Electrostatic protection circuit, battery management device, battery pack, and electric device

Abstract

Embodiments of the present application provide an electrostatic protection circuit, a battery management device, a battery pack, and an electric device. The electrostatic protection circuit comprises: a first electrostatic protection unit, configured to be electrically connected between a positive output terminal and a negative electrode of a battery module, wherein the first electrostatic protection unit comprises at least one capacitor; and / or a second electrostatic protection unit, configured to be electrically connected between a negative output terminal and the negative electrode of the battery module, wherein the second electrostatic protection unit comprises at least one capacitor. In the present application, electrostatic charges are coupled to ground by providing capacitors, thereby achieving an anti-static function; the circuit is simple, and electrostatic protection costs are reduced.

Description

An electrostatic protection circuit, a battery management device, a battery pack and a power utilization device

[0001] The present application claims priority to the Chinese patent application No. 202411320499.4, filed on September 20, 2024, and entitled "An electrostatic protection circuit, a battery management device, a battery pack and a power utilization device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of electronic technology, and in particular, to an electrostatic protection circuit, a battery management device, a battery pack and a power utilization device. BACKGROUND

[0003] In the current battery management device, static electricity can be generated due to friction, induction, conduction and other mechanisms when handling and moving the battery, cable and related components. Static electricity can cause damage to the battery and thus cause safety accidents, which can cause harm to the human body and equipment. Therefore, electrostatic protection is crucial for battery safety.

[0004] In the related art, a battery is protected by setting an electrostatic protection circuit. For example, the battery management device adopts an ESD (Electro-Static discharge) or TVS (Transient Voltage Suppressor) scheme to achieve electrostatic protection. The TVS and ESD absorb surge energy by fast response and limit the excessive voltage within a bearable range, thereby protecting electronic devices from damage. However, the TVS and ESD devices have high costs, resulting in high manufacturing costs of the electrostatic protection circuit. Moreover, the TVS and ESD have a risk of failure, which can cause the battery management device to heat up, and thus an additional fuse device needs to be added, further increasing the electrostatic protection cost of the battery. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide an electrostatic protection circuit, a battery management device, a battery pack and a power utilization device to reduce the electrostatic protection cost of the battery. The specific technical solutions are as follows:

[0006] In a first aspect, the embodiments of the present application provide an electrostatic protection circuit, comprising: a first electrostatic protection unit configured to be electrically connected between a positive output terminal and a negative electrode of a battery module, the first electrostatic protection unit comprising at least one capacitor; and / or a second electrostatic protection unit configured to be electrically connected between a negative output terminal and the negative electrode of the battery module, the second electrostatic protection unit comprising at least one capacitor.

[0007] In a possible embodiment, the first electrostatic protection unit includes a plurality of capacitors, each capacitor in the plurality of capacitors being connected in series; and / or, the second electrostatic protection unit includes a plurality of capacitors, each capacitor in the plurality of capacitors being connected in series.

[0008] In a possible embodiment, the third electrostatic protection unit includes at least one capacitor, and the fourth electrostatic protection unit includes at least one capacitor.

[0009] In a possible embodiment, the third electrostatic protection unit includes a plurality of capacitors, each capacitor in the plurality of capacitors being connected in series; and the fourth electrostatic protection unit includes a plurality of capacitors, each capacitor in the plurality of capacitors being connected in series.

[0010] In a possible embodiment, the fifth electrostatic protection unit includes at least one capacitor.

[0011] In a possible embodiment, the electrostatic protection circuit includes the first electrostatic protection unit and the second electrostatic protection unit, the second end of the fifth electrostatic protection unit is electrically connected to the first end of the second electrostatic protection unit, and the second end of the second electrostatic protection unit is configured to be electrically connected to the negative electrode of the battery module.

[0012] In a possible embodiment, the fifth electrostatic protection unit includes a plurality of capacitors, each capacitor in the plurality of capacitors being connected in series.

[0013] In a second aspect, the embodiments of the present application provide a battery management device, including the electrostatic protection circuit of any one of the first aspect.

[0014] In a third aspect, an embodiment of the present application provides a battery pack, comprising a battery module, a connector, and the battery management device according to the second aspect, the battery module comprising a plurality of battery cells; the connector comprising a positive output terminal and a negative output terminal; and the battery management device being electrically connected to the battery module and the connector respectively.

[0015] In a possible embodiment, the negative electrode of the battery module, the positive output terminal, and the negative output terminal are coupled to the ground respectively.

[0016] In a fourth aspect, an embodiment of the present application provides a power consumption device, comprising a load and the battery pack according to any one of the third aspect.

[0017] The embodiments of the present application have the following beneficial effects:

[0018] The electrostatic protection circuit, the battery management device, the battery pack, and the power consumption device provided by the embodiments of the present application, the electrostatic protection circuit comprises: a first electrostatic protection unit configured to be electrically connected between the positive output terminal and the negative electrode of the battery module, the first electrostatic protection unit comprising at least one capacitor; and / or a second electrostatic protection unit configured to be electrically connected between the negative output terminal and the negative electrode of the battery module, the second electrostatic protection unit comprising at least one capacitor. In the present application, the capacitors are configured to couple static electricity to the ground to achieve the anti-static function. Compared with the scheme of using multiple groups of ESD (Electro-Static discharge, static electricity discharge) or TVS (Transient Voltage Suppressor, transient voltage suppressor) to achieve electrostatic protection in the related art, the circuit is simple, and the electrostatic protection cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which are included to provide a further understanding of the present application, form a part of the present application and illustrate the illustrative embodiments of the present application and the description thereof, and do not constitute improper limitations on the present application.

[0020] FIG. 1a is a first structural schematic diagram of the electrostatic protection circuit provided by the embodiments of the present application;

[0021] FIG. 1b is a second structural schematic diagram of the electrostatic protection circuit provided by the embodiments of the present application;

[0022] FIG. 1c is a third structural schematic diagram of the electrostatic protection circuit provided by the embodiments of the present application;

[0023] FIG. 2 is a schematic diagram of electrostatic discharge of the electrostatic protection circuit provided by the embodiments of the present application;

[0024] Fig. 3a is a fourth structural schematic diagram of the electrostatic protection circuit according to an embodiment of the present application;

[0025] Fig. 3b is a fifth structural schematic diagram of the electrostatic protection circuit according to an embodiment of the present application;

[0026] Fig. 3c is a sixth structural schematic diagram of the electrostatic protection circuit according to an embodiment of the present application;

[0027] Fig. 4 is a seventh structural schematic diagram of the electrostatic protection circuit according to an embodiment of the present application;

[0028] Fig. 5 is an eighth structural schematic diagram of the electrostatic protection circuit according to an embodiment of the present application;

[0029] Fig. 6 is a ninth structural schematic diagram of the electrostatic protection circuit according to an embodiment of the present application;

[0030] Fig. 7 is a first structural schematic diagram of the battery management device according to an embodiment of the present application;

[0031] Fig. 8 is a second structural schematic diagram of the battery management device according to an embodiment of the present application;

[0032] Fig. 9 is a structural schematic diagram of the battery pack according to an embodiment of the present application;

[0033] Fig. 10 is a structural schematic diagram of the power consumption device according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] To make the objects, technical solutions, and advantages of the present application clearer, the following further describes the present application with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0035] The technical solutions in the embodiments of the present application will be described clearly and in detail with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The following specific embodiments are exemplary rather than limiting, and are intended to provide a basic understanding of the present application, and are not intended to identify key or decisive elements or limit the scope of protection.

[0036] In the related art, the battery management device adopts the scheme of ESD (Electro-Static discharge) or TVS (Transient Voltage Suppressor) to realize electrostatic protection. The TVS and the ESD limit the excessively high voltage within a bearable range by quickly responding and absorbing surge energy, thereby protecting the electronic device from damage. The ESD is mainly used for static electricity prevention. The static electricity prevention requires a low capacitance value, and therefore the capacitance value of the ESD is low, while the capacitance value of the TVS is high. Since the cost of the TVS and the ESD device is high, the manufacturing cost of the electrostatic protection circuit is high, and the TVS and the ESD have a failure risk, which may cause the battery management device to heat, and an additional fuse device (for example, a fuse) needs to be added, further increasing the cost of the above electrostatic protection scheme.

[0037] When designing a board layer of a printed circuit board (PCB), the anti-static capability is enhanced by increasing the number of PCB board layers and increasing the grounding area. For example, compared with a double-layer board (the layout of the circuit of the double-layer board is limited to two surfaces thereof), the design scheme of a four-layer board (the top and bottom layers are signal layers, and the middle two layers are power supply layers and ground layers) effectively increases the grounding area, thereby enhancing the electrostatic protection capability. However, increasing the number of PCB board layers increases the cost and the size.

[0038] In this application, as a specific example, the battery management device is a printed circuit board, and the battery management device is provided with a chip (also referred to as a micro control unit), a capacitor, a resistor, a switch, a positive output terminal P+, a negative output terminal P-, and the like. The inventor found, in the process of implementing this application, that the positive output terminal P+, the negative output terminal P-, and the battery module negative electrode B- have a high-voltage electrical gap in the PCB, and in the PCB design, the positive output terminal P+ and the battery module negative electrode B- are in different networks, and the negative output terminal P- and the battery module negative electrode B- are in different networks. The above three terminals are not directly associated with the design from the circuit connection and the PCB design layout. Coupling the positive output terminal P+ and the battery module negative electrode B- and coupling the negative output terminal P- and the battery module negative electrode B- are very unconventional designs in the circuit design of the battery management device.

[0039] To improve the above problems, the inventors further found that the network where the battery module negative electrode B- on the PCB is located has a large area of copper plating, the network where the positive electrode output terminal P+ and the negative electrode output terminal P- are located is an external port electrically connected with external equipment, and the area of copper plating is small. During electrostatic testing or actual use of the battery management device, static electricity is easily generated at the external port, which is coupled into other circuits in the battery management device through the positive electrode output terminal P+ and the negative electrode output terminal P-, and may cause risks such as chip damage and capacitor overvoltage breakdown, and therefore it is necessary to quickly discharge the static electricity on the positive electrode output terminal P+ and the negative electrode output terminal P- to reduce the risk of failure of electronic components on the PCB.

[0040] Because the network where the battery module negative electrode B- is located has a large area of copper plating, a low-impedance static electricity discharge path is provided, and the network serves as a floating ground (the floating ground means that the ground of the circuit is not connected to the ground by a conductor) of the battery management device. When solving the technical problem that static electricity signals are coupled into other circuits in the battery management device through the positive electrode output terminal P+ and the negative electrode output terminal P- to cause interference or impact on other circuits or electronic components, the inventors use the technical principle that there is a potential difference between the network where the positive electrode output terminal P+ is located and the network where the battery module negative electrode B- is located, there is a potential difference between the network where the negative electrode output terminal P- is located and the network where the battery module negative electrode B- is located, and the voltage across the capacitor cannot change abruptly, and set a capacitor between the positive electrode output terminal P+ and the negative electrode output terminal P-, a capacitor between the positive electrode output terminal P+ and the battery module negative electrode B-, and a capacitor between the negative electrode output terminal P- and the battery module negative electrode B-, so that the static electricity on the positive electrode output terminal P+ and the negative electrode output terminal P- is quickly transmitted to the floating ground through the capacitors to achieve static electricity discharge and reduce the risk of static electricity signals flowing into other circuits.

[0041] Based on the above design concept, the application provides a static electricity protection circuit 1, as shown in FIGS. 1a, 1b and 1c, which is arranged on a battery management device and includes a first static electricity protection unit 11 and / or a second static electricity protection unit 12. The battery management device is electrically connected with a positive electrode B+ and a negative electrode B- of a battery module through an electrical connector (for example, a busbar), and is electrically connected with a first connector (for example, a power plug, not shown in the figure) on a battery pack through a power harness, the first connector including a positive electrode output terminal P+ and a negative electrode output terminal P-, and the first connector being used to externally connect a second connector on an electrical equipment, the second connector being provided with a positive electrode terminal and a negative electrode terminal. The positive electrode output terminal P+ is connected with the positive electrode terminal on the second connector, and the negative electrode output terminal P- is connected with the negative electrode terminal on the second connector, so as to achieve electrical connection between the battery pack and the electrical equipment. As an example of the application, the battery module is in a discharging mode, and the battery module supplies power to a load (for example, a motor) of the electrical equipment, and the electrical equipment is an electric vehicle (for example, an electric bicycle, an electric motorcycle, etc.).

[0042] In some embodiments of the application, the power consuming device includes: power tools (including garden power tools and household power tools, such as electric lawn mowers, electric drills, etc.), electric cleaning tools (such as floor sweepers, vacuum cleaners, etc.), aircraft (such as agricultural drones, consumer drones), energy storage systems (such as household energy storage systems, commercial energy storage systems, industrial energy storage systems, uninterruptible power supplies (UPS) and the like.

[0043] One end of the first electrostatic protection unit 11 is coupled to the battery module negative electrode B-, and the other end of the first electrostatic protection unit 11 is coupled to the positive electrode output terminal P+. In the layout and wiring design of the battery management device, one end of the first electrostatic protection unit 11 is connected to the floating ground network, that is, connected to the battery module negative electrode B-, and the floating ground network covers the pad at one end of the first electrostatic protection unit 11 when copper is laid. The other end of the first electrostatic protection unit 11 is connected to the positive electrode output terminal P+ network, and the positive electrode output terminal P+ network covers the pad at the other end of the first electrostatic protection unit 11 when copper is laid. In the layout and wiring design of the battery management device, the positive electrode output terminal P+ and the battery module negative electrode B- are coupled to the same network through the first electrostatic protection unit 11. When static electricity exists on the positive electrode output terminal P+, the static electricity discharge loop is: P+→first electrostatic protection unit 11→battery module negative electrode B-→ground. Because a large area of copper is laid on the network where the battery module negative electrode B- is located, a large equivalent capacitance is formed between this network and the ground, providing a low-impedance static electricity discharge path to quickly discharge static electricity on the positive electrode output terminal P+.

[0044] In some embodiments of the application, the first electrostatic protection unit 11 includes a capacitor C. When static electricity exists on the positive electrode output terminal P+, the capacitor quickly couples the static electricity to the floating ground, thereby quickly discharging the static electricity on the positive electrode output terminal P+.

[0045] In yet some embodiments of the application, the first electrostatic protection unit 11 includes a plurality of capacitors C, and the plurality of capacitors are connected in series. If the first electrostatic protection unit 11 includes only one capacitor, the failure of the capacitor will cause static electricity to be unable to be coupled to the floating ground. If one or several capacitors in the plurality of series-connected capacitors fail, static electricity on the positive electrode output terminal P+ is coupled to the floating ground through the remaining capacitors, thereby improving the reliability of the electrostatic protection unit.

[0046] In some embodiments of the present application, one end of the second electrostatic protection unit 12 is coupled to the battery module negative electrode B-, and the other end of the second electrostatic protection unit 12 is coupled to the negative output terminal P-. In the layout and wiring design of the battery management device, one end of the second electrostatic protection unit 12 is connected to the floating ground network, that is, connected to the battery module negative electrode B-, and the floating ground network covers the pad at one end of the second electrostatic protection unit 12 when copper is laid. The other end of the second electrostatic protection unit 12 is connected to the negative output terminal P- network, and the negative output terminal P- network covers the pad at the other end of the second electrostatic protection unit 12 when copper is laid. By coupling the negative output terminal P- and the battery module negative electrode B- to the same network through the second electrostatic protection unit 12, when static electricity exists on the negative output terminal P-, the static electricity discharge loop is: P-→second electrostatic protection unit 12→battery module negative electrode B-→ground. Because a large area of copper is laid on the network where the battery module negative electrode B- is located, a low-impedance static electricity discharge path is provided to quickly discharge the static electricity on the negative output terminal P-.

[0047] In some embodiments of the present application, the second electrostatic protection unit 12 includes a capacitor C, and when static electricity exists on the negative output terminal P-, the static electricity is quickly coupled to the floating ground through the capacitor, thereby quickly discharging the static electricity on the negative output terminal P-.

[0048] In yet some embodiments of the present application, the second electrostatic protection unit 12 includes a plurality of capacitors C, and the plurality of capacitors are connected in series. If the second electrostatic protection unit 12 includes only one capacitor, the failure of the capacitor will cause static electricity to be unable to be coupled to the floating ground. If one or more capacitors of the plurality of series-connected capacitors fail, the static electricity on the negative output terminal P- is coupled to the floating ground through the remaining capacitors, thereby improving the reliability of the electrostatic protection unit.

[0049] After the static electricity is coupled to the floating ground, the static electricity is further coupled to the ground through the floating ground, thereby discharging the static electricity, as shown in FIG. 2. In the layout and wiring design of the battery management device, the large-area copper coverage of the floating ground network enables the floating ground network and the ground to have a large equivalent capacitance, thereby achieving the purpose of quickly discharging static electricity.

[0050] In some embodiments of the present application, the power wire harness corresponding to the positive output terminal P+ and the power wire harness corresponding to the negative output terminal P- also have equivalent capacitances to the ground, as shown in FIG. 2. The static electricity is discharged by coupling the power wire harness corresponding to the positive output terminal P+ to the ground, and the static electricity is discharged by coupling the power wire corresponding to the negative output terminal P- to the ground.

[0051] In the above embodiments of the application, by arranging the capacitors between the positive output terminal P+ and the battery module negative electrode B-, and between the negative output terminal P- and the battery module negative electrode B-, when static electricity exists on the positive output terminal P+, the capacitors are used to quickly couple the static electricity to the floating ground, and when static electricity exists on the negative output terminal P-, the capacitors are used to quickly couple the static electricity to the floating ground. Compared with the scheme of using ESD or TVS to achieve static electricity protection in the related art, the cost of static electricity protection is effectively reduced. Moreover, the static electricity protection scheme using capacitors for static electricity coupling reduces the board layer design, and further reduces the cost and size of the PCB. In addition, the static electricity protection scheme in the embodiments has the characteristics of low cost and small size, and ingeniously associates two independent networks to achieve the purpose of quickly discharging static electricity to the floating ground, simply and effectively achieving static electricity protection, and having strong practicality in the actual application of the circuit. In summary, the static electricity protection circuit provided in the embodiments has the advantages of simple design, low cost, small actual product space occupied by the circuit structure, and good static electricity protection capability.

[0052] Referring to FIGS. 3a, 3b and 3c, on the basis of the above embodiments, the static electricity protection circuit 1 further includes a third static electricity protection unit 13 and a fourth static electricity protection unit 14.

[0053] One end of the third static electricity protection unit 13 is coupled to the battery module positive electrode B+, and the other end of the third static electricity protection unit 13 is coupled to the positive output terminal P+. In the layout and wiring design of the battery management device, one end of the third static electricity protection unit 13 is connected to the B+ network, the B+ network covers the pad of one end of the third static electricity protection unit 13 when copper is laid, the other end of the third static electricity protection unit 13 is connected to the P+ network, and the P+ network covers the pad of the other end of the third static electricity protection unit 13 when copper is laid.

[0054] In some embodiments of the application, the third static electricity protection unit 13 includes a capacitor C, and when static electricity exists on the positive output terminal P+, the capacitor is used to quickly couple the static electricity to the battery module positive electrode B+.

[0055] In yet some embodiments of the application, the third static electricity protection unit 13 includes a plurality of capacitors C, and the plurality of capacitors are connected in series. If the third static electricity protection unit 13 includes only one capacitor, failure of the capacitor will cause static electricity to be unable to be coupled to the battery module positive electrode B+, and failure of one or more capacitors in the plurality of series-connected capacitors will cause static electricity on the positive output terminal P+ to be coupled to the battery module positive electrode B+ through the remaining capacitors, thereby improving the reliability of the static electricity protection unit.

[0056] One end of the fourth electrostatic protection unit 14 is coupled to the battery module negative pole B-, and the other end of the fourth electrostatic protection unit 14 is coupled to the battery module positive pole B+. In the layout and wiring design of the battery management device, one end of the fourth electrostatic protection unit 14 is connected to the floating ground network, i.e., connected to the battery module negative pole B-, the floating ground network covers the pad of one end of the fourth electrostatic protection unit 14 when copper is laid, and the other end of the fourth electrostatic protection unit 14 is connected to the B+ network, and the B+ network covers the pad of the other end of the fourth electrostatic protection unit 14 when copper is laid.

[0057] In some embodiments of the present application, the fourth electrostatic protection unit 14 includes a capacitor C, and when the third electrostatic protection unit 13 couples static electricity from the positive output terminal P+ to the battery module positive pole B+, the fourth electrostatic protection unit 14 quickly couples static electricity to the floating ground through the capacitor, thereby quickly discharging static electricity on the positive output terminal P+.

[0058] In some embodiments of the present application, the fourth electrostatic protection unit 14 includes a plurality of capacitors C, and the plurality of capacitors are connected in series. If the fourth electrostatic protection unit 14 includes only one capacitor, the failure of the capacitor will cause static electricity to be unable to be coupled to the floating ground, and if one or several capacitors in the plurality of series-connected capacitors fail, static electricity on the battery module positive pole B+ is coupled to the floating ground through the remaining capacitors, thereby improving the reliability of the electrostatic protection unit.

[0059] On the basis of the first electrostatic protection unit 11, the third electrostatic protection unit 13 and the fourth electrostatic protection unit 14 provide another electrostatic coupling path: when static electricity exists on the positive output terminal P+, the static electricity is coupled to the floating ground, i.e., the battery module negative pole B-, through the third electrostatic protection unit 13 and the fourth electrostatic protection unit 14, and finally coupled to the ground through the floating ground to discharge the static electricity. The static electricity discharge path on the positive output terminal P+ is: positive output terminal P+→third electrostatic protection unit 13→fourth electrostatic protection unit 14→battery module negative pole B-→ground. The multiple electrostatic coupling paths provide more paths for static electricity discharge, more quickly discharge static electricity, and protect the anti-static function of the battery management device. Moreover, when one or several electrostatic coupling paths fail, static electricity is discharged through the remaining electrostatic coupling paths, thereby improving the reliability of the anti-static function.

[0060] It can be understood that the circuit structure shown in FIG. 3a is based on the circuit structure shown in FIG. 1a, the circuit structure shown in FIG. 3b is based on the circuit structure shown in FIG. 1b, and the circuit structure shown in FIG. 3c is based on the circuit structure shown in FIG. 1c.

[0061] Referring to FIG. 4, FIG. 4 is a seventh structure schematic diagram of the electrostatic protection circuit 1 provided by an embodiment of the present application, and the electrostatic protection circuit 1 further includes a fifth electrostatic protection unit 15 on the basis of the foregoing embodiments of the present application.

[0062] One end of the fifth electrostatic protection unit 15 is coupled to the positive output terminal P+, and the other end of the fifth electrostatic protection unit 15 is coupled to the negative output terminal P-. In the layout wiring design of the battery management device, one end of the fifth electrostatic protection unit 15 is connected to the P+ network, the P+ network covers the pad of one end of the fifth electrostatic protection unit 15 when copper is laid, and the other end of the fifth electrostatic protection unit 15 is connected to the P- network, and the P- network covers the pad of the other end of the fifth electrostatic protection unit 15 when copper is laid.

[0063] In some embodiments of the present application, the fifth electrostatic protection unit 15 includes a capacitor C, and when static electricity exists on the positive output terminal P+, the static electricity is quickly coupled to the negative output terminal P- through the capacitor.

[0064] In some embodiments of the present application, the fifth electrostatic protection unit 15 includes a plurality of capacitors C, and the plurality of capacitors are connected in series. If the fifth electrostatic protection unit 15 includes only one capacitor, the failure of the capacitor will cause the static electricity to be unable to be coupled to the negative output terminal P-. If one or several capacitors in the plurality of series-connected capacitors fail, the static electricity on the positive output terminal P+ is coupled to the negative output terminal P- through the remaining capacitors, thereby improving the reliability of the electrostatic protection unit.

[0065] After the static electricity on the positive output terminal P+ is coupled to the negative output terminal P-, the static electricity is coupled to the floating ground, i.e., the negative electrode B- of the battery module, through the second electrostatic protection unit 12, and is discharged through the coupling between the floating ground and the ground.

[0066] On the basis of the above-mentioned circuit structure, the fifth electrostatic protection unit 15 further provides a static electricity coupling path: when static electricity exists on the positive output terminal P+, the static electricity is coupled to the floating ground, i.e., the negative electrode B- of the battery module, through the fifth electrostatic protection unit 15 and the second electrostatic protection unit 12, and is discharged through the coupling between the floating ground and the ground. The static electricity discharge path of the positive output terminal P+ is: positive output terminal P+→fifth electrostatic protection unit 15→second electrostatic protection unit 12→negative electrode B- of the battery module→ground. The multiple static electricity coupling paths provide more paths for static electricity discharge, more quickly discharge static electricity, and protect the anti-static function of the battery management device. Moreover, when one or several static electricity coupling paths fail, the static electricity is discharged through the remaining static electricity coupling paths, thereby improving the reliability of the anti-static function.

[0067] It can be understood that the circuit structure shown in FIG. 4 is based on the circuit structure shown in FIG. 3c, and the circuit structure shown in FIG. 5 is based on the circuit structure shown in FIG. 1c.

[0068] It can be understood that, for the fifth electrostatic protection unit 15 based on other circuit structures, the present application does not make redundant description.

[0069] As a specific embodiment of the present application, each electrostatic protection unit includes multiple capacitors, as shown in FIG. 6, the first electrostatic protection unit 11 includes a first capacitor C1 and a second capacitor C2, the second electrostatic protection unit 12 includes a third capacitor C3 and a fourth capacitor C4, the third electrostatic protection unit 13 includes a fifth capacitor C5 and a sixth capacitor C6, the fourth electrostatic protection unit 14 includes a seventh capacitor C7 and an eighth capacitor C8, and the fifth electrostatic protection unit 15 includes a ninth capacitor C9 and a tenth capacitor C10. In this embodiment, the electrostatic protection circuit provides four electrostatic discharge paths, including three electrostatic discharge paths of the positive output terminal P+ and one electrostatic discharge path of the negative output terminal P-, and the electrostatic discharge paths are respectively: the positive output terminal P+→the first electrostatic protection unit 11→the battery module negative electrode B-, the positive output terminal P+→the third electrostatic protection unit 13→the fourth electrostatic protection unit 14→the battery module negative electrode B-, the positive output terminal P+→the fifth electrostatic protection unit 15→the second electrostatic protection unit 12→the battery module negative electrode B-, and the negative output terminal P-→the second electrostatic protection unit 12→the battery module negative electrode B-.

[0070] Generally speaking, the larger the capacitance of the capacitor, the stronger the ability to store electric charge, so when discharging static electricity, the capacitor with large capacitance can better absorb and neutralize static charge, effectively reducing the influence of static electricity on the circuit or equipment. Of course, the larger the capacitance of the capacitor, the better, and by selecting a capacitor with an appropriate capacitance, for example, a capacitor with a capacitance of 47nf and 100nf, the electrostatic protection performance can be ensured to be in the best state.

[0071] In some embodiments of the present application, the capacitances in the same electrostatic protection unit are the same. For example, the first capacitor C1 and the second capacitor C2 in the first electrostatic protection unit 11 have the same capacitance of 100nf.

[0072] In some embodiments of the present application, the capacitances in the same electrostatic protection unit are different. For example, the first capacitor C1 in the first electrostatic protection unit 11 has a capacitance of 100nf, and the second capacitor C2 has a capacitance of 47nf.

[0073] In some embodiments of the present application, the capacitances in different electrostatic protection units are different. For example, the first capacitor C1 and the second capacitor C2 in the first electrostatic protection unit 11 have a capacitance of 100nf, and the third capacitor C3 and the fourth capacitor in the second electrostatic protection unit have a capacitance of 47nf.

[0074] In some embodiments of the present application, the capacitance values of the capacitors in different electrostatic protection units are the same. For example, the capacitance values of the first capacitor C1 and the second capacitor C2 in the first electrostatic protection unit 11 are 100 nf, and the capacitance values of the third capacitor C3 and the fourth capacitor in the second electrostatic protection unit are 100 nf.

[0075] Specifically, when static electricity exists on the positive output terminal P+, the static electricity is coupled to the battery module negative electrode B- through the first capacitor C1 and the second capacitor C2 in the first electrostatic protection circuit 11, the static electricity is coupled to the battery module negative electrode B- through the fifth capacitor C5 and the sixth capacitor C6 in the third electrostatic protection circuit 13, the static electricity is coupled to the battery module negative electrode B- through the seventh capacitor C7 and the eighth capacitor C8 in the fourth electrostatic protection unit 14, and the static electricity is coupled to the battery module negative electrode B- through the ninth capacitor C9 and the tenth capacitor C10 in the fifth electrostatic protection circuit 15 and the third capacitor C3 and the fourth capacitor C4 in the second electrostatic protection unit 12. When static electricity exists on the negative output terminal P-, the static electricity is coupled to the battery module negative electrode B- through the third capacitor C3 and the fourth capacitor C4 in the second electrostatic protection unit 12. Finally, when static electricity exists on the positive output terminal P+, the static electricity is discharged through the coupling of the positive output terminal P+, the negative output terminal P-, the battery module negative electrode B- and the ground; and when static electricity exists on the negative output terminal P-, the static electricity is discharged through the coupling of the negative output terminal P-, the battery module negative electrode B- and the ground.

[0076] The multiple electrostatic coupling paths provide more paths for electrostatic discharge, more quickly discharge static electricity, and guarantee the anti-static function of the battery management device. Moreover, when one or several electrostatic coupling paths fail, the static electricity is discharged through the remaining electrostatic coupling paths, improving the reliability of the anti-static function.

[0077] In some embodiments of the present application, on the basis of the circuit structure shown in FIG. 4, the electrostatic protection function is realized by replacing the capacitors with air-bonding or sharp-point discharge pads. When designing the PCB, a sharp-point discharge part is arranged on the pad, the sharp-point discharge part is a pair of sharp-angle triangles pointing to each other, and is made of a copper foil layer during the PCB wiring process. When static electricity discharge occurs, the sharp-point structures of the two pads discharge to each other, thereby reducing the damage to the device and the circuit.

[0078] The embodiments of the present application also provide a battery management device 2, as shown in FIG. 7. The battery management device 2 comprises the electrostatic protection circuit 1 in any of the above embodiments.

[0079] In one example, as shown in FIG. 8, which is a structural schematic diagram of the battery management device 2 (based on the electrostatic protection circuit shown in FIG. 6), the battery management device 2 further comprises a fuse F1, a control module 21, a first switch Q1, a second switch Q2, and a first resistor R1.

[0080] The function of the fuse F1 is to protect the safe operation of the circuit by fusing itself to cut off the current when the current in the circuit abnormally rises to a certain limit. The first resistor R1 is a sampling resistor, which functions to collect the current.

[0081] The battery management device 2 is used to monitor the voltage of each cell in the battery module, the current of the charging and discharging circuit, and the temperature of the cell (the battery module includes a plurality of cells), and controls the on-off of the first switch Q1 and the second switch Q2 through the control module 21 to control the charging and discharging process of the battery module. When the battery pack is in a normal working state (including normal charging and normal discharging), the control module 21 controls the first switch Q1 and the second switch Q2 to be turned on, and when the battery pack is in an abnormal state, the control module 21 controls the first switch Q1 and the second switch Q2 to be turned off, thereby protecting the safety of the cell. It can be understood that the abnormal state of the battery pack includes overcurrent, overvoltage, overtemperature, and overdischarge.

[0082] The embodiment of the present application also provides a battery pack 3 for storing and providing electric energy, as shown in FIG. 9, which comprises a battery module 31, a connector 32 (a first connector), and the battery management device 2 described in the above embodiment, and the battery management device 2 is electrically connected with the battery module 31 and the connector 32 respectively. As described above, the connector 32 comprises a positive output terminal P+ and a negative output terminal P-.

[0083] The embodiment of the present application also provides a use electric device 4, as shown in FIG. 10, which comprises a load 41 and the battery pack 3 described in the above embodiment.

[0084] It should be noted that, in this document, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between the entities or operations.

[0085] The description herein and the above embodiments are provided so that those skilled in the art can implement or use the disclosure of the present application. Various modifications of the disclosure of the present application will be apparent to those skilled in the art, and the general principles defined herein can also be applied to other variations. Therefore, the disclosure of the present application is not limited to the examples and designs described herein, but is given the broadest scope consistent with the principles and novel features disclosed herein.

[0086] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. An electrostatic protection circuit, comprising: a first electrostatic protection unit configured to be electrically connected between a positive output terminal and a negative electrode of a battery module, the first electrostatic protection unit comprising at least one capacitor; and / or, a second electrostatic protection unit configured to be electrically connected between a negative output terminal and the negative electrode of the battery module, the second electrostatic protection unit comprising at least one capacitor.

2. The electrostatic protection circuit of claim 1, wherein: the first electrostatic protection unit comprises a plurality of capacitors, each capacitor of the plurality of capacitors being connected in series; and / or, the second electrostatic protection unit comprises a plurality of capacitors, each capacitor of the plurality of capacitors being connected in series.

3. The electrostatic discharge protection circuit of claim 1 or 2, wherein, comprising: a third electrostatic protection unit, a first end of the third electrostatic protection unit being electrically connected to a first end of the first electrostatic protection unit, the first end of the third electrostatic protection unit being further configured to be electrically connected to the positive output terminal, a second end of the third electrostatic protection unit being configured to be electrically connected to a positive electrode of a battery module; a fourth electrostatic protection unit, a first end of the fourth electrostatic protection unit being electrically connected to a second end of the third electrostatic protection unit, the first end of the fourth electrostatic protection unit being further configured to be electrically connected to the positive electrode of the battery module, a second end of the fourth electrostatic protection unit being configured to be electrically connected to a negative electrode of the battery module; the third electrostatic protection unit comprising at least one capacitor, the fourth electrostatic protection unit comprising at least one capacitor.

4. The electrostatic protection circuit of claim 3, wherein: the third electrostatic protection unit comprises a plurality of capacitors, each capacitor of the plurality of capacitors being connected in series; the fourth electrostatic protection unit comprises a plurality of capacitors, each capacitor of the plurality of capacitors being connected in series.

5. The electrostatic discharge protection circuit of claim 1, wherein, comprising: a fifth electrostatic protection unit, a first end of the fifth electrostatic protection unit being electrically connected to a first end of the first electrostatic protection unit, the first end of the fifth electrostatic protection unit being further configured to be electrically connected to the positive output terminal, a second end of the fifth electrostatic protection unit being configured to be electrically connected to the negative output terminal; the fifth electrostatic protection unit comprising at least one capacitor.

6. The electrostatic protection circuit of claim 5, wherein: the electrostatic protection circuit comprises the first electrostatic protection unit and the second electrostatic protection unit, the second end of the fifth electrostatic protection unit being electrically connected to a first end of the second electrostatic protection unit, a second end of the second electrostatic protection unit being configured to be electrically connected to the negative electrode of the battery module.

7. The electrostatic protection circuit of claim 5 or 6, wherein: the fifth electrostatic protection unit comprises a plurality of capacitors, each capacitor of the plurality of capacitors being connected in series.

8. A battery management device, comprising the electrostatic protection circuit of any one of claims 1 to 7.

9. A battery pack, comprising a battery module, a connector, and the battery management device of claim 8, the battery module comprising a plurality of battery cells; the connector comprising a positive output terminal and a negative output terminal; the battery management device being electrically connected to the battery module and the connector, respectively.

10. The battery pack of claim 9, wherein, The negative electrode of the battery module, the positive electrode output terminal, and the negative electrode output terminal are respectively coupled to ground.

11. An electrical device comprising a load and the battery pack of claim 9 or 10.

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