Sampling circuit, calibration method thereof, battery management system and electric device

Abstract

The application discloses a sampling circuit and a calibration method thereof, a battery management system and a power utilization device. The calibration method comprises the following steps: acquiring the voltage of a first type of sampling point and the voltage of a second type of sampling point; determining a calibration factor corresponding to the first type of sampling point according to the voltage of the first type of sampling point and the voltage of the second type of sampling point; and correcting the voltage of the first type of sampling point based on the calibration factor to obtain the voltage of the first type of sampling point after correction. The application can solve the problem of poor sampling accuracy of the sampling points in the sampling circuit.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to a sampling circuit and its calibration method, a battery management system, and an electrical device. Background Technology

[0002] With increasing environmental pollution, market demand for new energy vehicles is expanding, and the requirements for new energy vehicle technology are becoming increasingly stringent, especially regarding safety performance. To improve the safety of new energy vehicles, it is necessary to sample some components (such as batteries) within them.

[0003] However, the inventors of this application have discovered that, over time, the components in the sampling circuit will age, causing the sampling accuracy of some sampling points in the sampling circuit to deteriorate, resulting in lower accuracy of the sampling results. Summary of the Invention

[0004] This application provides a sampling circuit and its calibration method, a battery management system, and an electrical device, which can solve the problem of poor sampling accuracy of sampling points in the sampling circuit.

[0005] In a first aspect, this application provides a calibration method for a sampling circuit. The calibration method includes: acquiring the voltage of a first type of sampling point and the voltage of a second type of sampling point; determining a calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point; and correcting the voltage of the first type of sampling point based on the calibration factor to obtain the corrected voltage of the first type of sampling point.

[0006] In the technical solution of this application embodiment, the calibration factor corresponding to the first type of sampling point is calculated using the voltage of the second type of sampling point with higher sampling accuracy, and the voltage of the first type of sampling point is corrected based on the calibration factor to obtain the corrected voltage of the first type of sampling point. This allows the first type of sampling point to have the same or similar sampling accuracy as the second type of sampling point, thereby improving the sampling accuracy of the first type of sampling point in the sampling circuit and ensuring that the sampling result has high accuracy.

[0007] Optionally, according to some embodiments of this application, determining the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point includes: determining the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point at multiple times and the voltage of the second type of sampling point at multiple times.

[0008] According to some embodiments of this application, optionally, determining the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point includes: establishing a relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point based on the voltage of the first type of sampling point at multiple times and the voltage of the second type of sampling point at multiple times; and determining the calibration factor corresponding to the first type of sampling point based on the relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0009] Optionally, according to some embodiments of this application, determining the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point includes: establishing a first relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point based on the voltage of the first type of sampling point acquired at a first time and the voltage of the second type of sampling point acquired at the first time; establishing a second relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point based on the voltage of the first type of sampling point acquired at a second time and the voltage of the second type of sampling point acquired at the second time; and determining the calibration factor corresponding to the first type of sampling point based on the first relationship and the second relationship.

[0010] According to some embodiments of this application, optionally, the voltage of the first type of sampling point includes the voltage of the first type of sampling point relative to the first reference potential, and the voltage of the second type of sampling point includes the voltage of the second type of sampling point relative to the second reference potential; establishing a first relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point based on the voltage of the first type of sampling point acquired at the first time and the voltage of the second type of sampling point acquired at the first time includes: establishing a first relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point based on the voltage difference between the first reference potential and the second reference potential, the voltage of the first type of sampling point acquired at the first time, and the voltage of the second type of sampling point acquired at the first time.

[0011] Optionally, according to some embodiments of this application, establishing a second relationship between the voltages of the first type of sampling points and the second type of sampling points based on the voltages of the first type of sampling points obtained at the second time and the voltages of the second type of sampling points obtained at the second time includes: establishing a second relationship between the voltages of the first type of sampling points and the second type of sampling points based on the voltage difference between the first reference potential and the second reference potential, the voltages of the first type of sampling points obtained at the second time, and the voltages of the second type of sampling points obtained at the second time.

[0012] According to some embodiments of this application, optionally, the calibration factor includes a first calibration parameter and a second calibration parameter; the step of correcting the voltage of the first type of sampling points based on the calibration factor to obtain the corrected voltage of the first type of sampling points includes: calculating the product between the voltage of the first type of sampling points and the first calibration parameter; calculating the sum of the product and the second calibration parameter to obtain the corrected voltage of the first type of sampling points.

[0013] According to some embodiments of this application, optionally, the voltage of the first type of sampling point includes the voltage of the first type of sampling point relative to the first reference potential, and the voltage of the second type of sampling point includes the voltage of the second type of sampling point relative to the second reference potential; the step of calculating the sum of the product and the second calibration parameter to obtain the corrected voltage of the first type of sampling point includes: calculating the voltage difference between the first reference potential and the second reference potential, and the sum of the product and the second calibration parameter to obtain the corrected voltage of the first type of sampling point.

[0014] Secondly, this application provides a sampling circuit, comprising: a first type of sampling branch electrically connected to a device under test (DUT), the first type of sampling branch being provided with a first type of voltage divider module and a first type of sampling point; a second type of sampling branch electrically connected to the DUT, the second type of sampling branch being provided with a second type of voltage divider module, a switch module, and a second type of sampling point; and a sampling processing module electrically connected to the first type of sampling point and the second type of sampling point, the sampling processing module being used to correct the voltage of the first type of sampling point based on a calibration factor, the calibration factor being determined based on the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0015] According to some embodiments of this application, optionally, the first type of sampling branch is electrically connected to the first reference voltage terminal, and the second type of sampling branch is electrically connected to the second reference voltage terminal; the voltage of the first type of sampling point includes the voltage of the first type of sampling point relative to the first reference voltage terminal, and the voltage of the second type of sampling point includes the voltage of the second type of sampling point relative to the second reference voltage terminal.

[0016] According to some embodiments of this application, optionally, the first type of sampling branch includes a first sampling branch, a first end of which is electrically connected to a first electrode of the device under test, a second end of which is electrically connected to a first reference voltage terminal, and a first type of sampling point includes a first sampling point located in the first sampling branch; the second type of sampling branch includes a second sampling branch, a first end of which is electrically connected to a first electrode of the device under test, a second end of which is electrically connected to a second reference voltage terminal, and a second type of sampling point includes a second sampling point located in the second sampling branch; the switching module includes a first switching module, and the second sampling point samples when the first switching module is turned on.

[0017] According to some embodiments of this application, optionally, the first type of sampling branch includes a third sampling branch, the first end of the third sampling branch is electrically connected to the first reference voltage terminal, the second end of the third sampling branch is electrically connected to the second electrode of the device under test, and the first type of sampling point includes a third sampling point located in the third sampling branch; the second type of sampling branch includes a fourth sampling branch, the first end of the fourth sampling branch is electrically connected to the second reference voltage terminal, the second end of the fourth sampling branch is electrically connected to the second electrode of the device under test, and the second type of sampling point includes a fourth sampling point located in the fourth sampling branch; the switching module includes a second switching module, and the fourth sampling point samples when the second switching module is turned on.

[0018] According to some embodiments of this application, optionally, the sampling circuit further includes a third switching module, the first end of which is electrically connected to the first electrode of the device under test; the first type of sampling branch further includes a fifth sampling branch, the first end of which is electrically connected to the second end of the third switching module, the second end of which is electrically connected to the first reference voltage terminal, and the first type of sampling point further includes a fifth sampling point located in the fifth sampling branch.

[0019] According to some embodiments of this application, optionally, the sampling circuit further includes a fourth switching module, the first end of which is electrically connected to the second electrode of the device under test; the first type of sampling branch further includes a sixth sampling branch, the first end of which is electrically connected to the first reference voltage terminal, the second end of which is electrically connected to the second end of the fourth switching module, and the first type of sampling point further includes a sixth sampling point located in the sixth sampling branch.

[0020] According to some embodiments of this application, optionally, the voltage at the first reference voltage terminal is greater than 0V and less than the maximum value of the sampling range of the sampling chip.

[0021] According to some embodiments of this application, optionally, the first sampling branch includes a first voltage divider module, a second voltage divider module, and a first sampling point; the first terminal of the first voltage divider module is electrically connected to the first electrode of the device under test, and the second terminal of the first voltage divider module is electrically connected to the first sampling point; the first terminal of the second voltage divider module is electrically connected to the first sampling point, and the second terminal of the second voltage divider module is electrically connected to the first reference voltage terminal; the sum of the resistance values ​​of the first voltage divider module and the second voltage divider module ranges from 25 to 30 megohms.

[0022] According to some embodiments of this application, optionally, the sampling circuit further includes a follower; the first input terminal of the follower is electrically connected to the first type of sampling point, the second input terminal of the follower is electrically connected to the output terminal of the follower, the first power input terminal of the follower is electrically connected to the positive power supply voltage signal terminal, the second power input terminal of the follower is electrically connected to the ground terminal, the output terminal of the follower is electrically connected to the voltage acquisition terminal of the sampling chip; the potential reference terminal of the sampling chip is electrically connected to the ground terminal.

[0023] Thirdly, this application provides a battery management system, which includes the sampling circuit provided in the second aspect.

[0024] Fourthly, this application provides an electrical device that includes a battery management system as provided in the third aspect. Attached Figure Description

[0025] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0026] Figure 1 A schematic flowchart illustrating a calibration method for a sampling circuit provided in an embodiment of this application;

[0027] Figure 2 A circuit connection diagram of the sampling circuit provided in an embodiment of this application;

[0028] Figure 3 A schematic flowchart of step S102 in the calibration method of the sampling circuit provided in the embodiments of this application;

[0029] Figure 4 Another schematic flowchart illustrating the calibration method for the sampling circuit provided in the embodiments of this application;

[0030] Figure 5 A schematic flowchart of step S103 in the calibration method of the sampling circuit provided in the embodiments of this application;

[0031] Figure 6 Another circuit connection diagram of the sampling circuit provided in the embodiments of this application;

[0032] Figure 7This is another schematic flowchart illustrating the calibration method for the sampling circuit provided in the embodiments of this application;

[0033] Figure 8 Another circuit connection diagram of the sampling circuit provided in the embodiments of this application;

[0034] Figure 9 Another circuit connection diagram of the sampling circuit provided in the embodiments of this application;

[0035] Figure 10 This is another circuit connection diagram of the sampling circuit provided in the embodiments of this application.

[0036] The accompanying drawings are not necessarily drawn to scale. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0039] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0040] In the description of the embodiments of this application, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0041] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0042] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] To improve the safety of new energy vehicles, it is often necessary to sample some devices under test (such as batteries) in the vehicles. In the embodiments of this application, the devices under test include, but are not limited to, power batteries. Power batteries include, but are not limited to, lithium-ion batteries, lithium metal batteries, lead-acid batteries, nickel-metal hydride batteries, lithium-sulfur batteries, lithium-air batteries, or sodium-ion batteries, and are not limited thereto. In terms of scale, power batteries can be individual cells, battery modules, or battery packs, and are not limited thereto.

[0044] The inventors have observed that, over time, components in the sampling circuit age, leading to a decrease in the sampling accuracy of some sampling points and consequently, lower sampling accuracy. This is particularly true in some sampling branches of the sampling circuit, where, to protect components and reduce costs, high-resistance, low-precision voltage divider modules (such as resistors) are typically used. As these voltage divider modules age, their accuracy further decreases, resulting in even lower sampling accuracy at the sampling points in these branches and ultimately, lower sampling accuracy.

[0045] To address the aforementioned technical problems, this application provides a sampling circuit and its calibration method, a battery management system, and a power-consuming device. The method calculates the calibration factor corresponding to the first type of sampling point using the voltage of a second type of sampling point with higher sampling accuracy, and corrects the voltage of the first type of sampling point based on the calibration factor, obtaining the corrected voltage of the first type of sampling point. This allows the first type of sampling point to have the same or similar sampling accuracy as the second type of sampling point, thus improving the sampling accuracy of the first type of sampling point in the sampling circuit and ensuring high accuracy of the sampling results.

[0046] The calibration method for the sampling circuit provided in the embodiments of this application will be introduced first below.

[0047] Figure 1 This is a schematic flowchart illustrating a calibration method for a sampling circuit provided in an embodiment of this application. Figure 1 As shown, the calibration method for the sampling circuit provided in this application embodiment may include S101 to S103.

[0048] S101. Obtain the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0049] The first type of sampling point and the second type of sampling point can be different sampling points in the sampling circuit.

[0050] S102. Determine the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0051] In some embodiments, the sampling accuracies of the first type of sampling points and the second type of sampling points may be different; for example, the sampling accuracies of the second type of sampling points may be higher than those of the first type of sampling points. Since the voltage accuracy of the second type of sampling points is higher, the voltage of the first type of sampling points can be corrected using the voltage of the second type of sampling points. For example, in S202, the calibration factor corresponding to the first type of sampling points can be determined based on the voltages of the first type of sampling points and the voltages of the second type of sampling points.

[0052] S103. Based on the calibration factor, the voltage of the first type of sampling point is corrected to obtain the corrected voltage of the first type of sampling point.

[0053] After obtaining the calibration factor corresponding to the first type of sampling point, the voltage of the first type of sampling point can be corrected based on the calibration factor, thereby obtaining the corrected voltage of the first type of sampling point.

[0054] The calibration method of the sampling circuit in this application calculates the calibration factor corresponding to the first type of sampling point using the voltage of the second type of sampling point with higher sampling accuracy, and corrects the voltage of the first type of sampling point based on the calibration factor to obtain the corrected voltage of the first type of sampling point. This allows the first type of sampling point to have the same or similar sampling accuracy as the second type of sampling point, thereby improving the sampling accuracy of the first type of sampling point in the sampling circuit and ensuring that the sampling result has high accuracy.

[0055] To facilitate understanding, the calibration method for the sampling circuit is described below with reference to the circuit structure of the sampling circuit in some application embodiments. It should be noted that the calibration method for the sampling circuit in this application is not limited to the sampling circuits shown in the following figures.

[0056] Figure 2 This is a schematic diagram of a sampling circuit provided in an embodiment of this application. Figure 1As shown, in some embodiments, the sampling circuit 10 may include a first sampling branch 101 and a second sampling branch 102. Both the first sampling branch 101 and the second sampling branch 102 are electrically connected to the device under test 20. The first sampling branch 101 is provided with a first voltage divider module FL1 and a first sampling point UL1. The second sampling branch 102 is provided with a second voltage divider module FL2, a switch module K, and a second sampling point UL2. The switch module K is disposed in the second sampling branch 102, and when the switch module K is turned on, the second sampling point UL2 performs sampling. In the embodiments of this application, the device under test 20 may include, for example, a power battery.

[0057] For example, the resistance values ​​of the first type of voltage divider module FL1 and the second type of voltage divider module FL2 can be different. Figure 2 As shown, since the second type of sampling branch 102 has a switching module K, when the output voltage of the device under test 20 is large, the switching module K can be disconnected to avoid damage to the devices in the second type of sampling branch 102 (such as the second type of voltage divider module FL2). Therefore, compared with the first type of sampling branch 101, the second type of sampling branch 102 can use resistors with relatively small resistance and relatively high accuracy, thus the sampling accuracy of the second type of sampling point UL2 is higher.

[0058] Combination Figure 1 and Figure 2 As shown, in S101, for example, the voltage of the first type of sampling point UL1 and the voltage of the second type of sampling point UL2 can be collected.

[0059] Since the voltage of the second type of sampling point UL2 has higher accuracy, the voltage of the first type of sampling point UL1 can be corrected using the voltage of the second type of sampling point UL2. For example, in S102, the calibration factor corresponding to the first type of sampling point UL1 can be calculated based on the voltage of the first type of sampling point UL1 and the voltage of the second type of sampling point UL2.

[0060] In S103, after obtaining the calibration factor corresponding to the first type of sampling point UL1, the voltage of the first type of sampling point can be corrected based on the calibration factor corresponding to the first type of sampling point UL1, thereby obtaining the corrected voltage of the first type of sampling point.

[0061] The calibration method of the sampling circuit in this application calculates the calibration factor corresponding to the first type of sampling point using the voltage of the second type of sampling point with higher sampling accuracy, and corrects the voltage of the first type of sampling point based on the calibration factor to obtain the corrected voltage of the first type of sampling point. This allows the first type of sampling point to have the same or similar sampling accuracy as the second type of sampling point, thereby improving the sampling accuracy of the first type of sampling point in the sampling circuit and ensuring that the sampling result has high accuracy.

[0062] To facilitate understanding, examples are provided below to illustrate the implementation process of each step.

[0063] According to some embodiments of this application, optionally, S102, determining the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point, may specifically include the following steps:

[0064] The calibration factor corresponding to the first type of sampling point is determined based on the voltage of the first type of sampling point at multiple times and the voltage of the second type of sampling point at multiple times.

[0065] In some embodiments, the calibration factor may include two or more parameters to be determined. Therefore, in S102, the calibration factor corresponding to the first type of sampling point can be determined based on the voltages of the first type of sampling points obtained at multiple times (e.g., two or more times) and the voltages of the second type of sampling points obtained at multiple times.

[0066] It should be noted that in some other embodiments of this application, the calibration factor may also include a parameter to be determined. Accordingly, in S102, the calibration factor corresponding to the first type of sampling point can be determined based on the voltage of the first type of sampling point acquired at one time and the voltage of the second type of sampling point acquired at another time, and this application is not limited thereto.

[0067] Figure 3 This is a schematic flowchart of step S102 in the calibration method for the sampling circuit provided in an embodiment of this application. For example... Figure 3 As shown, according to some embodiments of this application, optionally, S102, determining the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point, may specifically include the following steps S301 and S302:

[0068] S301. Based on the voltages of the first type of sampling points at multiple times and the voltages of the second type of sampling points at multiple times, establish the relationship between the voltages of the first type of sampling points and the voltages of the second type of sampling points.

[0069] S302. Determine the calibration factor corresponding to the first type of sampling point based on the relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0070] Multiple time points can be two or more. When determining the calibration factor corresponding to the first type of sampling point, the relationship between the voltages of the first type of sampling point and the voltages of the second type of sampling point can be established or determined firstly based on the voltages of the first type of sampling point and the voltages of the second type of sampling point at multiple time points. Then, after obtaining the relationship between the voltages of the first type of sampling point and the voltages of the second type of sampling point, the calibration factor corresponding to the first type of sampling point can be determined.

[0071] Figure 4 This is another schematic flowchart illustrating the calibration method for the sampling circuit provided in an embodiment of this application. For example... Figure 4 As shown, according to some embodiments of this application, optionally, S101, obtaining the voltage of the first type of sampling point and the voltage of the second type of sampling point, may specifically include the following steps S401 and S402.

[0072] S401. At the first moment, acquire the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0073] For example, at the first time t1, the voltage V11 of the first type of sampling point and the voltage V21 of the second type of sampling point can be collected.

[0074] S402. At the second moment, acquire the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0075] For example, at the second time t2, the voltage V12 of the first type of sampling point and the voltage V22 of the second type of sampling point can be collected.

[0076] The first moment and the second moment are different moments, and the time interval between the first moment and the second moment can be flexibly adjusted according to the actual situation. This application embodiment does not limit this.

[0077] Accordingly, S102, based on the voltage of the first type of sampling point and the voltage of the second type of sampling point, the calibration factor corresponding to the first type of sampling point is determined, which may specifically include the following steps S403 to S405.

[0078] S403. Based on the voltage of the first type of sampling point obtained at the first moment and the voltage of the second type of sampling point obtained at the first moment, establish a first relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0079] For example, in some examples, the expression for the first relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point is as follows:

[0080] V21=K*V11+B (1)

[0081] The calibration factor corresponding to the first type of sampling point may include the first calibration parameter K and the second calibration parameter B.

[0082] S404. Based on the voltage of the first type of sampling point obtained at the second time and the voltage of the second type of sampling point obtained at the second time, establish a second relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0083] For example, in some examples, the expression for the second relationship between the voltage of the first type of sampling points and the voltage of the second type of sampling points is as follows:

[0084] V22=K*V12+B (2)

[0085] S405. Based on the first and second relations, determine the calibration factor corresponding to the first type of sampling points.

[0086] For example, by combining the expression (1) of the first relation and the expression (2) of the second relation, the magnitudes of the calibration factors K and B corresponding to the first type of sampling points can be calculated.

[0087] Figure 5 This is a schematic flowchart of step S103 in the calibration method of the sampling circuit provided in the embodiments of this application. Figure 5 As shown, according to some embodiments of this application, optionally, S103, based on the calibration factor, corrects the voltage of the first type of sampling points to obtain the corrected voltage of the first type of sampling points, which may include the following steps S501 and S502.

[0088] S501. Calculate the product between the voltage of the first type of sampling point and the first calibration parameter.

[0089] S502. Calculate the sum of the product and the second calibration parameter to obtain the voltage of the first type of sampling point after correction.

[0090] For example, in some cases, the voltage of the first type of sampling points can be corrected according to the following expression:

[0091] V1x'=K*V1 x+B (3)

[0092] Where V1x represents the voltage of the first type of sampling point, V1x' represents the corrected voltage of the first type of sampling point, K represents the first calibration parameter, and B represents the second calibration parameter.

[0093] According to some embodiments of this application, optionally, the reference potentials of the first type of sampling points and the second type of sampling points may be different. For example, the voltage of the first type of sampling points may include the voltage of the first type of sampling points relative to the first reference potential, and the voltage of the second type of sampling points may include the voltage of the second type of sampling points relative to the second reference potential. The first reference potential and the second reference potential may be different.

[0094] For example, assuming the actual voltage of the first type of sampling point is +4V and the voltage of the first reference potential is +2.5V, the voltage of the first type of sampling point can be the voltage difference between the actual voltage of the first type of sampling point and the voltage of the first reference potential, such as +1.5V.

[0095] For example, assuming the actual voltage of the second type of sampling point is +4V and the voltage of the second reference potential is 0V, the voltage of the second type of sampling point can be the voltage difference between the actual voltage of the second type of sampling point and the voltage of the second reference potential, such as +4V.

[0096] In some embodiments, S403, establishing a first relationship between the voltages of the first type of sampling points and the voltages of the second type of sampling points based on the voltages of the first type of sampling points acquired at the first time and the voltages of the second type of sampling points acquired at the first time, may include the following steps:

[0097] Based on the voltage difference between the first reference potential and the second reference potential, the voltage of the first type of sampling point obtained at the first moment, and the voltage of the second type of sampling point obtained at the first moment, a first relationship is established between the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0098] For example, in some examples, the expression for the first relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point is as follows:

[0099] V21=K*V11+B+ΔV (4)

[0100] The calibration factor corresponding to the first type of sampling point may include the first calibration parameter K and the second calibration parameter B, and ΔV represents the voltage difference between the first reference potential and the second reference potential.

[0101] In some embodiments, S404, establishing a second relationship between the voltages of the first type of sampling points and the voltages of the second type of sampling points based on the voltages of the first type of sampling points acquired at the second time and the voltages of the second type of sampling points acquired at the second time, may include the following steps:

[0102] Based on the voltage difference between the first reference potential and the second reference potential, the voltage of the first type of sampling point obtained at the second time, and the voltage of the second type of sampling point obtained at the second time, a second relationship is established between the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0103] For example, in some examples, the expression for the second relationship between the voltage of the first type of sampling points and the voltage of the second type of sampling points is as follows:

[0104] V22=K*V12+B+ΔV (5)

[0105] The calibration factor corresponding to the first type of sampling point may include the first calibration parameter K and the second calibration parameter B, and ΔV represents the voltage difference between the first reference potential and the second reference potential.

[0106] In S405, for example, by combining the expression (4) of the first relation and the expression (5) of the second relation, the magnitudes of the calibration factors K and B corresponding to the first type of sampling points can be calculated.

[0107] According to some embodiments of this application, optionally, S502, calculating the sum of the product and the second calibration parameter to obtain the corrected voltage of the first type of sampling point, may include the following steps:

[0108] The voltage difference between the first reference potential and the second reference potential, the sum of the product of the voltage of the first type of sampling point and the first calibration parameter, and the second calibration parameter are calculated to obtain the corrected voltage of the first type of sampling point.

[0109] For example, in some cases, the voltage of the first type of sampling points can be corrected according to the following expression:

[0110] V1 x'=K*V1 x+B+ΔV (6)

[0111] Where V1x represents the voltage of the first type of sampling point, V1x' represents the corrected voltage of the first type of sampling point, K represents the first calibration parameter, B represents the second calibration parameter, and ΔV represents the voltage difference between the first reference potential and the second reference potential.

[0112] Figure 6 This is another circuit connection diagram of the sampling circuit provided in an embodiment of this application. (See diagram below.) Figure 6 As shown, according to some embodiments of this application, optionally, the first type of sampling branch 101 can be electrically connected to the first reference voltage terminal Vref, and the second type of sampling branch 102 can be electrically connected to the second reference voltage terminal V2. The first reference potential may include the potential of the first reference voltage terminal Vref, and the second reference potential may include the potential of the second reference voltage terminal V2. For example, the second reference voltage terminal V2 may be a ground terminal GND.

[0113] Figure 7 This is another schematic flowchart illustrating the calibration method for the sampling circuit provided in the embodiments of this application. For example... Figure 7 As shown, according to some embodiments of this application, optionally, before determining the calibration factor corresponding to the first type of sampling point in S102 based on the voltage of the first type of sampling point and the voltage of the second type of sampling point, the calibration method of the sampling circuit may further include the following steps:

[0114] S701. Determine whether the difference between the voltage of the first type of sampling point and the voltage of the second type of sampling point is less than or equal to a preset error threshold. The size of the preset error threshold can be flexibly adjusted according to the actual situation, and this embodiment does not limit it.

[0115] If the difference between the voltage of the first type of sampling point and the voltage of the second type of sampling point is greater than the preset error threshold, it indicates that the first type of sampling branch where the first type of sampling point is located has a fault and can be reported for repair.

[0116] Accordingly, S102, based on the voltages of the first type of sampling points and the voltages of the second type of sampling points, determines the calibration factor corresponding to the first type of sampling points, which may specifically include the following steps:

[0117] If the difference between the voltage of the first type of sampling point and the voltage of the second type of sampling point is less than or equal to a preset error threshold, the calibration factor corresponding to the first type of sampling point is determined based on the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0118] Figure 8 This is another circuit connection diagram of the sampling circuit provided in an embodiment of this application. (See diagram below.) Figure 8 As shown, according to some embodiments of this application, optionally, the first type of sampling branch 101 may include a first sampling branch 601. A first end of the first sampling branch 601 is electrically connected to a first electrode of the device under test 20, and a second end of the first sampling branch 601 is electrically connected to a first reference voltage terminal Vref. The first type of sampling point UL1 may include a first sampling point U1 located in the first sampling branch 601. Exemplarily, the first electrode of the device under test 20 may be the positive electrode of the device under test 20.

[0119] The second type of sampling branch 102 may include a second sampling branch 602. The first end of the second sampling branch 602 is electrically connected to the first electrode of the device under test 20, and the second end of the second sampling branch 602 is electrically connected to the second reference voltage terminal V2. The second type of sampling point 602 may include a second sampling point U2 located in the second sampling branch 602. The switching module K may include a first switching module K1, and when the first switching module K1 is turned on, the second sampling point U2 performs sampling.

[0120] In some embodiments, the first calibration factor corresponding to the first sampling point can be calculated based on the voltage of the first sampling point and the voltage of the second sampling point.

[0121] For example, in some examples, at a first time t1, the voltage V11a of the first sampling point U1 and the voltage V21a of the second sampling point U2 can be collected. At a second time t2, the voltage V12a of the first sampling point U1 and the voltage V22a of the second sampling point U2 can be collected. Next, based on the voltage difference between the voltage at the first reference voltage terminal and the voltage at the second reference voltage terminal, and the voltages of the first and second sampling points acquired at the first time, a first relationship between the voltages of the first and second sampling points is established. Based on the voltage difference between the voltage at the first and second reference voltage terminals, and the voltages of the first and second sampling points acquired at the second time, a second relationship between the voltages of the first and second sampling points is established.

[0122] The expression for the first relationship between the voltage at the first sampling point and the voltage at the second sampling point is as follows:

[0123] V21 a=K1*V11 a+B1+ΔV (7)

[0124] Where K1 and B1 are the first calibration factors corresponding to the first sampling point U1, and ΔV represents the voltage difference between the voltage at the first reference voltage terminal and the voltage at the second reference voltage terminal.

[0125] For example, in some examples, the expression for the second relationship between the voltage at the first sampling point and the voltage at the second sampling point is as follows:

[0126] V22a=K1*V12a+B1+ΔV (8)

[0127] For example, by combining the expression (7) of the first relation and the expression (8) of the second relation, the magnitudes of the first calibration factors K1 and B1 corresponding to the first sampling point U1 can be calculated.

[0128] Accordingly, in some embodiments, the voltage of the first sampling point can be corrected based on the first calibration factor to obtain the corrected voltage of the first sampling point.

[0129] For example, in some cases, the voltage at the first sampling point can be corrected according to the following expression:

[0130] V1 ax'=K1*V1 ax+B1+ΔV (9)

[0131] Where V1 ax represents the voltage of the first sampling point, and V1 ax' represents the corrected voltage of the first sampling point.

[0132] Continue as Figure 8As shown, according to some embodiments of this application, optionally, the first type of sampling branch 101 may include a third sampling branch 603. A first terminal of the third sampling branch 603 is electrically connected to a first reference voltage terminal Vref, and a second terminal of the third sampling branch 603 is electrically connected to the second electrode of the device under test 20. Exemplarily, the second electrode of the device under test 20 may be the negative electrode of the device under test 20. The first type of sampling point UL1 may include a third sampling point U3 located in the third sampling branch 603.

[0133] The second type of sampling branch 102 may include a fourth sampling branch 604. The first terminal of the fourth sampling branch 604 is electrically connected to the second reference voltage terminal V2, and the second terminal of the fourth sampling branch 604 is electrically connected to the second electrode of the device under test 20. The second type of sampling point UL2 may include a fourth sampling point U4 located in the fourth sampling branch 604. The switching module K may include a second switching module K2. When the second switching module K2 is turned on, the fourth sampling point U4 performs sampling.

[0134] In some embodiments, the second calibration factor corresponding to the third sampling point can be calculated based on the voltage of the third sampling point and the voltage of the fourth sampling point.

[0135] The process for determining the second calibration factor can be found in the process for determining the first calibration factor as described above, and will not be repeated here.

[0136] In some embodiments, the voltage of the third sampling point can be corrected based on the second calibration factor to obtain the corrected voltage of the third sampling point.

[0137] The correction process for the voltage at the third sampling point can be found in the correction processes for the voltage at the first type of sampling point and the voltage at the first sampling point, and will not be repeated here.

[0138] Continue as Figure 8 As shown, according to some embodiments of this application, the sampling circuit 10 may optionally include a third switch module K3, the first terminal of which is electrically connected to the first electrode of the device under test 20.

[0139] The first type of sampling branch 101 may further include a fifth sampling branch 605, the first end of which is electrically connected to the second end of the third switch module K3, and the second end of which is electrically connected to the first reference voltage terminal Vref. The first type of sampling point UL1 may further include a fifth sampling point U5 located in the fifth sampling branch 605.

[0140] In some embodiments, the third calibration factor corresponding to the fifth sampling point can be calculated based on the voltage of the fifth sampling point and the voltage of the second sampling point.

[0141] The process for determining the third calibration factor can be found in the process for determining the first calibration factor as described above, and will not be repeated here.

[0142] In some embodiments, the voltage of the fifth sampling point can be corrected based on a third calibration factor to obtain the corrected voltage of the fifth sampling point.

[0143] The correction process for the voltage at the fifth sampling point can be found in the correction processes for the voltage at the first type of sampling point and the voltage at the first sampling point, and will not be repeated here.

[0144] Continue as Figure 8 As shown, according to some embodiments of this application, the sampling circuit 10 may optionally include a fourth switch module K4, the first end of which is electrically connected to the second electrode of the device under test 20.

[0145] The first type of sampling branch 101 may further include a sixth sampling branch 606, the first terminal of which is electrically connected to the first reference voltage terminal Vref, and the second terminal of which is electrically connected to the second terminal of the fourth switch module K4. The first type of sampling point UL1 may further include a sixth sampling point U6 located in the sixth sampling branch 606.

[0146] In some embodiments, the fourth calibration factor corresponding to the sixth sampling point can be calculated based on the voltage of the sixth sampling point and the voltage of the fourth sampling point.

[0147] The process for determining the fourth calibration factor can be found in the process for determining the calibration factor and the first calibration factor described above, and will not be repeated here.

[0148] In some embodiments, the voltage of the sixth sampling point can be corrected based on the fourth calibration factor to obtain the corrected voltage of the sixth sampling point.

[0149] The correction process for the voltage at the sixth sampling point can be found in the correction processes for the voltage at the first type of sampling point and the voltage at the first sampling point, and will not be repeated here.

[0150] Figure 9 This is another circuit connection diagram of the sampling circuit provided in an embodiment of this application. (See diagram below.) Figure 9As shown, according to some embodiments of this application, optionally, the sampling circuit 10 may further include a sampling processing module 701. The sampling processing module 701 may be electrically connected to a first type of sampling point UL1 and a second type of sampling point UL2, respectively. The sampling processing module 701 may be used to acquire the voltage of the first type of sampling point UL1 and the voltage of the second type of sampling point UL2, and to correct the voltage of the first type of sampling point UL1 based on a calibration factor, which is determined based on the voltage of the first type of sampling point UL1 and the voltage of the second type of sampling point UL2. In some examples, the sampling processing module 701 may include a sampling chip, which is used to acquire the voltage of the first type of sampling point UL1 and the voltage of the second type of sampling point UL2, and to correct the voltage of the first type of sampling point UL1 based on a calibration factor. That is, the sampling chip can not only be used to acquire voltage, but also to correct the voltage of the first type of sampling point based on a calibration factor.

[0151] In other examples, the sampling processing module 701 may include a sampling chip and a processing chip, the sampling chip being electrically connected to the processing chip. The sampling chip is used to acquire the voltage of a first type of sampling point UL1 and the voltage of a second type of sampling point UL2. The processing chip is used to correct the voltage of the first type of sampling point UL1 based on a calibration factor. That is, the sampling chip is only used to acquire voltage, and the processing chip is used to correct the voltage of the first type of sampling point based on a calibration factor.

[0152] The voltage at the first reference voltage terminal Vref can be greater than 0V and less than the maximum value of the sampling range of the sampling processing module. For example, assuming the sampling range of the sampling processing module is 0 to +5V, then the maximum value of the sampling range is +5V. The voltage at the first reference voltage terminal Vref can be less than +5V.

[0153] Combination Figure 8 and Figure 9 As shown, the first type of sampling points UL1 (such as the first sampling point U1, the third sampling point U3, the fifth sampling point U5, and the sixth sampling point U6) can be sampled relative to the first reference voltage terminal Vref. The voltage Vf of the first reference voltage terminal Vref can be greater than 0V and less than the maximum value of the sampling range Max-AD of the sampling processing module. This allows for positive and negative voltage sampling of the first type of sampling points UL1; that is, the voltage of the first type of sampling point UL1 is negative when the sampling input is between 0 and Vf, and positive when the sampling input is between Vf and Max-AD. By combining the various sampling points, the required relative voltage can be obtained. For example, the output voltage of the device under test 20 can be calculated based on the sum of the voltage of the first sampling point U1 and the voltage of the third sampling point U3.

[0154] like Figure 8As shown, according to some embodiments of this application, optionally, the first sampling branch 601 may include a first voltage divider module r1, a second voltage divider module r2, and a first sampling point U1. Exemplarily, both the first voltage divider module r1 and the second voltage divider module r2 may include resistors.

[0155] The first end of the first voltage divider module r1 is electrically connected to the first electrode of the device under test 20, and the second end of the first voltage divider module r1 is electrically connected to the first sampling point U1.

[0156] The first terminal of the second voltage divider module r2 is electrically connected to the first sampling point U1, and the second terminal of the second voltage divider module r2 is electrically connected to the first reference voltage terminal Vref.

[0157] like Figure 8 As shown, the voltage output from the first electrode of the device under test 20 can be transmitted to the first reference voltage terminal Vref through the first sampling branch 601, and then to the ground terminal GND. Therefore, when the voltage output from the first electrode of the device under test 20 is high, it may damage the device in the first sampling branch 601. In order to meet the withstand voltage requirements of the sampling circuit and to protect the sampling circuit, in some embodiments, at least one of the first voltage divider module r1 and the second voltage divider module r2 can be a resistor with a large resistance value.

[0158] For example, in some examples, the sum of the resistance values ​​of the first voltage divider module r1 and the second voltage divider module r2 may range from 25 to 30 megohms.

[0159] In this way, since the first voltage divider module r1 and / or the second voltage divider module r2 use resistors with large resistance values, even if the voltage output by the device under test 20 is large, the voltage withstand requirement of the sampling circuit can be met.

[0160] like Figure 8 As shown, according to some embodiments of this application, optionally, the second sampling branch 602 includes a third voltage divider module r3, a fourth voltage divider module r4, a first switch module K1, and a second sampling point U2. The third sampling branch 603 includes a fifth voltage divider module r5, a sixth voltage divider module r6, and a third sampling point U3. The fourth sampling branch 604 includes a seventh voltage divider module r7, an eighth voltage divider module r8, a second switch module K2, and a fourth sampling point U4. The fifth sampling branch 605 includes a ninth voltage divider module r9, a tenth voltage divider module r10, and a fifth sampling point U5. The sixth sampling branch 606 includes an eleventh voltage divider module r11, a twelfth voltage divider module r12, and a sixth sampling point U6.

[0161] The first end of the third voltage divider module r3 is electrically connected to the first electrode of the device under test 20, and the second end of the third voltage divider module r3 is electrically connected to the first end of the first switch module K1.

[0162] The second terminal of the first switching module K1 is electrically connected to the second sampling point U2. The first terminal of the fourth voltage divider module r4 is electrically connected to the second sampling point U2, and the second terminal of the fourth voltage divider module r4 is electrically connected to the second reference voltage terminal V2.

[0163] The first terminal of the fifth voltage divider module r5 is electrically connected to the first reference voltage terminal Vref, and the second terminal of the fifth voltage divider module r5 is electrically connected to the third sampling point U3. The first terminal of the sixth voltage divider module r6 is electrically connected to the third sampling point U3, and the second terminal of the sixth voltage divider module r6 is electrically connected to the second electrode of the device under test 20.

[0164] The first terminal of the seventh voltage divider module r7 is electrically connected to the second reference voltage terminal V2, and the second terminal of the seventh voltage divider module r7 is electrically connected to the first terminal of the second switch module K2. The second terminal of the second switch module K2 is electrically connected to the fourth sampling point U4. The first terminal of the eighth voltage divider module r8 is electrically connected to the fourth sampling point U4, and the second terminal of the eighth voltage divider module r8 is electrically connected to the second electrode of the device under test 20.

[0165] The first terminal of the ninth voltage divider module r9 is electrically connected to the second terminal of the third switch module K3, and the second terminal of the ninth voltage divider module r9 is electrically connected to the fifth sampling point U5. The first terminal of the tenth voltage divider module r10 is electrically connected to the fifth sampling point U5, and the second terminal of the tenth voltage divider module r10 is electrically connected to the first reference voltage terminal Vref.

[0166] The first terminal of the eleventh voltage divider module r11 is electrically connected to the first reference voltage terminal Vref, and the second terminal of the eleventh voltage divider module r11 is electrically connected to the sixth sampling point U6. The first terminal of the twelfth voltage divider module r12 is electrically connected to the sixth sampling point U6, and the second terminal of the twelfth voltage divider module r12 is electrically connected to the second electrode of the device under test 20.

[0167] Figure 10 This is another circuit connection diagram of the sampling circuit provided in an embodiment of this application. (See diagram below.) Figure 10 As shown, according to some embodiments of this application, the sampling circuit 10 may optionally include a sampling processing module 701 and a follower 702.

[0168] The first input terminal of the follower 702 is electrically connected to the first type of sampling point UL1. Figure 6 and Figure 10 As shown, the first type of sampling point UL1 includes, but is not limited to, the first sampling point U1, the third sampling point U3, the fifth sampling point U5, and the sixth sampling point U6. That is, the first sampling point U1, the third sampling point U3, the fifth sampling point U5, and the sixth sampling point U6 can all be electrically connected to the first input terminal of the follower 702.

[0169] The second input terminal of the follower 702 can be electrically connected to the output terminal of the follower 702. The first power input terminal of the follower 702 is electrically connected to the positive power supply voltage signal terminal VCC. The second power input terminal of the follower 702 is electrically connected to the ground terminal GND. The output terminal of the follower 702 is electrically connected to the voltage acquisition terminal of the sampling processing module 701.

[0170] The potential reference terminal of the sampling processing module 701 is electrically connected to the ground terminal GND. The sampling processing module 701 can be used to collect the voltage of the first type of sampling point UL1.

[0171] The sampling processing module 701 has a relatively high internal resistance. Therefore, when the resistance of the voltage divider module in the first sampling branch 101 is low, the sampling accuracy of the first sampling point UL1 is less affected by the internal resistance of the sampling processing module 701, resulting in higher sampling accuracy for the first sampling point UL1. However, when the resistance of the voltage divider module in the first sampling branch 101 (such as the first voltage divider module r1 and the second voltage divider module r2 in the first sampling branch 601) is high, the difference between its resistance and the internal resistance of the sampling processing module 701 is small. The internal resistance of the sampling processing module 701 will then perform voltage division, leading to lower sampling accuracy for the first sampling point UL1.

[0172] Since the follower 702 has the characteristics of high impedance input and high impedance output, adding the follower 702 between the first type of sampling point UL1 and the sampling processing module 701 is equivalent to isolating the voltage divider module in the first type of sampling branch 101 from the internal resistance in the sampling processing module 701. This reduces the impact of the internal resistance in the sampling processing module 701 on the sampling accuracy of the first type of sampling point UL1, ensuring that the first type of sampling point UL1 still has high sampling accuracy even when the resistance of the voltage divider module in the first type of sampling branch 101 is large.

[0173] The follower 702 also has an amplification function, that is, it can amplify the voltage of the first type of sampling point UL1 by a preset factor before transmitting it to the sampling processing module 701. The preset factor can be flexibly adjusted according to the actual situation, and this embodiment does not limit it.

[0174] For example, in some embodiments, the follower 702 can be amplified by a preset ratio of 1:1. In other embodiments, the follower 702 can also be amplified by a preset ratio of 1:n, where n is greater than 1.

[0175] Thus, when the resistance of the voltage divider module in the first type of sampling branch 101 is relatively large, the sampling accuracy of the first type of sampling point UL1 can be further improved by adding a follower to amplify the voltage value of the first type of sampling point UL1.

[0176] Based on the calibration method of the sampling circuit provided in the above embodiments, this application also provides a sampling circuit.

[0177] like Figure 9 As shown, the sampling circuit 10 provided in this embodiment may include a first type of sampling branch 101, a second type of sampling branch 102, and a sampling processing module 701. The first type of sampling branch 101 is electrically connected to the device under test 20, and is provided with a first type of voltage divider module FL1 and a first type of sampling point UL1. The second type of sampling branch 102 is electrically connected to the device under test 20, and is provided with a second type of voltage divider module FL2, a switch module K, and a second type of sampling point UL2. The sampling processing module 701 is electrically connected to the first type of sampling point UL1 and the second type of sampling point UL2, respectively. The sampling processing module 701 is used to correct the voltage of the first type of sampling point UL1 based on a calibration factor, which is determined based on the voltage of the first type of sampling point UL1 and the voltage of the second type of sampling point UL2.

[0178] The circuit structure of the sampling circuit has been described in detail above and will not be repeated here.

[0179] The sampling circuit of this application embodiment calculates the calibration factor corresponding to the first type of sampling point using the voltage of the second type of sampling point with higher sampling accuracy, and corrects the voltage of the first type of sampling point based on the calibration factor to obtain the corrected voltage of the first type of sampling point. This allows the first type of sampling point to have the same or similar sampling accuracy as the second type of sampling point, thereby improving the sampling accuracy of the first type of sampling point in the sampling circuit and ensuring that the sampling result has high accuracy.

[0180] According to some embodiments of this application, optionally, the sampling processing module 701 may include a sampling chip, which is used to acquire the voltage of a first type of sampling point UL1 and the voltage of a second type of sampling point UL2, and to correct the voltage of the first type of sampling point UL1 based on a calibration factor. That is, the sampling chip can not only be used to acquire voltage, but also to correct the voltage of the first type of sampling point based on a calibration factor.

[0181] According to some embodiments of this application, optionally, the sampling processing module 701 may include a sampling chip and a processing chip, wherein the sampling chip and the processing chip are electrically connected, and the sampling chip is used to acquire the voltage of a first type of sampling point UL1 and the voltage of a second type of sampling point UL2. The processing chip is used to correct the voltage of the first type of sampling point UL1 based on a calibration factor. That is, the sampling chip is only used to acquire voltage, and the processing chip is used to correct the voltage of the first type of sampling point based on a calibration factor.

[0182] According to some embodiments of this application, optionally, the first type of sampling branch is electrically connected to the first reference voltage terminal, and the second type of sampling branch is electrically connected to the second reference voltage terminal; the voltage of the first type of sampling point includes the voltage of the first type of sampling point relative to the first reference voltage terminal, and the voltage of the second type of sampling point includes the voltage of the second type of sampling point relative to the second reference voltage terminal.

[0183] According to some embodiments of this application, optionally, the first type of sampling branch includes a first sampling branch, a first end of which is electrically connected to a first electrode of the device under test, a second end of which is electrically connected to a first reference voltage terminal, and a first type of sampling point includes a first sampling point located in the first sampling branch; the second type of sampling branch includes a second sampling branch, a first end of which is electrically connected to a first electrode of the device under test, a second end of which is electrically connected to a second reference voltage terminal, and a second type of sampling point includes a second sampling point located in the second sampling branch; the switching module includes a first switching module, and the second sampling point samples when the first switching module is turned on.

[0184] According to some embodiments of this application, optionally, the first type of sampling branch includes a third sampling branch, the first end of the third sampling branch is electrically connected to the first reference voltage terminal, the second end of the third sampling branch is electrically connected to the second electrode of the device under test, and the first type of sampling point includes a third sampling point located in the third sampling branch; the second type of sampling branch includes a fourth sampling branch, the first end of the fourth sampling branch is electrically connected to the second reference voltage terminal, the second end of the fourth sampling branch is electrically connected to the second electrode of the device under test, and the second type of sampling point includes a fourth sampling point located in the fourth sampling branch; the switching module includes a second switching module, and the fourth sampling point samples when the second switching module is turned on.

[0185] According to some embodiments of this application, optionally, the sampling circuit further includes a third switching module, the first end of which is electrically connected to the first electrode of the device under test; the first type of sampling branch further includes a fifth sampling branch, the first end of which is electrically connected to the second end of the third switching module, the second end of which is electrically connected to the first reference voltage terminal, and the first type of sampling point further includes a fifth sampling point located in the fifth sampling branch.

[0186] According to some embodiments of this application, optionally, the sampling circuit further includes a fourth switching module, the first end of which is electrically connected to the second electrode of the device under test; the first type of sampling branch further includes a sixth sampling branch, the first end of which is electrically connected to the first reference voltage terminal, the second end of which is electrically connected to the second end of the fourth switching module, and the first type of sampling point further includes a sixth sampling point located in the sixth sampling branch.

[0187] The circuit structure of the sampling circuit has been described in detail above and will not be repeated here.

[0188] According to some embodiments of this application, optionally, the voltage at the first reference voltage terminal is greater than 0V and less than the maximum value of the sampling range of the sampling chip.

[0189] According to some embodiments of this application, optionally, the first sampling branch includes a first voltage divider module, a second voltage divider module, and a first sampling point; the first terminal of the first voltage divider module is electrically connected to the first electrode of the device under test, and the second terminal of the first voltage divider module is electrically connected to the first sampling point; the first terminal of the second voltage divider module is electrically connected to the first sampling point, and the second terminal of the second voltage divider module is electrically connected to the first reference voltage terminal; the sum of the resistance values ​​of the first voltage divider module and the second voltage divider module ranges from 25 to 30 megohms.

[0190] like Figure 8 As shown, according to some embodiments of this application, optionally, the second sampling branch 602 includes a third voltage divider module r3, a fourth voltage divider module r4, a first switch module K1, and a second sampling point U2. The third sampling branch 603 includes a fifth voltage divider module r5, a sixth voltage divider module r6, and a third sampling point U3. The fourth sampling branch 604 includes a seventh voltage divider module r7, an eighth voltage divider module r8, a second switch module K2, and a fourth sampling point U4. The fifth sampling branch 605 includes a ninth voltage divider module r9, a tenth voltage divider module r10, and a fifth sampling point U5. The sixth sampling branch 606 includes an eleventh voltage divider module r11, a twelfth voltage divider module r12, and a sixth sampling point U6.

[0191] The first end of the third voltage divider module r3 is electrically connected to the first electrode of the device under test 20, and the second end of the third voltage divider module r3 is electrically connected to the first end of the first switch module K1.

[0192] The second terminal of the first switching module K1 is electrically connected to the second sampling point U2. The first terminal of the fourth voltage divider module r4 is electrically connected to the second sampling point U2, and the second terminal of the fourth voltage divider module r4 is electrically connected to the second reference voltage terminal V2.

[0193] The first terminal of the fifth voltage divider module r5 is electrically connected to the first reference voltage terminal Vref, and the second terminal of the fifth voltage divider module r5 is electrically connected to the third sampling point U3. The first terminal of the sixth voltage divider module r6 is electrically connected to the third sampling point U3, and the second terminal of the sixth voltage divider module r6 is electrically connected to the second electrode of the device under test 20.

[0194] The first terminal of the seventh voltage divider module r7 is electrically connected to the second reference voltage terminal V2, and the second terminal of the seventh voltage divider module r7 is electrically connected to the first terminal of the second switch module K2. The second terminal of the second switch module K2 is electrically connected to the fourth sampling point U4. The first terminal of the eighth voltage divider module r8 is electrically connected to the fourth sampling point U4, and the second terminal of the eighth voltage divider module r8 is electrically connected to the second electrode of the device under test 20.

[0195] The first terminal of the ninth voltage divider module r9 is electrically connected to the second terminal of the third switch module K3, and the second terminal of the ninth voltage divider module r9 is electrically connected to the fifth sampling point U5. The first terminal of the tenth voltage divider module r10 is electrically connected to the fifth sampling point U5, and the second terminal of the tenth voltage divider module r10 is electrically connected to the first reference voltage terminal Vref.

[0196] The first terminal of the eleventh voltage divider module r11 is electrically connected to the first reference voltage terminal Vref, and the second terminal of the eleventh voltage divider module r11 is electrically connected to the sixth sampling point U6. The first terminal of the twelfth voltage divider module r12 is electrically connected to the sixth sampling point U6, and the second terminal of the twelfth voltage divider module r12 is electrically connected to the second electrode of the device under test 20.

[0197] According to some embodiments of this application, optionally, the sampling circuit further includes a follower; the first input terminal of the follower is electrically connected to the first type of sampling point, the second input terminal of the follower is electrically connected to the output terminal of the follower, the first power input terminal of the follower is electrically connected to the positive power supply voltage signal terminal, the second power input terminal of the follower is electrically connected to the ground terminal, the output terminal of the follower is electrically connected to the voltage acquisition terminal of the sampling chip; the potential reference terminal of the sampling chip is electrically connected to the ground terminal.

[0198] Based on the sampling circuit 10 provided in the above embodiments, this application also provides a battery management system (BMS). The battery management system provided in this application embodiment may include the sampling circuit 10 provided in the above embodiments.

[0199] The battery management system provided in this application uses the voltage of the second type of sampling point with higher sampling accuracy to calculate the calibration factor corresponding to the first type of sampling point, and corrects the voltage of the first type of sampling point based on the calibration factor to obtain the corrected voltage of the first type of sampling point. This allows the first type of sampling point to have the same or similar sampling accuracy as the second type of sampling point, thereby improving the sampling accuracy of the first type of sampling point in the sampling circuit and ensuring that the sampling results have high accuracy.

[0200] Based on the sampling circuit 10 or battery management system provided in the above embodiments, this application also provides an electrical device, which includes the sampling circuit 10 or battery management system provided in the above embodiments. In some specific embodiments, the electrical device may optionally be a vehicle. The vehicle may be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle; the new energy vehicle may be a pure electric vehicle, a hybrid electric vehicle, or a range-extended vehicle, etc.

[0201] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A calibration method for a sampling circuit, characterized in that, The sampling circuit includes a first type of sampling branch and a second type of sampling branch. The first type of sampling branch includes a first type of sampling point, and the second type of sampling branch includes a second type of sampling point. When the first type of sampling point and the second type of sampling point are connected to the device under test, voltage sampling is performed respectively. The sampling accuracy of the second type of sampling point is greater than that of the first type of sampling point. The method includes: Obtain the voltage of the first type of sampling point and the voltage of the second type of sampling point; Based on the voltages of the first type of sampling points and the voltages of the second type of sampling points, determine the calibration factor corresponding to the first type of sampling points; Based on the calibration factor, the voltage of the first type of sampling points is corrected to obtain the corrected voltage of the first type of sampling points.

2. The calibration method according to claim 1, characterized in that, The step of determining the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point includes: The calibration factor corresponding to the first type of sampling point is determined based on the voltage of the first type of sampling point at multiple times and the voltage of the second type of sampling point at multiple times.

3. The calibration method according to claim 1 or 2, characterized in that, The step of determining the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point includes: Based on the voltages of the first type of sampling points at multiple times and the voltages of the second type of sampling points at multiple times, establish the relationship between the voltages of the first type of sampling points and the voltages of the second type of sampling points; Based on the relationship between the voltage of the first type of sampling points and the voltage of the second type of sampling points, the calibration factor corresponding to the first type of sampling points is determined.

4. The calibration method according to claim 3, characterized in that, The step of determining the calibration factor corresponding to the first type of sampling point based on the voltage of the first type of sampling point and the voltage of the second type of sampling point includes: Based on the voltages of the first type of sampling points and the second type of sampling points acquired at the first moment, a first relationship is established between the voltages of the first type of sampling points and the voltages of the second type of sampling points. Based on the voltage of the first type of sampling point obtained at the second time and the voltage of the second type of sampling point obtained at the second time, a second relationship is established between the voltage of the first type of sampling point and the voltage of the second type of sampling point; Based on the first relationship and the second relationship, determine the calibration factor corresponding to the first type of sampling points.

5. The calibration method according to claim 4, characterized in that, The voltage of the first type of sampling point includes the voltage of the first type of sampling point relative to the first reference potential, and the voltage of the second type of sampling point includes the voltage of the second type of sampling point relative to the second reference potential; Based on the voltages of the first type of sampling points and the second type of sampling points acquired at the first moment, a first relationship is established between the voltages of the first type of sampling points and the voltages of the second type of sampling points, including: A first relationship is established between the voltage of the first type of sampling point and the voltage of the second type of sampling point based on the voltage difference between the first reference potential and the second reference potential, the voltage of the first type of sampling point obtained at the first time, and the voltage of the second type of sampling point obtained at the first time.

6. The calibration method according to claim 5, characterized in that, The step of establishing a second relationship between the voltages of the first type of sampling points and the voltages of the second type of sampling points based on the voltages of the first type of sampling points acquired at the second time and the voltages of the second type of sampling points acquired at the second time includes: A second relationship is established between the voltage of the first type of sampling point and the voltage of the second type of sampling point based on the voltage difference between the first reference potential and the second reference potential, the voltage of the first type of sampling point obtained at the second time, and the voltage of the second type of sampling point obtained at the second time.

7. The calibration method according to claim 1 or 2, characterized in that, The calibration factor includes a first calibration parameter and a second calibration parameter; The step of correcting the voltage of the first type of sampling points based on the calibration factor to obtain the corrected voltage of the first type of sampling points includes: Calculate the product of the voltage at the first type of sampling point and the first calibration parameter; The sum of the product and the second calibration parameter is calculated to obtain the corrected voltage of the first type of sampling point.

8. The calibration method according to claim 7, characterized in that, The voltage of the first type of sampling point includes the voltage of the first type of sampling point relative to the first reference potential, and the voltage of the second type of sampling point includes the voltage of the second type of sampling point relative to the second reference potential; The step of calculating the sum of the product and the second calibration parameter to obtain the corrected voltage of the first type of sampling points includes: The voltage difference between the first reference potential and the second reference potential is calculated, and the sum of the product and the second calibration parameter is obtained to obtain the corrected voltage of the first type of sampling point.

9. A sampling circuit, characterized in that, include: The first type of sampling branch is electrically connected to the device under test, and the first type of sampling branch is provided with a first type of voltage divider module and a first type of sampling point; The second type of sampling branch is electrically connected to the device under test. The second type of sampling branch is provided with a second type of voltage divider module, a switch module, and a second type of sampling point. When the first type of sampling point and the second type of sampling point are connected to the device under test, voltage sampling is performed respectively. The sampling accuracy of the second type of sampling point is greater than that of the first type of sampling point. A sampling processing module is electrically connected to the first type of sampling points and the second type of sampling points respectively. The sampling processing module is used to correct the voltage of the first type of sampling points based on a calibration factor, which is determined based on the voltage of the first type of sampling points and the voltage of the second type of sampling points.

10. The sampling circuit according to claim 9, characterized in that, The first type of sampling branch is electrically connected to the first reference voltage terminal, and the second type of sampling branch is electrically connected to the second reference voltage terminal; The voltage of the first type of sampling point includes the voltage of the first type of sampling point relative to the first reference voltage terminal, and the voltage of the second type of sampling point includes the voltage of the second type of sampling point relative to the second reference voltage terminal.

11. The sampling circuit according to claim 9 or 10, characterized in that, The first type of sampling branch includes a first sampling branch, a first end of the first sampling branch is electrically connected to the first electrode of the device under test, a second end of the first sampling branch is electrically connected to a first reference voltage terminal, and the first type of sampling point includes a first sampling point located in the first sampling branch; The second type of sampling branch includes a second sampling branch, the first end of which is electrically connected to the first electrode of the device under test, and the second end of which is electrically connected to the second reference voltage terminal. The second type of sampling point includes a second sampling point located in the second sampling branch. The switching module includes a first switching module, and the second sampling point performs sampling when the first switching module is turned on.

12. The sampling circuit according to claim 10, characterized in that, The first type of sampling branch includes a third sampling branch, the first end of the third sampling branch is electrically connected to the first reference voltage terminal, the second end of the third sampling branch is electrically connected to the second electrode of the device under test, and the first type of sampling point includes a third sampling point located in the third sampling branch; The second type of sampling branch includes a fourth sampling branch. The first end of the fourth sampling branch is electrically connected to the second reference voltage terminal, and the second end of the fourth sampling branch is electrically connected to the second electrode of the device under test. The second type of sampling point includes a fourth sampling point located in the fourth sampling branch. The switching module includes a second switching module. When the second switching module is turned on, the fourth sampling point performs sampling.

13. The sampling circuit according to claim 10, characterized in that, The sampling circuit further includes a third switching module, the first terminal of which is electrically connected to the first electrode of the device under test. The first type of sampling branch also includes a fifth sampling branch, the first end of which is electrically connected to the second end of the third switching module, the second end of which is electrically connected to the first reference voltage terminal, and the first type of sampling point also includes a fifth sampling point located in the fifth sampling branch.

14. The sampling circuit according to claim 10, characterized in that, The sampling circuit further includes a fourth switch module, the first terminal of which is electrically connected to the second electrode of the device under test. The first type of sampling branch also includes a sixth sampling branch, the first end of which is electrically connected to the first reference voltage terminal, the second end of which is electrically connected to the second terminal of the fourth switch module, and the first type of sampling point also includes a sixth sampling point located in the sixth sampling branch.

15. The sampling circuit according to claim 10, characterized in that, The voltage at the first reference voltage terminal is greater than 0V and less than the maximum value of the sampling range of the sampling chip.

16. The sampling circuit according to claim 11, characterized in that, The first sampling branch includes a first voltage divider module, a second voltage divider module, and the first sampling point; The first terminal of the first voltage divider module is electrically connected to the first electrode of the device under test, and the second terminal of the first voltage divider module is electrically connected to the first sampling point. The first terminal of the second voltage divider module is electrically connected to the first sampling point, and the second terminal of the second voltage divider module is electrically connected to the first reference voltage terminal. The sum of the resistance values ​​of the first voltage divider module and the second voltage divider module ranges from 25 to 30 megohms.

17. The sampling circuit according to claim 9 or 10, characterized in that, The sampling circuit also includes a follower; The first input terminal of the follower is electrically connected to the first type of sampling point, the second input terminal of the follower is electrically connected to the output terminal of the follower, the first power input terminal of the follower is electrically connected to the positive power supply voltage signal terminal, the second power input terminal of the follower is electrically connected to the ground terminal, and the output terminal of the follower is electrically connected to the voltage acquisition terminal of the sampling chip. The potential reference terminal of the sampling chip is electrically connected to the ground terminal.

18. A battery management system, characterized in that, Includes the sampling circuit as described in any one of claims 9 to 17.

19. An electrical appliance, characterized in that, Includes the battery management system as described in claim 18.

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