit protection of the battery pack 11.

[0076] In some embodiments, reference Figure 4 The first metal segment 210 is provided with a tab welding hole 211 extending along the length direction, and a plurality of via holes 221 are provided along the width direction at the connection between the first metal segment 210 and the second metal segment 220.

[0077] Specifically, the tab welding hole 211 allows the first narrow-diameter metal part 21 and the second narrow-diameter metal part 22 to be used as a busbar, and the entire battery module 111 does not need to add additional connecting components. The narrow-diameter copper busbar is provided with at least one via 221 along the width direction at the narrow diameter. For example, as 2, 3, etc., the via 221 can be provided with a cross-sectional area at the narrow diameter. When the current is overloaded, the narrow diameter of the narrow-diameter copper busbar will be quickly melted due to high-temperature deformation, reducing the melting time, improving the melting efficiency of the narrow-diameter copper busbar, and thus improving the short-circuit protection efficiency of the first short-circuit protection module 20. Among them, the melting simulation test results of the narrow-diameter copper busbar are as follows: Figure 5 As shown in the figure, when the short-circuit current reaches 8000A, the narrow-diameter copper busbar can quickly fuse within 1s.

[0078] In some embodiments, reference Figure 1 、 Figure 2 and Figure 6 The second short-circuit protection module includes a fuse 30 , which is connected in series with the positive electrode or the negative electrode of the battery pack 11 .

[0079] Specifically, the fuse 30, as a thermal fuse, is a passive high-current fuse protection device. When a short-circuit current occurs in the charge-discharge circuit formed by the battery pack 11, the fuse 30 heats up to its melting point faster than it releases heat, quickly blocking the current. When the fuse 30 blows, the sand inside it acts as an arc extinguisher, absorbing energy to form lava, which then insulates the circuit from the load 90, eliminating the risk of electric shock. The fuse 30 is connected in series with the positive or negative electrode of the battery pack 11. Preferably, the fuse 30 is set at the positive electrode of the battery pack 11, that is, the fuse 30 is set between the positive electrode of the battery pack 11 and the load 90, which can protect the entire battery pack 10 from short circuits and meet the short-circuit protection requirements of the battery pack 10. When the short-circuit current ranges from 1500A to 10KA, the fuse 30 automatically melts to cut off the charge-discharge circuit and complete the short-circuit protection. The short-circuit current refers to the high-current pulse discharge generated by the external short circuit of the battery pack 11.

[0080] In some embodiments, reference Figure 1 The third short-circuit protection module 40 includes a first charge and discharge unit 41, which is connected in series with the positive electrode or the negative electrode of the battery pack 11. The first charge and discharge unit 41 includes a discharge switch tube 410 and a charge switch tube 420 connected in series.

[0081] Specifically, the charge-discharge circuit can be controlled by turning the first charge-discharge unit 41 on and off. When the entire battery pack short-circuits, or when a fault in an electrical device or the battery pack management system causes a short circuit, the first charge-discharge unit 41 is triggered to disconnect the charge-discharge circuit, providing short-circuit protection. The discharge switch 410 and the charge switch 420 can be connected in series to the positive or negative electrode of the battery pack 11. These switches control the direction of current flow in the charge-discharge circuit and its connection and disconnection.

[0082] It should be noted that the controller 70 can independently control the on / off switching of the discharge switch 410 and the charge switch 420. The charge-discharge circuit can only be disconnected when both the discharge switch 410 and the charge switch 420 are turned off. The charge-discharge circuit can be connected by turning on either switch. During the charging process, the charge switch 420 is in the on state and the discharge switch 410 is in the off state. However, the charging current can still flow through the first body diode 4102 within the discharge switch 410, thereby connecting the charging circuit. During the discharging process, the discharge switch 410 is in the on state and the charge switch 420 is in the off state. However, the discharge current can still flow through the second body diode 4202 within the charge switch 420, thereby connecting the discharge circuit.

[0083] In some embodiments, reference Figures 7 to 9 The discharging switch tube 410 is a first N-type MOS tube 4101, and the charging switch tube 420 is a second N-type MOS tube 4201. The source of the first N-type MOS tube 4101 is connected to the positive electrode of the battery pack 11, the drain of the first N-type MOS tube 4101 is connected to the drain of the second N-type MOS tube 4201, and a first body diode 4102 is connected between the source and drain of the first N-type MOS tube 4101.

[0084] The source of the second N-type MOS transistor 4201 is connected to the load 90 , the gate of the second N-type MOS transistor 4201 and the gate of the first N-type MOS transistor 4101 are both connected to the controller 70 , and a second body diode 4202 is connected between the source and drain of the second N-type MOS transistor 4201 .

[0085] Specifically, the first N-type MOS transistor 4101 and the second N-type MOS transistor 4201 can be disposed on the protection board 100 and connected in series to the positive or negative electrode of the battery pack 11 to provide active or passive protection against low short-circuit currents (500A to 1500A) in the battery pack 11, as well as active protection against failures in electrical equipment or the battery pack management system. The positive terminal of the first body diode 4102 is connected to the source of the first N-type MOS transistor 4101, and the negative terminal of the first body diode 4102 is connected to the drain of the first N-type MOS transistor 4101. The positive terminal of the second body diode 4202 is connected to the source of the second N-type MOS transistor 4201, and the negative terminal of the second body diode 4202 is connected to the drain of the second N-type MOS transistor 4201.

[0086] During the charging process, the second N-type MOS transistor 4201 is turned on and the first N-type MOS transistor 4101 is turned off. The charging current can flow through the first body diode 4102 and flow from the positive terminal to the negative terminal of the first body diode 4102, thereby achieving conduction of the charging circuit. During the discharging process, the first N-type MOS transistor 4101 is turned on and the second N-type MOS transistor 4201 is turned off. The discharging current can flow through the second body diode 4202 and flow from the positive terminal to the negative terminal of the second body diode 4202, thereby achieving conduction of the discharging circuit.

[0087] In this example, the controller 70 controls the on / off switching of the first N-type MOS transistor 4101 and the second N-type MOS transistor 4201 by controlling the gate signals of the first N-type MOS transistor 4101 and the second N-type MOS transistor 4201. The gates of the first N-type MOS transistor 4101 and the second N-type MOS transistor 4201 are both connected to the controller 70 via the AFE chip 612. The charge-discharge circuit can only be disconnected if both the first N-type MOS transistor 4101 and the second N-type MOS transistor 4201 are disconnected. Turning on either the first N-type MOS transistor 4101 or the second N-type MOS transistor 4201 can connect the charge-discharge circuit, thereby enabling charging and discharging operations of the battery pack 11.

[0088] On the one hand, the first charge and discharge unit 41 is used for active switching protection for small short-circuit currents when the entire battery pack is short-circuited. When the protection board 100 detects a current of 500A~1500A through the current detection unit, the protection board 100 controls the first N-type MOS tube 4101 and the second N-type MOS tube 4201 to fuse through software to complete short-circuit protection. On the other hand, when the electrical equipment or the battery pack management system fails and short-circuits, when the protection board 100 detects a thermal runaway or collision signal, the protection board 100 controls the first N-type MOS tube 4101 and the second N-type MOS tube 4201 to fuse through software to complete short-circuit protection.

[0089] In some embodiments, reference Figure 7 and Figure 8 The third short-circuit protection module 40 also includes a second charge and discharge unit 42, which is connected in parallel with the first charge and discharge unit 41. The second charge and discharge unit 42 includes a first resistor 421 and a P-type MOS transistor 422 connected in series, wherein a third body diode 423 is connected between the source and drain of the P-type MOS transistor 422.

[0090] Specifically, the positive electrode of the battery pack 11 is connected in series with the second charge and discharge unit 42, that is, the positive electrode of the battery pack 11 is connected in sequence to the first resistor 421 and the P-type MOS transistor 422. The second charge and discharge unit 42 is connected in parallel with the first charge and discharge unit 41, and the P-type MOS transistor 422 can control the conduction and disconnection of the second charge and discharge unit 42. When the second charge and discharge unit 42 is turned on, the first charge and discharge unit 41 is in the disconnected state, which can realize the pre-charge and pre-discharge operations of the battery pack 11, and avoid damage to the first N-type MOS transistor 4101 and the second N-type MOS transistor 4201 caused by excessive transient current. Among them, the resistance value of the first resistor 421 can be set according to actual needs and is not particularly limited in the embodiment of the present application.

[0091] It can be understood that if the third short-circuit protection module 40 includes a first charge and discharge unit 41 and a second charge and discharge unit 42, the first charge and discharge unit 41 and the second charge and discharge unit 42 must be disconnected to achieve the disconnection of the charge and discharge circuit; if the first charge and discharge unit 41 is turned on and the second charge and discharge unit 42 is disconnected, the battery pack 11 performs a formal charge and discharge operation; if the first charge and discharge unit 41 is disconnected and the second charge and discharge unit 42 is turned on, the battery pack 11 performs a pre-charge and discharge operation.

[0092] In some embodiments, reference Figure 7 and Figure 8 The second charge and discharge unit 42 further includes an anti-reverse diode 424 , the positive terminal of the anti-reverse diode 424 is connected to the P-type MOS tube 422 , and the negative terminal of the anti-reverse diode 424 is connected to the load 90 .

[0093] Specifically, the anti-reverse diode 424 is connected between the P-type MOS transistor 422 and the load 90 to control the direction of current flow and prevent the current from flowing in the reverse direction.

[0094] In some embodiments, reference Figure 1 and Figure 7 The fourth short-circuit protection module 50 includes a first fuse 51 and / or a second fuse 52, wherein the first fuse 51 and the second fuse 52 are connected in parallel to form a first parallel circuit, and the first parallel circuit is connected in series with the positive electrode or the negative electrode of the battery pack 11.

[0095] Specifically, the first fuse 51 and the second fuse 52 can be connected in series to the positive or negative electrode of the battery pack 11, preferably to the positive electrode. The fourth short-circuit protection module 50 includes the first fuse 51 or the second fuse 52. Blowing the first fuse 51 or the second fuse 52 can disconnect the charge and discharge circuit. The fourth short-circuit protection module 50 includes the first fuse 51 and the second fuse 52. Blowing the first fuse 51 and the second fuse 52 can disconnect the charge and discharge circuit.

[0096] In this example, the fourth short-circuit protection module 50 is used, on the one hand, when the entire battery pack is short-circuited, the short-circuit current range is 500A~10KA, the first fuse 51 and the second fuse 52 are blown to complete the short-circuit protection; on the other hand, when the electrical equipment or the battery pack management system fails and short-circuits, when the protection board 100 detects a thermal runaway or collision signal, the software controls the first fuse 51 and the second fuse 52 to melt to complete the short-circuit protection.

[0097] In some embodiments, reference Figure 7 The first fuse 51 is a two-terminal fuse, and the second fuse 52 is a three-terminal fuse.

[0098] Specifically, refer to Figure 10 and Figure 11 Both the two-terminal fuse and the three-terminal fuse are installed on the protection board 100, and are arranged on the two sides of the protection board 100 opposite the first charge and discharge unit 41. The two-terminal fuse is a current protection device with passive switching control. When the short-circuit current exceeds the limit, the two-terminal fuse will automatically melt and cut off the charge and discharge circuit for protection. The three-terminal fuse is a battery protection device with active or passive switching control. It can forcibly control the cutoff of the charge and discharge circuit for protection.

[0099] In some embodiments, reference Figure 1 and Figure 7 The short-circuit protection circuit also includes a current detection module 60 and a controller 70. The current detection module 60 is used to detect the current information of the charge and discharge circuit. The signal output end of the current detection module 60 is electrically connected to the signal input end of the controller 70. The signal output end of the controller 70 is electrically connected to the third short-circuit protection module 40 and the fourth short-circuit protection module 50 respectively.

[0100] Specifically, the current detection module 60 is used to detect the current information of the charge and discharge circuit, and determine whether a short circuit occurs in the charge and discharge circuit based on the detected current information. When it is determined that a short circuit occurs in the charge and discharge circuit, the short circuit information is sent to the controller 70. The controller 70 can be a microcontroller unit (MCU), which controls the third short circuit protection module 40 and / or the fourth short circuit protection module 50 to cut off the charge and discharge circuit in response to the short circuit information. Among them, the third short circuit protection module 40 cuts off the charge and discharge circuit, which means that the first charge and discharge unit 41 and the second charge and discharge unit 42 are both disconnected, that is, the first N-type MOS transistor 4101 and the second N-type MOS transistor 4201 are both disconnected, and the P-type MOS transistor 422 is disconnected. The fourth short circuit protection module 50 cuts off the charge and discharge circuit, which means that the first fuse 51 and the second fuse 52 are both disconnected.

[0101] In some embodiments, reference Figure 1 and Figure 7 , the current detection module 60 includes a first current acquisition unit 61 and / or a second current acquisition unit 62, wherein the first current acquisition unit 61 and the second current acquisition unit 62 are connected in series;

[0102] The first current acquisition unit 61 includes a first sampling resistor 611 and an AFE chip 612 connected in parallel; the second current acquisition unit 62 includes a second sampling resistor 621 and an OPA chip 622 connected in parallel.

[0103] Specifically, the current detection module 60 can be integrated into the protection board 100. The first current acquisition unit 61 and the second current acquisition unit 62 can both acquire current information from the charge and discharge circuits. Based on the acquired current information, the fault type of the battery pack 10 can be determined, and the short-circuit protection mode of the battery pack 10 can be determined. The AFE (Active Front End) chip functions as a rectifier / feedback unit. It acquires current information from the charge and discharge circuits through a first sampling resistor 611 and sends the acquired current information to the controller 70. The OPA (Operational Amplifier) ​​chip is an integrated circuit primarily used for current amplification and signal processing. It acquires current information from the charge and discharge circuits through a second sampling resistor 621 and sends the acquired current information to the controller 70. The resistance values ​​of the first sampling resistor 611 and the second sampling resistor 621 can be set according to actual needs and are not specifically limited in this application. Among them, in addition to the integrated current detection module 60, the third short-circuit protection module 40 and the fourth short-circuit protection module 50, the controller 70, the AFE chip 612, and the OPA chip 622, the protection board 100 can also integrate other conventional devices, such as a heating control module 110, etc. The heating control module 110 is used to heat the battery pack 11. The heating control module 110 includes a two-terminal fuse and a P-type MOS tube connected in series, which will not be elaborated in this application.

[0104] The short-circuit protection circuit of the battery pack provided in the embodiment of the present application can achieve full current protection, and can protect from the minimum fault current to the maximum short-circuit current (500A~10KA). It has the characteristics of good stability, strong reliability, comprehensiveness, and a wide range of protection current. It can be used for short-circuit protection of electrical equipment such as electric motorcycles.

[0105] The second aspect of the present invention refers to Figure 12 , providing a short circuit protection method for a battery pack, comprising:

[0106] Preset fault types of the battery pack 10, including short circuit of the battery pack 11 itself, short circuit of the entire battery pack, and fault of the power-consuming device corresponding to the battery pack or the battery pack management system;

[0107] According to the fault type of the battery pack 10, at least one of the first short-circuit protection module 20, the second short-circuit protection module, the third short-circuit protection module 40 and the fourth short-circuit protection module 50 is triggered to cut off the charge and discharge circuit; wherein,

[0108] When a short circuit occurs in the battery pack 11 itself, the first short circuit protection module 20 is triggered to cut off the charge and discharge circuit;

[0109] When a short circuit occurs in the entire battery pack, at least one of the first short circuit protection module 20, the second short circuit protection module, the third short circuit protection module 40 and the fourth short circuit protection module 50 is triggered to cut off the charge and discharge circuit;

[0110] When the power-consuming device corresponding to the battery pack or the battery pack management system fails, the third short-circuit protection module 40 and / or the fourth short-circuit protection module 50 are triggered to cut off the charge and discharge circuit.

[0111] Specifically, short-circuit modes in the battery pack 10 are categorized into three main types: the first being a short circuit in the battery pack 11 itself, the second being a short circuit in the charge-discharge circuit formed by the battery pack 11, and the third being a short circuit caused by a fault in the power-consuming device or the battery pack management system associated with the battery pack 11. Different short-circuit protection modes are determined based on the fault type of the battery pack 11. Short-circuit protection can be implemented using one or more combinations, enhancing the comprehensiveness and reliability of the short-circuit protection provided by the battery pack 10.

[0112] In some embodiments, reference Figure 12 , the short circuit protection method of the battery pack includes:

[0113] If it is detected that the short-circuit current of the battery pack 11 itself reaches a first current threshold range, it is determined that the fault type of the battery pack 11 is a short circuit of the battery pack 11 itself. For example, the first current threshold range may be 8000A~10KA;

[0114] If it is detected that the short-circuit current of the charge-discharge circuit reaches the second current threshold range or the third current threshold range, it is determined that the fault type of the battery pack 10 is a short circuit in the charge-discharge circuit formed by the battery pack 11; wherein the second current threshold range is greater than the third current threshold range; for example, the second current threshold range may be 1500A~10KA, and the third current threshold range may be 500A~1500A;

[0115] If it is detected that the battery pack is thermally out of control or the electric device corresponding to the battery pack is colliding, the fault type of the battery pack is determined to be a fault of the electric device corresponding to the battery pack or the battery pack management system.

[0116] For example, when a first type of short circuit occurs, that is, when a short-circuit current greater than 8000A is detected, the first short-circuit protection module 20 is triggered to cut off the charge and discharge circuit, completing the short-circuit protection of the battery pack. When a second type of short circuit occurs, that is, when a short-circuit current of 1500A~10KA is detected, at least one of the first short-circuit protection module 20, the second short-circuit protection module, and the fourth short-circuit protection module 50 is triggered to cut off the charge and discharge circuit; when a short-circuit current of 500A~1500A is detected, the third short-circuit protection module 40 and / or the fourth short-circuit protection module 50 is triggered to cut off the charge and discharge circuit. When a third type of short circuit occurs, that is, thermal runaway of the battery pack 10 is detected, the third short-circuit protection module 40 and / or the fourth short-circuit protection module 50 is triggered to cut off the charge and discharge circuit; or when a collision of the entire vehicle is detected, the third short-circuit protection module 40 and / or the fourth short-circuit protection module 50 is triggered to cut off the charge and discharge circuit.

[0117] Among them, the thermal runaway information of the battery pack 10 can be obtained through the voltage information and temperature information collected by the AFE, and the controller 70 can process and calculate whether the battery pack 10 has thermal runaway, wherein the thermal runaway trigger judgment conditions are: a) the trigger object generates a voltage drop, and the drop value exceeds 25% of the initial voltage; b) the temperature of the monitoring point reaches the maximum operating temperature specified by the manufacturer; c) the temperature rise rate dT / dt of the monitoring point ≥ 1°C / s, and lasts for more than 3s, wherein dT is the temperature change, and dt is the time change. The vehicle collision information corresponding to the battery pack 10 can be detected by displacement sensors installed on the vehicle, etc. This part is a prior art and will not be elaborated in the embodiments of this application. In some embodiments, reference Figure 12 If it is detected that the short-circuit current of the battery pack 11 itself reaches a first current threshold range, the first narrow-diameter metal member 21 and / or the second narrow-diameter metal member 22 are melted at the connection to cut off the charge and discharge circuit;

[0118] If it is detected that the short-circuit current of the charge-discharge circuit reaches a second current threshold range, at least one of the following operations is triggered: the first narrow-diameter metal part 21 is melted at the connection, the second narrow-diameter metal part 22 is melted at the connection, the fuse 30 is melted, the two-terminal fuse is melted, and the three-terminal fuse is melted;

[0119] If it is detected that the short-circuit current of the charge-discharge loop reaches a third current threshold range, at least one of the following operations is triggered: the two-terminal fuse is blown, the three-terminal fuse is blown, the first charge-discharge unit 41 is disconnected, and the second charge-discharge unit 42 is disconnected;

[0120] If thermal runaway of the battery pack 10 is detected, at least one of the following operations is triggered: the two-terminal fuse is blown, the three-terminal fuse is blown, the first charge and discharge unit 41 is disconnected, and the second charge and discharge unit 42 is disconnected;

[0121] If a collision is detected with the electrical device corresponding to the battery pack 10 , at least one of the following operations is triggered: a two-terminal fuse blows, a three-terminal fuse blows, the first charge and discharge unit 41 is disconnected, and the second charge and discharge unit 42 is disconnected.

[0122] Specifically, if the short-circuit current of the battery pack 11 itself is detected to be greater than 8000A, the first short-circuit protection module 20 is triggered, and the first narrow-diameter metal member 21 and / or the second narrow-diameter metal member 22 are melted at the connection to cut off the charge and discharge circuit. If the short-circuit current of the charge and discharge circuit is detected to reach the second current threshold range of 1500A~10KA, one or more short-circuit protection modules of the first short-circuit protection module 20, the second short-circuit protection module, and the fourth short-circuit protection module 50 are triggered to cut off the charge and discharge circuit. If thermal runaway of the battery pack 10 or a collision with an electrical device is detected, the third short-circuit protection module 40 and / or the fourth short-circuit protection module 50 are triggered to cut off the charge and discharge circuit.

[0123] The short-circuit protection method of the battery pack provided in the embodiment of the present application has passed the battery pack 5mΩ short-circuit test certification. The test method and judgment criteria comply with the "Safety Requirements for Power Batteries for Electric Vehicles" GB 38031-2020 standard, that is, the battery system undergoes an external short-circuit protection test in accordance with 8.2.1.3. There should be no leakage, shell rupture, fire or explosion, and the insulation resistance after the test should be no less than 100Ω / V.

[0124] The short-circuit protection method of the battery pack provided in the embodiment of the present application has passed the battery pack 20mΩ short-circuit test certification. The test method and judgment criteria comply with section 5.2.1.4 of the "Safety Technical Specifications for Lithium-ion Batteries for Electric Bicycles" GB 43854-2024 standard, that is, the battery pack should not leak, rupture, catch fire, or explode when tested according to the test method of 6.4.1.4.

[0125] The short-circuit protection method of the battery pack provided in the embodiment of the present application has also passed the experimental certification of secondary protection, that is, when the battery pack is short-circuited due to overcurrent, two short-circuit protection modes are triggered to cut off the charging and discharging circuits to complete short-circuit protection.

[0126] A third aspect of the present invention provides a battery pack 10 comprising the short-circuit protection circuit of the battery pack described in any embodiment of the present application.

[0127] Specifically, the specific technical features and technical effects of the battery pack 10 are consistent with the technical features and technical effects of the short-circuit protection circuit of the battery pack, and will not be repeated in the embodiments of this application.

[0128] A fourth aspect of the present invention provides a battery pack management system, comprising: the battery pack 10 and the load 90 described in any embodiment of the present application, wherein the short-circuit protection circuit is connected in series with the load 90 to form a charge and discharge loop.

[0129] Specifically, the specific technical features and technical effects of the battery pack management system are consistent with the technical features and technical effects of the short-circuit protection circuit of the battery pack, and will not be repeated in the embodiments of this application.

[0130] The short circuit protection circuit of the present application can be used for different types of battery packs 10, such as platform battery packs, standard battery packs, other customized battery packs, etc. For example, the structure of a typical battery pack is as follows: Figure 2 shown.

[0131] The fifth aspect of the present invention provides an electrical device, which includes the short-circuit protection circuit of the battery pack described in any embodiment of the present application, or includes the battery pack described in any embodiment of the present application, or includes the battery pack management system of any embodiment of the present application.

[0132] Specifically, the specific technical features and technical effects of the electrical equipment are consistent with the technical features and technical effects of the short-circuit protection circuit of the battery pack, and will not be repeated in the embodiments of this application.

[0133] It should be noted that electrical equipment can be vehicles such as electric motorcycles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present utility model do not impose any special restrictions on the above-mentioned electrical equipment.

[0134] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the utility model disclosed herein is not limited to technical solutions formed by a specific combination of the aforementioned technical features. It also encompasses other technical solutions formed by any combination of the aforementioned technical features or their equivalents, without departing from the concept of the utility model. For example, a technical solution formed by replacing the aforementioned features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A short circuit protection circuit for a battery pack, characterized in that: include: At least one short circuit protection module among a first short circuit protection module (20), a second short circuit protection module, a third short circuit protection module (40) and a fourth short circuit protection module (50), wherein the first short circuit protection module (20), the second short circuit protection module, the third short circuit protection module (40) and the fourth short circuit protection module (50) are respectively used to be connected in series with the battery pack (11) to form a charge and discharge circuit; The first short-circuit protection module (20) is used to cut off the charge-discharge circuit when a short circuit occurs in the battery pack (11) itself; at least one of the first short-circuit protection module (20), the second short-circuit protection module, the third short-circuit protection module (40) and the fourth short-circuit protection module (50) is used to cut off the charge-discharge circuit when a short circuit occurs in the entire battery pack; the third short-circuit protection module (40) and / or the fourth short-circuit protection module (50) are further used to cut off the charge-discharge circuit when a power-consuming device corresponding to the battery pack or a battery pack management system fails.

2. The short-circuit protection circuit of the battery pack according to claim 1, characterized in that: The first short-circuit protection module (20) comprises a first narrow-diameter metal member (21) and a second narrow-diameter metal member (22), wherein the first narrow-diameter metal member (21) and the second narrow-diameter metal member (22) are respectively electrically connected to the positive electrode and the negative electrode of the battery pack (11) and / or the battery module (111) constituting the battery pack (11); The first narrow-diameter metal member (21) and the second narrow-diameter metal member (22) both comprise a first metal segment (210) and a second metal segment (220) that are connected, and a flow area at a connection point between the first metal segment (210) and the second metal segment (220) is smaller than a flow area of ​​the first metal segment (210) and smaller than a flow area of ​​the second metal segment (220).

3. The short-circuit protection circuit of the battery pack according to claim 2, characterized in that: The width of the first metal segment (210) and the second metal segment (220) at the connection point is smaller than the width of the first metal segment (210), and smaller than the width of the second metal segment (220).

4. The short-circuit protection circuit of the battery pack according to claim 3, characterized in that: The first metal segment (210) is provided with a tab welding hole (211) extending in the length direction, and a plurality of via holes (221) are provided at the connection between the first metal segment (210) and the second metal segment (220) along the width direction.

5. The short-circuit protection circuit of the battery pack according to claim 1, characterized in that: The second short-circuit protection module comprises a fuse (30), and the fuse (30) is connected in series with the positive electrode or the negative electrode of the battery pack (11).

6. The short-circuit protection circuit of the battery pack according to claim 1, characterized in that: The third short-circuit protection module (40) comprises a first charge-discharge unit (41), the first charge-discharge unit (41) being connected in series with the positive electrode or the negative electrode of the battery pack (11), and the first charge-discharge unit (41) comprising a discharge switch tube (410) and a charge switch tube (420) connected in series.

7. The short-circuit protection circuit of the battery pack according to claim 6, characterized in that: The discharge switch tube (410) is a first N-type MOS tube (4101), and the charge switch tube (420) is a second N-type MOS tube (4201); the source of the first N-type MOS tube (4101) is connected to the positive electrode of the battery pack (11); the drain of the first N-type MOS tube (4101) is connected to the drain of the second N-type MOS tube (4201); and a first body diode (4102) is connected between the source and drain of the first N-type MOS tube (4101); The source of the second N-type MOS transistor (4201) is connected to the load (90), the gate of the second N-type MOS transistor (4201) and the gate of the first N-type MOS transistor (4101) are both connected to the controller (70), and a second body diode (4202) is connected between the source and drain of the second N-type MOS transistor (4201).

8. The short-circuit protection circuit of the battery pack according to claim 7, characterized in that: The third short-circuit protection module (40) further comprises a second charge-discharge unit (42), the second charge-discharge unit (42) being connected in parallel with the first charge-discharge unit (41), the second charge-discharge unit (42) comprising a first resistor (421) and a P-type MOS transistor (422) connected in series, wherein a third body diode (423) is connected between the source and the drain of the P-type MOS transistor (422).

9. The short-circuit protection circuit of the battery pack according to claim 8, characterized in that: The second charge and discharge unit (42) further includes an anti-reverse diode (424), the positive terminal of the anti-reverse diode (424) is connected to the P-type MOS tube (422), and the negative terminal of the anti-reverse diode (424) is connected to the load (90).

10. The short-circuit protection circuit of the battery pack according to claim 1, characterized in that: The fourth short-circuit protection module (50) comprises a first fuse (51) and / or a second fuse (52), wherein the first fuse (51) and the second fuse (52) are connected in parallel to form a first parallel circuit, and the first parallel circuit is connected in series with the positive electrode or the negative electrode of the battery pack (11).

11. The short-circuit protection circuit of the battery pack according to claim 10, characterized in that: The first fuse (51) is a two-terminal fuse, and the second fuse (52) is a three-terminal fuse.

12. The short-circuit protection circuit of the battery pack according to claim 1, characterized in that: The short-circuit protection circuit further comprises a current detection module (60) and a controller (70). The current detection module (60) is used to detect current information of the charge-discharge circuit. The signal output end of the current detection module (60) is electrically connected to the signal input end of the controller (70). The signal output end of the controller (70) is electrically connected to the third short-circuit protection module (40) and the fourth short-circuit protection module (50), respectively.

13. The short circuit protection circuit of the battery pack according to claim 12, characterized in that: The current detection module (60) comprises a first current acquisition unit (61) and / or a second current acquisition unit (62), wherein the first current acquisition unit (61) and the second current acquisition unit (62) are connected in series; The first current acquisition unit (61) comprises a first sampling resistor (611) and an AFE chip (612) connected in parallel; the second current acquisition unit (62) comprises a second sampling resistor (621) and an OPA chip (622) connected in parallel.

14. A battery pack (10), characterized in that: A short-circuit protection circuit for a battery pack comprising any one of claims 1-13.

15. A battery pack management system, characterized in that: The invention comprises the battery pack (10) according to claim 14 and a load (90), wherein the short-circuit protection circuit and the load (90) are connected in series to form a charge-discharge loop.

16. An electrical device, characterized in that: A short-circuit protection circuit for a battery pack comprising any one of claims 1 to 13, or a battery pack (10) comprising the battery pack according to claim 14, or a battery pack management system comprising the battery pack according to claim 15.

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