Battery management system, battery pack, and electrical apparatus

Abstract

Provided in the present disclosure are a battery management system, a battery pack, and an electrical apparatus. The battery management system comprises: a plurality of switch assemblies, each switch assembly being connected between a battery and a corresponding load, and said assemblies being used for establishing or severing a connection between the battery and the corresponding load; a sampling circuit, the sampling circuit comprising sampling branch circuits in one-to-one correspondence with the plurality of switch assemblies, and each sampling branch circuit being used for collecting the voltage at a sampling measurement point, wherein a first end of each sampling branch circuit is connected to a corresponding switch assembly, and the connection point is a sampling measurement point; a second end of each sampling branch circuit is connected to a voltage source, and the connection point is a reference sampling point; and a third end of each sampling branch circuit is connected to a sampling module; the voltage source, which is used for providing reference voltages to the reference sampling points; and the sampling module, which is connected to a high voltage ground and is used for obtaining the voltage of each sampling measurement point relative to the corresponding reference sampling point.

Description

Battery management system, battery pack and power-consuming device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to the Chinese patent application filed with the China Patent Office on November 30, 2023, with application number 202311644337.1 and invention name “Sampling Circuit, Battery Management System, Battery Pack and Electrical Device”, the entire contents of which are incorporated by reference into this disclosure. Technical Field

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

[0004] With the development of new energy technologies, batteries are increasingly used in various electrical devices, such as mobile phones, laptops, electric vehicles, electric airplanes, electric ships, etc.

[0005] During the operation of an electrical device, the power supply provides power to each unit, ensuring normal operation. Multiple relay switches are typically installed in the high-voltage circuits corresponding to the positive and negative poles of the battery. To ensure the reliability of the battery during use, voltage sampling is performed at various detection points in the battery, and corresponding processing is performed based on the sampling results.

[0006] However, the circuit design for voltage sampling in the related art is complex and costly. Summary of the Invention

[0007] The embodiments of the present disclosure provide a battery management system, a battery pack, and an electrical device, which optimize the circuit design of a sampling circuit and improve the reliability of battery operation.

[0008] In a first aspect, an embodiment of the present disclosure provides a battery management system, including:

[0009] a plurality of switch assemblies, each switch assembly being connected between the battery and a corresponding load, and being used to connect or disconnect the battery and the corresponding load;

[0010] The sampling circuit includes sampling branches corresponding to multiple switch components one by one, and each sampling branch is used to collect the voltage at a sampling detection point; wherein the first end of each sampling branch is connected to the corresponding switch component, and the connection point is the sampling detection point; the second end of each sampling branch is connected to the voltage source, and the connection point is the reference sampling point; and the third end of each sampling branch is connected to the sampling module;

[0011] A voltage source, used for providing a reference voltage for a reference sampling point;

[0012] The sampling module is connected to the high voltage ground and is used to obtain the voltage of each sampling detection point relative to the reference sampling point.

[0013] By providing a voltage source, a sampling module, and a sampling branch, the voltage source can provide a reference voltage to the reference sampling point, so that the voltage at the reference sampling point relative to the reference ground serves as the reference voltage. The sampling module determines the sampling result based on the sampling voltage at the sampling detection point relative to the reference sampling point, as well as the reference voltage between the reference sampling point and the reference ground. This allows the sampling branches to share the same reference sampling point and sample directly relative to the reference voltage, simplifying circuit design and reducing circuit costs. Furthermore, since the sampling module is connected to the high-voltage ground, the sampling module no longer needs to consider insulation withstand voltage issues, making the voltage withstand selection of switching devices more flexible. Furthermore, the sampling circuit is located in the high-voltage region and is no longer connected to the low-voltage region, which improves anti-interference performance and eliminates the need for isolation devices, thus achieving cost savings.

[0014] In one possible embodiment of the first aspect, the battery management system further includes a voltage conversion module, the voltage conversion module being connected to the voltage source and configured to convert a reference voltage of the voltage source to provide corresponding sampling ranges for sampling detection points with different reference voltage requirements. The reference voltage provided by the voltage source is thus adjustable, enabling each sampling detection point to perform sampling relative to a different reference voltage to meet different sampling requirements.

[0015] In one possible implementation of the first aspect, the multiple switch components include at least one first switch component and / or at least one second switch component, and the sampling branch includes: a first sampling branch corresponding to the first switch component, wherein the sampling detection point corresponding to the first sampling branch is connected to the first pole of the battery, or the sampling detection point corresponding to the first sampling branch is connected to the first pole of the battery via the first switch component; and a second sampling branch corresponding to the second switch component, wherein the sampling detection point corresponding to the second sampling branch is connected to the second pole of the battery via the second switch component. Voltage sampling can be performed at the sampling detection point connected to the first pole of the battery and the sampling detection point connected to the second pole of the battery, respectively, via the first sampling branch and the second sampling branch. This allows the first sampling branch and / or the second sampling branch to share the same reference sampling point and perform sampling directly relative to the reference voltage, thereby simplifying circuit design and reducing circuit cost.

[0016] In one possible implementation of the first aspect, the multiple switch assemblies further include parallel switch assemblies, and the sampling branch further includes: a third sampling branch connected to one end of the parallel switch assemblies; and a fourth sampling branch connected to the other end of the parallel switch assemblies. Thus, when at least two switch assemblies are connected in parallel, the at least two switch assemblies can reuse the same sampling branch (including the third sampling branch and the fourth sampling branch). This reuse of the sampling branches can also simplify circuit design and reduce circuit costs.

[0017] In one possible implementation of the first aspect, the sampling branch includes a first sampling unit and a second sampling unit, wherein the first sampling unit and the second sampling unit are connected in series. The first sampling unit and the second sampling unit are configured to divide the voltage at the sampling detection point so that the divided voltage falls within a sampling range.

[0018] In one possible implementation of the first aspect, the sampling points of the sampling branch include a first sampling point, the sampling module includes a first sampling terminal, the first sampling point is disposed between the first sampling unit and the second sampling unit, and the first sampling point is connected to the first sampling terminal of the sampling module. By connecting the first sampling terminal of the sampling module to the first sampling point of the sampling branch, voltage sampling of the sampling branch relative to a reference voltage is achieved.

[0019] In one possible implementation of the first aspect, the sampling points of the sampling branch include a second sampling point, the sampling module includes a second sampling terminal, the second sampling point of the sampling branch is disposed at both ends of the second sampling unit, and the second sampling point is connected to the second sampling terminal of the sampling module. By connecting the second sampling terminal of the sampling module to the second sampling point of the sampling branch, the voltage at both ends of the second sampling unit can be directly sampled, and the voltage at the sampling detection point relative to the reference sampling point can be determined by combining the voltage division ratio between the first sampling unit and the second sampling unit.

[0020] In a possible implementation of the first aspect, the second sampling terminal of the sampling module is a differential sampling terminal, and the voltages at both ends of the second sampling unit can be directly acquired through differential sampling.

[0021] In a possible implementation of the first aspect, the sampling branch further includes: a switch unit, the switch unit being configured to turn on the sampling branch. By providing the switch unit, the application of the sampling branch can be flexibly controlled.

[0022] In one possible implementation of the first aspect, the sampling module is connected to the switch unit, and the sampling module is used to control the switch unit to be turned on or off. By controlling the switch unit to be turned on by the sampling module, the switch unit can be turned on when sampling is required and turned off when sampling is not required, thereby improving the flexibility of sampling control.

[0023] In a possible implementation of the first aspect, the switch unit includes at least one of a transistor, a photoelectric device, and a relay. By providing the switch device, on-off control of the sampling branch can be achieved.

[0024] In one possible implementation of the first aspect, the voltage source is connected to the second electrode of the battery, and the reference voltage is the voltage difference between a reference sampling point and the second electrode of the battery. By using the second electrode of the battery as a reference ground, the sampling module can determine a sampling result based on a sampled voltage at a sampling point in the sampling branch relative to the reference sampling point, as well as a reference voltage between the reference sampling point and the reference ground.

[0025] In one possible implementation of the first aspect, the switch assembly includes any one of a main positive switch, a main negative switch, a pre-charge switch, a main positive DC charging switch, a main positive AC charging switch, a main negative charging switch, a heating switch, and a load switch. By sampling voltage at sampling detection points at both ends of each switch assembly, it can be determined whether a fault such as adhesion has occurred in the switch assembly based on a voltage difference across the switch assembly.

[0026] In one possible embodiment of the first aspect, the battery management system further includes: a low-voltage power supply; a power isolation module connected between the low-voltage power supply and a voltage source; a low-voltage control module; and a communication isolation module connected between a voltage input terminal of the low-voltage control module and a sampling output terminal of the sampling module. By providing a sampling circuit, the number of isolation modules in the battery management system can be reduced, thereby reducing the number of components and circuit costs.

[0027] In a second aspect, an embodiment of the present disclosure provides a battery pack, comprising a battery and a battery management system as in any one of the embodiments of the first aspect.

[0028] In a third aspect, an embodiment of the present disclosure provides an electrical device comprising a battery pack according to any one of the embodiments of the second aspect.

[0029] Compared with the related art, the battery management system, battery pack and power-consuming device provided by the embodiments of the present disclosure, by setting a voltage source, a sampling module and a sampling branch, can provide a reference voltage to the reference sampling point through the voltage source, so that the voltage of the reference sampling point relative to the reference ground is the reference voltage. The sampling module can determine the sampling result based on the sampling voltage of the sampling detection point relative to the reference sampling point and the reference voltage between the reference sampling point and the reference ground. In this way, the sampling branches share the same reference sampling point and directly sample relative to the reference voltage, which simplifies the circuit design and reduces the circuit cost. In addition, the sampling module is connected to the high-voltage ground, so that the sampling module no longer needs to consider the problem of insulation withstand voltage, and the withstand voltage selection of the switching device is relatively relaxed; and the sampling circuit belongs to the high-voltage area and is no longer connected to the low voltage, which can also improve the anti-interference performance and eliminate the need to set an isolation device, thereby achieving the purpose of saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0031] FIG1 is a schematic diagram of a module structure of a sampling circuit provided in an embodiment of the present disclosure;

[0032] FIG2 is a schematic diagram of a module structure of a sampling circuit provided in another embodiment of the present disclosure;

[0033] FIG3 is a schematic diagram of the module structure of a sampling circuit provided in yet another embodiment of the present disclosure;

[0034] FIG4 is a schematic diagram of the module structure of a sampling circuit provided in yet another embodiment of the present disclosure;

[0035] FIG5 is a schematic diagram of a module structure of a sampling circuit provided in yet another embodiment of the present disclosure;

[0036] FIG6 is a schematic diagram of the circuit structure of a sampling circuit provided in an embodiment of the present disclosure;

[0037] FIG7 is a schematic diagram of the circuit structure of a sampling circuit provided in another embodiment of the present disclosure;

[0038] FIG8 is a schematic diagram of a circuit structure of a conventional sampling method provided in an embodiment of the present disclosure;

[0039] FIG9 is a schematic diagram of a circuit structure of a differential sampling method provided in an embodiment of the present disclosure;

[0040] FIG10 is a schematic diagram of the circuit structure of a sampling circuit provided in yet another embodiment of the present disclosure;

[0041] FIG11 is a schematic diagram of the circuit structure of a sampling branch provided in an embodiment of the present disclosure;

[0042] FIG12 is a schematic diagram of the circuit structure of a sampling branch provided in another embodiment of the present disclosure;

[0043] FIG13 is a schematic diagram of the module structure of a battery management system provided in an embodiment of the present disclosure.

[0044] In the accompanying drawings: 10, sampling module; 20, sampling branch; 21, first sampling branch; 22, second sampling branch; 23, first sampling unit; 24, second sampling unit; 25, switch unit; 251, control component; 252, controlled component; 12, first sampling unit; 30, switch component; 40, battery; 50, voltage source; 60, voltage conversion module; Q1, first MOSFET; Qen, enable switch; Ls, light source; Po, light receiver; Q2, second MOSFET; Q3, third MOSFET; K1, main negative switch; K2, main positive switch; K3, pre-charge switch; K4, main positive DC charging switch; K5, main negative charging switch; K6, main positive AC charging switch; K7, heating switch; K8, load switch; 13, low-voltage power supply; 14, power isolation module; 15, communication isolation module; 16, low-voltage control module. DETAILED DESCRIPTION

[0045] The features and exemplary embodiments of various aspects of the present disclosure will be described in detail below. In order to make the purposes, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present disclosure, rather than to limit the present disclosure. For those skilled in the art, the present disclosure can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present disclosure by illustrating examples of the present disclosure.

[0046] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article, or device comprising the elements.

[0047] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other. The embodiments will be described in detail below with reference to the accompanying drawings.

[0048] With the development of new energy technologies, batteries are increasingly used in various electrical devices, such as mobile phones, laptops, electric vehicles, electric airplanes, electric ships, etc.

[0049] During the operation of an electrical device, the power supply provides power to each unit, ensuring normal operation. Multiple relay switches are typically installed in the high-voltage circuits corresponding to the positive and negative poles of the battery. To ensure the reliability of the battery during use, voltage sampling is performed at various detection points in the battery, and corresponding processing is performed based on the sampling results.

[0050] However, the circuit architecture for voltage sampling in related technologies has certain defects.

[0051] In order to solve the above technical problems, the embodiments of the present disclosure provide a sampling circuit, a battery management system, a battery pack, and an electric device. The sampling circuit provided by the embodiments of the present disclosure is first introduced below.

[0052] According to some embodiments of the present disclosure, referring to FIG1 , the present disclosure provides a sampling circuit comprising a voltage source 50 , a sampling module 10 , and a sampling branch 20 .

[0053] The voltage source 50 is connected to the reference sampling point, and the voltage source 50 can provide a reference voltage for the reference sampling point, so that the voltage of the reference sampling point relative to the reference ground is the reference voltage.

[0054] Taking the voltage source 50 maintaining the reference voltage at 5V as an example, if the voltage of the reference ground is 0V, the voltage source 50 can make the voltage at the reference sampling point 5V; if the voltage of the reference ground is 10V relative to the earth, the voltage source 50 can make the voltage at the reference sampling point 15V.

[0055] The sampling branch 20 may be connected between a corresponding sampling detection point and a reference sampling point in the battery 40 .

[0056] The sampling terminal of the sampling module 10 can be connected to the sampling branch 20. The sampling module 10 can obtain the sampling signal collected by the corresponding sampling branch 20 through the sampling terminal. Based on the sampling signal, the voltage of the sampling detection point corresponding to the sampling branch 20 relative to the reference sampling point can be determined. The voltage of the reference sampling point relative to the reference ground is a fixed reference voltage. Therefore, after determining the voltage of each sampling detection point relative to the reference sampling point, the sampling module 10 can calculate the sum of the voltage and the reference voltage to obtain the voltage of the sampling detection point relative to the reference ground.

[0057] It should be noted that when there are multiple sampling detection points, multiple sampling branches 20 can be provided corresponding to the multiple sampling detection points, with each sampling branch 20 connected between a corresponding sampling detection point and a reference sampling point. The multiple sampling terminals of the sampling module 10 are respectively connected to the multiple sampling branches 20. The sampling module 10 can obtain the voltage of each corresponding sampling detection point relative to the reference sampling point through each sampling terminal. By combining this with the reference voltage of the reference sampling point relative to the reference ground, voltage sampling at multiple sampling detection points relative to the reference ground can be achieved.

[0058] It should be noted that in the above embodiment, what is obtained are voltage samples of multiple sampling detection points relative to a fixed reference ground. In the actual sampling process, in addition to the reference ground, there may be sampling requirements for multiple reference points. When the sampling circuit needs to implement voltage sampling of multiple reference points, since the voltage of each sampling detection point relative to the reference ground is known, some sampling detection points can be determined from the multiple sampling detection points as reference points. The voltage of the remaining sampling detection points relative to each reference point is the difference between the voltage of the sampling detection point relative to the reference ground and the voltage of each reference point relative to the reference ground. That is, after determining the voltage of any sampling detection point relative to the reference ground, the sampling detection point can be used as a reference point to obtain the voltage of the remaining sampling detection points relative to the reference point.

[0059] In this embodiment, by providing a voltage source 50, a sampling module 10, and a sampling branch 20, a reference voltage can be provided to the reference sampling point via the voltage source 50, so that the voltage of the reference sampling point relative to the reference ground serves as the reference voltage. The sampling branch 20 can sample the voltage at the sampling detection point, and the sampling module 10, connected to the sampling branch 20, can obtain the sampled voltage of the corresponding sampling detection point relative to the reference sampling point. The sampling module 10 can determine the voltage of the sampling detection point relative to the reference ground based on the sampled voltage of the sampling detection point relative to the reference sampling point and the reference voltage between the reference sampling point and the reference ground. When there are multiple sampling detection points, some of the sampling detection points can also serve as reference points to obtain the voltage of the remaining sampling detection points relative to the reference point, thereby implementing voltage sampling at multiple reference points in the high-voltage sampling architecture.

[0060] It should be noted that in the related art, when implementing voltage sampling at multiple reference points, it is usually necessary to set up a sampling circuit architecture for each reference point. The sampling circuit architecture includes an isolated power supply module, a sampling chip, an isolated communication module, and a corresponding low-voltage controller. In other words, when implementing voltage sampling at multiple reference points, a large number of components need to be set up in the circuit architecture, resulting in high component costs and component space, which in turn affects the space and production costs of the overall device. Compared with the related art, the above embodiment provides a single reference ground to obtain the voltage of each sampling detection point relative to the reference ground. When implementing voltage sampling at multiple reference points, any sampling detection point can be used as a reference point, and the voltage of each sampling detection point relative to the reference point can be calculated. Moreover, since there is only one reference ground, there is no need to set up multiple sampling circuit architectures, which can effectively reduce the number and cost of components in the device.

[0061] According to some embodiments of the present disclosure, referring to FIG. 2 , the reference ground may be the second electrode of the battery 40 , the voltage source 50 may be connected to the second electrode of the battery 40 , and the reference voltage provided by the voltage source 50 is the voltage difference between the reference sampling point and the second electrode of the battery 40 .

[0062] In this embodiment, by using the second electrode of the battery 40 as a reference ground, the voltage at the reference sampling point relative to the second electrode of the battery 40 can be made into a reference voltage. After the sampling module obtains the voltage of the sampling detection point relative to the reference sampling point, the voltage at the sampling detection point relative to the second electrode of the battery 40 can be obtained by calculating the sum of the voltage and the reference voltage.

[0063] In the embodiment of the present disclosure, when the reference ground can be selected from the second pole of the battery 40, the reference ground can also be referred to as the "high-voltage ground". Taking Figure 2 as an example, the sampling module 10 can be connected to the high-voltage ground GND. The high-voltage ground GND can refer to the reference ground provided by the high-voltage system, for example, the high-voltage system can be a battery system. It should be noted that in this field, the operating voltage of the battery system belongs to Class B, for example, the maximum operating voltage is between 60V and 1500V, and therefore it is defined as a high-voltage system. At this time, the reference ground provided by the second pole of the battery 40 (that is, the negative pole of the battery 40) can generally be called the high-voltage ground GND.

[0064] It should also be noted that the sampling module 10 is connected to the high-voltage ground GND. This eliminates the need to consider insulation withstand voltage, making the selection of switch components with relatively relaxed withstand voltage requirements. Furthermore, the sampling circuits are all in the high-voltage region, with no connection to low voltage, thus eliminating the impact of common-mode interference. This improves anti-interference performance and eliminates the need for isolation components, saving costs. It should be noted that FIG2 is used as an example to illustrate the connection of the sampling module 10 to the high-voltage ground GND, but this is not a limitation. The sampling modules 10 in other figures are also connected to the high-voltage ground GND.

[0065] According to some embodiments of the present disclosure, with continued reference to FIG. 2 , the sampling circuit further includes a voltage conversion module 60 , which is connected to the voltage source 50 and is configured to convert the reference voltage of the voltage source to provide corresponding sampling ranges for sampling detection points with different reference voltage requirements.

[0066] The voltage conversion module 60 can be connected between the voltage source 50 and the reference sampling point. The voltage conversion module 60 can receive the reference voltage provided by the voltage source 50 and perform voltage conversion on the reference voltage to provide corresponding sampling ranges for sampling detection points with different reference voltage requirements. This adjustable reference voltage provided by the voltage source 50 enables each sampling detection point to sample with respect to different reference voltages, meeting different sampling requirements.

[0067] According to some embodiments of the present disclosure, please refer to Figures 3 to 5. As shown in Figure 3, the sampling branch 20 may include a first sampling branch 21; as shown in Figure 4, the sampling branch 20 may also include a second sampling branch 22; as shown in Figure 5, the sampling branch 20 may also include both the first sampling branch 21 and the second sampling branch 22.

[0068] As shown in FIG3 , the sampling detection point corresponding to the first sampling branch 21 can be directly connected to the first electrode of the battery 40 or connected to the first electrode of the battery 40 through the switch assembly 30. As shown in FIG4 , the sampling detection point corresponding to the second sampling branch 22 can be connected to the second electrode of the battery 40 through the switch assembly 30. The first electrode of the battery 40 can be the positive electrode, and the second electrode can be the negative electrode.

[0069] In the first sampling branch 21, when the sampling detection point is directly connected to the first terminal of the battery 40, the first sampling branch 21 can directly sample the voltage of the first terminal of the battery 40. When the reference ground is set to the second terminal of the battery 40, the voltage of the first terminal of the battery 40 relative to the second terminal of the battery 40, that is, the voltage across the battery 40, can be determined based on the sum of the voltage at the sampling detection point relative to the reference sampling point and the reference voltage.

[0070] In the first sampling branch 21 , when the sampling detection point is connected to the first pole of the battery 40 through the switch component 30 , when the switch component 30 is turned on, the voltages at both ends of the switch component 30 are consistent. At this time, the voltage at the sampling detection point is equal to the voltage of the first pole of the battery 40 .

[0071] When the switch assembly 30 is disconnected, a voltage difference exists across the switch assembly 30. Since one end of the switch assembly 30 is connected to the first terminal of the battery 40, the sampling branch 20 can be connected to the sampling detection point at the other end of the switch assembly 30. The sampling module 10 samples the voltage at the sampling detection point to determine the voltage at the sampling detection point relative to the reference sampling point. The voltage at the sampling detection point relative to the second terminal of the battery is obtained based on the sum of the voltage at the sampling detection point relative to the reference sampling point and the reference voltage.

[0072] In the second sampling branch 22, when the sampling detection point is connected to the second terminal of the battery 40 via the switch assembly 30, when the switch assembly 30 is turned on, the voltages across the switch assembly 30 are consistent, and the voltage at the sampling detection point is equal to the voltage at the second terminal of the battery 40. However, when the switch assembly 30 is turned off, a voltage difference exists across the switch assembly 30. Since one end of the switch assembly 30 is connected to the second terminal of the battery 40, the sampling branch 20 can be connected to the sampling detection point at the other end of the switch assembly 30. The sampling module 10 samples the voltage at the sampling detection point to determine the voltage at the sampling detection point relative to the reference sampling point. The voltage at the sampling detection point relative to the second terminal of the battery is then determined based on the sum of the voltage at the sampling detection point relative to the reference sampling point and the reference voltage.

[0073] In the above embodiment, taking the example of a battery 40 having a first electrode as the positive electrode and a second electrode as the negative electrode, when only the first sampling branch 21 is provided in the sampling branch 20, the sampling detection point corresponding to the first sampling branch 21 is the positive electrode sampling detection point. The voltage of the positive electrode sampling detection point relative to the second electrode of the battery can be sampled through the first sampling branch 21 and the sampling module 10. When only the second sampling branch 22 is provided in the sampling branch 20, the sampling detection point corresponding to the second sampling branch 22 is the negative electrode sampling detection point. The voltage of the negative electrode sampling detection point relative to the second electrode of the battery can be sampled through the second sampling branch 22 and the sampling module 10.

[0074] If the sampling branch 20 includes a first sampling branch 21 and a second sampling branch 22, the first sampling branch 21 can sample the voltage of the positive sampling detection point relative to the second pole of the battery, and the second sampling branch 22 can sample the voltage of the negative sampling detection point relative to the second pole of the battery, thereby enabling voltage sampling to be performed on all nodes in the positive and negative circuits where voltage sampling is required.

[0075] When the sampling branch 20 includes a first sampling branch 21 and a second sampling branch 22 , the number of the first sampling branch 21 is at least one, and the number of the second sampling branch 22 is also at least one.

[0076] Since the reference sampling points of the first sampling branch 21 and the second sampling branch 22 are consistent, after determining the voltage of the positive sampling detection point relative to the reference sampling point and the voltage of the negative sampling detection point relative to the reference sampling point, the sum of the voltage of the positive sampling detection point relative to the reference sampling point and the voltage of the negative sampling detection point relative to the reference sampling point can also be calculated to obtain the voltage of the positive sampling detection point relative to the negative sampling detection point.

[0077] When there are multiple first sampling branches 21 and second sampling branches 22, voltage sampling between any two positive sampling detection points, voltage sampling between any two negative sampling detection points, and voltage sampling between any positive sampling detection point and any negative sampling detection point can be achieved.

[0078] Taking voltage sampling between two positive sampling detection points as an example, based on the two first sampling branches 21 corresponding to the two positive sampling detection points, the sampling module 10 can respectively obtain the voltages of the two positive sampling detection points relative to the reference sampling point. The voltage difference between the two positive sampling detection points is the difference between the voltage of one positive sampling detection point relative to the reference sampling point and the voltage of the other positive sampling detection point relative to the reference sampling point.

[0079] When one of the two positive electrode sampling and detection points is directly connected to the first electrode of the battery, and the other is connected to the first electrode of the battery through the switch component 30, if the switch component 30 is turned on, the potentials of the two positive electrode sampling and detection points should be the same, that is, the voltage difference is 0. If the switch component 30 is normally turned off, there should be a certain voltage difference between the two positive electrode sampling and detection points.

[0080] After calculating the voltage difference between the two positive sampling detection points, the voltage difference can be compared with the preset voltage threshold. If the voltage difference is greater than the voltage threshold, it means that the switch component 30 is disconnected normally; if the voltage difference is less than the voltage threshold, it means that the switch component 30 is not disconnected normally, and there may be a fault such as relay adhesion.

[0081] The voltage threshold may be a fixed voltage or may be associated with the voltage across the battery 40. For example, when the voltage across the battery 40 is 800V, the voltage threshold may be 1%, 2%, or other proportions of the voltage across the battery 40.

[0082] Similarly, when sampling the voltage between two negative sampling detection points, the sampling module 10 can obtain the voltages of the two negative sampling detection points relative to the reference sampling point based on the two second sampling branches 22 corresponding to the two negative sampling detection points. The voltage difference between the two negative sampling detection points is the difference between the voltage of one negative sampling detection point relative to the reference sampling point and the voltage of the other negative sampling detection point relative to the reference sampling point.

[0083] When it is necessary to determine the voltage difference between two positive sampling detection points, the difference between the voltage of one positive sampling detection point relative to the reference sampling point and the voltage of the other positive sampling detection point relative to the reference sampling point can be calculated, thereby obtaining the voltage difference between the two positive sampling detection points; when it is necessary to determine the voltage difference between two negative sampling detection points, the difference between the voltage of one negative sampling detection point relative to the reference sampling point and the voltage of the other negative sampling detection point relative to the reference sampling point can be calculated, thereby obtaining the voltage difference between the two negative sampling detection points; when it is necessary to determine the voltage difference between a positive sampling detection point and a negative sampling detection point, the sum of the voltage of the positive sampling detection point relative to the reference sampling point and the voltage of the negative sampling detection point relative to the reference sampling point can be calculated, thereby obtaining the voltage difference between the positive sampling detection point and the negative sampling detection point.

[0084] According to some embodiments of the present disclosure, please refer to Figure 6. The above-mentioned switch assembly 30 may include any one of the main positive switch K2, the main negative switch K1, the pre-charging switch K3, the main positive DC charging switch K4, the main positive AC charging switch K6, the main negative charging switch K5, the heating switch K7 and the load switch K8.

[0085] The positive and negative electrodes of the battery 40 can be connected to corresponding charging devices, functional circuits, or loads via different switch assemblies 30. By providing a sampling point on the side of each switch assembly 30 away from the first or negative electrode of the battery 40 and sampling the voltage at the sampling point via the sampling branch 20, the status of each switch assembly 30 can be diagnosed in combination with the positive and negative electrode voltages of the battery 40, thereby improving the reliability of the battery during operation.

[0086] As an optional implementation, in the above embodiment, the positive electrode sampling detection points may include the sampling detection point connected to the positive electrode of battery 40 and the sampling detection points respectively passing through the main positive switch K2, the main positive DC charging switch K4, the main positive AC charging switch K6, the heating switch K7, and the load switch K8. That is, there may be six positive electrode sampling detection points. Similarly, the negative electrode sampling detection points may include the second electrode of the battery connected to the negative electrode of battery 40 and the sampling detection points respectively passing through the main negative switch K1 and the main negative charging switch K5. That is, there may be three negative electrode sampling detection points. When implementing voltage sampling at multiple reference points, at least one of the three negative electrode sampling detection points can be used as a reference point to calculate the voltage of any positive electrode sampling detection point relative to that reference point. That is, for the six positive electrode sampling detection points and the three negative electrode sampling detection points, the voltage of each positive electrode sampling detection point relative to each negative electrode sampling detection point can be obtained, for a total of 18 sampling voltages.

[0087] According to some embodiments of the present disclosure, referring to FIG. 7 , the sampling branch 20 may include a first sampling unit 23 and a second sampling unit 24 .

[0088] The first sampling unit 23 and the second sampling unit 24 are connected in series.

[0089] The first sampling unit 23 and the second sampling unit 24 can each be composed of a resistor. The number and resistance values ​​of the resistors in the first sampling unit 23 and the second sampling unit 24 can be set according to the normal voltage range of the sampling detection point to which the sampling branch 20 is connected. For example, when the voltage across the battery 40 is relatively high, if the normal voltage range of the sampling detection point includes a relatively high voltage, the first sampling unit 23 can be equipped with a resistor with a relatively high resistance value, and the second sampling unit 24 can be equipped with a resistor with a relatively low resistance value. This ensures that after the first sampling unit 23 and the second sampling unit 24 divide the voltage at the sampling detection point, the voltage difference across the second sampling unit 24 will not be too large to exceed the detection range of the sampling module 10, nor too small to affect the accuracy of the sampling result.

[0090] According to some embodiments of the present disclosure, referring to FIG. 8 , the sampling module 10 may include a first sampling terminal S1 , and the sampling points of the sampling branch 20 may include a first sampling point disposed between the first sampling unit 23 and the second sampling unit 24 .

[0091] The first sampling point of the sampling branch 20 may be connected to the first sampling terminal S1 of the sampling module 10 , and the sampling module 10 may obtain the voltage of the first sampling point through the first sampling terminal S1 .

[0092] After acquiring the voltage at the first sampling point through the first sampling point, the sampling module 10 can determine the voltage difference across the sampling branch 20 based on the equivalent resistance values ​​of the first sampling unit 23 and the second sampling unit 24. For example, if the equivalent resistance value of the first sampling unit 23 is R1, the equivalent resistance value of the second sampling unit 24 is R2, and the voltage value at the first sampling point is Vp and the reference voltage is Tsref, the formula for calculating the voltage difference across the sampling branch 20 is as follows: V1 = (Vp - Vref) * (R1 + R2) / R2;

[0093] Since both ends of the sampling branch 20 are connected to the sampling detection point and the reference sampling point respectively, the voltage difference between the two ends of the sampling branch 20 is the voltage difference between the sampling detection point and the reference sampling point.

[0094] When the reference ground is the second electrode of the battery, the sampling module 10 can determine the voltage of the sampling detection point relative to the second electrode of the battery based on the voltage difference between the two ends of the sampling branch 20 and the reference voltage provided by the voltage source 50, as follows: V = V1 + Vref;

[0095] Wherein, Vref is the reference voltage between the reference sampling point and the second electrode of the battery, and V is the voltage of the sampling detection point relative to the second electrode of the battery.

[0096] According to some embodiments of the present disclosure, referring to FIG. 9 , the sampling module 10 may include a second sampling terminal S2 , and the sampling points of the sampling branch 20 may include a second sampling point, which is disposed at both ends of the second sampling unit 24 , that is, the second sampling point includes at least two sampling points at both ends of the second sampling unit 24 .

[0097] The second sampling point of the sampling branch 20 can be connected to the second sampling terminal S2 of the sampling module 10, and the sampling module 10 can obtain the voltage of the second sampling point through the second sampling terminal S2. When there are two second sampling points, there are also two second sampling terminals S2 of the sampling module 10.

[0098] The sampling module 10 can directly sample the voltage across the second sampling unit 24 via the second sampling terminal S2. After determining the voltage across the second sampling unit 24, the voltage difference across the sampling branch 20 can be calculated based on the equivalent resistance values ​​of the first sampling unit 23 and the second sampling unit 24. For example, if the equivalent resistance value of the first sampling unit 23 is R1 and the equivalent resistance value of the second sampling unit 24 is R2, and the voltage across the second sampling unit 24 collected by the second sampling terminal S2 of the sampling module 10 is Vq, the formula for calculating the voltage difference across the sampling branch 20 is as follows: V2 = Vq * (R1 + R2) / R2;

[0099] Since both ends of the sampling branch 20 are connected to the sampling detection point and the reference sampling point respectively, the voltage difference between the two ends of the sampling branch 20 is the voltage difference between the sampling detection point and the reference sampling point.

[0100] When the reference ground is the second electrode of the battery, the sampling module 10 can determine the voltage of the sampling detection point relative to the second electrode of the battery based on the voltage difference between the two ends of the sampling branch 20 and the reference voltage provided by the voltage source 50, as follows: V = V2 + Vref;

[0101] Wherein, Vref is the reference voltage between the reference sampling point and the second electrode of the battery, and V is the voltage of the sampling detection point relative to the second electrode of the battery.

[0102] According to some embodiments of the present disclosure, the second sampling terminal S2 of the sampling module 10 may be a differential sampling terminal, that is, the second sampling terminal S2 may perform differential sampling on both ends of the second sampling unit 24 to obtain a voltage difference between both ends of the second sampling unit 24 .

[0103] The sampling module 10 may be a sampling chip, and the sampling mode of the sampling chip may be differential sampling or conventional sampling.

[0104] When the sampling chip uses differential sampling, the sampling terminal corresponding to the sampling branch 20 is the second sampling terminal S2, and the second sampling terminal S2 includes a positive sampling terminal and a negative sampling terminal. The positive sampling terminal should be connected to the terminal with a higher voltage between the two ends of the second sampling unit 24 in the sampling branch 20, and the negative sampling terminal should be connected to the terminal with a lower voltage between the two ends of the second sampling unit 24.

[0105] When sampling branch 20 is first sampling branch 21, the voltage between first sampling unit 23 and second sampling unit 24 is greater than the voltage at the reference sampling point. In this case, the positive sampling terminal of second sampling terminal S2 should be connected to the center of first sampling unit 23 and second sampling unit 24, while the negative sampling terminal should be connected to the other end of second sampling unit 24.

[0106] Conversely, when sampling branch 20 is second sampling branch 22, the voltage between first sampling unit 23 and second sampling unit 24 is lower than the voltage at the reference sampling point. In this case, the negative sampling terminal of second sampling terminal S2 should be connected between first sampling unit 23 and second sampling unit 24, while the positive sampling terminal should be connected to the other end of second sampling unit 24.

[0107] It should be noted that the sampling chip may include a plurality of second sampling terminals S2 . When a plurality of sampling detection points need to be detected in the sampling circuit, each second sampling terminal S2 may be connected to a corresponding sampling branch 20 .

[0108] According to some embodiments of the present disclosure, referring to FIG. 10 , the sampling branch 20 may further include a switch unit 25 , and the switch unit 25 may enable the sampling branch 20 to be conductive.

[0109] The switch unit 25 may be connected between the first sampling unit 23 and the second sampling unit 24 . The switch unit 25 may be switched between an on state and an off state to connect and disconnect the first sampling unit 23 and the second sampling unit 24 .

[0110] As shown in FIG10 , since the voltage between the positive and negative electrodes of the battery 40 needs to be detected in real time, the switch unit 25 may not be provided for the sampling branch 20 corresponding to the sampling detection point directly connected to the first electrode of the battery 40 , that is, the first sampling unit 23 and the second sampling unit 24 are always kept connected.

[0111] For sampling detection points connected to the first or negative electrode of the battery 40 via the switch assembly 30, it is not necessary to detect the disconnected state of the switch assembly 30 when the switch assembly 30 is not activated. Detecting the disconnected state of the switch assembly 30 is only necessary after the switch assembly 30 is turned on and performs its corresponding function, and then when the switch assembly 30 is controlled to be disconnected. Therefore, by providing the switch unit 25 in the sampling branch 20, it is possible to perform voltage sampling at the sampling detection points corresponding to the sampling branch 20. That is, when the switch assembly 30 is disconnected, the switch unit 25 is controlled to connect the first sampling unit 23 with the second sampling unit 24 to implement voltage sampling.

[0112] In another optional embodiment, the sampling branch 20 corresponding to the sampling detection point directly connected to the first pole of the battery 40 may also be provided with a switch unit 25 .

[0113] According to some embodiments of the present disclosure, please continue to refer to FIG. 10 , the sampling module 10 may be connected to the switch unit 25 , and the sampling module 10 may control the switch unit 25 to be turned on or off.

[0114] The sampling module may include a sampling chip, which may further include a switch control terminal, which may be connected to the switch unit 25 to control the conduction state of the switch unit 25. When the sampling function needs to be enabled, the sampling chip may send a conduction signal to the switch unit 25, causing the switch unit 25 to connect the first sampling unit 23 with the second sampling unit 24.

[0115] According to some embodiments of the present disclosure, the switch unit 25 may include but is not limited to at least one of a transistor, a photoelectric device, and a relay. The switch unit 25 may also be other switch devices or switch equipment capable of achieving on-off control.

[0116] According to some embodiments of the present disclosure, referring to FIG. 11 , the switch unit 25 may include a first MOSFET Q1 .

[0117] The first MOSFET Q1 may be connected between the first sampling unit 23 and the second sampling unit 24 , and a control terminal of the first MOSFET Q1 is connected to an enable signal terminal.

[0118] When the control terminal of the first MOSFET Q1 receives a disable signal, the first MOSFET is disconnected. At this time, the first sampling unit 23 and the second sampling unit 24 are not connected, and the sampling branch 20 does not work.

[0119] When the control terminal of the first MOSFET Q1 receives an enable signal, the first MOSFET is turned on. At this time, the first sampling unit 23 is connected to the second sampling unit 24. The sampling branch 20 can divide the voltage of the sampling detection point so that the sampling module 10 can obtain the voltage of the sampling detection point relative to the reference sampling point.

[0120] It is understandable that the switch unit 25 may be a MOSFET device, and may also include but is not limited to other power switch devices that can adapt to the voltage range of the corresponding sampling detection point.

[0121] According to some embodiments of the present disclosure, referring to FIG12 , the switch unit 25 may include a control component 251 and a controlled component 252 that are isolated from each other. The controlled component 252 is connected between the first sampling unit 23 and the second sampling unit 24 , and the control component 251 may control the on and off of the controlled component 252 .

[0122] The control component 251 can control the isolated controlled component 252 to turn on or off according to the corresponding control signal. When the controlled component 252 is turned on, the first sampling unit 23 and the second sampling unit 24 can be connected; when the controlled component 252 is turned off, the first sampling unit 23 and the second sampling unit 24 can be disconnected.

[0123] Unlike the aforementioned embodiment in which the first MOSFET Q1 is used as the switch unit 25, in this embodiment, the control component 251 and the controlled component 252 are isolated from each other. Since the voltage across the battery 40 is generally relatively high, if the controller providing the enable signal to the switch unit 25 is a high-voltage controller, the controller's signal terminal can be directly connected to the first MOSFET Q1, and the controller can control the conduction state of the first MOSFET Q1 to achieve on-off control of the sampling branch 20.

[0124] If the controller providing the control signal to switch unit 25 is a low-voltage controller, to prevent the high voltage flowing through sampling branch 20 from affecting the low-voltage controller, switch unit 25 can be configured with a control portion and a controlled portion that are isolated from each other. The control portion is connected to the low-voltage controller, while the controlled portion is connected to sampling branch 20 in the high-voltage environment. By isolating the controller from sampling branch 20, the controller can be isolated and protected, improving the reliability of voltage sampling in high-voltage environments.

[0125] According to some embodiments of the present disclosure, please continue to refer to FIG. 12 , the control component 251 may include an enabling switch Qen and a light source Ls connected in series, and the controlled component 252 may include a light receiver Po.

[0126] The control end of the enable switch Qen is connected to the enable signal end. When the enable switch Qen is turned on, it can connect the light source Ls to the power signal, thereby driving the light source Ls to emit light.

[0127] The light receiver Po may be connected between the first sampling unit 23 and the second sampling unit 24 and turned on when the light source Ls emits light.

[0128] In this embodiment, the controller in a low-voltage environment can send an enable signal to the enable switch Qen. When the enable switch Qen is turned on, it can drive the light source Ls to emit light. When the light source Ls emits light, the light receiver Po is turned on, connecting the first sampling unit 23 with the second sampling unit 24, so that the sampling module 10 can perform voltage sampling on the sampling detection point corresponding to the sampling branch 20.

[0129] According to some embodiments of the present disclosure, as shown in FIG. 12 , the light receiver Po may include a second MOSFET Q2 and a third MOSFET Q3 .

[0130] A first end of the second MOSFET Q2 is connected to the first sampling unit 23, a second end of the second MOSFET Q2 is connected to a first end of the third MOSFET Q3, and a second end of the third MOSFET Q3 is connected to the second sampling unit 24. An anode of the body diode of the second MOSFET Q2 is connected to an anode of the body diode of the third MOSFET Q3.

[0131] To prevent current from flowing unidirectionally through the body diode of a single MOSFET when it is off, the second MOSFET Q2 and the third MOSFET Q3 can be arranged in series. When both the second MOSFET Q2 and the third MOSFET Q3 are off, the body diode of the second MOSFET Q2 can limit the current from the sampling detection point to the reference sampling point, and the body diode of the third MOSFET Q3 can limit the current from the reference sampling point to the sampling detection point. Bidirectional current limiting between the sampling detection point and the reference sampling point can be achieved through the second MOSFET Q2 and the third MOSFET Q3.

[0132] Based on the same inventive concept, the present disclosure further provides a battery management system, which includes the sampling circuit of any of the above embodiments. It is understood that the battery management system has the beneficial effects of the sampling circuit provided by the embodiments of the present disclosure. For details, please refer to the detailed description of the sampling circuit in the above embodiments, and this embodiment will not be repeated here.

[0133] According to some embodiments of the present disclosure, the battery management system may include:

[0134] a plurality of switch assemblies, each switch assembly being connected between the battery and a corresponding load, and being used to connect or disconnect the battery and the corresponding load;

[0135] The sampling circuit includes sampling branches corresponding to multiple switch components one by one, and each sampling branch is used to collect the voltage at a sampling detection point; wherein the first end of each sampling branch is connected to the corresponding switch component, and the connection point is the sampling detection point; the second end of each sampling branch is connected to the voltage source, and the connection point is the reference sampling point; and the third end of each sampling branch is connected to the sampling module;

[0136] A voltage source, used for providing a reference voltage for a reference sampling point;

[0137] The sampling module is connected to the high voltage ground and is used to obtain the voltage of each sampling detection point relative to the reference sampling point.

[0138] In the embodiment of the present disclosure, by providing a voltage source, a sampling module, and a sampling branch, a reference voltage can be provided to the reference sampling point through the voltage source, so that the voltage of the reference sampling point relative to the reference ground is the reference voltage. The sampling module can determine the sampling result based on the sampling voltage of the sampling detection point relative to the reference sampling point and the reference voltage between the reference sampling point and the reference ground. This enables the sampling branches to share the same reference sampling point and directly sample relative to the reference voltage, simplifying the circuit design and reducing the circuit cost. In addition, the sampling module is connected to the high-voltage ground, so that the sampling module no longer needs to consider the insulation withstand voltage problem, and the withstand voltage selection of the switching device is relatively relaxed; and the sampling circuit belongs to the high-voltage area and is no longer connected to the low voltage, which can also improve the anti-interference performance and eliminate the need to set up an isolation device, thereby achieving the purpose of saving costs.

[0139] According to some embodiments of the present disclosure, the battery management system further includes a voltage conversion module, which is connected to a voltage source and is used to convert the reference voltage of the voltage source to provide corresponding sampling ranges for sampling detection points with different reference voltage requirements.

[0140] In the embodiment of the present disclosure, the reference voltage provided by the voltage source can be adjusted, so that each sampling detection point can perform sampling relative to a different reference voltage to meet different sampling requirements.

[0141] According to some embodiments of the present disclosure, the multiple switch components include at least one first switch component and / or at least one second switch component. Accordingly, the sampling branch includes: a first sampling branch arranged corresponding to the first switch component, the sampling detection point corresponding to the first sampling branch is connected to the first pole of the battery, or the sampling detection point corresponding to the first sampling branch is connected to the first pole of the battery through the first switch component; and a second sampling branch arranged corresponding to the second switch component, the sampling detection point corresponding to the second sampling branch is connected to the second pole of the battery through the second switch component.

[0142] In the disclosed embodiment, voltage sampling can be performed on a sampling detection point connected to the first pole of the battery and a sampling detection point connected to the second pole of the battery, respectively, through the first sampling branch and the second sampling branch. This enables the first sampling branch and / or the second sampling branch to share the same reference sampling point and perform sampling directly relative to the reference voltage, thereby simplifying circuit design and reducing circuit cost.

[0143] According to some embodiments of the present disclosure, the multiple switch components further include a parallel switch component, and the sampling branch further includes: a third sampling branch connected to one end of the parallel switch component; and a fourth sampling branch connected to the other end of the parallel switch component.

[0144] In the embodiments of the present disclosure, a parallel switch assembly may refer to at least two switch assemblies connected in parallel. Taking Figure 6 as an example, the at least two parallel switch assemblies may include a switch assembly where the main positive switch K2 is located and a switch assembly where the pre-charge switch K3 is located. One end of each of these two switch assemblies is connected to the third sampling branch 21a, and the other end of each of these two switch assemblies is connected to the fourth sampling branch 21b, thereby achieving sampling branch multiplexing.

[0145] It should be noted that, in addition to the corresponding switches, the switch assembly may also include other devices, which is not limited here. For example, for the switch assembly where the pre-charge switch K3 is located, the switch assembly can be regarded as consisting of the pre-charge switch K3 and the pre-charge resistor connected in series.

[0146] It should also be noted that in the disclosed embodiment, the sampling detection point corresponding to the third sampling branch 21a is directly connected to the first terminal of the battery 40, and the sampling detection point corresponding to the fourth sampling branch 21b is respectively connected to the first terminal of the battery 40 via parallel switch components (for example, including: the switch component where the main positive switch K2 is located and the switch component where the pre-charge switch K3 is located). After calculating the voltage difference between the two sampling detection points corresponding to the third sampling branch 21a and the fourth sampling branch 21b, this voltage difference can be compared with a preset voltage threshold to determine whether a fault such as relay sticking exists in the main positive switch K2 or the pre-charge switch K3.

[0147] That is, when at least two switch components are connected in parallel, the at least two switch components can reuse the same sampling branch (including the third sampling branch and the fourth sampling branch), thereby simplifying circuit design and reducing circuit cost by multiplexing the sampling branches.

[0148] According to some embodiments of the present disclosure, a sampling branch includes a first sampling unit and a second sampling unit, which are connected in series. Thus, by configuring the first sampling unit and the second sampling unit to divide the voltage at the sampling detection point, the divided voltage can be within a sampling range.

[0149] According to some embodiments of the present disclosure, the sampling points of the sampling branch include a first sampling point, and the sampling module includes a first sampling terminal. The first sampling point is disposed between the first sampling unit and the second sampling unit, and the first sampling point is connected to the first sampling terminal of the sampling module. Thus, by connecting the first sampling terminal of the sampling module to the first sampling point of the sampling branch, voltage sampling of the sampling branch relative to a reference voltage is achieved.

[0150] According to some embodiments of the present disclosure, the sampling points of the sampling branch include a second sampling point, and the sampling module includes a second sampling end; the second sampling points of the sampling branch are set at both ends of the second sampling unit; and the second sampling points are connected to the second sampling end of the sampling module.

[0151] In the embodiment of the present disclosure, by setting the second sampling terminal of the sampling module to be connected to the second sampling point of the sampling branch, the voltage at both ends of the second sampling unit can be directly sampled. In combination with the voltage division ratio of the first sampling unit and the second sampling unit, the voltage at the sampling detection point relative to the reference sampling point can be determined.

[0152] According to some embodiments of the present disclosure, the second sampling terminal of the sampling module is a differential sampling terminal, so that the voltages at both ends of the second sampling unit are differentially sampled by differential sampling, and the voltages at both ends of the second sampling unit can be directly obtained.

[0153] According to some embodiments of the present disclosure, the sampling branch further includes a switch unit, which is used to turn on the sampling branch. In this way, by providing the switch unit, the application of the sampling branch can be flexibly controlled.

[0154] According to some embodiments of the present disclosure, a sampling module is connected to a switch unit, and the sampling module is used to control the switch unit to be turned on or off. By controlling the switch unit through the sampling module, the switch unit can be turned on when sampling is required and turned off when sampling is not required, thereby improving the flexibility of sampling control.

[0155] According to some embodiments of the present disclosure, the switch unit includes at least one of a transistor, a photoelectric device, and a relay. Thus, by setting the switch device, on-off control of the sampling branch can be achieved.

[0156] According to some embodiments of the present disclosure, a voltage source is connected to the second terminal of the battery, and a reference voltage is the voltage difference between a reference sampling point and the second terminal of the battery. By using the second terminal of the battery as a reference ground, the sampling module can determine the sampling result based on the sampled voltage of the sampling point in the sampling branch relative to the reference sampling point, as well as the reference voltage between the reference sampling point and the reference ground.

[0157] According to some embodiments of the present disclosure, a switch assembly includes any one of a main positive switch, a main negative switch, a pre-charge switch, a main positive DC charging switch, a main positive AC charging switch, a main negative charging switch, a heating switch, and a load switch. By sampling the voltage at the sampling detection points at both ends of each switch assembly, it is possible to determine whether a fault such as adhesion has occurred in the switch assembly based on the voltage difference across the switch assembly.

[0158] According to some embodiments of the present disclosure, referring to FIG. 13 , the battery management system may further include a low-voltage power supply 13 , a power isolation module 14 , a communication isolation module 15 , and a low-voltage control module 16 .

[0159] The low-voltage power supply 13 can provide a reference voltage for the voltage source 50, and the power isolation module 14 can be connected between the low-voltage power supply 13 and the voltage source 50 to isolate the low-voltage power supply 13 from the voltage source 50. Because the voltage source 50 operates in a high-voltage environment and the low-voltage power supply 13 operates in a low-voltage environment, the power isolation module 14 can isolate the low-voltage environment from the high-voltage environment.

[0160] A first end of the communication isolation module 15 is connected to the sampling output end of the sampling module 10 , and a second end of the communication isolation module 15 is connected to the voltage input end of the low voltage control module 16 .

[0161] The communication isolation module 15 can be connected between the voltage input end of the low-voltage control module 16 and the sampling output end of the sampling module 10 , so that the sampling signal output by the sampling module 10 can be converted from an analog signal to a digital signal and sent to the low-voltage control module 16 .

[0162] The low-voltage control module 16 can determine the voltage at the corresponding sampling point relative to the reference sampling point based on the digital signal, and calculate the voltage at the sampling point relative to the reference ground based on the sum of the voltage and the reference voltage. When the reference ground is set to the second terminal of the battery, the voltage at the sampling point relative to the second terminal of the battery can be determined.

[0163] Based on the same inventive concept, the present disclosure further provides a battery pack, which includes a battery and the battery management system of any of the above embodiments. It is understood that the battery pack has the beneficial effects of the battery management system provided by the embodiments of the present disclosure.

[0164] Based on the same inventive concept, the present disclosure further provides an electrical device comprising the battery pack of any of the above embodiments. It is understood that the electrical device has the beneficial effects of the battery pack provided by the embodiments of the present disclosure. For details, please refer to the detailed description of the battery pack in the above embodiments, and this embodiment will not be repeated here.

[0165] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0166] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of the present disclosure are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a first data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0167] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0168] This article uses specific examples to illustrate the principles and implementation methods of the present disclosure. The above examples are only used to help understand the methods and core ideas of the present disclosure. The above are only preferred implementation methods of the present disclosure. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of the present disclosure, they can also make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concepts and technical solutions of the present disclosure to other occasions without improvement, should all be regarded as the scope of protection of the present disclosure. Industrial Applicability

[0169] In the embodiment of the present disclosure, by setting a voltage source, a sampling module and a sampling branch, a reference voltage can be provided to the reference sampling point through the voltage source, so that the voltage of the reference sampling point relative to the reference ground is the reference voltage. The sampling module can determine the sampling result based on the sampling voltage of the sampling detection point relative to the reference sampling point and the reference voltage between the reference sampling point and the reference ground. This enables the sampling branches to share the same reference sampling point and directly sample relative to the reference voltage, simplifying the circuit design and reducing the circuit cost. In addition, the sampling module is connected to the high-voltage ground, so that the sampling module no longer needs to consider the insulation withstand voltage problem, and the withstand voltage selection of the switching device is relatively relaxed; and the sampling circuit belongs to the high-voltage area and is no longer connected to the low voltage, which can also improve the anti-interference performance and eliminate the need to set up an isolation device, thereby achieving the purpose of saving costs.

Claims

1. A battery management system, comprising: A plurality of switch components, each of which is connected between a battery and a corresponding load, and is used to connect or disconnect the battery from the corresponding load; A sampling circuit, wherein the sampling circuit comprises sampling branches corresponding to the plurality of switch components one by one, and each sampling branch is used to collect the voltage of a sampling detection point; wherein the first end of each sampling branch is connected to the corresponding switch component, and the connection point is the sampling detection point; the second end of each sampling branch is connected to a voltage source, and the connection point is a reference sampling point; and the third end of each sampling branch is connected to a sampling module; The voltage source is used to provide a reference voltage for the reference sampling point; The sampling module is connected to the high voltage ground and is used to obtain the voltage of each sampling detection point relative to the reference sampling point.

2. The battery management system according to claim 1, wherein: The battery management system further comprises: A voltage conversion module is connected to the voltage source and is used to convert the reference voltage of the voltage source to provide corresponding sampling ranges for sampling detection points with different reference voltage requirements.

3. The battery management system according to claim 1 or 2, wherein: The plurality of switch components include at least one first switch component and / or at least one second switch component, and the sampling branch includes: A first sampling branch is arranged corresponding to the first switch component, and a sampling detection point corresponding to the first sampling branch is connected to a first pole of a battery, or the sampling detection point corresponding to the first sampling branch is connected to the first pole of the battery through the first switch component; A second sampling branch is arranged corresponding to the second switch component, and a sampling detection point corresponding to the second sampling branch is connected to the second pole of the battery through the second switch component.

4. The battery management system according to claim 1 or 2, wherein: The plurality of switch components further include switch components connected in parallel, and the sampling branch further includes: A third sampling branch connected to one end of the parallel switch assembly; The fourth sampling branch is connected to the other end of the parallel switch component.

5. The battery management system according to any one of claims 1 to 4, wherein: The sampling branch comprises: A first sampling unit and a second sampling unit, wherein the first sampling unit and the second sampling unit are connected in series.

6. The battery management system according to claim 5, wherein: The sampling point of the sampling branch includes a first sampling point, and the sampling module includes a first sampling end; The first sampling point is arranged between the first sampling unit and the second sampling unit; The first sampling point is connected to the first sampling end of the sampling module.

7. The battery management system according to claim 5, wherein: The sampling point of the sampling branch includes a second sampling point, and the sampling module includes a second sampling end; The second sampling points of the sampling branch are arranged at two ends of the second sampling unit; The second sampling point is connected to the second sampling end of the sampling module.

8. The battery management system according to claim 7, wherein: The second sampling terminal of the sampling module is a differential sampling terminal.

9. The battery management system according to any one of claims 5 to 8, wherein: The sampling branch also includes: A switch unit, wherein the switch unit is used to make the sampling branch conductive.

10. The battery management system according to claim 9, wherein: The sampling module is connected to the switch unit, and the sampling module is used to control the switch unit to be turned on or off.

11. The battery management system according to claim 9, wherein: The switch unit includes at least one of a transistor, a photoelectric device, and a relay.

12. The battery management system according to any one of claims 1 to 11, wherein: The voltage source is connected to the second electrode of the battery, and the reference voltage is the voltage difference between the reference sampling point and the second electrode of the battery.

13. The battery management system according to any one of claims 1 to 12, wherein: The switch assembly includes any one of a main positive switch, a main negative switch, a pre-charging switch, a main positive DC charging switch, a main positive AC charging switch, a main negative charging switch, a heating switch and a load switch.

14. The battery management system according to any one of claims 1 to 13, wherein: The battery management system further comprises: Low voltage power supply; A power isolation module, connected between the low voltage power supply and the voltage source; Low voltage control module; The communication isolation module is connected between the voltage input terminal of the low voltage control module and the sampling output terminal of the sampling module.

15. A battery pack comprising a battery and the battery management system according to any one of claims 1 to 14.

16. An electrical device comprising the battery pack according to claim 15.

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