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 voltage source connected with a reference sampling point and used for providing reference voltage for the reference sampling point; the sampling branch is connected between the sampling detection point and the reference sampling point; and the sampling end of the sampling module is connected with the 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 of the sampling detection point relative to the reference ground can be determined according to the voltage of the sampling detection point relative to the reference sampling point and the reference voltage, and when a plurality of sampling detection points exist, part of the sampling detection points can serve as reference points to determine the voltage of the rest sampling detection points relative to the reference points. And voltage sampling of a plurality of reference points is realized.

Description

Technical Field

[0001] The present application relates to the technical field of power management, and particularly 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 provided 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, including:

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

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

[0009] A sampling module, with its sampling end connected to the 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 voltage source, the sampling module, and the sampling branch, the voltage source can provide a reference voltage to the reference sampling point 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. Thus, the sampling branch shares the same reference sampling point and directly samples relative to the reference voltage, simplifying the circuit design and reducing the circuit cost.

[0011] In a possible implementation of the first aspect, the sampling branch includes: a first sampling branch, where 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 a switch assembly; and / or, a second sampling branch, where the sampling detection point corresponding to the second sampling branch is connected to the second pole of the battery through a switch assembly. By using the first sampling branch and the second sampling branch, voltage sampling can be performed on 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, achieving the sharing of the same reference sampling point by the first sampling branch and / or the second sampling branch, and directly sampling relative to the reference voltage, which simplifies the circuit design and reduces the circuit cost.

[0012] In a possible implementation of the first aspect, the voltage source is connected to the second pole of the battery, and the reference voltage is the voltage difference between the reference sampling point and the second pole of the battery. By using the second pole of the battery as the reference ground, the sampling module can determine the sampling result based on the sampling voltage of the sampling point in the sampling branch relative to the reference sampling point and the reference voltage between the reference sampling point and the reference ground.

[0013] In a possible implementation of the first aspect, the switch assembly includes at least 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 performing voltage sampling on the sampling detection points at both ends of each switch assembly, it is possible to determine whether a fault such as adhesion occurs in the switch assembly based on the voltage difference across the switch assembly.

[0014] In a possible implementation of the first aspect, the sampling branch includes: a first sampling unit and a second sampling unit, which are connected in series. By setting the first sampling unit and the second sampling unit to divide the voltage of the sampling detection point, the voltage after division can be made to fall within the sampling range.

[0015] In a possible implementation of the first aspect, the sampling point of the sampling branch includes a first sampling point, and the sampling module includes a first sampling terminal; 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 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 the reference voltage is achieved.

[0016] In a possible implementation manner of the first aspect, the sampling points of the sampling branch include a second sampling point, and the sampling module includes a second sampling terminal; the second sampling point of the sampling branch is arranged at both ends of the second sampling unit; 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 voltages at both ends of the second sampling unit can be directly sampled, and the voltage of the sampling detection point relative to the reference sampling point can be determined in combination with the voltage division ratio of the first sampling unit and the second sampling unit.

[0017] In a possible implementation manner of the first aspect, the second sampling terminal of the sampling module is a differential sampling terminal. The voltages at both ends of the second sampling unit can be directly obtained by means of differential sampling.

[0018] In a possible implementation manner of the first aspect, the sampling branch further includes: a switch unit for turning on the sampling branch. By providing the switch unit, the application of the sampling branch can be flexibly controlled.

[0019] In a possible implementation manner 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 turn on or off. By controlling the switch unit to turn on through the sampling module, the switch unit can be turned on when sampling is required and turned off when sampling is not required, improving the flexibility of sampling control.

[0020] In a possible implementation manner of the first aspect, the switch unit includes one of a transistor, an optoelectronic device, and a relay. By providing the switching device, the on / off control of the sampling branch can be realized.

[0021] In the 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. The battery management system further includes: a low-voltage power supply; a power isolation module connected between the low-voltage power supply and the voltage source; a communication isolation module connected to the sampling output terminal of the sampling module; and a low-voltage control module, the voltage input terminal of the low-voltage control module being connected to the communication isolation module. By providing the sampling circuit, the isolation modules in the battery management system can be reduced, thereby saving the number of components and circuit costs.

[0022] In the third aspect, an embodiment of the present application provides a battery pack, including the battery management system according to any one of the embodiments of the third aspect.

[0023] In the 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.

[0024] 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 provide a reference voltage to a reference sampling point through a voltage source, so that the voltage of the reference sampling point relative to the reference ground is the reference voltage. According to 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, the sampling module can determine the sampling result. Thus, the sampling branches share the same reference sampling point and directly sample relative to the reference voltage, simplifying the circuit design and reducing the circuit cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 is a schematic block diagram of a sampling circuit provided by an embodiment of the present application;

[0027] Figure 2 is a schematic block diagram of a sampling circuit provided by another embodiment of the present application;

[0028] Figure 3 is a schematic block diagram of a sampling circuit provided by still another embodiment of the present application;

[0029] Figure 4 is a schematic block diagram of a sampling circuit provided by yet another embodiment of the present application;

[0030] Figure 5 is a schematic block diagram of a sampling circuit provided by yet another embodiment of the present application;

[0031] Figure 6 is a schematic circuit diagram of a sampling circuit provided by an embodiment of the present application;

[0032] Figure 7 is a schematic circuit diagram of a sampling circuit provided by another embodiment of the present application;

[0033] Figure 8 is a schematic circuit diagram of a conventional sampling method provided by an embodiment of the present application;

[0034] Figure 9 is a schematic circuit diagram of a differential sampling method provided by an embodiment of the present application;

[0035] Figure 10 is a schematic circuit diagram of a sampling circuit provided by yet another embodiment of the present application;

[0036] Figure 11 It is a schematic diagram of the circuit structure of a sampling branch provided by an embodiment of the present application;

[0037] Figure 12 It is a schematic diagram of the circuit structure of a sampling branch provided by another embodiment of the present application;

[0038] Figure 13 It is a schematic diagram of the module structure of a battery management system provided by an embodiment of the present application.

[0039] In the drawings:

[0040] 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; 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 implementation manners

[0041] The features and exemplary embodiments of various aspects of the present application will be described in detail below. To make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to 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 intended to provide a better understanding of the present application by showing examples of the present application.

[0042] It should be noted that in this article, 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, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes 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.

[0043] 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.

[0044] With the development of new energy technologies, batteries are increasingly widely used in various electrical devices, such as mobile phones, laptops, battery-powered vehicles, electric vehicles, electric aircraft, electric ships, etc.

[0045] 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 positive and negative electrodes 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.

[0046] However, the circuit architecture for voltage sampling in related technologies has certain defects.

[0047] 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.

[0048] 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 voltage source 50, a sampling module 10 and a sampling branch 20.

[0049] The voltage source 50 is connected to a reference sampling point. 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.

[0050] Taking the example that the reference voltage is maintained at 5V by the voltage source 50, if the voltage of the reference ground is 0V, the voltage source 50 can make the voltage of 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 of the reference sampling point 15V.

[0051] The sampling branch 20 can be connected between the corresponding sampling detection point and the reference sampling point in the battery 40.

[0052] The sampling end 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 end, and the voltage of the corresponding sampling detection point relative to the reference sampling point can be determined according to the sampling signal. And the voltage of the reference sampling point relative to the reference ground is a fixed reference voltage. Therefore, after the sampling module 10 determines the voltage of each sampling detection point relative to the reference sampling point, the sum value of this voltage and the reference voltage can be calculated, so as to obtain the voltage of the sampling detection point relative to the reference ground.

[0053] It should be noted that when there are multiple sampling detection points, multiple sampling branches 20 corresponding to the multiple sampling detection points can be set, and each sampling branch 20 is connected between the corresponding sampling detection point and the reference sampling point. The multiple sampling ends of the sampling module 10 are respectively connected to the multiple sampling branches 20. The sampling module 10 can respectively obtain the voltages of the corresponding sampling detection points relative to the reference sampling point through each sampling end, and then combined with the reference voltage of the reference sampling point relative to the reference ground, the voltage sampling of the multiple sampling detection points relative to the reference ground can be realized.

[0054] It should be noted that the voltage sampling of multiple sampling detection points relative to a fixed reference ground is obtained in the above embodiments. In the actual sampling process, in addition to this reference ground, there may also be sampling requirements for multiple reference points. When the sampling circuit needs to realize the 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, this sampling detection point can be used as a reference point to obtain the voltages of the remaining sampling detection points relative to this reference point.

[0055] In this embodiment, by providing a voltage source 50, a sampling module 10, and a sampling branch 20, the voltage source 50 can supply a reference voltage to a reference sampling point so that the voltage of the reference sampling point relative to the reference ground is the reference voltage. The sampling branch 20 can sample the voltage of the sampling detection point. The sampling module 10 can obtain the sampling voltage of the corresponding sampling detection point relative to the reference sampling point by connecting to the sampling branch 20. The sampling module 10 can determine the voltage of the sampling detection point relative to the reference ground 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. When there are multiple sampling detection points, some of the sampling detection points can also be used as reference points, so as to obtain the voltages of the remaining sampling detection points relative to this reference point, realizing the voltage sampling of multiple reference points in the high-voltage sampling architecture.

[0056] It should be noted that in the related art, when implementing the voltage sampling of multiple reference points, generally a set of sampling circuit architectures needs to be provided for each reference point. This sampling circuit architecture includes an isolated power supply module, a sampling chip, an isolated communication module, and a corresponding low-voltage controller. That is, when implementing the voltage sampling of multiple reference points, a relatively large number of devices need to be provided in the circuit architecture, resulting in high device costs and device space, and further affecting the space and production costs of the overall device. Compared with the related art, in the above embodiment, by providing a single reference ground, the voltage of each sampling detection point relative to the reference ground can be obtained. When implementing the voltage sampling of multiple reference points, taking any sampling detection point as the reference point, the voltages of each sampling detection point relative to this reference point can be obtained through calculation. Moreover, since there is only one reference ground, there is no need to provide multiple sets of sampling circuit architectures, which can effectively reduce the number and cost of devices in the device.

[0057] According to some embodiments of the present application, please refer to Figure 2 , the above reference ground can be selected as the second pole of the battery 40. The voltage source 50 can be connected to the second pole 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 pole of the battery 40.

[0058] In this embodiment, by using the second pole of the battery 40 as the reference ground, the voltage of the reference sampling point relative to the second pole of the battery 40 can be made the reference voltage. After the sampling module obtains the voltage of the sampling detection point relative to the reference sampling point, calculating the sum of this voltage and the reference voltage can obtain the voltage of the sampling detection point relative to the second pole of the battery 40.

[0059] According to some embodiments of the present application, please refer to Figures 3 to 5 , as Figure 3 shown, the above sampling branch 20 can include a first sampling branch 21; as Figure 4 shown, the sampling branch 20 can also include a second sampling branch 22; asFigure 5 As shown, the sampling branch 20 may also include both the first sampling branch 21 and the second sampling branch 22.

[0060] As Figure 3 shown, the sampling detection point corresponding to the first sampling branch 21 may be directly connected to the first pole of the battery 40, or may be connected to the first pole of the battery 40 through the switch assembly 30. As Figure 4 shown, the sampling detection point corresponding to the second sampling branch 22 may be connected to the second pole of the battery 40 through the switch assembly 30. Among them, the first pole of the battery 40 may be the positive pole, and the second pole may be the negative pole.

[0061] In the first sampling branch 21, when the sampling detection point is directly connected to the first pole of the battery 40, the first sampling branch 21 can directly sample the voltage of the first pole of the battery 40. When the reference ground is set to the second pole of the battery 40, according to the sum of the voltage of the sampling detection point relative to the reference sampling point and the reference voltage, the voltage of the first pole of the battery 40 relative to the second pole of the battery 40, that is, the voltage across the battery 40, can be determined.

[0062] In the first sampling branch 21, when the sampling detection point is connected to the first pole of the battery 40 through the switch assembly 30, when the switch assembly 30 is turned on, the voltages at both ends of the switch assembly 30 are the same, and at this time the voltage of the sampling detection point is equal to the voltage of the first pole of the battery 40.

[0063] When the switch assembly 30 is turned off, there is a voltage difference across the switch assembly 30. Since one end of the switch assembly 30 is connected to the first pole of the battery 40, at this time the sampling branch 20 can be connected to the sampling detection point located at the other end of the switch assembly 30, and the sampling module 10 can sample the voltage of the sampling detection point to determine the voltage of the sampling detection point relative to the reference sampling point, and according to the sum of the voltage of the sampling detection point relative to the reference sampling point and the reference voltage, the voltage of the sampling detection point relative to the second pole of the battery can be obtained.

[0064] In the second sampling branch 22, when the sampling detection point is connected to the second pole of the battery 40 through the switch assembly 30, when the switch assembly 30 is turned on, the voltages at both ends of the switch assembly 30 are the same, and at this time the voltage of the sampling detection point is equal to the voltage of the second pole of the battery 40. When the switch assembly 30 is turned off, there is a voltage difference across the switch assembly 30. Since one end of the switch assembly 30 is connected to the second pole of the battery 40, at this time the sampling branch 20 can be connected to the sampling detection point located at the other end of the switch assembly 30, and the sampling module 10 can sample the voltage of the sampling detection point to determine the voltage of the sampling detection point relative to the reference sampling point, and according to the sum of the voltage of the sampling detection point relative to the reference sampling point and the reference voltage, the voltage of the sampling detection point relative to the second pole of the battery can be obtained.

[0065] In the above embodiments, taking the first pole of the battery 40 as the positive pole and the second pole as the negative pole as an example, 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 pole sampling detection point. Through the first sampling branch 21 and the sampling module 10, the voltage sampling of the positive pole sampling detection point relative to the second pole of the battery can be realized. 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 pole sampling detection point. Through the second sampling branch 22 and the sampling module 10, the voltage sampling of the negative pole sampling detection point relative to the second pole of the battery can be realized.

[0066] If the sampling branch 20 includes the first sampling branch 21 and the second sampling branch 22, the first sampling branch 21 can sample the voltage of the positive pole sampling detection point relative to the second pole of the battery, and the second sampling branch 22 can sample the voltage of the negative pole sampling detection point relative to the second pole of the battery, so that the voltage sampling of each node that needs to be voltage sampled in the positive pole loop and the negative pole loop can be performed.

[0067] When the sampling branch 20 includes the first sampling branch 21 and the second sampling branch 22, the number of the above first sampling branches 21 is at least one, and the number of the second sampling branches 22 is also at least one.

[0068] Since the reference sampling points of the first sampling branch 21 and the second sampling branch 22 are the same, after determining the voltage of the positive pole sampling detection point relative to the reference sampling point and the voltage of the negative pole sampling detection point relative to the reference sampling point, the sum value of the voltage of the positive pole sampling detection point relative to the reference sampling point and the voltage of the negative pole sampling detection point relative to the reference sampling point can also be calculated to obtain the voltage of the positive pole sampling detection point relative to the negative pole sampling detection point.

[0069] When the numbers of the first sampling branch 21 and the second sampling branch 22 are both multiple, the voltage sampling between any two positive pole sampling detection points, the voltage sampling between any two negative pole sampling detection points, and the voltage sampling between any one positive pole sampling detection point and any one negative pole sampling detection point can be realized.

[0070] Taking the voltage sampling between two positive pole sampling detection points as an example, according to the two first sampling branches 21 respectively corresponding to the two positive pole sampling detection points, the sampling module 10 can respectively obtain the voltages of the two positive pole sampling detection points relative to the reference sampling point. And the voltage difference between the two positive pole sampling detection points is the difference between the voltage of one positive pole sampling detection point relative to the reference sampling point and the voltage of the other positive pole sampling detection point relative to the reference sampling point.

[0071] When one of the two positive - electrode sampling detection points is directly connected to the first pole of the battery, and the other is connected to the first pole of the battery through the switch assembly 30. If the switch assembly 30 is turned on, the potentials of the two positive - electrode sampling detection points should be the same, that is, the voltage difference is 0. If the switch assembly 30 is normally turned off, there should be a certain voltage difference between the two positive - electrode sampling detection points.

[0072] After calculating the voltage difference between the two positive - electrode sampling detection points, the voltage difference can be compared with a preset voltage threshold. If the voltage difference is greater than the voltage threshold, it indicates that the switch assembly 30 is normally turned off; if the voltage difference is less than the voltage threshold, it indicates that the switch assembly 30 is not normally turned off, and there may be faults such as relay adhesion.

[0073] The above - mentioned voltage threshold can be a fixed voltage or can be associated with the voltage across the battery 40. For example, when the voltage across the battery 40 is 800V, the voltage threshold can be 1%, 2% or other ratios of the voltage across the battery 40.

[0074] Similarly, when sampling the voltage between the two negative - electrode sampling detection points, according to the two second sampling branches 22 corresponding to the two negative - electrode sampling detection points respectively, the sampling module 10 can respectively obtain the voltages of the two negative - electrode sampling detection points relative to the reference sampling point. And the voltage difference between the two negative - electrode sampling detection points is the difference between the voltage of one negative - electrode sampling detection point relative to the reference sampling point and the voltage of the other negative - electrode sampling detection point relative to the reference sampling point.

[0075] When it is necessary to determine the voltage difference between the two positive - electrode sampling detection points, the difference between the voltage of one positive - electrode sampling detection point relative to the reference sampling point and the voltage of the other positive - electrode sampling detection point relative to the reference sampling point can be calculated, so as to obtain the voltage difference between the two positive - electrode sampling detection points; when it is necessary to determine the voltage difference between the two negative - electrode sampling detection points, the difference between the voltage of one negative - electrode sampling detection point relative to the reference sampling point and the voltage of the other negative - electrode sampling detection point relative to the reference sampling point can be calculated, so as to obtain the voltage difference between the two negative - electrode sampling detection points; when it is necessary to determine the voltage difference between a positive - electrode sampling detection point and a negative - electrode sampling detection point, the sum of the voltage of the positive - electrode sampling detection point relative to the reference sampling point and the voltage of the negative - electrode sampling detection point relative to the reference sampling point can be calculated, so as to obtain the voltage difference between the positive - electrode sampling detection point and the negative - electrode sampling detection point.

[0076] According to some embodiments of the present application, please refer to Figure 6, the above-mentioned switch assembly 30 may include at least one of a main positive switch K2, a main negative switch K1, a pre-charge switch K3, a main positive DC charging switch K4, a main positive AC charging switch K6, a main negative charging switch K5, a heating switch K7, and a load switch K8.

[0077] The positive and negative electrodes of the battery 40 can be connected to corresponding charging devices, functional circuits, or loads through different switch assemblies 30. By setting sampling detection points on one side of each switch assembly 30 away from the positive or negative electrode of the battery 40, and sampling the voltage of the sampling detection points through the sampling branch 20, the state of each switch assembly 30 can be diagnosed by combining the positive electrode voltage and the negative electrode voltage of the battery 40, thereby improving the reliability during the operation of the battery.

[0078] As an alternative implementation manner, in the above embodiment, the positive electrode sampling detection points may include a sampling detection point connected to the positive electrode of the battery 40 and 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 6 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 the battery 40 and sampling detection points respectively passing through the main negative switch K1 and the main negative charging switch K5. That is, there may be 3 negative electrode sampling detection points. When realizing the voltage sampling of multiple reference points, at least one of the 3 negative electrode sampling detection points can be used as a reference point, and the voltage of any positive electrode sampling detection point relative to this reference point can be calculated. That is, for the 6 positive electrode sampling detection points and the 3 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, a total of 18 sampling voltages.

[0079] According to some embodiments of the present application, please refer to Figure 7 , the above-mentioned sampling branch 20 may include a first sampling unit 23 and a second sampling unit 24.

[0080] The first sampling unit 23 and the second sampling unit 24 are connected in series.

[0081] The first sampling unit 23 and the second sampling unit 24 can 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 can be set according to the normal voltage range of the sampling detection point connected to the 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 includes a relatively high voltage, the first sampling unit 23 can be set with a resistor of a relatively high resistance value, and the second sampling unit 24 can be set with a resistor of 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, 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.

[0082] According to some embodiments of the present application, please refer to Figure 8 , the sampling module 10 may include a first sampling terminal S1, and the sampling point of the sampling branch 20 may include a first sampling point, which is set in the middle of the first sampling unit 23 and the second sampling unit 24.

[0083] The first sampling point of the sampling branch 20 can be connected to the first sampling terminal S1 of the sampling module 10, and the sampling module 10 can obtain the voltage of the first sampling point through the first sampling terminal S1.

[0084] After the sampling module 10 obtains the voltage of the first sampling point through the first sampling point, it can determine the voltage difference between the two ends of the sampling branch 20 according to the equivalent resistance values of the first sampling unit 23 and the second sampling unit 24. For example, when the equivalent resistance value of the first sampling unit 23 is R1, the equivalent resistance value of the second sampling unit 24 is R2, the voltage value of the first sampling point is Vp, and the reference voltage is Tsref, the formula for calculating the voltage difference between the two ends of the sampling branch 20 is as follows:

[0085] V1 = (Vp - Vref) * (R1 + R2) / R2;

[0086] Since the two ends of the sampling branch 20 are respectively connected to the sampling detection point and the reference sampling point, 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.

[0087] When the reference ground is the second pole of the battery, the sampling module 10 can determine the voltage of the sampling detection point relative to the second pole of the battery according to the voltage difference between the two ends of the sampling branch 20 and the reference voltage provided by the voltage source 50. The formula is as follows:

[0088] V = V1 + Vref;

[0089] Wherein, Vref is the reference voltage between the reference sampling point and the second pole of the battery, and V is the voltage of the sampling detection point relative to the second pole of the battery.

[0090] According to some embodiments of the present application, please refer to Figure 9 , the sampling module 10 may include a second sampling terminal S2, and the sampling point 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.

[0091] The second sampling point of the sampling branch 20 may be connected to the second sampling terminal S2 of the sampling module 10, and the sampling module 10 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 10 is also 2.

[0092] The sampling module 10 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 between both ends of the sampling branch 20 can be calculated according to the equivalent resistance values of the first sampling unit 23 and the second sampling unit 24. For example, when 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 at both ends of 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 between both ends of the sampling branch 20 is as follows:

[0093] V2 = Vq * (R1 + R2) / R2;

[0094] Since both ends of the sampling branch 20 are respectively connected to the sampling detection point and the reference sampling point, the voltage difference between both ends of the sampling branch 20 is the voltage difference between the sampling detection point and the reference sampling point.

[0095] When the reference ground is the second pole of the battery, the sampling module 10 can determine the voltage of the sampling detection point relative to the second pole of the battery according to the voltage difference between both ends of the sampling branch 20 and the reference voltage provided by the voltage source 50. The formula is as follows:

[0096] V = V2 + Vref;

[0097] Wherein, Vref is the reference voltage between the reference sampling point and the second pole of the battery, and V is the voltage of the sampling detection point relative to the second pole of the battery.

[0098] According to some embodiments of the present application, the second sampling terminal S2 of the above 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 the voltage difference between both ends of the second sampling unit 24.

[0099] The above sampling module 10 may be a sampling chip, and the sampling method of the sampling chip may be differential sampling or conventional sampling.

[0100] When the sampling method of the sampling chip is differential sampling, the corresponding sampling end of the sampling branch 20 is the second sampling end S2, and the second sampling end S2 includes a positive sampling end and a negative sampling end. Among them, the positive sampling end should be connected to the end with the higher voltage among the two ends of the second sampling unit 24 in the sampling branch 20, and the negative sampling end is connected to the end with the lower voltage among the two ends of the second sampling unit 24.

[0101] When the sampling branch 20 is the first sampling branch 21, the intermediate voltage between the first sampling unit 23 and the second sampling unit 24 is greater than the voltage of the reference sampling point. At this time, the positive sampling end in the second sampling end S2 should be connected to the middle between the first sampling unit 23 and the second sampling unit 24, and the negative sampling end is connected to the other end of the second sampling unit 24.

[0102] Conversely, when the sampling branch 20 is the second sampling branch 22, the intermediate voltage between the first sampling unit 23 and the second sampling unit 24 is less than the voltage of the reference sampling point. At this time, the negative sampling end in the second sampling end S2 should be connected to the middle between the first sampling unit 23 and the second sampling unit 24, and the positive sampling end is connected to the other end of the second sampling unit 24.

[0103] It should be noted that the above sampling chip may include multiple second sampling ends S2. When multiple sampling detection points need to be detected in the sampling circuit, each second sampling end S2 can be connected to the corresponding sampling branch 20.

[0104] According to some embodiments of the present application, please refer to Figure 10 Above, the sampling branch 20 may further include a switch unit 25, and the switch unit 25 can conduct the sampling branch 20.

[0105] The switch unit 25 can be connected between the first sampling unit 23 and the second sampling unit 24, and the switch unit 25 can be switched between a conducting state and a disconnecting state to realize the connection and disconnection between the first sampling unit 23 and the second sampling unit 24.

[0106] As Figure 10 shown, since the voltage between the positive electrode and the negative electrode of the battery 40 needs to be detected in real time, therefore, for the sampling branch 20 corresponding to the sampling detection point directly connected to the first pole of the battery 40, the switch unit 25 may not be provided, that is, the first sampling unit 23 and the second sampling unit 24 are always kept connected.

[0107] For the sampling detection point connected to the first pole or the negative pole of the battery 40 through the switch component 30, when the switch component 30 is not activated, it is not necessary to detect the open state of the switch component 30. Only when the switch component 30 is turned on and performs the corresponding function and then the switch component 30 is controlled to turn off, it is necessary to detect the open state of the switch component 30. Therefore, by providing the switch unit 25 in the sampling branch 20, it is possible to control the switch unit 25 to connect the first sampling unit 23 and the second sampling unit 24 when voltage sampling needs to be performed on the sampling detection point corresponding to the sampling branch 20, that is, when the switch component 30 is turned off, so as to achieve voltage sampling.

[0108] In another alternative 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 the switch unit 25.

[0109] According to some embodiments of the present application, please continue to refer to Figure 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.

[0110] 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 switch unit 25 to control the on 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 to cause the switch unit 25 to connect the first sampling unit 23 and the second sampling unit 24.

[0111] According to some embodiments of the present application, the above switch unit 25 may include, but is not limited to, one of a transistor, an optoelectronic device, and a relay. The switch unit 25 may also be other switch devices or switch equipment that can implement on-off control, etc.

[0112] According to some embodiments of the present application, please refer to Figure 11 , the above switch unit 25 may include a first MOSFET Q1.

[0113] The first MOSFET Q1 may be connected between the first sampling unit 23 and the second sampling unit 24, and the control terminal of the first MOSFET Q1 is connected to the enable signal terminal.

[0114] When a non-enable signal is received at the control terminal of the first MOSFET Q1, the first MOSFER is turned off. 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.

[0115] When an enabling signal is received at the control terminal of the first MOSFET Q1, the first MOSFET is turned on. At this time, the first sampling unit 23 is connected to the second sampling unit 24, and the sampling branch 20 can divide the voltage at the sampling detection point so that the sampling module 10 can obtain the voltage at the sampling detection point relative to the reference sampling point.

[0116] It can be understood that the above-mentioned switching unit 25 can be a MOSFET device, or can include but is not limited to other power switching devices that can adapt to the voltage range of the corresponding sampling detection point.

[0117] According to some embodiments of the present application, please refer to Figure 12 , the above-mentioned switching unit 25 can include an isolated control component 251 and a controlled component 252. The controlled component 252 is connected between the first sampling unit 23 and the second sampling unit 24, and the control component 251 can control the on and off of the controlled component 252.

[0118] The control component 251 can control the isolated controlled component 252 to conduct or turn off according to the corresponding control signal. When the controlled component 252 is turned on, it can connect the first sampling unit 23 and the second sampling unit 24; when the controlled component 252 is turned off, it can disconnect the first sampling unit 23 and the second sampling unit 24.

[0119] Different from the above embodiment using the first MOSFET Q1 as the switching 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 usually a relatively high voltage, when the controller providing the enabling signal for the switching unit 25 is a controller in a high-voltage environment, the signal terminal of the controller can be directly connected to the first MOSFET Q1, and the on-state of the first MOSFET Q1 can be controlled by the controller to realize the switching control of the sampling branch 20.

[0120] If the controller providing the control signal for the switching unit 25 is a controller in a low-voltage environment, in order to avoid the influence of the high voltage flowing through the sampling branch 20 on the controller in the low-voltage environment, the switching unit 25 can be set as an isolated control part and a controlled part. The control part is connected to the controller in the low-voltage environment, and the controlled part is connected to the sampling branch 20 in the high-voltage environment. By isolating the controller from the sampling branch 20, the isolation protection of the controller can be realized, and the reliability of voltage sampling in the high-voltage environment can be improved.

[0121] According to some embodiments of the present application, please continue to refer to Figure 12 , the above-mentioned control component 251 can include a series-connected enabling switch Qen and a light source Ls, and the controlled component 252 can include a light receiver Po.

[0122] The control terminal of the enable switch Qen is connected to the enable signal terminal. 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.

[0123] The light receiver Po can be connected between the first sampling unit 23 and the second sampling unit 24 and is turned on when the light source Ls emits light.

[0124] In this embodiment, the controller in the 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 and 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.

[0125] According to some embodiments of the present application, as Figure 12 shown, the above light receiver Po may include a second MOSFET Q2 and a third MOSFET Q3.

[0126] The first end of the second MOSFET Q2 is connected to the first sampling unit 23, the second end of the second MOSFET Q2 is connected to the first end of the third MOSFET Q3, and the second end of the third MOSFET Q3 is connected to the second sampling unit 24. The positive poles of the body diodes of the second MOSFET Q2 and the third MOSFET Q3 are connected.

[0127] To avoid the situation where current can still flow unidirectionally through the body diode of a single MOSFET when it is turned off, the second MOSFET Q2 and the third MOSFET Q3 can be arranged in series relatively. When both the second MOSFET Q2 and the third MOSFET Q3 are turned off, the body diode of the second MOSFET Q2 can limit the current flowing from the sampling detection point to the reference sampling point, and the body diode of the third MOSFET Q3 can limit the current flowing from the reference sampling point to the sampling detection point. The two-way current limitation between the sampling detection point and the reference sampling point can be achieved through the second MOSFET Q2 and the third MOSFET Q3.

[0128] Based on the same inventive concept, the present application also provides a battery management system. 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 in the embodiments of the present application. For the specific description of the sampling circuit, reference can be made to the above embodiments, and details will not be repeated in this embodiment.

[0129] According to some embodiments of the present application, please refer to Figure 13, the above 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.

[0130] The low-voltage power supply 13 may provide a reference voltage for the voltage source 50. The power isolation module 14 may 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. Since 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.

[0131] The first end of the communication isolation module 15 is connected to the sampling output end of the sampling module 10, and the second end of the communication isolation module 15 is connected to the voltage input end of the low-voltage control module 16.

[0132] The communication isolation module 15 may convert the sampling signal output by the sampling module 10 from an analog signal to a digital signal and send the digital signal to the low-voltage control module 16.

[0133] The low-voltage control module 16 may determine the voltage of the corresponding sampling detection point relative to the reference sampling point according to the digital signal, and calculate the voltage of the sampling detection point relative to the reference ground according to the sum value of the voltage and the reference voltage. When the reference ground is set to the second pole of the battery, the voltage of the sampling detection point relative to the second pole of the battery can be determined.

[0134] Based on the same inventive concept, the present application also provides a battery pack, which includes 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.

[0135] Based on the same inventive concept, the present application also provides an electrical device, which 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 may be made to the specific descriptions of the battery pack in the above embodiments, and details will not be repeated in this embodiment.

[0136] 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.

[0137] 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 used to perform 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, ROMs, flash memories, erasable ROMs (EROMs), 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.

[0138] It should be noted that in this article, the term "including", "comprising", or any other variant thereof is 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 a process, method, article, or device.

[0139] In this article, specific examples are used to elaborate on the principles and implementation manners of the present application. The descriptions of the above examples are only used to help understand the method and its core idea of the present application. The above is only the preferred implementation manner of the present application. It should be noted that due to the limitations of literal expression and objectively existing 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 also 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, should all be regarded as the protection scope of the present application.

Claims

1. A sampling circuit, characterized in that, it includes: a voltage source connected to a reference sampling point, and the voltage source is used to provide a reference voltage for the reference sampling point; a sampling branch connected between a sampling detection point and the reference sampling point; a sampling module, the sampling end of the sampling module is connected to the 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 sampling branch includes: a first sampling branch, 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 a switch component; and / or, a second sampling branch, the sampling detection point corresponding to the second sampling branch is connected to the second pole of the battery through a switch component.

3. The sampling circuit according to claim 1 or 2, characterized in that, the voltage source is connected to the second pole of the battery, and the reference voltage is the voltage difference between the reference sampling point and the second pole of the battery.

4. The sampling circuit according to claim 2, characterized in that, the switch component includes at least 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.

5. The sampling circuit according to claim 1 or 2, characterized in that, the 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.

6. The sampling circuit according to claim 5, characterized in that, 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 sampling circuit according to claim 5, characterized in that, the sampling point of the sampling branch includes a second sampling point, and the sampling module includes a second sampling end; the second sampling point of the sampling branch 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.

8. The sampling circuit according to claim 7, characterized in that, the second sampling end of the sampling module is a differential sampling end.

9. The sampling circuit according to claim 5, characterized in that, the sampling branch further includes: a switch unit, and the switch unit is used to make the sampling branch conduct.

10. The sampling circuit according to claim 9, characterized in that, the sampling module is connected to the switch unit, and the sampling module is used to control the switch unit to conduct or disconnect.

11. The sampling circuit according to claim 9, characterized in that, the switch unit includes one of a transistor, an optoelectronic device, and a relay.

12. A battery management system, characterized in that, it includes the sampling circuit according to any one of claims 1-11, and the battery management system further includes: a low-voltage power supply; A power isolation module, connected between the low-voltage power supply and the voltage source; A communication isolation module, the communication isolation module being connected to the sampling output end of the sampling module; A low-voltage control module, the voltage input end of the low-voltage control module being connected to the communication isolation module.

13. A battery pack, Characterized in that, It includes a battery and the battery management system according to claim 12.

14. An electrical device, Characterized in that, It includes the battery pack according to claim 13.

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