Current sampling method and device and battery management system

Abstract

The invention provides a current sampling method, a current sampling device and a battery management system, which are characterized in that temperature sampling points of a shunt resistor are increased, target current is obtained based on first temperature and second temperature at two ends of the shunt resistor in combination with the working environment temperature of a sampling plate, and two target currents of two channels are obtained by selecting a two-channel shunt resistor. And judging whether the target current of the main channel is valid or not according to the consistency analysis result of the two target currents, and outputting the target current of the main channel as final sampling current when the target current of the main channel is valid. According to the current sampling method and device and the battery management system provided by the invention, the accuracy of obtaining the target current based on temperature correction can be effectively improved, so that the effectiveness of the final sampling current obtained based on consistency analysis of the two target currents can be ensured, the precision and reliability of current sampling are improved, and convenience is provided for high-precision management of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of current detection, and particularly relates to a current sampling method, device, and battery management system. Background Art

[0002] As the power source of new energy vehicles, the energy utilization efficiency of batteries is an important factor affecting the mileage of vehicles. To ensure the supervision of its energy utilization efficiency, it is necessary to accurately master the usage of batteries. In this regard, new energy vehicles and other industrial applications have put forward very high requirements for current detection in order to accurately master the state of batteries.

[0003] Currently, there are two common methods for current detection on the market. One is to achieve it through a mutual inductance coil, and the other is to use a high-precision shunt resistor (SHUNT resistor). According to Ohm's law, the voltage of the resistor is calculated to infer the current.

[0004] The advantages of high-precision shunt resistors are simple structure and high precision, but they are greatly affected by temperature, especially for high-power power batteries with a large temperature change range; the mutual inductance coil has a wide sampling range, but the structure is complex and the precision is not as good as that of the shunt. In the industry, to solve the precision problem and increase the system reliability, generally, full-temperature-range current tests are required to calibrate the sampling calculation formula. In actual acquisition, based on the calibrated calculation formula, the final current is calculated according to data such as the actual temperature of the SHUNT resistor and the circuit board temperature of the sampling circuit. However, in actual work, the temperature consistency of each part of the collector is poor, resulting in insufficient accuracy of the final current obtained according to the calibrated calculation formula. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to provide a current sampling method, device, and battery management system to solve the problem of insufficient accuracy of the final current obtained by the existing current sampling method.

[0006] One aspect of the present invention provides a current sampling method, including:

[0007] Collect the induction data of the first acquisition channel and the second acquisition channel of the shunt resistor to obtain a first sampling quantity and a second sampling quantity respectively;

[0008] Collect the working environment temperature, and substitute the working environment temperature into the third correction formula to obtain a third correction coefficient;

[0009] Combine the first sampling quantity and the second sampling quantity with the working environment temperature, and substitute them into the compensation formula respectively to obtain a first compensation quantity and a second compensation quantity respectively;

[0010] Collect the induction data of the first temperature sensor and the second temperature sensor on the shunt resistor to obtain the first temperature and the second temperature respectively, and substitute the first temperature and the second temperature into the first correction formula and the second correction formula respectively to obtain the first correction coefficient and the second correction coefficient, where the first temperature sensor and the second temperature sensor are respectively located at both ends of the current channel of the shunt resistor;

[0011] Substitute the first correction amount and the second correction amount into the current calculation formula including the first correction coefficient, the second correction coefficient and the third correction coefficient respectively to obtain the first target current and the second target current respectively;

[0012] Obtain the first difference rate between the first target current and the second target current, and when the first difference rate exceeds the preset first difference rate threshold, judge that the measurement is incorrect and issue a warning, otherwise output the first target current as the final sampled current.

[0013] Optionally, the first correction formula, the second correction formula and the third correction formula are all quadratic polynomials, and the coefficients of each term are obtained by pre-calibration.

[0014] Optionally, the correction formula is: C01 = C0 + A4 × T3 + B4, where C01 is the correction amount, C0 is the sampled amount, T3 is the working environment temperature, and A4 and B4 are constants obtained by pre-calibration;

[0015] The current calculation formula is: C = K × T11 × T21 × T31 × C01, where C is the target current, K is the calibration coefficient obtained according to the calibrated resistance value of the shunt resistor and Ohm's law, T11 is the first correction coefficient, T21 is the second correction coefficient, and T31 is the third correction coefficient.

[0016] Optionally, it further includes: converting the original sampled values of the first sampled amount, the second sampled amount, the first temperature, the second temperature and the working environment temperature into digital signals, and transmitting them to the main controller through an isolation transmission chip, so as to obtain the first target current and the second target current through the main controller, and obtain the sampling result.

[0017] Optionally, it further includes: collecting the voltage sampled value of the standard working voltage, and obtaining the second difference rate between the voltage sampled value and the target value of the preset standard working voltage. When the second difference rate exceeds the preset second difference rate threshold, judge that the measurement is incorrect and issue a warning, otherwise output the final sampled current.

[0018] Optionally, before the steps of substituting the first correction amount and the second correction amount into the current calculation formula respectively to obtain the first target current and the second target current, it further includes: determining whether the first sampling amount, the second sampling amount, the first temperature, the second temperature, and the working environment temperature are all effectively obtained, and after confirming that they are all effectively obtained, calculating the first target current and the second target current, otherwise continuously executing the determination process until it is confirmed that they are all effectively obtained or a warning is issued after the determination times out.

[0019] On the other hand, a current sampling device according to the present invention includes: a shunt resistor, a sampling module, and a management module, where

[0020] The management module includes a power supply unit and a main controller, and the power supply unit is used to provide a working power supply to the main controller and the sampling module;

[0021] A first temperature sensor and a second temperature sensor are arranged on the shunt resistor;

[0022] The sampling module includes a voltage stabilizing unit, a sampling chip, and a third temperature sensor. The voltage stabilizing unit is used to provide a standard working voltage to the sampling chip according to the isolated power supply provided by the management module;

[0023] The sampling chip is used to collect the induction data of the first acquisition channel and the second acquisition channel of the shunt resistor to respectively obtain a first sampling amount and a second sampling amount;

[0024] The sampling chip is also used to collect the induction data of the first temperature sensor, the second temperature sensor, and the third temperature sensor to respectively obtain a first temperature, a second temperature, and a working environment temperature;

[0025] The main controller is used to obtain the first sampling amount, the second sampling amount, the first temperature, the second temperature, and the working environment temperature from the sampling chip, and:

[0026] Substitute the first temperature and the second temperature into the first correction formula and the second correction formula respectively to obtain a first correction coefficient and a second correction coefficient, and substitute the working environment temperature into the third correction formula to obtain a third correction coefficient;

[0027] Combine the first sampling amount and the second sampling amount with the working environment temperature, and substitute them into the correction formula respectively to obtain a first correction amount and a second correction amount;

[0028] Substitute the first correction amount and the second correction amount into the current calculation formula including the first correction coefficient, the second correction coefficient, and the third correction coefficient respectively to obtain a first target current and a second target current;

[0029] Obtain a first difference rate between the first target current and the second target current according to the first target current and the second target current. When the first difference rate exceeds a preset first difference rate threshold, determine that a measurement error has occurred and issue a warning. Otherwise, output the first target current as the final sampled current.

[0030] Optionally, it further includes an SPI isolation unit provided between the management module and the sampling module. The SPI isolation unit is used to transmit the first sampling quantity, the second sampling quantity, the first temperature, the second temperature, and the working environment temperature to the main controller of the management module.

[0031] Optionally, it further includes an isolated power supply unit and a power sampling unit provided between the management module and the sampling module. Among them,

[0032] The isolated power supply unit is used to supply the power supply of the power supply unit to the voltage stabilizing unit;

[0033] The power sampling unit is used to sample the output voltage of the voltage stabilizing unit to provide a voltage sampling value of the standard working voltage to the main controller;

[0034] The main controller is further used to obtain a second difference rate between the voltage sampling value and the target value of the preset standard working voltage. When the second difference rate exceeds a preset second difference rate threshold, determine that a measurement error has occurred and issue a warning. Otherwise, output the final sampled current.

[0035] The present invention further provides a battery management system, including the above-mentioned current sampling device.

[0036] The current sampling method provided by the present invention samples the temperatures at both ends of the current channel of the shunt resistor to obtain a first temperature and a second temperature, corrects the first temperature and the second temperature at both ends and adds them to the current calculation formula, which can reduce the influence of the actual uneven temperature distribution, improve the accuracy of the finally obtained sampled current. At the same time, the dual-channel data of the shunt resistor are collected to obtain two target currents, and the validity of the measurement is judged based on the consistency degree of the first target current and the second target current. When the difference rate between the two target currents exceeds the preset first difference rate threshold, it is judged that the measurement is incorrect and a warning is issued. Otherwise, the first target current of the main channel is output as the finally sampled current. And when the measurement is incorrect, it can indicate that the current environment is too different from the calibrated environment, the battery is not working properly, and the upper management system can reduce the battery working power according to the issued warning to ensure system safety. The current sampling method provided by the present invention can improve the accuracy of the calculated target current, facilitate the precise management of the battery, and based on the consistency analysis of the two target currents with high accuracy, it can further judge the working effectiveness of the system, thereby improving the effectiveness of the finally obtained sampled current and the reliability of the current sampling. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of the main structure of the current sampling device in an embodiment of the present invention;

[0038] Figure 2 is a schematic diagram of the main flow of the current sampling method in an embodiment of the present invention.

[0039] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0041] It should be noted that when an element is referred to as being "fixedly provided on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0043] To solve the problem of insufficient accuracy of the final current obtained by the current sampling method in the prior art, the present invention provides a current sampling method and a current sampling device, which increase the temperature sampling points of the shunt resistor, obtain the target current based on the first temperature and the second temperature at both ends of the shunt resistor and in combination with the operating ambient temperature of the sampling board, and select a dual-channel shunt resistor to obtain two target currents of two channels, so as to judge whether the target current of the main channel is valid according to the consistency analysis result of the two target currents. When it is judged to be valid, the target current of the main channel is output as the final sampling current, which can effectively increase the accuracy of obtaining the target current based on temperature correction, and further ensure the effectiveness of the final sampling current obtained based on the consistency analysis of the two target currents, improve the accuracy and reliability of current sampling, and facilitate the high-precision management of the battery.

[0044] Specifically, as Figure 1 shown, it is a schematic diagram of the main structure of the current sampling device of this embodiment, including: a shunt resistor 10, a sampling module 20, and a management module 30.

[0045] The management module 30 includes a power supply unit 31 and a main controller 32. The power supply unit 31 is used to provide a working power supply to the main controller 32 and the sampling module 20. The SBC (System Basis Chip) can be selected to meet the power management requirements. To avoid the influence of power interference between the management module 30 and the sampling module 20 on the measurement accuracy, an isolated power supply unit 41 is used to provide an isolated power supply to the sampling module 20.

[0046] The shunt resistor 10 is used to be connected to the circuit under test, and generates an induction signal under the drive of the current in the circuit under test. A first temperature sensor N1 and a second temperature sensor N2 are respectively arranged at both ends thereof, so as to obtain temperature information of two points on the shunt resistor 10 through the first temperature sensor N1 and the second temperature sensor N2. And in this embodiment, the shunt resistor 10 has dual sampling channels and can provide two-way induction signal outputs.

[0047] The sampling module 20 includes a voltage stabilizing unit 21, a sampling chip 22, and a third temperature sensor N3. The voltage stabilizing unit 21 is used to provide a standard working voltage to the sampling chip 22 according to the isolated power supply provided by the management module 30 to ensure the working accuracy of the sampling chip 22.

[0048] The sampling chip 22 is used to collect the induction data of the first acquisition channel and the second acquisition channel of the shunt resistor 10, so as to obtain the first sampling quantity and the second sampling quantity respectively. Corresponding to the shunt resistor 10, the original first sampling quantity and the second sampling quantity are generally voltage quantities.

[0049] The sampling chip 22 is also used to collect the induction data of the first temperature sensor N1, the second temperature sensor N2 and the third temperature sensor N3, so as to obtain the first temperature, the second temperature and the working environment temperature respectively.

[0050] The main controller 32 is the main calculator, which is used to obtain the first sampling quantity, the second sampling quantity, the first temperature, the second temperature and the working environment temperature from the sampling chip 22, and combine the preset calculation formula to obtain the final sampling current.

[0051] Each temperature data is also corrected through the corresponding correction formula, so as to obtain each corrected dilution with higher consistency with the actual temperature. Specifically, the main controller 32 is also used to substitute the first temperature and the second temperature into the first correction formula and the second correction formula respectively, so as to obtain the first correction coefficient and the second correction coefficient respectively, and substitute the working environment temperature into the third correction formula to obtain the third correction coefficient.

[0052] For the original sampling quantity obtained by sampling the shunt resistor 10, the data is also affected by the working temperature of the sampling chip 22. Correspondingly, the main controller 32 is also used to combine the first sampling quantity and the second sampling quantity with the working environment temperature, and substitute them into the compensation formula respectively, so as to obtain the first compensation quantity and the second compensation quantity respectively, so as to improve the matching of the sampling data with the actual current.

[0053] Substitute the first correction coefficient, the second correction coefficient and the third correction coefficient into the current calculation formula to obtain the complete calculation formula, and then substitute the first compensation quantity and the second compensation quantity into the complete calculation formula respectively, so as to obtain the first target current and the second target current respectively. The obtained first target current and the second target current are the actual currents of the first sampling channel and the second sampling channel of the shunt resistor 10.

[0054] Further, perform reliability judgment. Obtain the first difference rate of the first target current and the second target current according to the first target current and the second target current, and when the first difference rate exceeds the preset first difference rate threshold, judge that the measurement is incorrect and issue a warning. Otherwise, use the first sampling channel as the main channel and output the corresponding first target current as the final sampling current.

[0055] The first difference rate threshold is, for example, 5%. Taking the first target current as the denominator, when the difference between the second target current and the first target current exceeds 5% of the first target current, it can be considered that the detection environment exceeds the reasonable range, the battery state is abnormal, or the sampling circuit is abnormal. At this time, the sampling result is invalid. A warning is sent to the upper control system through the main controller 32, and the upper control system reduces the working and usage power of the battery, stops charging, or even disconnects the main power circuit, etc., to reduce the power consumption risk.

[0056] By correcting with three-point temperature information, the accuracy of the obtained first target current and second target current can be effectively improved, the response accuracy to the temperature change of the environment where they are located can be improved, so that the judgment accuracy of battery working abnormality based on the consistency between the second target current and the first target current is guaranteed, and the output response speed of the current sampling device is fast, which can quickly sense the working abnormality of the battery, thereby shortening the time-consuming for predicting the power consumption safety risk, taking preventive measures in advance, and improving safety.

[0057] Among them, in addition to having structural requirements for the shunt resistor 10, for the sampling chip 22, two channels can also be set up to form two relatively independent complete sampling channels, reducing the influence of the failure of the sampling chip 22. Moreover, for dual-channel sampling, they can be redundant to each other. When a hardware problem occurs in one channel, sampling detection can still be achieved through the other channel, ensuring the availability of the system and reducing the risk of downtime.

[0058] To further improve the reliability of the measurement result, an SPI isolation unit 43 is also provided between the management module 30 and the sampling module 20. The SPI isolation unit 43 can be implemented based on an SPI communication chip and is used to transmit the first sampling quantity, the second sampling quantity, the first temperature, the second temperature, and the working environment temperature to the main controller 32 of the management module 30. Correspondingly, the sampling chip 22 converts the collected first sampling quantity, the second sampling quantity, the first temperature, the second temperature, and the working environment temperature into digital signals for output, reducing the influence of signal transmission distortion and ensuring the reliability of the finally obtained sampling current.

[0059] To further improve the confidence level of the sampling results, a power supply sampling unit 42 is also provided between the management module 30 and the sampling module 20. The power supply sampling unit 42 is used to sample the output voltage of the voltage stabilizing unit 21 to provide a voltage sampling value of the standard working voltage to the main controller 32. The main controller 32 is further used to obtain a second difference rate between the voltage sampling value and the target value of the preset standard working voltage. When the second difference rate exceeds the preset second difference rate threshold, it is determined that the sampling data of the sampling chip 22 is untrustworthy, the measurement is incorrect, and a warning is issued. Otherwise, the final sampling current is output. The upper control system can report the system problem to the user according to this warning so as to repair the problem in time. And in an emergency situation, a temporary power management scheme can be called to meet the emergency use requirements of the upper device. The present invention mainly provides a current sampling scheme and does not make a special limitation on the control manner of the upper device. Therefore, the control logic of the upper device is not described in detail herein.

[0060] The present invention also provides a current sampling method. Please refer to Figure 2 , which includes:

[0061] Step S11: Collect the induction data of the first acquisition channel and the second acquisition channel of the shunt resistor to respectively obtain a first sampling quantity and a second sampling quantity;

[0062] Step S12: Collect the working environment temperature, and substitute the working environment temperature into a third correction formula to obtain a third correction coefficient;

[0063] Step S20: Combine the first sampling quantity and the second sampling quantity with the working environment temperature and substitute them into a compensation formula respectively to obtain a first compensation quantity and a second compensation quantity respectively;

[0064] Step S13: Collect the induction data of the first temperature sensor and the second temperature sensor on the shunt resistor to respectively obtain a first temperature and a second temperature, and substitute the first temperature and the second temperature into a first correction formula and a second correction formula respectively to obtain a first correction coefficient and a second correction coefficient respectively, where the first temperature sensor and the second temperature sensor are respectively located at both ends of the current channel of the shunt resistor;

[0065] Step S30: Substitute the first compensation quantity and the second compensation quantity into a current calculation formula including the first correction coefficient, the second correction coefficient and the third correction coefficient respectively to obtain a first target current and a second target current respectively;

[0066] Step S40: Obtain a first difference rate between the first target current and the second target current. When the first difference rate exceeds a preset first difference rate threshold, determine that there is a measurement error and issue a warning. Otherwise, output the first target current as the final sampled current.

[0067] As a specific example, the first correction formula, the second correction formula, and the third correction formula are all quadratic polynomials, and the coefficients of each term are obtained by pre-calibration according to the specific selection of the first temperature sensor N1, the second temperature sensor N2, and the third temperature sensor N3. For example, the first correction formula is: T11 = A1×T12 + B1×T1 + C1, the second correction formula is: T21 = A2×T22 + B2×T2 + C2, and the third correction formula is: T31 = A3×T3 2 + B3×T3 + C3, where A1, B1, C1, A2, B2, C2, A3, B3, and C3 are all pre-calibrated constants, T1 is the first temperature, T2 is the second temperature, T3 is the working environment temperature, T11 is the first correction coefficient, T21 is the second correction coefficient, and T31 is the third correction coefficient.

[0068] The compensation formula is: C01 = C0 + A4×T3 + B4, where C01 is the compensation amount, C0 is the sampled amount, T3 is the working environment temperature, and A4 and B4 are pre-calibrated constants.

[0069] The current calculation formula is: C = K×T11×T21×T31×C01, where C is the target current, and K is a calibration coefficient obtained in advance according to the calibrated resistance value of the shunt resistor and Ohm's law.

[0070] According to different product types, the sampled amount provided by the sampling chip 22 to the main controller 32 is a voltage amount or a current amount. Correspondingly, the calibration of K needs to be adjusted specifically according to the specific value to ensure that the unit of the obtained target current is the current unit. Other calibrated constants can also be adjusted adaptively synchronously, which specifically needs to be determined by specific experimental tests according to the calibration conditions. It can be understood that those skilled in the art can calibrate the above parameters according to the existing technology and scientific principles. This application does not elaborate on the specific calibration methods and specific values here.

[0071] To reduce the influence of signal distortion during transmission, it further includes: converting the original sampled values of the first sampled amount, the second sampled amount, the first temperature, the second temperature, and the working environment temperature into digital signals, and transmitting them to the main controller through an isolation transmission chip, so as to obtain the first target current and the second target current through the main controller and obtain the sampling result. The isolation transmission chip can select an SPI communication chip.

[0072] To further detect the reliability of sampling, it further includes: collecting the voltage sampling value of the standard working voltage, and obtaining the second difference rate between the voltage sampling value and the target value of the preset standard working voltage. When the second difference rate exceeds the preset second difference rate threshold, it is determined that the measurement is incorrect and a warning is issued; otherwise, the final sampled current is output. By monitoring the standard working voltage, it is possible to avoid the fluctuation of the current sampling data caused by voltage fluctuation and output incorrect data, and further improve the reliability of the output final sampled current.

[0073] To ensure that the output current is the accurate value after correction, before the steps of substituting the first correction amount and the second correction amount into the current calculation formula respectively to obtain the first target current and the second target current, it further includes: determining whether the first sampling amount, the second sampling amount, the first temperature, the second temperature, and the working environment temperature are all effectively obtained. After confirming that they are all effectively obtained, the calculation of the first target current and the second target current is performed; otherwise, the determination process is continuously executed until it is confirmed that they are all effectively obtained or a warning is issued after the determination times out. By monitoring the data acquisition, it is possible to avoid the system outputting incorrect data based on the initial assignment when no valid sampling data is received.

[0074] The present invention also provides a battery management system, including the above-mentioned current sampling device. The accuracy and reliability of the obtained final sampled current are guaranteed, which can improve the control accuracy of the battery state and facilitate the improvement of the battery management efficiency. Moreover, the abnormal problems of the battery can be predicted in advance through the abnormal warning of current sampling, improving the risk control ability and the safety of battery use.

[0075] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0076] The above-described embodiments only represent several specific implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A current sampling method, characterized in that, Including: Collecting the induction data of the first acquisition channel and the second acquisition channel of the shunt resistor to respectively obtain a first sampling quantity and a second sampling quantity; Collecting the working environment temperature, substituting the working environment temperature into a third correction formula to obtain a third correction coefficient; Combining the first sampling quantity and the second sampling quantity with the working environment temperature and respectively substituting them into a compensation formula to respectively obtain a first compensated quantity and a second compensated quantity; Collecting the induction data of the first temperature sensor and the second temperature sensor on the shunt resistor to respectively obtain a first temperature and a second temperature, and respectively substituting the first temperature and the second temperature into a first correction formula and a second correction formula to respectively obtain a first correction coefficient and a second correction coefficient, wherein the first temperature sensor and the second temperature sensor are respectively located at both ends of the current channel of the shunt resistor; Substituting the first compensated quantity and the second compensated quantity into a current calculation formula including the first correction coefficient, the second correction coefficient and the third correction coefficient to respectively obtain a first target current and a second target current; Obtaining a first difference rate between the first target current and the second target current, and when the first difference rate exceeds a preset first difference rate threshold, determining a measurement error and issuing a warning, otherwise outputting the first target current as the final sampled current.

2. The current sampling method according to claim 1, wherein The first correction formula, the second correction formula and the third correction formula are all quadratic polynomials, and the coefficients of each term are obtained by pre-calibration.

3. The current sampling method according to claim 1 or 2, wherein The compensation formula is: C01 = C0 + A4 × T3 + B4, where C01 is the compensated quantity, C0 is the sampling quantity, T3 is the working environment temperature, and A4 and B4 are constants obtained by pre-calibration; The current calculation formula is: C = K × T11 × T21 × T31 × C01, where C is the target current, K is a calibration coefficient obtained according to the calibrated resistance value of the shunt resistor and Ohm's law, T11 is the first correction coefficient, T21 is the second correction coefficient, and T31 is the third correction coefficient.

4. The current sampling method according to claim 1, characterized in that Further including: Converting the original sampling values of the first sampling quantity, the second sampling quantity, the first temperature, the second temperature and the working environment temperature into digital signals, and transmitting them to the main controller through an isolation transmission chip, so as to obtain the first target current and the second target current through the main controller and obtain a sampling result.

5. The current sampling method according to claim 1, wherein Further including: Collecting a voltage sampling value of a standard working voltage, obtaining a second difference rate between the voltage sampling value and a target value of a preset standard working voltage, and when the second difference rate exceeds a preset second difference rate threshold, determining a measurement error and issuing a warning, otherwise outputting the final sampled current.

6. The current sampling method according to claim 1, characterized in that, Before the steps of substituting the first correction amount and the second correction amount into the current calculation formula respectively to obtain the first target current and the second target current, it further includes: judging whether the first sampling amount, the second sampling amount, the first temperature, the second temperature and the working environment temperature are all effectively obtained, and after confirming that they are all effectively obtained, calculating the first target current and the second target current, otherwise continuously executing the judgment process until it is confirmed that they are all effectively obtained or a warning is issued after the judgment times out.

7. A current sampling device, characterized in that, It includes: A shunt resistor, a sampling module and a management module, wherein, The management module includes a power supply unit and a main controller, and the power supply unit is used to provide working power for the main controller and the sampling module; A first temperature sensor and a second temperature sensor are arranged on the shunt resistor; The sampling module includes a voltage stabilizing unit, a sampling chip and a third temperature sensor, and the voltage stabilizing unit is used to provide a standard working voltage for the sampling chip according to the isolated power supply provided by the management module; The sampling chip is used to collect the induction data of the first acquisition channel and the second acquisition channel of the shunt resistor to respectively obtain a first sampling amount and a second sampling amount; The sampling chip is also used to collect the induction data of the first temperature sensor, the second temperature sensor and the third temperature sensor to respectively obtain a first temperature, a second temperature and a working environment temperature; The main controller is used to obtain the first sampling amount, the second sampling amount, the first temperature, the second temperature and the working environment temperature from the sampling chip, and: Substitute the first temperature and the second temperature into the first correction formula and the second correction formula respectively to obtain a first correction coefficient and a second correction coefficient, and substitute the working environment temperature into the third correction formula to obtain a third correction coefficient; Combine the first sampling amount and the second sampling amount with the working environment temperature and substitute them into the correction formula respectively to obtain a first correction amount and a second correction amount; Substitute the first correction amount and the second correction amount into the current calculation formula including the first correction coefficient, the second correction coefficient and the third correction coefficient respectively to obtain a first target current and a second target current; Obtain the first difference rate of the first target current and the second target current according to the first target current and the second target current, and when the first difference rate exceeds the preset first difference rate threshold, judge that the measurement is incorrect and issue a warning, otherwise output the first target current as the final sampling current.

8. The current sampling device according to claim 7, characterized in that It further includes an SPI isolation unit arranged between the management module and the sampling module, and the SPI isolation unit is used to transmit the first sampling amount, the second sampling amount, the first temperature, the second temperature and the working environment temperature to the main controller of the management module.

9. The current sampling device according to claim 7, wherein It further includes an isolated power supply unit and a power sampling unit arranged between the management module and the sampling module, wherein, The isolated power supply unit is used to supply the power supply of the power supply unit to the voltage stabilizing unit; The power supply sampling unit is used to sample the output voltage of the voltage stabilizing unit to provide a voltage sampling value of the standard operating voltage to the main controller; The main controller is further configured to obtain a second difference rate between the voltage sampling value and a target value of a preset standard operating voltage, and when the second difference rate exceeds a preset second difference rate threshold, determine a measurement error and issue a warning, otherwise output the final sampled current.

10. A battery management system, characterized in that, It includes the current sampling device according to any one of claims 7 to 9.

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