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

Abstract

The invention 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 points and the voltage of a second type of sampling points; determining a calibration factor corresponding to the first type of sampling points according to the voltage of the first type of sampling points and the voltage of the second type of sampling points; and based on the calibration factor, correcting the voltage of the first type of sampling points to obtain the corrected voltage of the first type of sampling points. The problem that the sampling precision of the sampling points in the sampling circuit is poor can be solved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a sampling circuit and a calibration method thereof, a battery management system and an electrical device. Background Art

[0002] As environmental pollution becomes increasingly serious, the market demand for new energy vehicles continues to expand, and the requirements for new energy vehicle technology are becoming increasingly stringent, especially the safety performance of new energy vehicles. In order to improve the safety of new energy vehicles, it is necessary to sample some devices under test (such as batteries) in new energy vehicles.

[0003] However, the inventors of the present application have found that, as time goes by, the components in the sampling circuit will age, causing the sampling accuracy of some sampling points in the sampling circuit to deteriorate, resulting in low accuracy of the sampling results. Summary of the invention

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

[0005] In a first aspect, the present application provides a calibration method for a sampling circuit, the calibration method comprising: obtaining a voltage of a first type of sampling point and a 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 corrected voltage of the first type of sampling point.

[0006] In the technical solution of the embodiment of the present application, 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, so that the first type of sampling point can also have the same or similar sampling accuracy as the second type of sampling point, that is, the sampling accuracy of the first type of sampling point in the sampling circuit is improved, thereby ensuring that the sampling result has a higher accuracy.

[0007] According to some embodiments of the present application, optionally, determining a calibration factor corresponding to the first-type sampling point according to the voltage of the first-type sampling point and the voltage of the second-type sampling point includes: determining the calibration factor corresponding to the first-type sampling point according to the voltage of the first-type sampling point at multiple moments and the voltage of the second-type sampling point at multiple moments.

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

[0009] According to some embodiments of the present application, optionally, determining the calibration factor corresponding to the first-type sampling point according to the voltage of the first-type sampling point and the voltage of the second-type sampling point includes: establishing a first relationship between the voltage of the first-type sampling point and the voltage of the second-type sampling point according to the voltage of the first-type sampling point acquired at a first moment and the voltage of the second-type sampling point acquired at the first moment; establishing a second relationship between the voltage of the first-type sampling point and the voltage of the second-type sampling point according to the voltage of the first-type sampling point acquired at a second moment and the voltage of the second-type sampling point acquired at the second moment; and determining the calibration factor corresponding to the first-type sampling point according to the first relationship and the second relationship.

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

[0011] According to some embodiments of the present application, optionally, the establishing a second relationship between the voltage of the first-type sampling point and the voltage of the second-type sampling point according to the voltage of the first-type sampling point acquired at the second moment and the voltage of the second-type sampling point acquired at the second moment includes: establishing a second relationship between the voltage of the first-type sampling point and the voltage of the second-type sampling point according to a voltage difference between the first reference potential and the second reference potential, the voltage of the first-type sampling point acquired at the second moment, and the voltage of the second-type sampling point acquired at the second moment.

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

[0013] According to some embodiments of the present application, optionally, the voltage of the first type of sampling point includes the voltage of the first type of sampling point relative to a 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 a second reference potential; and the 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, the sum of the product and the second calibration parameter, and obtaining the corrected voltage of the first type of sampling point.

[0014] In a second aspect, the present application provides a sampling circuit, which includes: a first-type sampling branch, the first-type sampling branch is electrically connected to a device under test, and the first-type sampling branch is provided with a first-type voltage divider module and a first-type sampling point; a second-type sampling branch, the second-type sampling branch is electrically connected to the device under test, and the second-type sampling branch is provided with a second-type voltage divider module, a switch module and a second-type sampling point; a sampling processing module, the sampling processing module is electrically connected to the first-type sampling point and the second-type sampling point respectively, and the sampling processing module is used to correct the voltage of the first-type sampling point based on a calibration factor, and the calibration factor is determined according to the voltage of the first-type sampling point and the voltage of the second-type sampling point.

[0015] According to some embodiments of the present 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 the present application, optionally, 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, and a second end of the first sampling branch is electrically connected to the 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, a first end of the second sampling branch is electrically connected to the first electrode of the device under test, and a second end of the second sampling branch 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, and the switch module includes a first switch module, and the second sampling point performs sampling when the first switch module is turned on.

[0017] According to some embodiments of the present application, optionally, the first type of sampling branch includes a third sampling branch, a first end of the third sampling branch is electrically connected to the first reference voltage end, and a 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, a first end of the fourth sampling branch is electrically connected to the second reference voltage end, and a 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, and the switch module includes a second switch module, and the fourth sampling point performs sampling when the second switch module is turned on.

[0018] According to some embodiments of the present application, optionally, the sampling circuit further includes a third switch module, a first end of the third switch module is electrically connected to the first electrode of the device under test; the first type of sampling branch further includes a fifth sampling branch, a first end of the fifth sampling branch is electrically connected to the second end of the third switch module, a second end of the fifth sampling branch is electrically connected to the first reference voltage end, 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 the present application, optionally, the sampling circuit further includes a fourth switch module, a first end of the fourth switch module is electrically connected to the second electrode of the device under test; the first type of sampling branch further includes a sixth sampling branch, a first end of the sixth sampling branch is electrically connected to the first reference voltage end, a second end of the sixth sampling branch is electrically connected to the second end of the fourth switch 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 the present application, optionally, the voltage of 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 the present application, optionally, the first sampling branch includes a first voltage divider module, a second voltage divider module and a first sampling point; the first end of the first voltage divider module is electrically connected to the first electrode of the device under test, and the second end of the first voltage divider module is electrically connected to the first sampling point; the first end of the second voltage divider module is electrically connected to the first sampling point, and the second end of the second voltage divider module is electrically connected to the first reference voltage end; the sum of the resistance value of the first voltage divider module and the resistance value of the second voltage divider module ranges from 25 to 30 megohms.

[0022] According to some embodiments of the present application, optionally, 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 collection terminal of the sampling chip; the potential reference terminal of the sampling chip is electrically connected to the ground terminal.

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

[0024] In a fourth aspect, the present application provides an electrical device, which includes a battery management system as provided in the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0026] Figure 1 A schematic diagram of a flow chart of a calibration method for a sampling circuit provided in an embodiment of the present application;

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

[0028] Figure 3 A schematic diagram of a flow chart of S102 in the calibration method of the sampling circuit provided in an embodiment of the present application;

[0029] Figure 4 Another schematic flow chart of a calibration method for a sampling circuit provided in an embodiment of the present application;

[0030] Figure 5 A schematic diagram of a flow chart of S103 in the calibration method of the sampling circuit provided in an embodiment of the present application;

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

[0032] Figure 7A schematic diagram of another flow chart of a calibration method for a sampling circuit provided in an embodiment of the present application;

[0033] Figure 8 A schematic diagram of another circuit connection of the sampling circuit provided in the embodiment of the present application;

[0034] Fig. 9 A schematic diagram of another circuit connection of the sampling circuit provided in the embodiment of the present application;

[0035] Fig.10 A schematic diagram of another circuit connection of the sampling circuit provided in an embodiment of the present application.

[0036] In the drawings, the drawings are not necessarily drawn to scale. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0039] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0040] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0041] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0042] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0043] In order to improve the safety of new energy vehicles, it is usually necessary to sample some devices to be tested (such as batteries) in new energy vehicles. In the embodiment of the present application, the devices to be tested include, for example, but are not limited to power batteries. Among them, power batteries include but are not limited to lithium-ion batteries, lithium metal batteries, lead-acid batteries, nickel-ion batteries, nickel-metal hydride batteries, lithium-sulfur batteries, lithium-air batteries or sodium-ion batteries, which are not limited here. In terms of scale, the power battery can be a single cell, a battery module or a battery pack, which is not limited here.

[0044] The inventors have noticed that as time goes by, the devices in the sampling circuit will age, which will cause the sampling accuracy of some sampling points in the sampling circuit to deteriorate, resulting in a low accuracy of the sampling results. In particular, in some sampling branches in the sampling circuit, in order to protect the devices and reduce costs, these sampling branches usually use voltage divider modules (such as resistors) with large resistance and low accuracy. As time goes by, the voltage divider modules age, and the accuracy of these voltage divider modules with large resistance and low accuracy becomes lower, resulting in the sampling accuracy of the sampling points in these sampling branches becoming worse, resulting in a low accuracy of the sampling results.

[0045] In order to solve the above technical problems, the present application provides a sampling circuit and a calibration method thereof, a battery management system and an electric device, wherein the voltage of the second type of sampling point with higher sampling accuracy is used to calculate the calibration factor corresponding to the first type of sampling point, 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, so that the first type of sampling point can also have the same or similar sampling accuracy as the second type of sampling point, that is, the sampling accuracy of the first type of sampling point in the sampling circuit is improved, thereby ensuring that the sampling result has a higher accuracy.

[0046] The following first introduces the calibration method of the sampling circuit provided in the embodiment of the present application.

[0047] Figure 1 A flow chart of a calibration method for a sampling circuit provided in an embodiment of the present application. Figure 1 As shown, the calibration method of the sampling circuit provided in the embodiment of the present application may include S101 to S103.

[0048] S101 : Obtain voltages of first-type sampling points and voltages of second-type sampling points.

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

[0050] S102: Determine 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.

[0051] In some embodiments, for example, the sampling accuracy of the first type of sampling point and the second type of sampling point may be different, for example, the sampling accuracy of the second type of sampling point may be higher than the sampling accuracy of the first type of sampling point. Since the voltage accuracy of the second type of sampling point is higher, the voltage of the first type of sampling point may be corrected by using the voltage of the second type of sampling point. For example, in S202, the calibration factor corresponding to the first type of sampling point may be determined according to the voltage of the first type of sampling point and the voltage of the second type of sampling point.

[0052] S103 , based on the calibration factor, calibrate the voltage of the first type of sampling point to obtain the calibrated voltage of the first type of sampling point.

[0053] After the calibration factors corresponding to the first type of sampling points are obtained, the voltages of the first type of sampling points may be corrected based on the calibration factors corresponding to the first type of sampling points, thereby obtaining the corrected voltages of the first type of sampling points.

[0054] The calibration method of the sampling circuit in the embodiment of the present application calculates the calibration factor corresponding to the first type of sampling point by 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, so that the first type of sampling point can also have the same or similar sampling accuracy as the second type of sampling point, that is, the sampling accuracy of the first type of sampling point in the sampling circuit is improved, thereby ensuring that the sampling result has higher accuracy.

[0055] For ease of understanding, the calibration method of the sampling circuit is described below in conjunction with the circuit structure of the sampling circuit in some application embodiments. It should be noted that the calibration method of the sampling circuit in the embodiment of the present application is not limited to the sampling circuit shown in the following figures.

[0056] Figure 2 A circuit connection diagram of a sampling circuit provided in an embodiment of the present application. Figure 1As shown, in some embodiments, the sampling circuit 10 may include a first type of sampling branch 101 and a second type of sampling branch 102. The first type of sampling branch 101 and the second type of sampling branch 102 are both electrically connected to the device under test 20. The first type of sampling branch 101 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 provided with a second type of voltage divider module FL2, a switch module K and a second type of sampling point UL2. The switch module K is arranged in the second type of sampling branch 102, and the second type of sampling point UL2 is sampled when the switch module K is turned on. In the embodiment of the present application, the device under test 20 includes, for example, but is not limited to, a power battery.

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

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

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

[0061] The calibration method of the sampling circuit in the embodiment of the present application calculates the calibration factor corresponding to the first type of sampling point by 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, so that the first type of sampling point can also have the same or similar sampling accuracy as the second type of sampling point, that is, the sampling accuracy of the first type of sampling point in the sampling circuit is improved, thereby ensuring that the sampling result has higher accuracy.

[0062] To facilitate understanding, the implementation process of each step is described below with examples.

[0063] According to some embodiments of the present application, optionally, S102, 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, may specifically include the following steps:

[0064] According to the voltages of the first type of sampling points at multiple moments and the voltages of the second type of sampling points at multiple moments, the calibration factors corresponding to the first type of sampling points are determined.

[0065] In some embodiments, the calibration factor may include, for example, two or more parameters to be obtained. Therefore, in S102, the calibration factor corresponding to the first type of sampling point may be determined according to the voltage of the first type of sampling point obtained at multiple moments (such as two or more moments) and the voltage of the second type of sampling point obtained at multiple moments.

[0066] It should be noted that, in some other embodiments of the present application, the calibration factor may also include, for example, a parameter to be obtained. Accordingly, in S102, the calibration factor corresponding to the first type of sampling point may be determined according to the voltage of the first type of sampling point obtained at a time and the voltage of the second type of sampling point obtained at a time, but the present application is not limited thereto.

[0067] Figure 3 A flow chart of S102 in the calibration method of the sampling circuit provided in the embodiment of the present application. Figure 3 As shown, according to some embodiments of the present application, optionally, S102, 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, may specifically include the following steps S301 and S302:

[0068] S301 . Establish a relationship between the voltage of the first type of sampling points and the voltage of the second type of sampling points at multiple moments according to the voltage of the first type of sampling points at multiple moments and the voltage of the second type of sampling points at multiple moments.

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

[0070] The multiple moments may be two or more moments. When determining the calibration factor corresponding to the first type of sampling point, the relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point may be established or determined first according to the voltage of the first type of sampling point at multiple moments and the voltage of the second type of sampling point at multiple moments. Then, after obtaining the relationship between 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 may be determined.

[0071] Figure 4 Another flow chart of the calibration method of the sampling circuit provided in the embodiment of the present application. Figure 4 As shown, according to some embodiments of the present 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 a first moment, obtain voltages of first-type sampling points and voltages of second-type sampling points.

[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 may be collected.

[0074] S402 . At a second moment, obtain voltages of first-type sampling points and voltages of second-type sampling points.

[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 may be collected.

[0076] Among them, 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 actual conditions, and the embodiment of the present application does not limit this.

[0077] Accordingly, S102, determining the calibration factors corresponding to the first type of sampling points according to the voltages of the first type of sampling points and the voltages of the second type of sampling points, may specifically include the following steps S403 to S405.

[0078] S403 . Establish a first relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point according to the voltage of the first type of sampling point acquired at the first moment and the voltage of the second type of sampling point acquired at the first moment.

[0079] For example, in some examples, the expression of 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 factors corresponding to the first type of sampling points may include a first calibration parameter K and a second calibration parameter B.

[0082] S404: Establish a second relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point according to the voltage of the first type of sampling point acquired at the second moment and the voltage of the second type of sampling point acquired at the second moment.

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

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

[0085] S405: Determine a calibration factor corresponding to the first type of sampling points according to the first relationship and the second relationship.

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

[0087] Figure 5 A flow chart of S103 in the calibration method of the sampling circuit provided in the embodiment of the present application. Figure 5 As shown, according to some embodiments of the present application, optionally, S103, based on the calibration factor, correcting the voltage of the first type of sampling point to obtain the corrected voltage of the first type of sampling point may include the following steps S501 and S502.

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

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

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

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

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

[0093] According to some embodiments of the present 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 that 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 collected 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 that the actual voltage of the second type of sampling point is +4V and the voltage of the second reference potential is 0V, the collected 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 voltage of the first type of sampling point and the voltage of the second type of sampling point according to the voltage of the first type of sampling point acquired at the first moment and the voltage of the second type of sampling point acquired at the first moment, may include the following steps:

[0097] A first relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point is established according to 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 moment, and the voltage of the second type of sampling point acquired at the first moment.

[0098] For example, in some examples, the expression of 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 factors corresponding to the first type of sampling points may include a first calibration parameter K and a second calibration parameter B, and ΔV represents a voltage difference between the first reference potential and the second reference potential.

[0101] In some embodiments, S404, establishing a second relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point according to the voltage of the first type of sampling point acquired at the second moment and the voltage of the second type of sampling point acquired at the second moment, may include the following steps:

[0102] A second relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point is established according to 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 second moment, and the voltage of the second type of sampling point acquired at the second moment.

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

[0104] V22=K*V12+B+ΔV (5)

[0105] The calibration factors corresponding to the first type of sampling points may include a first calibration parameter K and a second calibration parameter B, and ΔV represents a 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 relationship and the expression (5) of the second relationship, 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 the present 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 product of the voltage of the first type of sampling point and the first calibration parameter, and the sum of the second calibration parameter are calculated to obtain the corrected voltage of the first type of sampling point.

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

[0110] V1 x'=K*V1 x+B+ΔV (6)

[0111] Wherein, V1 x represents the voltage of the first type of sampling point, V1 x' represents the voltage of the first type of sampling point after correction, 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 Another circuit connection diagram of the sampling circuit provided in the embodiment of the present application. Figure 6 As shown, according to some embodiments of the present 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 can include the potential of the first reference voltage terminal Vref, and the second reference potential can include the potential of the second reference voltage terminal V2. Exemplarily, the second reference voltage terminal V2 can be the ground terminal GND.

[0113] Figure 7 Another flow chart of the calibration method of the sampling circuit provided in the embodiment of the present application is shown in FIG. Figure 7 As shown, according to some embodiments of the present application, optionally, before S102, determining the 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, 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 preset error threshold can be flexibly adjusted according to actual conditions, and this embodiment of the application does not limit this.

[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 means that the first type of sampling branch where the first type of sampling point is located is faulty and can be reported for repair.

[0116] Accordingly, S102, determining the 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, may specifically include the following steps:

[0117] When 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 the preset error threshold, the calibration factor corresponding to the first type of sampling point is determined according to 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 the embodiment of the present application. Figure 8 As shown, according to some embodiments of the present application, optionally, the first type of sampling branch 101 may include a first sampling branch 601. The first end of the first sampling branch 601 is electrically connected to the first electrode of the device under test 20, the second end of the first sampling branch 601 is electrically connected to the first reference voltage terminal Vref, and 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. A first end of the second sampling branch 602 is electrically connected to the first electrode of the device under test 20, and a 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 switch module K may include a first switch module K1, and the second sampling point U2 performs sampling when the first switch module K1 is turned on.

[0120] In some embodiments, a first calibration factor corresponding to the first sampling point may be calculated according to the voltage at the first sampling point and the voltage at the second sampling point.

[0121] For example, in some examples, the voltage V11a of the first sampling point U1 and the voltage V21a of the second sampling point U2 may be collected at the first time t1. At the second time t2, the voltage V12a of the first sampling point U1 and the voltage V22a of the second sampling point U2 may be collected. Next, according to the voltage difference between the voltage of the first reference voltage terminal and the voltage of the second reference voltage terminal, the voltage of the first sampling point acquired at the first time and the voltage of the second sampling point, a first relationship between the voltage of the first sampling point and the voltage of the second sampling point is established. According to the voltage difference between the voltage of the first reference voltage terminal and the voltage of the second reference voltage terminal, the voltage of the first sampling point and the voltage of the second sampling point acquired at the second time, a second relationship between the voltage of the first sampling point and the voltage of the second sampling point is established.

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

[0123] V21a=K1*V11a+B1+ΔV (7)

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

[0125] For example, in some examples, the expression of 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 relationship and the expression (8) of the second relationship, 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 at the first sampling point may be corrected based on the first calibration factor to obtain a corrected voltage at the first sampling point.

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

[0130] V1ax'=K1*V1ax+B1+ΔV (9)

[0131] Wherein, V1 ax represents the voltage at the first sampling point, and V1 ax′ represents the voltage at the first sampling point after correction.

[0132] Continue as Figure 8As shown, according to some embodiments of the present application, optionally, the first type of sampling branch 101 may include a third sampling branch 603. A first end of the third sampling branch 603 is electrically connected to the first reference voltage end Vref, and a second end 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 a 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, a first end of the fourth sampling branch 604 is electrically connected to the second reference voltage end V2, and a second end 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 switch module K may include a second switch module K2, and the fourth sampling point U4 performs sampling when the second switch module K2 is turned on.

[0134] In some embodiments, the second calibration factor corresponding to the third sampling point may be calculated according to the voltage at the third sampling point and the voltage at the fourth sampling point.

[0135] The process of determining the second calibration factor may refer to the process of determining the calibration factor and the first calibration factor, which will not be described in detail here.

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

[0137] The calibration process of the voltage at the third sampling point may refer to the calibration process of the voltage at the first type of sampling point and the calibration process of the voltage at the first sampling point, which will not be described in detail here.

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

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

[0140] In some embodiments, a third calibration factor corresponding to the fifth sampling point may be calculated according to the voltage at the fifth sampling point and the voltage at the second sampling point.

[0141] The process of determining the third calibration factor may refer to the process of determining the calibration factor and the first calibration factor, which will not be described in detail here.

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

[0143] The calibration process of the voltage at the fifth sampling point may refer to the calibration process of the voltage at the first type of sampling point and the calibration process of the voltage at the first sampling point, which will not be described in detail here.

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

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

[0146] In some embodiments, a fourth calibration factor corresponding to the sixth sampling point may be calculated according to the voltage at the sixth sampling point and the voltage at the fourth sampling point.

[0147] The process of determining the fourth calibration factor may refer to the process of determining the calibration factor and the first calibration factor, which will not be described in detail here.

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

[0149] The calibration process of the voltage at the sixth sampling point may refer to the calibration process of the voltage at the first type of sampling point and the calibration process of the voltage at the first sampling point, which will not be described in detail here.

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

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

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

[0153] Combination Figure 8 and Fig. 9 As shown, the first type of sampling point 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. Among them, the voltage Vf of the first reference voltage terminal Vref can be greater than 0V, and can be less than the maximum value Max-AD of the sampling range of the sampling processing module. In this way, the positive and negative voltage sampling of the first type of sampling point UL1 can be achieved, that is, the voltage of the first type of sampling point UL1 with a sampling input in the range of 0 to Vf is a negative voltage, and the voltage of the first type of sampling point UL1 with a sampling input in the range of Vf to Max-AD is a positive voltage. Through the combination of various sampling points, it can be converted into the required relative voltage. 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 the present application, optionally, the first sampling branch 601 may include a first voltage dividing module r1, a second voltage dividing module r2 and a first sampling point U1. Exemplarily, both the first voltage dividing module r1 and the second voltage dividing module r2 may include resistors.

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

[0156] A first end of the second voltage dividing module r2 is electrically connected to the first sampling point U1 , and a second end of the second voltage dividing module r2 is electrically connected to the first reference voltage end Vref.

[0157] like Figure 8 As shown, the voltage output by 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 transmitted to the ground terminal GND. Therefore, when the voltage output by the first electrode of the device under test 20 is high, the device in the first sampling branch 601 may be damaged. 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 use a resistor with a larger resistance value.

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

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

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

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

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

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

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

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

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

[0167] Fig.10 This is another circuit connection diagram of the sampling circuit provided in the embodiment of the present application. Fig.10 As shown, according to some embodiments of the present application, optionally, the sampling circuit 10 may further 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 sampling point UL1. Figure 6 and Fig.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 follower 702 can be electrically connected to the output terminal of follower 702, the first power input terminal of follower 702 is electrically connected to the positive power supply voltage signal terminal VCC, the second power input terminal of follower 702 is electrically connected to the ground terminal GND, and the output terminal of follower 702 is electrically connected to the voltage collection terminal of the sampling processing module 701.

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

[0171] The internal resistance in the sampling processing module 701 is relatively large, so when the resistance value of the voltage divider module in the first type sampling branch 101 is relatively small, the sampling accuracy of the first type sampling point UL1 is relatively less affected by the internal resistance in the sampling processing module 701, and the sampling accuracy of the first type sampling point UL1 is relatively high. When the resistance value of the voltage divider module in the first type 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 relatively large, the difference in resistance value with the internal resistance in the sampling processing module 701 is small, and the internal resistance in the sampling processing module 701 will be divided, thereby making the sampling accuracy of the first type sampling point UL1 relatively low.

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

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

[0174] For example, in some embodiments, the follower 702 may amplify according to a preset multiple of 1: 1. In other embodiments, the follower 702 may amplify according to a preset multiple of 1:n, where n is greater than 1.

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

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

[0177] like Fig. 9 As shown, the sampling circuit 10 provided in the embodiment of the present application may include a first-type sampling branch 101, a second-type sampling branch 102, and a sampling processing module 701. The first-type sampling branch 101 is electrically connected to the device under test 20, and the first-type sampling branch 101 is provided with a first-type voltage divider module FL1 and a first-type sampling point UL1. The second-type sampling branch 102 is electrically connected to the device under test 20, and the second-type sampling branch 102 is provided with a second-type voltage divider module FL2, a switch module K, and a second-type sampling point UL2. The sampling processing module 701 is electrically connected to the first-type sampling point UL1 and the second-type sampling point UL2, respectively, and the sampling processing module 701 is used to calibrate the voltage of the first-type sampling point UL1 based on a calibration factor, and the calibration factor is determined according to the voltage of the first-type sampling point UL1 and the voltage of the second-type 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 the embodiment of the present application calculates the calibration factor corresponding to the first type of sampling point by 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, so that the first type of sampling point can also have the same or similar sampling accuracy as the second type of sampling point, that is, the sampling accuracy of the first type of sampling point in the sampling circuit is improved, thereby ensuring that the sampling result has higher accuracy.

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

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

[0182] According to some embodiments of the present 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 the present application, optionally, 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, and a second end of the first sampling branch is electrically connected to the 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, a first end of the second sampling branch is electrically connected to the first electrode of the device under test, and a second end of the second sampling branch 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, and the switch module includes a first switch module, and the second sampling point performs sampling when the first switch module is turned on.

[0184] According to some embodiments of the present application, optionally, the first type of sampling branch includes a third sampling branch, a first end of the third sampling branch is electrically connected to the first reference voltage end, and a 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, a first end of the fourth sampling branch is electrically connected to the second reference voltage end, and a 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, and the switch module includes a second switch module, and the fourth sampling point performs sampling when the second switch module is turned on.

[0185] According to some embodiments of the present application, optionally, the sampling circuit further includes a third switch module, a first end of the third switch module is electrically connected to the first electrode of the device under test; the first type of sampling branch further includes a fifth sampling branch, a first end of the fifth sampling branch is electrically connected to the second end of the third switch module, a second end of the fifth sampling branch is electrically connected to the first reference voltage end, 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 the present application, optionally, the sampling circuit further includes a fourth switch module, a first end of the fourth switch module is electrically connected to the second electrode of the device under test; the first type of sampling branch further includes a sixth sampling branch, a first end of the sixth sampling branch is electrically connected to the first reference voltage end, a second end of the sixth sampling branch is electrically connected to the second end of the fourth switch 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 the present application, optionally, the voltage of 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 the present application, optionally, the first sampling branch includes a first voltage divider module, a second voltage divider module and a first sampling point; the first end of the first voltage divider module is electrically connected to the first electrode of the device under test, and the second end of the first voltage divider module is electrically connected to the first sampling point; the first end of the second voltage divider module is electrically connected to the first sampling point, and the second end of the second voltage divider module is electrically connected to the first reference voltage end; the sum of the resistance value of the first voltage divider module and the resistance value of the second voltage divider module ranges from 25 to 30 megohms.

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

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

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

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

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

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

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

[0197] According to some embodiments of the present application, optionally, 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 collection 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 embodiment, the present application further provides a battery management system (BMS). The battery management system provided in the embodiment of the present application may include the sampling circuit 10 provided in the above embodiment.

[0199] The battery management system provided in the embodiment of the present application calculates the calibration factor corresponding to the first type of sampling point by 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, so that the first type of sampling point can also have the same or similar sampling accuracy as the second type of sampling point, that is, the sampling accuracy of the first type of sampling point in the sampling circuit is improved, thereby ensuring that the sampling result has a higher accuracy.

[0200] Based on the sampling circuit 10 or the battery management system provided in the above embodiment, the present application also provides an electric device, which includes the sampling circuit 10 provided in the above embodiment or the battery management system provided in the above embodiment. In some specific embodiments, the electric device can be a vehicle. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.

[0201] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present 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: include: Obtaining the voltage of the first type of sampling point and the voltage of the second type of sampling point; Determine 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; Based on the calibration factor, the voltage of the first-type sampling point is corrected to obtain the corrected voltage of the first-type sampling point.

2. The calibration method according to claim 1, characterized in that: The step of determining the calibration factors corresponding to the first-type sampling points according to the voltages of the first-type sampling points and the voltages of the second-type sampling points includes: The calibration factors corresponding to the first-type sampling points are determined according to the voltages of the first-type sampling points at multiple moments and the voltages of the second-type sampling points at multiple moments.

3. The calibration method according to claim 1 or 2, characterized in that: The step of determining the calibration factors corresponding to the first-type sampling points according to the voltages of the first-type sampling points and the voltages of the second-type sampling points includes: According to the voltages of the first type of sampling points at multiple moments and the voltages of the second type of sampling points at multiple moments, establishing a relationship between the voltages of the first type of sampling points and the voltages of the second type of sampling points; According to the relationship between the voltage of the first-type sampling point and the voltage of the second-type sampling point, a calibration factor corresponding to the first-type sampling point is determined.

4. The calibration method according to any one of claims 1 to 3, characterized in that: The step of determining the calibration factors corresponding to the first-type sampling points according to the voltages of the first-type sampling points and the voltages of the second-type sampling points 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 according to the voltage of the first type of sampling point acquired at a first moment and the voltage of the second type of sampling point acquired at the first moment; Establishing a second relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point according to the voltage of the first type of sampling point acquired at a second moment and the voltage of the second type of sampling point acquired at the second moment; According to the first relationship and the second relationship, a calibration factor corresponding to the first type of sampling points is determined.

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 a 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 a 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 obtained at a first moment, comprising: A first relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point is established according to 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 moment, and the voltage of the second type of sampling point acquired at the first moment.

6. The calibration method according to claim 5, characterized in that: The establishing a second relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point according to the voltage of the first type of sampling point acquired at the second moment and the voltage of the second type of sampling point acquired at the second moment comprises: A second relationship between the voltage of the first type of sampling point and the voltage of the second type of sampling point is established according to 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 second moment, and the voltage of the second type of sampling point acquired at the second moment.

7. The calibration method according to any one of claims 1 to 6, 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 point based on the calibration factor to obtain the corrected voltage of the first type of sampling point includes: Calculating the product of the voltage of 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 a 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 a second reference potential; The calculating the sum of the product and the second calibration parameter to obtain the corrected voltage of the first type of sampling point includes: The voltage difference between the first reference potential and the second reference potential, the sum of the product and the second calibration parameter are calculated to obtain the corrected voltage of the first type of sampling point.

9. A sampling circuit, characterized in that: include: A first type of sampling branch, 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 dividing module and a first type of sampling point; A second type of sampling branch, the second type of sampling branch is electrically connected to the device under test, and 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; A sampling processing module, the sampling processing module is electrically connected to the first type of sampling points and the second type of sampling points respectively, and the sampling processing module is used to correct the voltage of the first type of sampling points based on a calibration factor, and the calibration factor is determined according to 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 voltages of the first-type sampling points include voltages of the first-type sampling points relative to the first reference voltage terminal, and the voltages of the second-type sampling points include voltages of the second-type sampling points 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 a first electrode of the device under test, a second end of the first sampling branch is electrically connected to a first reference voltage end, 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, a first end of the second sampling branch is electrically connected to the first electrode of the device under test, a second end of the second sampling branch is electrically connected to the second reference voltage end, the second type of sampling point includes a second sampling point located in the second sampling branch, the switch module includes a first switch module, and the second sampling point performs sampling when the first switch module is turned on.

12. The sampling circuit according to any one of claims 9 to 11, characterized in that: The first type of sampling branch includes a third sampling branch, a first end of the third sampling branch is electrically connected to the first reference voltage end, a 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, a first end of the fourth sampling branch is electrically connected to the second reference voltage end, a 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 switch module includes a second switch module, and the fourth sampling point performs sampling when the second switch module is turned on.

13. The sampling circuit according to any one of claims 9 to 12, characterized in that: The sampling circuit further includes a third switch module, a first end of the third switch module is electrically connected to the first electrode of the device under test; The first type of sampling branch also includes a fifth sampling branch, a first end of the fifth sampling branch is electrically connected to the second end of the third switch module, a second end of the fifth sampling branch is electrically connected to the first reference voltage end, 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 any one of claims 9 to 13, characterized in that: The sampling circuit further includes a fourth switch module, a first end of the fourth switch module is electrically connected to the second electrode of the device under test; The first type of sampling branch also includes a sixth sampling branch, a first end of the sixth sampling branch is electrically connected to the first reference voltage end, a second end of the sixth sampling branch is electrically connected to the second end 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 any one of claims 9 to 14, characterized in that: The voltage of 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 any one of claims 9 to 15, characterized in that: The first sampling branch includes a first voltage dividing module, a second voltage dividing module and the first sampling point; A first end of the first voltage divider module is electrically connected to a first electrode of the device under test, and a second end of the first voltage divider module is electrically connected to the first sampling point; A first end of the second voltage dividing module is electrically connected to the first sampling point, and a second end of the second voltage dividing module is electrically connected to the first reference voltage end; The sum of the resistance of the first voltage divider module and the resistance of the second voltage divider module ranges from 25 to 30 megohms.

17. The sampling circuit according to any one of claims 9 to 16, 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 collection 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: The method comprises the sampling circuit as claimed in any one of claims 9 to 17.

19. An electrical device, characterized in that: Comprising a battery management system as claimed in claim 18.

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