Battery management system and electric device

Abstract

The present application discloses a battery management system and an electric device. The battery management system comprises a first circuit and a protection circuit, wherein the first circuit is connected to the protection circuit, and the protection circuit is used for reducing the amplitude of an interference signal entering the first circuit. The embodiments of the present application can improve the reliability of the battery management system.

Description

Battery management system and power consumption device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202322979832.X, filed on November 3, 2023, entitled “Battery Management System and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery management technology, and in particular to a battery management system and an electrical device. Background Art

[0004] With the rapid development of social economy and the continuous advancement of automobile technology, the number of cars in use is increasing. Cars have gradually become an indispensable means of transportation in people's daily lives. Batteries in electrical devices serve as power sources and can power the electrical modules in the car. They are an indispensable component in the car.

[0005] A battery management system (BMS) can be used to manage batteries.

[0006] However, there is a problem in the related art that the battery management system has low reliability.

[0007] Application Contents

[0008] The present application provides a battery management system and an electrical device, which can improve the reliability of the battery management system.

[0009] In a first aspect, the present application provides a battery management system, comprising a first circuit and a protection circuit; the first circuit is connected to the protection circuit, and the protection circuit is used to reduce the amplitude of an interference signal entering the first circuit.

[0010] In an embodiment of the present application, a protection circuit is provided, and the protection circuit can be used to reduce the amplitude of the interference signal entering the first circuit. In this way, the interference intensity of the interference signal connected to the first circuit can be reduced, thereby reducing the possibility of error frames generated in the communication of the first circuit, which is beneficial to avoid extreme situations that damage the first circuit, thereby helping to improve the reliability of the battery management system.

[0011] In one possible implementation of the first aspect, the first circuit is connected to a first reference ground, the first reference ground is connected to a second reference ground, one end of the first capacitor is connected to the second reference ground, and the other end of the first capacitor is connected to the negative electrode of the battery through the switch module;

[0012] The protection circuit includes a first protection circuit connected between a first reference ground and a second reference ground, and is used to reduce the amplitude of an interference signal entering the first circuit through the first capacitor.

[0013] In an embodiment of the present application, the first reference ground and the second reference ground are no longer directly connected. Instead, a first protection circuit is provided between the first reference ground and the second reference ground. Since the first protection circuit can be used to reduce the amplitude of the interference signal entering the first circuit from the first capacitor, the interference intensity of the interference signal from the first capacitor received by the first circuit can be reduced, thereby reducing the possibility of error frames generated in the communication of the first circuit, which is beneficial to avoid extreme situations that damage the first circuit, thereby helping to improve the reliability of the battery management system.

[0014] In a possible implementation of the first aspect, the first protection circuit includes a first branch connected between the first reference ground and the second reference ground, and the first branch is used to reduce the amplitude of the AC interference signal entering the first circuit.

[0015] The interference signal may include an AC signal. The embodiment of the present application can reduce the interference of the AC interference signal from the first capacitor received by the first circuit by setting the first branch.

[0016] In a possible implementation of the first aspect, the first branch includes a first resistor and a second capacitor, which are connected in series. The combination of the first resistor and the second capacitor can reduce the amplitude of the AC interference signal connected to the first circuit.

[0017] In a possible implementation of the first aspect, the first protection circuit further includes a second branch, which is connected in parallel with the first branch, and the second branch is used to reduce the amplitude of the DC interference signal entering the first circuit.

[0018] The interference signal may include a DC signal. The embodiment of the present application can reduce the interference of the DC interference signal on the first circuit by setting a second branch.

[0019] In a possible implementation of the first aspect, the second branch includes a second resistor.

[0020] The interference signal may include a DC signal. By setting the second resistor, the amplitude of the DC interference signal connected to the first circuit can be reduced.

[0021] In a possible implementation of the first aspect, the battery management system further includes a second circuit, the second circuit being connected to the battery via a communication line;

[0022] The protection circuit includes a second protection circuit connected between the first circuit and the second circuit, and is used to reduce the amplitude of an interference signal entering the first circuit from the second circuit.

[0023] In an embodiment of the present application, a second protection circuit is provided between the second circuit and the first circuit. Since the second protection circuit can be used to reduce the amplitude of the interference signal entering the first circuit from the second circuit, the interference intensity of the interference signal from the second circuit received by the first circuit can be reduced, thereby reducing the possibility of error frames generated in the communication of the first circuit, which is beneficial to avoid extreme situations that damage the first circuit, thereby helping to improve the reliability of the battery management system.

[0024] In a possible implementation of the first aspect, the second protection circuit includes a third branch, and the third branch is used to reduce the amplitude of the AC interference signal entering the first circuit.

[0025] The interference signal transmitted from the second circuit to the first circuit is usually an AC signal. In the embodiment of the present application, by setting the third branch, the interference of the AC interference signal from the second circuit received by the first circuit can be reduced.

[0026] In a possible implementation of the first aspect, the third branch includes a third resistor and a third capacitor, and the third resistor and the third capacitor are connected in series.

[0027] The interference signal may include an AC signal. The capacitor can be used to pass AC and block DC. Through the combination of the third resistor and the third capacitor, the amplitude of the AC interference signal connected to the first circuit can be reduced.

[0028] Based on the same application concept, in a second aspect, an embodiment of the present application provides an electrical device, comprising a battery and a battery management system as described in any embodiment of the first aspect.

[0029] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0031] FIG1 is a schematic structural diagram of a battery management system according to an embodiment of the present application;

[0032] FIG2 is a schematic structural diagram of a battery management system according to another embodiment of the present application;

[0033] FIG3 shows a comparative example of FIG2 ;

[0034] FIG4 is a schematic structural diagram of a battery management system according to another embodiment of the present application;

[0035] FIG5 is a schematic structural diagram of a battery management system according to another embodiment of the present application;

[0036] FIG6 is a schematic structural diagram of a battery management system according to another embodiment of the present application;

[0037] FIG7 is a schematic structural diagram of a battery management system according to another embodiment of the present application;

[0038] FIG8 is a schematic diagram of a module structure of an electric device according to an embodiment of the present application.

[0039] In the accompanying drawings, the drawings are not necessarily drawn to scale.

[0040] In the attached figure:

[0041] 10. Battery management system;

[0042] 11. First circuit;

[0043] 12. Protection circuit;

[0044] 121, first protection circuit; 1211, first branch; 1212, second branch;

[0045] 122, second protection circuit; 1223, third branch;

[0046] 131. First switch module; 132. Second switch module;

[0047] 141. Shell; 142. Vehicle body;

[0048] 15. Second circuit;

[0049] 161, first communication line; 162, second communication line; 163, third communication line;

[0050] 100. Electrical equipment. DETAILED DESCRIPTION

[0051] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0052] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0053] The terms "first", "second" and the like in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0054] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0055] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0056] The battery management system may include a first circuit, such as some low-voltage circuits of the battery management system. The voltage of the low-voltage circuit is relatively low. In some cases, the first circuit may be exposed to interference signals. The applicant's research has found that if the amplitude of the interference signal is too large, it may cause error frames in the communication of the first circuit. In extreme cases, it may even damage the first circuit, resulting in low reliability of the battery management system.

[0057] In order to solve the above technical problems, the embodiments of the present application provide a battery management system and an electrical device. The battery management system and the electrical device provided in the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0058] The following first introduces the battery management system provided by the application embodiment.

[0059] FIG1 is a schematic diagram of a power supply control circuit according to an embodiment of the present application. As shown in FIG1 , the battery management system 10 may include a first circuit 11 and a protection circuit 12 .

[0060] The first circuit 11 is connected to the protection circuit 12 , and the protection circuit 12 can be used to reduce the amplitude of the interference signal entering the first circuit 11 .

[0061] In the embodiment of the present application, since a protection circuit 12 is provided, and the protection circuit 12 can be used to reduce the amplitude of the interference signal entering the first circuit 11, the interference intensity of the interference signal connected to the first circuit 11 can be reduced, thereby reducing the possibility of error frames generated in the communication of the first circuit 11, which is beneficial to avoid extreme situations that damage the first circuit, thereby helping to improve the reliability of the battery management system.

[0062] Exemplarily, the battery management system 10 can be set on a circuit board, which may include a low-voltage area and a high-voltage area. The low-voltage area can be used to set the first circuit 11 of the battery management system 10, and the high-voltage area can be used to set the second circuit 15 of the battery management system 10 (the second circuit will be introduced below).

[0063] It should be noted that the voltage in the high-voltage area is greater than the voltage in the low-voltage area, and the operating voltage of the first circuit 11 is less than the operating voltage of the second circuit. The voltage sizes of the high-voltage area and the low-voltage area are relative, and the operating voltage of the first circuit 11 and the operating voltage of the second circuit are also relative. This application does not limit the specific values ​​or ranges of the voltages in the high-voltage area and the low-voltage area, nor does it limit the specific values ​​or ranges of the operating voltages of the first circuit 11 and the second circuit.

[0064] For example, the first circuit 11 may include, but is not limited to, a power circuit module, a control module, and a storage module. The power circuit module may supply power to the electrical components of the battery management system 10. The control module may be used to control the turning off of switching components, process signals, and the like. The storage module may be used to store signals.

[0065] Exemplarily, the power circuit module may include but is not limited to a DCDC converter.

[0066] Exemplarily, the control module may be a chip or circuit that performs related actions according to characteristic instructions. For example, the control module may be a microcontroller unit (MCU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. For another example, the control module may include an external clock, random access memory (RAM), read-only memory (ROM), etc.

[0067] It should be noted that the functional modules included in the first circuit 11 and the description of the functions and structures of the functional modules in the above example are merely exemplary, and the present application does not limit the specific structure of the first circuit 11.

[0068] The present application does not limit the specific structure of the protection circuit 12, as long as the protection circuit 12 can reduce the amplitude of the interference signal entering the first circuit 11. Some examples of the protection circuit 12 are introduced below.

[0069] In some embodiments, as shown in Figure 2, the first circuit 11 is connected to a first reference ground GND, which is connected to a second reference ground PE. Equivalent capacitances are respectively provided between the positive and negative electrodes of the battery BAT and the second reference ground PE. Hereinafter, the equivalent capacitance between the negative electrode of the battery BAT and the second reference ground PE is referred to as a first capacitor CYN, and the equivalent capacitance between the positive electrode of the battery BAT and the second reference ground PE is referred to as a second Y-capacitor CYP. Furthermore, the positive and negative electrodes of the battery BAT may each be connected to a switch module. Hereinafter, the switch module connected to the negative electrode of the battery BAT is referred to as a first switch module 131, and the switch module connected to the positive electrode of the battery BAT is referred to as a second switch module 132.

[0070] One end of the first capacitor CYN is connected to the second reference ground PE, and the other end of the first capacitor CYN is connected to the negative electrode of the battery BAT via the first switch module 131. One end of the second Y capacitor CYP is connected to the second reference ground PE, and the other end of the second Y capacitor CYP is connected to the positive electrode of the battery BAT via the second switch module 132.

[0071] The protection circuit may include a first protection circuit 121 connected between the first reference ground GND and the second reference ground PE. The first protection circuit 121 may be used to reduce the amplitude of an interference signal entering the first circuit 11 through the first capacitor CYN.

[0072] The first reference ground GND can be understood as a low voltage reference ground, and the second reference ground PE can be understood as a high voltage reference ground. The absolute value of the voltage of the first reference ground GND can be smaller than the absolute value of the voltage of the second reference ground PE.

[0073] Exemplarily, the battery management system may include a battery management unit (BMU), the battery management unit includes a housing 141 , the first circuit 11 is connected to a first reference ground GND, and the first reference ground GND is connected to the housing 141 .

[0074] Exemplarily, the battery BAT and the battery management system may be used for an electrical device, the electrical device may include an electrical device, and the second reference ground PE may be connected to the vehicle body 142 of the electrical device.

[0075] For example, the housing 141 may be fixed to the vehicle body 142 by bolts or other connection methods.

[0076] For example, the first switch module 131 and the second switch module 132 can perform an on-off operation. The first switch module 131 and the second switch module 132 can include switches of the type of relays.

[0077] For comparison, please refer to Figure 3. The similarities between Figure 3 and Figure 2 are not repeated here. The differences include: Figure 3 does not include a first protection circuit, and the first reference ground GND and the second reference ground PE are directly connected. Due to the presence of first capacitor CYN, when first switch module 131 is closed, the high-frequency interference signal generated by the closure of first switch module 131 is transmitted through first capacitor CYN to first reference ground GND and first circuit 11. Due to the lack of protection measures, the interference signal entering first reference ground GND and first circuit 11 is barely attenuated, which can easily cause error frames on the communication line connected to first reference ground GND, and in extreme cases, damage the circuit board. The thick solid line with an arrow in Figure 3 represents the path of the interference signal.

[0078] However, in the embodiment of the present application, the first reference ground GND and the second reference ground PE are no longer directly connected. Instead, a first protection circuit 121 is provided between the first reference ground GND and the second reference ground PE. Since the first protection circuit 121 can be used to reduce the amplitude of the interference signal entering the first circuit 11 from the first capacitor CYN, the interference intensity of the interference signal from the first capacitor CYN received by the first circuit 11 can be reduced, thereby reducing the possibility of error frames generated in the communication of the first circuit 11, which is beneficial to avoid extreme situations that damage the first circuit, thereby helping to improve the reliability of the battery management system.

[0079] In some embodiments, as shown in FIG4 , the first protection circuit may include a first branch 1211 , the first branch 122 being connected between the first reference ground GND and the second reference ground PE, and the first branch 1211 being used to reduce the amplitude of the AC interference signal entering the first circuit 11 .

[0080] The interference signal may include an AC signal. In the embodiment of the present application, by providing the first branch 1211 , interference of the AC interference signal from the first Y capacitor CYN received by the first circuit 11 can be reduced.

[0081] In the signal transmission path, the greater the impedance, the lower the amplitude of the received signal. As an example, the first branch 1211 can be used to increase the impedance between the first reference ground GND and the second reference ground PE.

[0082] It should be noted that the use of first branch 1211 to increase impedance refers to a direct connection between the first reference ground GND and the second reference ground PE. In a direct connection between the first reference ground GND and the second reference ground PE, the impedance between the first reference ground GND and the second reference ground PE is relatively low. In the embodiment of the present application, the first reference ground GND and the second reference ground PE are connected via first branch 1211, which can increase impedance.

[0083] For example, the impedance value of the first branch 1211 may be a fixed value. For another example, the impedance value of the first branch 1211 may also vary with the scene. For example, the impedance value of the first branch 1211 may increase as the amplitude of the interference signal increases.

[0084] In some embodiments, as shown in FIG. 4 , the first branch 1211 may include a first resistor R1 and a second capacitor C2 , and the first resistor R1 and the second capacitor C2 are connected in series.

[0085] The greater the resistance of the first resistor R1, the greater the impedance of the first branch 1211. The interference signal may include an AC signal, and the capacitor can be used to pass AC and block DC. The combination of the first resistor R1 and the second capacitor C2 can reduce the amplitude of the AC interference signal connected to the first circuit 11.

[0086] The resistance value of the first resistor R1 and the capacitance value of the second capacitor C2 can be set according to actual needs. For example, the resistance value of the first resistor R1 is 1M ohm, and the capacitance value of the second capacitor C2 is 10uF. It should be noted that the specific parameters of the components mentioned in this embodiment and other embodiments are merely examples, and the specific parameters of the components in this application may include but are not limited to these.

[0087] In some embodiments, as shown in FIG5 , the first protection circuit 121 may further include a second branch 1212 , which is connected in parallel with the first branch 1211 . The second branch 1212 may be used to reduce the amplitude of a DC interference signal entering the first circuit 11 .

[0088] The interference signal may include a DC signal. In the embodiment of the present application, by providing the second branch 1212 , the interference of the DC interference signal on the first circuit 11 can be reduced.

[0089] It is understandable that the first protection circuit 121 includes a first branch 1211 and a second branch 1222 connected in parallel, so that the first protection circuit 121 can reduce the amplitude of the interference signal entering the first circuit 11 regardless of whether the interference signal is an AC signal or a DC signal.

[0090] As described above, in a signal transmission path, the greater the impedance, the lower the amplitude of the received signal. As an example, the second branch 1212 can also be used to increase the impedance between the first reference ground GND and the second reference ground PE.

[0091] It should be noted that the use of second branch 1212 to increase impedance is relative to a direct connection between the first reference ground GND and the second reference ground PE. In a direct connection between the first reference ground GND and the second reference ground PE, the impedance between the first reference ground GND and the second reference ground PE is relatively low. In the embodiment of the present application, the first reference ground GND and the second reference ground PE are connected via second branch 1212, which can increase impedance.

[0092] For example, the impedance value of the second branch 1212 may be a fixed value. For another example, the impedance value of the second branch 1212 may also vary with the scene. For example, the impedance value of the second branch 1212 may increase with the increase of the interference signal amplitude.

[0093] In some embodiments, as shown in FIG. 5 , the second branch 1212 may include a second resistor R2 .

[0094] The greater the resistance of the second resistor R2, the greater the impedance of the second branch 1212. The interference signal may include a DC signal. By setting the second resistor R2, the amplitude of the DC interference signal connected to the first circuit 11 can be reduced.

[0095] The resistance value of the second resistor R2 can be set according to actual needs. For example, the resistance value of the second resistor R2 is 1M ohm.

[0096] 6 , the first circuit 11 may be connected to multiple first reference grounds GND, which are connected to the housing 141. The number of first protection circuits 121 may include multiple, and the multiple first reference grounds GND are connected to the second reference ground PE through the multiple first protection circuits 121.

[0097] For example, each first protection circuit 121 may include a first branch 1211 and a second branch 1212 connected in parallel. The resistance value of the first resistor R1 in different first branches 1211 may be the same, the capacitance value of the second capacitor C2 in different first branches 1211 may be the same, and the resistance value of the second resistor R2 in different second branches 1212 may be the same.

[0098] In some embodiments, as shown in FIG7 , the battery management system may further include a second circuit 15 , which is connected to the battery BAT via a communication line. The second circuit 15 may be configured to collect signals, which may be transmitted to the first circuit 11 . The first circuit 11 may analyze and process the signals collected by the second circuit 15 .

[0099] The protection circuit further includes a second protection circuit 122 . The second protection circuit 122 is connected between the first circuit 11 and the second circuit 15 . The second protection circuit 122 can be used to reduce the amplitude of an interference signal entering the first circuit 11 from the second circuit 15 .

[0100] In Figure 7, the thick solid line with an arrow indicates the path of the interference signal. The interference signal can reach the second circuit 15 through the first communication line and / or the second communication line, and then reach the first circuit 11. If there is no protection against this interference signal path, the amplitude of the interference signal received by the first circuit 11 through this path will be large, which can easily cause communication error frames in the modules of the first circuit 11, and in extreme cases, damage the circuit board.

[0101] In the embodiment of the present application, a second protection circuit 122 is provided between the second circuit 15 and the first circuit 11. Since the second protection circuit 122 can be used to reduce the amplitude of the interference signal entering the first circuit 11 from the second circuit 15, the interference intensity of the interference signal from the second circuit 15 received by the first circuit 11 can be reduced, thereby reducing the possibility of error frames generated in the communication of the first circuit 11, which is beneficial to avoid extreme situations that damage the first circuit, thereby helping to improve the reliability of the battery management system.

[0102] For example, the communication line may include a first communication line 161 and a second communication line 162. The first communication line may include a daisy chain harness, and the second communication line 162 may include a high-voltage harness.

[0103] For example, the second circuit 15 may include, but is not limited to, a voltage acquisition module, a current acquisition module, and an insulation detection module. The voltage acquisition module may be used to acquire single cell voltage and total battery voltage, etc. The current acquisition module may be used to acquire battery current, etc. The insulation detection module may be used to detect battery insulation resistance.

[0104] For example, the voltage acquisition module may include, but is not limited to, a sampling resistor, a switching device, and an analog-to-digital converter. The current acquisition module may include, but is not limited to, a current sensor. The insulation detection module may include, but is not limited to, a sampling resistor, a switching device, an operational amplifier, and the like.

[0105] In some embodiments, as shown in FIG. 7 , the second protection circuit 122 may include a third branch 1223 . The third branch 1223 may be used to reduce the amplitude of the AC interference signal entering the first circuit 11 .

[0106] The interference signal transmitted from the second circuit 15 to the first circuit 11 is usually an AC signal. In the embodiment of the present application, by providing the third branch 1223 , the interference of the AC interference signal from the second circuit 15 received by the first circuit 11 can be reduced.

[0107] As described above, in a signal transmission path, the greater the impedance, the lower the amplitude of the received signal. As an example, the third branch 1223 can be used to increase the impedance between the first circuit 11 and the second circuit 15.

[0108] It should be noted that the third branch 1223 is used to increase impedance relative to the direct connection between the first circuit 11 and the second circuit 15 with almost no impedance. When the first circuit 11 and the second circuit 15 are directly connected with almost no impedance, the impedance between the first circuit 11 and the second circuit 15 is almost negligible. However, in the embodiment of the present application, the first circuit 11 and the second circuit 15 are connected via the third branch 1223, and the third branch 1223 can increase the impedance.

[0109] For example, the impedance value of the third branch 1223 may be a fixed value. For another example, the impedance value of the third branch 1223 may also vary with the scene. For example, the impedance value of the third branch 1223 may increase as the amplitude of the interference signal increases.

[0110] In some embodiments, as shown in FIG. 7 , the third branch 1223 may include a third resistor R3 and a third capacitor CY, and the third resistor R3 and the third capacitor CY are connected in series.

[0111] The third capacitor CY is an isolation capacitor between the second circuit 15 and the first circuit 11 .

[0112] The greater the resistance of the third resistor R3, the greater the impedance of the third branch 1223. The interference signal may include an AC signal, and the capacitor can be used to pass AC and block DC. The combination of the third resistor R3 and the third capacitor CY can reduce the amplitude of the AC interference signal connected to the first circuit 11.

[0113] Similarly, the resistance value of the third resistor R3 and the capacitance value of the third capacitor CY can be set according to actual needs, and this application does not limit this.

[0114] 7 , the battery management system may further include a third communication line 163 connected to the first circuit 11. At least a portion of the interference signal received by the first circuit 11 may be discharged through the third communication line 163. The third communication line 163 may include a low-voltage wiring harness.

[0115] It should be noted that the first reference ground and the second reference ground in the embodiments of the present application may be relative, and the absolute value of the voltage of the first reference ground may be smaller than the absolute value of the voltage of the second reference ground. The first circuit and the second circuit in the embodiments of the present application may also be relative, and the voltage of the first circuit may be smaller than the voltage of the second circuit.

[0116] It should also be noted that alternative solutions based on reducing the amplitude of the interference signal by increasing the impedance of the protection circuit are all within the scope of protection of this application.

[0117] Based on the same application concept, this application also provides an electrical device. As shown in Figure 8, the electrical device 100 includes a battery BAT and a battery management system 10. The battery management system 10 is the battery management system 10 described in any of the above embodiments. It is understood that the electrical device has the beneficial effects of the battery management system provided in the embodiments of this application. For details, please refer to the detailed description of the battery management system in the above embodiments, and this embodiment will not be repeated here.

[0118] It should be noted that in the embodiments shown in the above figures, the resistor is represented as a single resistor, and the capacitor is represented as a single capacitor. In other embodiments, the resistor may be an integration of resistors connected in series, in parallel, or in a hybrid configuration, and the capacitor may be an integration of capacitors connected in series, in parallel, or in a hybrid configuration. The specific parameters of each device may be set according to actual needs, and this application does not limit this.

[0119] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0120] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. A battery management system, comprising a first circuit and a protection circuit; The first circuit is connected to the protection circuit, and the protection circuit is used to reduce the amplitude of the interference signal entering the first circuit.

2. The battery management system according to claim 1, wherein: The first circuit is connected to a first reference ground, the first reference ground is connected to a second reference ground, one end of a first capacitor is connected to the second reference ground, and the other end of the first capacitor is connected to a negative electrode of a battery through a switch module; The protection circuit includes a first protection circuit, which is connected between the first reference ground and the second reference ground, and is used to reduce the amplitude of an interference signal entering the first circuit through the first capacitor.

3. The battery management system according to claim 2, wherein: The first protection circuit includes a first branch, the first branch is connected between the first reference ground and the second reference ground, and the first branch is used to reduce the amplitude of the AC interference signal entering the first circuit.

4. The battery management system according to claim 3, wherein: The first branch includes a first resistor and a second capacitor, and the first resistor and the second capacitor are connected in series.

5. The battery management system according to claim 3, wherein: The first protection circuit also includes a second branch, which is connected in parallel with the first branch, and the second branch is used to reduce the amplitude of the DC interference signal entering the first circuit.

6. The battery management system according to claim 5, wherein: The second branch includes a second resistor.

7. The battery management system according to any one of claims 1 to 6, wherein: The battery management system further comprises a second circuit, wherein the second circuit is connected to the battery via a communication line; The protection circuit includes a second protection circuit connected between the first circuit and the second circuit, and the second protection circuit is used to reduce the amplitude of an interference signal entering the first circuit from the second circuit.

8. The battery management system according to claim 7, wherein: The second protection circuit includes a third branch, and the third branch is used to reduce the amplitude of the AC interference signal entering the first circuit.

9. The battery management system according to claim 8, wherein: The third branch includes a third resistor and a third capacitor, and the third resistor and the third capacitor are connected in series.

10. An electrical device, comprising: Battery; And a battery management system as described in any one of claims 1 to 9.

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