Sampling circuit, battery management system, battery pack and electric device

Abstract

The invention discloses a sampling circuit, a battery management system, a battery pack and an electric device. The sampling circuit comprises a reference voltage module connected with a reference sampling point and used for providing a first reference voltage for the reference sampling point; the first sampling branch is connected between the corresponding sampling detection point and the reference sampling point; and the sampling end of the sampling module is connected with the first sampling branch, and the sampling module is used for acquiring the voltage of the sampling detection point relative to the reference sampling point. According to the embodiment of the invention, the voltage sampling of the sampling detection points with different voltages can be realized, when a plurality of sampling detection points exist, the same reference sampling point is shared, and the potential difference between two sampling detection points can be calculated according to the potential difference of any two sampling detection points relative to the reference sampling point. Therefore, circuit detection between sampling detection points can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of power management, and particularly relates to a sampling circuit, a battery management system, a battery pack, and an electrical device. Background Art

[0002] With the development of new energy technologies, batteries are increasingly widely used in various electrical devices, such as mobile phones, laptop computers, battery cars, electric vehicles, electric airplanes, electric ships, etc.

[0003] During the operation of an electrical device, a power source can supply power to each electrical unit so that each electrical unit can operate normally. Multiple relay switches are usually arranged in the high-voltage lines corresponding to the positive and negative electrodes of the battery. To ensure the reliability of the battery during use, it is necessary to sample the voltage at each detection point in the battery and perform corresponding execution processing based on the sampling results.

[0004] However, in the related art, the circuit design for voltage sampling is complex and costly. Summary of the Invention

[0005] Embodiments of the present application provide a sampling circuit, a battery management system, a battery pack, and an electrical device, which optimize the circuit design of the sampling circuit and improve the reliability of battery operation.

[0006] In a first aspect, an embodiment of the present application provides a sampling circuit, which includes:

[0007] A reference voltage module, connected to a reference sampling point, and the reference voltage module is used to provide a first reference voltage for the reference sampling point;

[0008] A first sampling branch, connected between a corresponding sampling detection point and the reference sampling point;

[0009] A sampling module, the sampling end of the sampling module is connected to the first sampling branch, and the sampling module is used to obtain the voltage of the sampling detection point relative to the reference sampling point.

[0010] By setting the reference voltage module to provide a first reference voltage for the reference sampling point, the voltage of the sampling detection point relative to the reference sampling point can be sampled using the first sampling branch. The sampling module can determine the voltage of each sampling detection point relative to the reference sampling point, thereby realizing voltage sampling of different voltage sampling detection points. Moreover, when there are multiple sampling detection points, by sharing the same reference sampling point, the potential difference between two sampling detection points can be calculated based on the potential difference between any two sampling detection points relative to the reference sampling point, thereby realizing circuit detection between the sampling detection points.

[0011] In a possible implementation of the first aspect, the reference voltage module includes: a voltage source for providing a second reference voltage; and a voltage conversion module connected to the voltage source for converting the second reference voltage into a first reference voltage. By setting the voltage source to provide the second reference voltage and then using the voltage conversion module to convert the second reference voltage into the first reference voltage, each sampling and detection point can sample relative to the first reference voltage or the second reference voltage, meeting different sampling requirements.

[0012] In a possible implementation of the first aspect, the first reference voltage is less than the second reference voltage. By setting the first reference voltage to be less than the second reference voltage, a larger sampling range can be provided for the sampling and detection points with higher voltages and the sampling and detection points with lower voltages respectively, ensuring the accuracy of the sampling results.

[0013] In a possible implementation of the first aspect, the voltage source is connected to the second pole of the battery, and the second reference voltage is the voltage of the output voltage of the voltage source relative to the second pole of the battery. By using the second pole of the battery as the reference ground, the voltage source can provide the first reference voltage relative to the second pole of the battery for the reference sampling point.

[0014] In a possible implementation of the first aspect, the sampling circuit further includes: a second sampling branch connected to the first pole of the battery and the voltage source; the voltage source is used to provide the first reference voltage for the second sampling branch; and a sampling module connected to the second sampling branch for obtaining the voltage of the first pole of the battery relative to the second pole of the battery. Through the second sampling branch, the voltage of the first pole of the battery relative to the second pole of the battery can be sampled, so as to directly obtain the voltage across the battery and realize the voltage sampling of the battery.

[0015] In a possible implementation of the first aspect, the first sampling branch includes: a first-pole sampling branch, and the sampling and detection point corresponding to the first-pole sampling branch is connected to the first pole of the battery through a first switch component; and / or a second-pole sampling branch, and the sampling and detection point corresponding to the second-pole sampling branch is connected to the second pole of the battery through a second switch component. Through the first-pole sampling branch and the second-pole sampling branch, the sampling and detection points of positive voltage and the sampling and detection points of negative voltage can be sampled respectively, and the sampling voltages of each sampling and detection point can be obtained, realizing the voltage sampling of the high-voltage circuit.

[0016] In a possible implementation of the first aspect, the first switch component includes at least one of a main positive switch, a pre-charge switch, a main positive DC charging switch, and a main positive AC charging switch, and the second switch component includes at least one of a main negative switch and a main negative charging switch. By sampling the voltage of each sampling and detection point respectively, problems such as whether the above switches are stuck can also be detected according to the sampling results, realizing the status diagnosis of the switch component.

[0017] In a possible implementation of the first aspect, the voltage conversion module includes: a first voltage dividing unit connected between a voltage source and a reference sampling point; a voltage stabilizing unit connected to the reference sampling point. By providing the first voltage dividing unit and the voltage stabilizing unit, a relatively high second reference voltage can be clamped to output a relatively low first reference voltage.

[0018] In a possible implementation of the first aspect, the voltage conversion module further includes a second voltage dividing unit connected in parallel with the voltage stabilizing unit. The second voltage dividing unit can cooperate with the first voltage dividing unit to perform voltage division, and when an abnormality such as an open circuit occurs in the voltage stabilizing unit, the voltage at the reference sampling point will not be too high.

[0019] In a possible implementation of the first aspect, the first sampling branch includes: a first sampling unit and a second sampling unit connected in series. By dividing the voltage at the sampling detection point through the first sampling unit and the second sampling unit, the voltage across the second sampling unit can be made to fall within the sampling range of the sampling module.

[0020] In a possible implementation of the first aspect, the first sampling branch includes a first sampling point, and the sampling module includes a first sampling terminal; the first sampling point is provided between the first sampling unit and the second sampling unit; the first sampling point is connected to the first sampling terminal of the sampling module. By adopting the conventional sampling method of connecting the first sampling terminal of the sampling module to the first sampling point of the first sampling branch, the voltage at the midpoint between the first sampling unit and the second sampling unit can be directly sampled, and in combination with the voltage division ratio of the first sampling unit and the second sampling unit, the voltage of the sampling detection point relative to the reference sampling point can be determined.

[0021] In a possible implementation of the first aspect, the first sampling branch includes a second sampling point, and the sampling module includes a second sampling terminal; the second sampling point is provided at both ends of the second sampling unit; the second sampling point is connected to the second sampling terminal of the sampling module. By adopting the differential sampling method of connecting the second sampling terminal of the sampling module to the second sampling point of the first sampling branch, the voltage across the second sampling unit can be directly sampled, and in combination with the voltage division ratio of the first sampling unit and the second sampling unit, the voltage of the sampling detection point relative to the reference sampling point can be determined.

[0022] In a possible implementation of the first aspect, the second sampling terminal of the sampling module is a differential sampling terminal. By means of differential sampling, the voltage across the second sampling unit can be directly obtained.

[0023] In a possible implementation of the first aspect, the first sampling branch further includes: a sampling control switch, which is connected between the first sampling unit and the second sampling unit; the sampling control switch is used to turn on or off the first sampling branch. The sampling control switch can disconnect the sampling branch when voltage sampling is not required to save resources.

[0024] In a second aspect, an embodiment of the present application provides a battery management system, including the sampling circuit according to any one of the embodiments of the first aspect.

[0025] In a third aspect, an embodiment of the present application provides a battery pack, including a battery and the battery management system according to any one of the embodiments of the second aspect.

[0026] In a fourth aspect, an embodiment of the present application provides an electrical device, including the electrical device according to any one of the embodiments of the fourth aspect.

[0027] Compared with the related art, the sampling circuit, battery management system, battery pack, and electrical device provided by the embodiments of the present application can sample the voltage of the sampling detection point relative to the reference sampling point by setting the reference voltage module to provide the first reference voltage for the reference sampling point through the first sampling branch. The sampling module can determine the voltage of each sampling detection point relative to the reference sampling point, so as to realize the voltage sampling of different voltage sampling detection points. And when there are multiple sampling detection points, by sharing the same reference sampling point, the potential difference between any two sampling detection points can be calculated according to the potential difference between the two sampling detection points relative to the reference sampling point, so as to realize the circuit detection between the sampling detection points. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 is a schematic module structure diagram of a sampling circuit provided by an embodiment of the present application;

[0030] Figure 2 is a schematic module structure diagram of a sampling circuit provided by another embodiment of the present application;

[0031] Figure 3 is a schematic module structure diagram of a sampling circuit provided by still another embodiment of the present application;

[0032] Figure 4 is a schematic module structure diagram of a sampling circuit provided by yet another embodiment of the present application;

[0033] Figure 5 It is a schematic diagram of the module structure of the sampling circuit provided by another embodiment of the present application;

[0034] Figure 6 It is a schematic diagram of the module structure of the sampling circuit provided by another embodiment of the present application;

[0035] Figure 7 It is a schematic diagram of the circuit structure of the sampling circuit provided by an embodiment of the present application;

[0036] Figure 8 It is a schematic diagram of the circuit structure of the conventional sampling method provided by an embodiment of the present application;

[0037] Figure 9 It is a schematic diagram of the circuit structure of the differential sampling method provided by an embodiment of the present application.

[0038] In the drawings:

[0039] 10. Reference voltage module; 20. First sampling branch; 30. Sampling module; 40. Battery; 50. Second sampling branch; 11. Voltage source; 12. Voltage conversion module; 121. First voltage dividing unit; 122. Voltage stabilizing unit; 123. Second voltage dividing unit; 21. First pole sampling branch; 22. Second pole sampling branch; 23. First sampling unit; 24. Second sampling unit; 25. Sampling control switch; Rs. Reference sampling point; Sd. Sampling detection point; GND-R. Reference ground; Ps. First sampling point; Ns. Second sampling point; 61. First switch component; 62. Second switch component; 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. Detailed implementation manners

[0040] The features and exemplary embodiments of various aspects of the present application will be described in detail below. For the purpose of making the objectives, technical solutions and advantages of the present application more clear and understandable, the present application 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 application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application.

[0041] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0042] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The embodiments will be described in detail below with reference to the accompanying drawings.

[0043] With the development of new energy technologies, batteries are increasingly widely used in various electrical devices, such as mobile phones, laptop computers, battery-powered vehicles, electric vehicles, electric aircraft, electric ships, etc.

[0044] During the operation of an electrical device, a power source can supply power to each electrical unit so that each electrical unit can operate normally. Multiple relay switches are usually provided in the high-voltage lines corresponding to the first and second poles of the battery. To ensure the reliability of the battery during use, it is necessary to perform voltage sampling on each detection point in the battery and perform corresponding execution processing based on the sampling results.

[0045] However, there are certain defects in the circuit architecture for voltage sampling in the related art.

[0046] To solve the above technical problems, the embodiments of the present application provide a sampling circuit, a battery management system, a battery pack and an electrical device. The sampling circuit provided by the embodiments of the present application will be introduced first below.

[0047] According to some embodiments of the present application, please refer to Figure 1 , the present application provides a sampling circuit. The sampling circuit includes a reference voltage module 10, a first sampling branch 20, and a sampling module 30.

[0048] The reference voltage module 10 is connected to the reference sampling point Rs. The reference voltage module 10 can provide a first reference voltage for the reference sampling point Rs so that the voltage of the reference sampling point Rs relative to the reference ground GND-R is the first reference voltage.

[0049] Taking the case where the voltage source 11 maintains the first reference voltage at 2.5V as an example, if the voltage of the reference ground GND-R is 0V, the voltage source 11 can make the voltage at the reference sampling point Rs be 2.5V; if the voltage of the reference ground GND-R is 10V relative to the ground, the voltage source 11 can make the voltage at the reference sampling point Rs be 12.5V.

[0050] The first sampling branch 20 can be connected between the corresponding sampling detection point Sd and the reference sampling point Rs in the battery 40. The first sampling branch 20 can perform voltage sampling on the sampling detection point Sd.

[0051] The sampling end of the sampling module 30 can be connected to the first sampling branch 20. According to the sampling signal received by the sampling end from the first sampling branch 20, the sampling module 30 can determine the voltage of the corresponding sampling detection point Sd relative to the reference sampling point Rs of the first sampling branch 20.

[0052] It can be understood that the sampling module 30 has a corresponding sampling range, and the voltage of the sampling signal it can collect should be within this sampling range. When the sampling module 30 uses the reference ground GND-R as the 0 voltage reference, the first reference voltage provided by the reference voltage module 10 for the reference ground GND-R based on the reference ground GND-R serves as the bias voltage of the sampling module 30. Therefore, the first reference voltage should be within the sampling range of the sampling module 30, so that the sampling signal obtained by the sampling module 30 does not exceed the sampling range of the sampling module 30.

[0053] Among multiple sampling detection points Sd, the potential differences between some sampling detection points Sd and the reference ground GND-R are positive values, and the potential differences between some other sampling detection points Sd and the reference ground GND-R are negative values.

[0054] In the related art, usually the negative electrode of the battery 40 is used as the reference ground GND-R. When the negative electrode of the battery 40 is used as the sampling reference of the sampling module 30, for some sampling detection points Sd with voltages higher than the reference ground GND-R, the sampling module 30 can normally perform sampling to obtain the voltages of these sampling detection points Sd relative to the reference ground GND-R. However, for some other sampling detection points Sd with voltages lower than the reference ground GND-R, the sampling module 30 cannot normally perform sampling. That is, in the related art, since the sampling port of the sampling chip can only collect positive voltages, it is impossible to sample some sampling detection points Sd with voltages lower than the voltage of the negative electrode of the battery 40. For example, as Figure 2 shown, the reference voltage module 10 can be connected to the second pole of the battery 40 to use the second pole of the battery 40 as the reference ground GND-R. At this time, for the sampling detection point Sd outside the main negative relay where the voltage may be lower than the second pole of the battery 40, voltage sampling cannot be achieved, thus unable to meet the voltage sampling requirements of the battery 40.

[0055] In the above embodiments, please refer to Figure 3 , for multiple sampling detection points Sd, a plurality of first sampling branches 20 respectively corresponding to the multiple sampling detection points Sd can be set, and each first sampling branch 20 is connected between the corresponding sampling detection point Sd and the reference sampling point Rs. A plurality of sampling ends of the sampling module 30 are respectively connected to the plurality of first sampling branches 20. The sampling module 30 can respectively obtain the voltages of the corresponding sampling detection points Sd relative to the reference sampling point Rs through the respective sampling ends, and then combine the first reference voltage between the reference sampling point Rs and the reference ground GND-R, so as to realize the voltage sampling of the multiple sampling detection points Sd relative to the reference ground GND-R.

[0056] Since the first reference voltage is maintained between the reference sampling point Rs and the reference ground GND-R, for some sampling detection points Sd with voltages higher than the reference ground GND-R, the sampling module 30 can normally realize the voltage sampling of the sampling detection point Sd. For another part of the sampling detection points Sd with voltages lower than the reference ground GND-R, since the first reference voltage is higher than the voltages of this part of the sampling detection points Sd, the sampling module 30 can obtain the potential difference between the reference sampling point Rs and this part of the sampling detection points Sd by collecting the positive voltage, and then determine the voltages of this part of the sampling detection points Sd relative to the reference ground GND-R according to the first reference voltage between the reference sampling point Rs and the reference ground GND-R, so as to realize the negative voltage sampling function.

[0057] After obtaining the potential differences between the respective sampling detection points Sd and the reference sampling point Rs, the potential difference between any two sampling detection points Sd can be calculated based on the potential differences between the two sampling detection points Sd and the reference sampling point Rs.

[0058] In this embodiment, by setting the reference voltage module 10 to provide the first reference voltage for the reference sampling point Rs, the voltage of the sampling detection point Sd relative to the reference sampling point Rs can be sampled by using the first sampling branch 20. The sampling module 30 can determine the voltages of the respective sampling detection points Sd relative to the reference sampling point Rs, so as to realize the voltage sampling of the sampling detection points Sd with different voltages. Moreover, when there are multiple sampling detection points Sd, by sharing the same reference sampling point Rs, based on the potential differences between any two sampling detection points Rd and the reference sampling point Rs, the potential difference between the two sampling detection points Rd can be calculated, so as to realize the circuit detection between the sampling detection points Rd.

[0059] According to some embodiments of the present application, please refer to Figure 4 , the above reference voltage module 10 may include a voltage source 11 and a voltage conversion module 12.

[0060] The voltage source 11 can provide a second reference voltage. The voltage conversion module 12 can be connected to the voltage source 11 and convert the second reference voltage output by the voltage source 11 into a first reference voltage.

[0061] The voltage conversion module 12 can be connected between the voltage source 11 and the reference sampling point Rs. The voltage conversion module 12 can receive the second reference voltage provided by the voltage source 11 and perform voltage conversion on the second reference voltage to obtain a first reference voltage.

[0062] The above-mentioned second reference voltage and first reference voltage can be set according to the sampling range of the sampling module 30. For example, the second reference voltage can be set as the maximum range voltage of the sampling module 30. At this time, the voltage conversion module 12 can perform step-down conversion on the second reference voltage to obtain a first reference voltage lower than the second reference voltage. When using the sampling module 30 to perform voltage sampling, by reasonably setting the resistance values of the voltage-dividing resistors in the first sampling branch 20, when the sampling module 30 performs voltage sampling on the sampling detection point Sd with a positive voltage relative to the reference ground GND-R, the voltage range of the sampled signal collected is between the first reference voltage and the maximum range voltage; when performing voltage sampling on the sampling detection point Sd with a negative voltage relative to the reference ground GND-R, the voltage range of the sampled signal collected is between the first reference voltage and the minimum range voltage. That is, by setting the voltage of the reference sampling point Rs as the first reference voltage, it is possible to realize voltage sampling of the sampling detection point Sd with a positive voltage and the sampling detection point Sd with a negative voltage through the sampling module 30.

[0063] By setting the voltage source 11 to provide a second reference voltage and then using the voltage conversion module 12 to convert the second reference voltage into a first reference voltage, it is possible to make each sampling detection point sample relative to the first reference voltage or the second reference voltage, meeting different sampling requirements.

[0064] According to some embodiments of the present application, the above-mentioned first reference voltage can be less than the second reference voltage. That is, the voltage conversion module 12 plays a step-down role, converting the higher second reference voltage into a lower first reference voltage.

[0065] In some examples, the first reference voltage can be one-half of the second reference voltage. For example, when the second reference voltage is 5V, it means that the potential difference between the output voltage of the voltage source 11 and the reference ground GND-R is 5V. At this time, the first reference voltage can be set as one-half of the second reference voltage, that is, 2.5V, indicating that the potential difference between the reference sampling point Rs and the reference ground GND-R is 2.5V.

[0066] Taking the maximum sampling range of the sampling module 30 as 5V as an example, when the voltage at a certain sampling detection point Sd is higher than the reference ground GND-R, the voltage between the sampling detection point Sd and the reference sampling point Rs can be sampled and divided by the corresponding first sampling branch 20. By adjusting the resistance values of the respective resistors in the corresponding first sampling branch 20, the divided voltage output at the sampling end of the first sampling branch 20 can be made not to exceed the maximum sampling range of the sampling module 30. Since the sampling module 30 is based on the reference ground GND-R at this time, the divided voltage output by the first sampling branch 20 should be at least higher than the voltage of the reference sampling point Rs relative to the reference ground GND-R. That is, the voltage output at the sampling end of the first sampling branch 20 is between 2.5V and 5V.

[0067] When the voltage at a certain sampling detection point Sd is lower than the reference ground GND-R, a similar method can also be adopted. The first sampling branch 20 can sample and divide the voltage between the reference sampling point Rs and the sampling detection point Sd. It can be understood that the divided voltage output by the first sampling branch 20 at this time is a positive voltage, and this positive voltage is lower than the voltage of the reference sampling point Rs relative to the reference ground GND-R. That is, the voltage output at the sampling end of the first sampling branch 20 is between 0V and 2.5V.

[0068] The above sampling detection point Sd with a voltage higher than the reference ground GND-R is the sampling detection point Sd for positive voltage, and the sampling detection point Sd with a voltage lower than the reference ground GND-R is the sampling detection point Sd for negative voltage. For the sampling detection point Sd for positive voltage and the sampling detection point Sd for negative voltage, the sampling module 30 can both perform voltage sampling through the first sampling branch 20 and calculate the voltage of the sampling detection point Sd relative to the reference sampling point Rs.

[0069] According to some embodiments of the present application, please continue to refer to Figure 4 , the above reference ground GND-R can be selected as the second pole of the battery 40, the voltage source 11 can be connected to the second pole of the battery 40, and the second reference voltage provided by the voltage source 11 is the voltage difference between the output voltage of the voltage source 11 and the voltage of the second pole of the battery 40.

[0070] In this embodiment, by using the second pole of the battery 40 as the reference ground GND-R, the voltage of the output voltage of the voltage source 11 relative to the second pole of the battery 40 can be made the second reference voltage. The voltage conversion module 12 can convert this second reference voltage into a first reference voltage so that the voltage of the reference sampling point Rs relative to the second pole of the battery 40 is the first reference voltage.

[0071] According to some embodiments of the present application, please refer to Figure 5 , the above sampling circuit may further include a second sampling branch 50.

[0072] The second sampling branch 50 can be connected to the first pole of the battery 40 and the voltage source 11. The voltage source 11 can provide a first reference voltage to the second sampling branch 50 as a bias voltage.

[0073] The second sampling branch 50 can sample and divide the voltage of the first pole of the battery 40, and use the second reference voltage output by the voltage source 11 as a bias voltage, so that the sampling signal output by the second sampling branch 50 meets the sampling range of the sampling module 30.

[0074] One of the sampling terminals of the sampling module 30 can be connected to the sampling terminal of the second sampling branch 50, and obtain the sampled and divided sampling signal output by the second sampling branch 50. The sampling module 30 can calculate the voltage of the first pole of the battery 40 relative to the reference ground GND-R according to this sampling signal. Since the reference ground GND-R is the second pole of the battery 40, the voltage calculated by the sampling module 30 is the voltage across the two poles of the battery 40.

[0075] Please refer to Figure 6 , among the above-mentioned multiple sampling detection points Sd, it can include a first sampling point Ps and a second sampling point Ns.

[0076] The first sampling point Ps can be a sampling detection point Sd connected to the first pole of the battery 40 through the first switch component 61, and the second sampling point Ns can be a sampling detection point Sd connected to the second pole of the battery 40 through the second switch component 62.

[0077] Taking a first sampling point Ps among the multiple sampling detection points Sd as an example, the first sampling point Ps is connected to the first pole of the battery 40 through the first switch component 61. When the first switch component 61 is normally conducting, the voltage of the first sampling point Ps is the same as the voltage of the first pole of the battery 40. When the first switch component 61 is disconnected, there will be a certain difference between the voltage of the first sampling point Ps and the voltage of the first pole of the battery 40. Therefore, after controlling the first switch component 61 to disconnect, the sampling module 30 can obtain the voltage between the first pole of the battery 40 and the reference ground GND-R, that is, the second pole of the battery 40, and perform voltage sampling on the first sampling point Ps through the first sampling branch 20 corresponding to the first sampling point Ps and the sampling module 30. The sampling result generated by the sampling module 30 is the voltage of the first sampling point Ps relative to the reference sampling point Rs. Combining the first reference voltage between the reference sampling point Rs and the reference ground GND-R, the voltage of the first sampling point Ps relative to the reference ground GND-R can be determined. By comparing the voltage between the first pole and the second pole of the battery 40 and the voltage of the first sampling point Ps relative to the second pole of the battery 40, it can be determined whether the first switch component 61 has a fault such as adhesion after disconnection.

[0078] As an alternative embodiment, the above method for detecting the adhesion of the first switch component 61 may be to determine whether the difference between the voltage of the first pole of the battery 40 relative to the reference ground GND-R and the voltage of the first sampling point Ps relative to the reference ground GND-R is less than a preset voltage threshold. If the difference between the sampling voltages of the two sampling points is less than the preset voltage threshold, it can be determined that the first switch component 61 is adhered and fails to open normally; if the difference between the sampling voltages of the two sampling points is greater than the preset voltage threshold, it can be determined that the first switch component 61 opens normally.

[0079] Taking a second sampling point Ns among the multiple sampling detection points Sd as an example, after the sampling module 30 determines the voltage of the second sampling point Ns relative to the reference sampling point Rs according to the sampling signal output by the first sampling branch 20. For any first sampling point Ps, it can be determined that the potential difference between the first sampling point Ps and the second sampling point Ns is the difference between the voltage of the first sampling point Ps relative to the reference sampling point Rs and the voltage of the second sampling point Ns relative to the reference sampling point Rs. That is, according to the voltage of a certain second sampling point Ns relative to the reference sampling point Rs, the voltage of any first sampling point Ps relative to the second sampling point Ns can be obtained, so that any second sampling point Ns can be used as a reference point to realize voltage sampling with multiple reference points.

[0080] According to some embodiments of the present application, please continue to refer to Figure 6 The above first sampling branch may include a first pole sampling branch 21, and / or a second pole sampling branch 22.

[0081] The sampling detection point corresponding to the first pole sampling branch 21 is the first sampling point Ps, and the sampling detection point corresponding to the second pole sampling branch 22 is the second sampling point Ns. The first sampling point Ps can be connected to the first pole of the battery 40 through the first switch component 61, and the second sampling point Ns can be connected to the second pole of the battery 40 through the second switch component 62.

[0082] When the first sampling point Ps is included in the multiple sampling detection points Sd, the first pole sampling branch 21 corresponding to the first sampling point Ps can be set, and the first pole sampling branch 21 can sample the voltage of the first sampling point Ps relative to the reference sampling point Rs.

[0083] Similarly, when the second sampling point Ns is included in the multiple sampling detection points Sd, the second pole sampling branch 22 corresponding to the second sampling point Ns can be set, and the second pole sampling branch 22 can sample the voltage of the second sampling point Ns relative to the reference sampling point Rs.

[0084] When the first sampling point Ps and the second sampling point Ns are respectively included in multiple sampling detection points, the corresponding first pole sampling branch 21 and second pole sampling branch 22 can be respectively set to realize the voltage sampling of the first sampling point Ps relative to the reference sampling point Rs and the voltage sampling of the second sampling point Ns relative to the reference sampling point Rs. Through the first pole sampling branch 21 and the second pole sampling branch 22, the voltage sampling of the sampling detection point of the positive voltage and the sampling detection point of the negative voltage can be respectively performed, and the sampling voltage of each sampling detection point Sd can be obtained, realizing the voltage sampling of the high-voltage loop.

[0085] Please continue to refer to Figure 7 , according to some embodiments of the present application, the above voltage conversion module 12 may include a first voltage dividing unit 121 and a voltage stabilizing unit 122.

[0086] The first voltage dividing unit 121 is connected between the voltage source 11 and the reference sampling point Rs. The voltage stabilizing unit 122 is connected to the reference sampling point Rs. The breakdown voltage of the voltage stabilizing unit 122 is the first reference voltage.

[0087] After the second reference voltage output by the voltage source 11 is divided by the first voltage dividing unit 121, it is still greater than the second reference voltage. At this time, the voltage stabilizing unit 122 can play a voltage stabilizing role and limit the voltage divided by the first voltage dividing unit 121 to the first reference voltage.

[0088] The first voltage dividing unit 121 can play a role of voltage division protection to avoid the direct connection between the voltage source 11 and the voltage stabilizing unit 122. At this time, the voltage across the first voltage dividing unit 121 is the difference between the second reference voltage and the first reference voltage.

[0089] According to some embodiments of the present application, the above voltage conversion module 12 may further include a second voltage dividing unit 123 connected in parallel with the voltage stabilizing unit 122.

[0090] The first voltage dividing unit 121 and the second voltage dividing unit 123 can form a voltage dividing circuit. When the voltage stabilizing unit 122 is open-circuited, by reasonably setting the resistance values of the first voltage dividing unit 121 and the second voltage dividing unit 123, the voltage divided by the second voltage dividing unit 123 can be made the first reference voltage. At this time, the voltage between the reference sampling point Rs and the reference ground GND-R can still remain the first reference voltage.

[0091] In some examples, the above first voltage dividing unit 121 and second voltage dividing unit 123 may be resistors, and the voltage stabilizing unit 122 may be a voltage stabilizing diode.

[0092] In another alternative embodiment, the above voltage conversion module 12 may further include, but is not limited to, a DC-DC (Direct Current-Direct Current) conversion module, an LDO (low dropout regulator), or other devices or chips capable of converting the second reference voltage into the first reference voltage.

[0093] According to some embodiments of the present application, please refer to Figure 7 , the above first sampling branch 20 may include a first sampling unit 23 and a second sampling unit 24.

[0094] The first sampling unit 23 and the second sampling unit 24 are connected in series.

[0095] The first sampling unit 23 and the second sampling unit 24 may be respectively composed of resistors. The number and resistance value of the resistors in the first sampling unit 23 and the second sampling unit 24 may be set according to the normal voltage range of the sampling detection point Sd connected to the first sampling branch 20. For example, when the voltage across the battery 40 is relatively high, if the normal voltage range of the sampling detection point Sd includes a relatively high voltage, the first sampling unit 23 may be provided with a resistor having a relatively high resistance value, and the second sampling unit 24 may be provided with a resistor having a relatively low resistance value, so that after the first sampling unit 23 and the second sampling unit 24 divide the voltage of the sampling detection point Sd, the voltage difference across the second sampling unit 24 will not be too large to exceed the detection range of the sampling module 30, nor will it be too small to affect the accuracy of the sampling result.

[0096] According to some embodiments of the present application, please refer to Figure 8 , the sampling module 30 may include a first sampling terminal S1, and the first sampling branch 20 may include a first sampling point, which is provided in the middle of the first sampling unit 23 and the second sampling unit 24.

[0097] The first sampling point of the first sampling branch 20 may be connected to the first sampling terminal S1 of the sampling module 30, and the sampling module 30 may obtain the voltage of the first sampling point through the first sampling terminal S1.

[0098] After the sampling module 30 obtains the voltage of the first sampling point through the first sampling point, it may determine the voltage difference between the two ends of the first sampling branch 20 according to the equivalent resistance values of the first sampling unit 23 and the second sampling unit 24.

[0099] According to some embodiments of the present application, please refer to Figure 9, the sampling module 30 may include a second sampling terminal S2, and the first sampling branch 20 may include a second sampling point, which is disposed on both sides of the second sampling unit 24, that is, the second sampling point includes at least two sampling points on both sides of the second sampling unit 24.

[0100] The second sampling point of the first sampling branch 20 may be connected to the second sampling terminal S2 of the sampling module 30, and the sampling module 30 may obtain the voltage of the second sampling point through the second sampling terminal S2. When there are 2 second sampling points, the second sampling terminal S2 of the sampling module 30 is also 2.

[0101] The sampling module 30 can directly sample the voltages at both ends of the second sampling unit 24 through the second sampling terminal S2. After determining the voltages at both ends of the second sampling unit 24, the voltage difference at both ends of the first sampling branch 20 can be calculated according to the equivalent resistance values of the first sampling unit 23 and the second sampling unit 24.

[0102] According to some embodiments of the present application, the second sampling terminal S2 of the sampling module 30 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 the voltage difference at both ends of the second sampling unit 24.

[0103] The sampling module 30 may be a sampling chip, and the sampling method of the sampling chip may be differential sampling or conventional sampling.

[0104] When the sampling method of the sampling chip is differential sampling, the corresponding sampling terminal of the first 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. Among them, the positive sampling terminal should be connected to the end with the higher voltage among the two ends of the second sampling unit 24 in the first sampling branch 20, and the negative sampling terminal is connected to the end with the lower voltage among the two ends of the second sampling unit 24.

[0105] When the first sampling branch 20 is the first-pole sampling branch 21, the intermediate voltage of the first sampling unit 23 and the second sampling unit 24 is greater than the voltage of the reference sampling point Rs. At this time, the positive sampling terminal in the second sampling terminal S2 should be connected to the middle of the first sampling unit 23 and the second sampling unit 24, and the negative sampling terminal is connected to the other end of the second sampling unit 24.

[0106] Conversely, when the first sampling branch 20 is the second-pole sampling branch 22, the intermediate voltage of the first sampling unit 23 and the second sampling unit 24 is less than the voltage of the reference sampling point Rs. At this time, the negative sampling terminal in the second sampling terminal S2 should be connected to the middle of the first sampling unit 23 and the second sampling unit 24, and the positive sampling terminal is connected to the other end of the second sampling unit 24.

[0107] It should be noted that the above 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 can be connected to a corresponding first sampling branch 20.

[0108] According to some embodiments of the present application, please continue to refer to Figure 7 , the above first sampling branch 20 may further include a sampling control switch 25, and the sampling control switch 25 may be connected between the first sampling unit 23 and the second sampling unit 24.

[0109] The sampling control switch 25 can be switched between the on state and the off state to realize the conduction and disconnection of the first sampling branch 20. Moreover, when the sampling control switch 25 is disconnected, the first sampling branch 20 is disconnected, and at this time, the sampling module 30 cannot obtain the sampling signal.

[0110] When voltage sampling needs to be performed on a certain sampling detection point Sd, the sampling control switch 25 in the first sampling branch 20 corresponding to the sampling detection point Sd can be controlled to conduct, and when voltage sampling is not required, the sampling control switch 25 can be controlled to disconnect.

[0111] The circuit architecture of the second sampling branch 50 may be the same as or similar to the above first sampling branch 20, and will not be elaborated here.

[0112] According to some embodiments of the present application, the sampling module 30 may be connected to the sampling control switch 25, and the sampling module 30 may control the sampling control switch 25 to conduct or disconnect.

[0113] The above sampling module may include a sampling chip, and the sampling chip may further include a switch control terminal, and the switch control terminal may be connected to the sampling control switch 25 to control the conduction state of the sampling control switch 25. When the sampling function needs to be enabled, the sampling chip may send a conduction signal to the sampling control switch 25 to cause the sampling control switch 25 to connect the first sampling unit 23 and the second sampling unit 24.

[0114] According to some embodiments of the present application, the above sampling control switch 25 may include, but is not limited to, one of a transistor, an optoelectronic device, and a relay. The sampling control switch 25 may also be other switch devices or switch equipment that can realize on-off control, etc.

[0115] According to some embodiments of the present application, please refer to Figure 7 , the above first switch assembly 61 may include at least one of a main positive switch K2, a pre-charge switch K3, a main positive DC charging switch K4, and a main positive AC charging switch K6, and the second switch assembly 62 may include at least one of a main negative switch K1 and a main negative charging switch K5.

[0116] Taking the main negative switch K1 as an example, the sampling point connected to the second pole of the battery 40 through the main negative switch K1 is the second sampling point Ns1. The corresponding sampling module 30 of the second sampling point Ns1 can obtain the voltage of the second sampling point Ns1 relative to the reference sampling point Rs. After any first sampling point Ps relative to the reference sampling point Rs is obtained by other sampling modules 30, the voltage of any first sampling point Ps relative to the second sampling point Ns1 can be calculated according to the difference between the two voltages, so as to obtain the voltages of each first sampling point Ps when the second sampling point Ns1 is used as the reference.

[0117] As Figure 7 shown, GPIO1 - GPIO6 are respectively multiple sampling terminals of the sampling module 30, and each sampling terminal is respectively connected to the corresponding first sampling branch 20 or the second sampling branch 50 to sample the voltage of each sampling detection point Sd.

[0118] As an optional implementation manner, taking the first sampling point Ps1 corresponding to the main positive switch K2 as an example, when the first reference voltage is 2.5V, the voltage of the first sampling point Ps1 relative to the reference sampling point Rs is:

[0119] U Ps1 =(U_GPIO2 - 2.5) / Ra*(Ra + Rb);

[0120] Wherein, U_GPIO2 is the voltage collected by the GPIO2 port of the sampling module 30, Ra is the equivalent resistance of the second sampling unit 24 in the corresponding first sampling branch 20, and Rb is the equivalent resistance of the first sampling unit 23.

[0121] Similarly, the voltage of the second sampling point Ns1 relative to the reference sampling point Rs is:

[0122] U Ns1 =(U_GPIO5 - 2.5) / Ra*(Ra + Rb);

[0123] Wherein, U_GPIO5 is the voltage collected by the GPIO5 port of the sampling module 30.

[0124] After calculating the voltage U Ps1 of the first sampling point Ps1 relative to the reference sampling point Rs and the voltage U Ns1 of the second sampling point Ns1 relative to the reference sampling point Rs, the voltage of the first sampling point Ps1 relative to the second sampling point Ns1 can be calculated as:

[0125] U Ps1-Ns1 =U Ps1 -U Ns1 =(U_GPIO2 - U_GPIO5) / Ra*(Ra + Rb);

[0126] As can be seen from the above analysis, after determining the voltage of any first sampling point relative to the reference sampling point Rs, the voltage of the first sampling point relative to the second sampling point Ns1 can be calculated, thereby realizing voltage sampling with the second sampling point Ns1 as the reference point.

[0127] Similarly, the sampling point connected to the second pole of the battery 40 through the main negative charging switch K5 can be the second sampling point Ns2. Through a manner similar to the above embodiment, when taking the second sampling point Ns as the reference, the voltages of each first sampling point Ps can be obtained. That is, the second pole of the battery 40, the second sampling point Ns1, and the second sampling point Ns2 can all be used as reference points to obtain the voltages of each first sampling point Ps relative to the reference point.

[0128] Based on the same inventive concept, the present application also provides a battery management system, and the battery management system includes the sampling circuit in any of the above embodiments. It can be understood that the battery management system has the beneficial effects of the sampling circuit provided by the embodiments of the present application. For specific details, reference can be made to the specific descriptions of the sampling circuit in the above embodiments, and details will not be repeated in this embodiment.

[0129] Based on the same inventive concept, the present application also provides a battery pack, and the battery pack includes a battery and the battery management system in any of the above embodiments. It can be understood that the battery pack has the beneficial effects of the battery management system provided by the embodiments of the present application.

[0130] Based on the same inventive concept, the present application also provides an electrical device, and the electrical device includes the battery pack in any of the above embodiments. It can be understood that the electrical device has the beneficial effects of the battery pack provided by the embodiments of the present application. For specific details, reference can be made to the specific descriptions of the battery pack in the above embodiments, and details will not be repeated in this embodiment.

[0131] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0132] The functional blocks shown in the above-described structural block diagrams can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application-specific integrated circuit (ASIC), appropriate firmware, a plug-in, a functional card, and so on. When implemented in software, the elements of the present application are programs or code segments for performing the required tasks. The program or code segment can be stored in a machine-readable medium or transmitted over a transmission medium or communication link via a first data signal carried in a carrier wave. A "machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical discs, hard disks, fiber optic media, radio frequency (RF) links, and so on. The code segment can be downloaded via a computer network such as the Internet, an intranet, and so on.

[0133] It should be noted that in this document, the terms "including", "comprising", or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device that includes a series of elements includes not only those elements but also other elements not expressly listed, or elements that are inherent to such process, method, article, or device.

[0134] Specific examples are used in this article to illustrate the principles and implementation manners of the present application. The description of the above examples is only for helping to understand the method and its core idea of the present application. The above are only the preferred implementation manners of the present application. It should be noted that due to the limitation of literal expression and objectively infinite specific structures, for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements, refinements, or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes, or combinations, or directly applying the concept and technical solution of the present application to other occasions without improvement, shall all be regarded as the protection scope of the present application.

Claims

1. A sampling circuit, characterized in that, it includes: a reference voltage module, connected to a reference sampling point, and the reference voltage module is used to provide a first reference voltage for the reference sampling point; a first sampling branch, and the first sampling branch is connected between a corresponding sampling detection point and the reference sampling point; a sampling module, the sampling end of the sampling module is connected to the first sampling branch, and the sampling module is used to obtain the voltage of the sampling detection point relative to the reference sampling point.

2. The sampling circuit according to claim 1, characterized in that, the reference voltage module includes: a voltage source, and the voltage source is used to provide a second reference voltage; a voltage conversion module, connected to the voltage source, and used to convert the second reference voltage into the first reference voltage.

3. The sampling circuit according to claim 2, characterized in that, the first reference voltage is less than the second reference voltage.

4. The sampling circuit according to claim 2 or 3, characterized in that, the voltage source is connected to the second pole of the battery, and the second reference voltage is the voltage of the output voltage of the voltage source relative to the second pole of the battery.

5. The sampling circuit according to claim 4, characterized in that, the sampling circuit further includes: a second sampling branch, connected to the first pole of the battery and the voltage source; the voltage source is used to provide a first reference voltage for the second sampling branch; the sampling module is connected to the second sampling branch, and is used to obtain the voltage of the first pole of the battery relative to the second pole of the battery.

6. The sampling circuit according to any one of claims 1-3, characterized in that, the first sampling branch includes: a first pole sampling branch, and the sampling detection point corresponding to the first pole sampling branch is connected to the first pole of the battery through a first switch component; and / or, a second pole sampling branch, and the sampling detection point corresponding to the second pole sampling branch is connected to the second pole of the battery through a second switch component.

7. The sampling circuit according to claim 6, characterized in that, the first switch component includes at least one of a main positive switch, a pre-charge switch, a main positive DC charging switch, and a main positive AC charging switch, and the second switch component includes at least one of a main negative switch and a main negative charging switch.

8. The sampling circuit according to claim 2 or 3, characterized in that, the voltage conversion module includes: a first voltage dividing unit, and the first voltage dividing unit is connected between the voltage source and the reference sampling point; a voltage stabilizing unit, and the voltage stabilizing unit is connected to the reference sampling point.

9. The sampling circuit according to claim 8, characterized in that, the voltage conversion module further includes a second voltage dividing unit connected in parallel with the voltage stabilizing unit.

10. The sampling circuit according to any one of claims 1-3, characterized in that, the first sampling branch includes: a first sampling unit and a second sampling unit, and the first sampling unit and the second sampling unit are connected in series.

11. The sampling circuit according to claim 10, characterized in that, the first 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.

12. The sampling circuit according to claim 10, characterized in that the first sampling branch includes a second sampling point, and the sampling module includes a second sampling end; The second sampling point is arranged at both ends of the second sampling unit; The second sampling point is connected to the second sampling end of the sampling module.

13. The sampling circuit according to claim 12, characterized in that the second sampling end of the sampling module is a differential sampling end.

14. The sampling circuit according to claim 10, characterized in that the first sampling branch further includes: a sampling control switch, the sampling control switch is connected between the first sampling unit and the second sampling unit; the sampling control switch is used to turn on or off the first sampling branch.

15. A battery management system, characterized in that it includes the sampling circuit according to any one of claims 1-14.

16. A battery pack, characterized in that it includes a battery and the battery management system according to claim 15.

17. An electrical device, characterized in that it includes the battery pack according to claim 16.

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