Residual discharge capacity determination method, current sampling system and vehicle

Abstract

The invention relates to a residual discharge capacity determination method, a current sampling system and a vehicle. The method comprises the steps that if a battery management system determines that a power utilization scene of a vehicle is a preset large-current power utilization scene, the residual discharge capacity is determined according to the current, collected by a first current sampling device, of a power battery; if the battery management system determines that the power utilization scene of the vehicle is a preset small-current power utilization scene, the residual discharge capacity is determined according to the current, collected by a second current sampling device, of the power battery, and the sampling bandwidth corresponding to the first current sampling device is larger than that corresponding to the second current sampling device. Therefore, the battery management system can determine the residual discharge capacity according to the current of the power battery collected by different current sampling devices under the power consumption scenes corresponding to different current magnitudes, so that the requirement of the battery management system on the current sampling precision of the power battery under different power consumption scenes is met; therefore, the estimation precision of the residual discharge capacity of the power battery is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of vehicles, and in particular, to a method for determining a remaining discharge capacity, a current sampling system, and a vehicle. Background Art

[0002] At present, the current collection device commonly used in vehicles is a single current sensor device. The battery management system on the vehicle can estimate the SOC (State of Charge, referring to the remaining discharge capacity of the power battery) through the ampere-hour integration method based on the current size of the power battery collected by the single current sensor device.

[0003] However, as the market share of electric vehicles continues to increase, the power usage scenarios of vehicles are increasing. The numerical accuracy collected by a single current sensor is difficult to adapt to various power usage scenarios, that is, the error of the collected current may be large and cannot meet the current sampling accuracy requirements when calculating SOC. The continuous accumulation of SOC errors will cause problems such as overcharging, over-discharging, and SOC zero jumps in the power battery, posing a safety hazard and affecting the normal use of the vehicle. Summary of the invention

[0004] An object of the present disclosure is to provide a method for determining a remaining discharge capacity, a current sampling system, and a vehicle to improve the accuracy of the determined remaining discharge capacity.

[0005] In order to achieve the above object, the present disclosure provides a method for determining a remaining discharge capacity in a first aspect, comprising:

[0006] If it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario, determining the remaining discharge capacity according to the current of the power battery collected by the first current sampling device;

[0007] If it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario, determining the remaining discharge capacity according to the current of the power battery collected by the second current sampling device;

[0008] Wherein, the sampling bandwidth corresponding to the first current sampling device is greater than the sampling bandwidth corresponding to the second current sampling device.

[0009] Optionally, the method further comprises:

[0010] If it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario, controlling the first switch between the second current sampling device and the battery management system to be closed, so that the power supply in the battery management system provides power to the second current sampling device;

[0011] The second current sampling device is used to collect the current of the power battery.

[0012] Optionally, the method further comprises:

[0013] If it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario, the first switch between the second current sampling device and the battery management system is controlled to be disconnected.

[0014] In order to achieve the above object, the second aspect of the present disclosure provides a current sampling system, comprising:

[0015] A first current sampling device and a second current sampling device connected in series with the first current sampling device, wherein the first current sampling device and the second current sampling device are connected in series on a power supply circuit between a power battery and an electrical device;

[0016] a battery management system connected to the first current sampling device and the second current sampling device, and configured to determine the remaining discharge capacity according to the current of the power battery collected by the first current sampling device if the power usage scenario of the vehicle is determined to be a preset high-current power usage scenario; and determine the remaining discharge capacity according to the current of the power battery collected by the second current sampling device if the power usage scenario of the vehicle is determined to be a preset low-current power usage scenario;

[0017] Wherein, the sampling bandwidth corresponding to the first current sampling device is greater than the sampling bandwidth corresponding to the second current sampling device.

[0018] Optionally, the current sampling system further includes:

[0019] a first switch, wherein the battery management system is further connected to the second current sampling device through the first switch;

[0020] The battery management system is further configured to control the first switch to be closed if it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario;

[0021] The second current sampling device is used to collect the current of the power battery when the first switch is closed.

[0022] Optionally, the battery management system is further used to control the first switch to disconnect if it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario.

[0023] Optionally, the battery management system includes a power supply;

[0024] The power supply is connected to the second current sampling device through the first switch, and is used to provide electrical energy to the second current sampling device.

[0025] Optionally, the first current sampling device is a resistive shunt; and the second current sampling device is a Hall current sensor.

[0026] Optionally, the current sampling system further includes:

[0027] A first filter;

[0028] The battery management system is connected to the first current sampling device through the first filter.

[0029] Optionally, the current sampling system further includes:

[0030] A second filter;

[0031] The battery management system is connected to the first switch through the second filter; or the first switch is connected to the second current sampling device through the second filter.

[0032] A third aspect of the present disclosure provides a vehicle, comprising:

[0033] Electrical equipment;

[0034] A power battery, connected to the electrical device, for supplying power to the electrical device;

[0035] A current sampling system, wherein the current sampling system is the current sampling system provided in the second aspect of the present disclosure.

[0036] Optionally, the vehicle further includes an information prompting unit connected to the battery management system for displaying the remaining discharge capacity of the power battery.

[0037] In the above technical solution, if the battery management system determines that the vehicle's power usage scenario is a preset high-current power usage scenario, the remaining discharge capacity is determined based on the current of the power battery collected by the first current sampling device; if the battery management system determines that the vehicle's power usage scenario is a preset low-current power usage scenario, the remaining discharge capacity is determined based on the current of the power battery collected by the second current sampling device, wherein the sampling bandwidth corresponding to the first current sampling device is greater than the sampling bandwidth corresponding to the second current sampling device. The current sampling devices with different sampling bandwidths have different current accuracies. In this way, the battery management system can determine the remaining discharge capacity based on the current of the power battery collected by different current sampling devices in power usage scenarios corresponding to different current sizes, thereby meeting the battery management system's requirements for the current sampling accuracy of the power battery in different power usage scenarios, thereby improving the estimation accuracy of the remaining discharge capacity of the power battery.

[0038] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0040] Figure 1 is a flow chart of a method for determining a remaining discharge capacity provided by an exemplary embodiment of the present disclosure.

[0041] Figure 2 is a block diagram of a current sampling system provided by an exemplary embodiment of the present disclosure.

[0042] Figure 3 is a block diagram of a current sampling system provided by an exemplary embodiment of the present disclosure.

[0043] Figure 4 is a block diagram of a vehicle provided by an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0044] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0045] Figure 1 FIG. 1 is a flow chart of a method for determining the remaining discharge capacity provided by an exemplary embodiment of the present disclosure. The method can be applied to the battery management system 203 of the current sampling system 20. Figure 1 As shown, the method may include S101 to S102.

[0046] S101 , if it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario, the remaining discharge capacity is determined according to the current of the power battery 22 collected by the first current sampling device 201 .

[0047] For example, the first current sampling device 201 can be a resistive shunt. The resistive shunt is a non-isolated current sampling device that can identify the current size by the change in voltage difference based on the principle that a voltage difference is generated across the resistor when a DC current passes through the resistor. The preset high-current power usage scenarios may include power usage scenarios such as vehicle charging and vehicle driving. When it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario, the battery management system 203 can estimate the specific value of the SOC based on the ampere-hour integration method and the current of the power battery 22 collected by the first current sampling device 201.

[0048] S102 : If it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario, the remaining discharge capacity is determined according to the current of the power battery 22 collected by the second current sampling device 202 .

[0049] For example, the second current sampling device 202 may be a Hall current sensor. A Hall current sensor is an isolated current acquisition device. When current passes through a magnetic field, a Hall potential is generated. The magnitude of the current can be indirectly determined by the magnitude of the Hall potential. The preset low-current power usage scenarios may include power usage scenarios such as the vehicle sentinel mode and a vehicle refrigerator. When it is determined that the vehicle's power usage scenario is a preset low-current power usage scenario, the battery management system 203 may estimate the specific value of the SOC based on the ampere-hour integration method and the current of the power battery 22 collected by the second current sampling device 202.

[0050] The sampling bandwidth corresponding to the first current sampling device 201 is greater than the sampling bandwidth corresponding to the second current sampling device 202 .

[0051] The sampling bandwidth corresponding to the first current sampling device 201 can be determined according to the maximum discharge power of the vehicle. For example, the sampling bandwidth corresponding to the first current sampling device 201 can be set to a value greater than 800 A. The sampling bandwidth corresponding to the second current sampling device 202 can be determined according to the maximum power consumption in the vehicle's low current power consumption scenarios such as the vehicle sentinel mode and the vehicle refrigerator. For example, the value range of the sampling bandwidth corresponding to the second current sampling device 202 can be set to 5A to 20A.

[0052] The error range and sampling accuracy of the current sampling device are related to its full range (sampling bandwidth). For example, the error range may be ±0.5% of its full range (sampling bandwidth).

[0053] Taking the case where the vehicle is in a low current power consumption scenario, the actual current of the power battery 22 is 8A, the sampling bandwidth corresponding to the first current sampling device 201 is 900A, and the sampling bandwidth corresponding to the second current sampling device 202 is 20A as an example, the value range collected by the first current sampling device 201 is 8±4.5A, and the value range collected by the second current sampling device 202 is 8±0.05A. In other words, the current value collected by the second current sampling device 202 with a smaller sampling bandwidth has higher accuracy and a smaller error range.

[0054] In the scenario of high current consumption, since the actual current of the power battery 22 is a relatively large value, even if there is an error in the current collected by the first current sampling device 201, the effect of the error on the SOC calculation is extremely small and can be almost ignored. However, in the scenario of low current consumption, the actual current of the power battery 22 is a relatively small value. Even if the current collected by the first current sampling device 201 is within the allowable range of its own error, it may have a large deviation from the actual value, making the calculated SOC error larger, and the scenario of low current consumption has higher requirements for the current sampling accuracy. Therefore, in the scenario of low current consumption, the current of the power battery 22 can be more accurately collected through the second current sampling device 202 with a smaller sampling bandwidth, thereby improving the accuracy of the calculated SOC.

[0055] In the above technical solution, if the battery management system 203 determines that the vehicle's power usage scenario is a preset high-current power usage scenario, the remaining discharge capacity is determined according to the current of the power battery collected by the first current sampling device 201; if the battery management system 203 determines that the vehicle's power usage scenario is a preset low-current power usage scenario, the remaining discharge capacity is determined according to the current of the power battery collected by the second current sampling device 202, wherein the sampling bandwidth corresponding to the first current sampling device 201 is greater than the sampling bandwidth corresponding to the second current sampling device 202. The current sampling devices with different sampling bandwidths have different current accuracies. In this way, the battery management system 203 can determine the remaining discharge capacity according to the current of the power battery 22 collected by different current sampling devices in power usage scenarios corresponding to different current sizes, thereby meeting the requirements of the battery management system 203 for the current sampling accuracy of the power battery 22 in different power usage scenarios, thereby improving the estimation accuracy of the remaining discharge capacity of the power battery.

[0056] Optionally, the method for determining the remaining discharge capacity provided by the present disclosure may further include:

[0057] If it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario, the first switch 204 between the second current sampling device 202 and the battery management system 203 is controlled to be closed, so that the power supply in the battery management system 203 provides power to the second current sampling device 202;

[0058] The second current sampling device 202 collects the current of the power battery 22 .

[0059] like Figure 3 As shown, the second current sampling device 202 and the battery management system 203 can be connected through a first switch 204. The first switch 204 can be any one of a MOS tube, a triode and a relay. The battery management system 203 can generate a first switch control instruction according to the power usage scenario, thereby controlling the closing and opening of the first switch 204.

[0060] If it is determined that the vehicle's power usage scenario is a preset low-current power usage scenario, it can be determined that the current of the power battery collected by the first current sampling device 201 is difficult to meet the current sampling accuracy requirements of the current power usage scenario. The first switch 204 can be controlled to be closed so that the power supply in the battery management system 203 provides power to the second current sampling device 202. In this way, the second current sampling device 202 starts working, and the battery management system 203 can obtain the current of the power battery 22 collected by the second current sampling device 202.

[0061] The power battery 22 on the vehicle can output high voltage electricity, and the corresponding electrical equipment 21 can be a high voltage electrical equipment. In other words, a series closed high voltage loop can be formed between the first current sampling device 201, the second current sampling device 202, the electrical equipment 21 and the power battery 22. However, the Hall-type current sensor for collecting small current data usually requires a low voltage power supply and cannot work normally under high voltage power supply. The working power supply of the battery management system 203 is usually a low voltage power supply. Therefore, the power supply in the battery management system 203 can provide power to the second current sampling device 202.

[0062] Optionally, the method for determining the remaining discharge capacity provided by the present disclosure may further include:

[0063] If it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario, the first switch 204 between the second current sampling device 202 and the battery management system 203 is controlled to be disconnected.

[0064] In this way, the current sampling accuracy can be improved by the second current sampling device 202, and the energy consumption of the current sampling system 20 can be reduced in a high current power usage scenario by controlling the first switch 204. In addition, in a high current power usage scenario, the current can be prevented from exceeding the sampling range of the second current sampling device 202.

[0065] In an optional embodiment, the method for determining the remaining discharge capacity provided by the present disclosure may further include:

[0066] If it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario, the second switch between the first current sampling device 201 and the battery management system 203 is controlled to be closed, and the current of the power battery 22 collected by the first current sampling device 201 is obtained;

[0067] If it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario, the second switch between the first current sampling device 201 and the battery management system 203 is controlled to be disconnected.

[0068] In this way, the energy consumed by the first current sampling device 201 for information transmission in a low current scenario can be reduced.

[0069] In another optional embodiment, the second switch may not be provided between the first current sampling device 201 and the battery management system 203 , that is, the first current sampling device 201 always uploads the collected current of the power battery 22 to the battery management system 203 .

[0070] For example, if the first current sampling device 201 is a resistive shunt, then after the first current sampling device 201 is connected to the power battery 22, it does not need to obtain additional power to support its own operation, and the energy consumed by the communication between the first current sampling device 201 and the battery management system 203 is relatively small; and the possibility of the vehicle being in a high current power consumption scenario is higher than that in a low current power consumption scenario. Therefore, in order to simplify the structure of the current sampling system 20, the second switch may not be set between the first current sampling device 201 and the battery management system 203.

[0071] Figure 2 FIG. 1 is a block diagram of a current sampling system provided by an exemplary embodiment of the present disclosure. Figure 1 As shown, the current sampling system 20 includes a first current sampling device 201 , a second current sampling device 202 connected in series with the first current sampling device 201 , and a battery management system 203 .

[0072] The first current sampling device 201 and the second current sampling device 202 are connected in series to the power supply circuit of the power battery 22 and the power-consuming device 21 .

[0073] For example, the first current sampling device 201 may be a resistive shunt. Figure 2 In the plane direction shown, the first current sampling device 201 may be located on the left side of the second current sampling device 202 ; for another example, the first current sampling device 201 may also be located on the right side of the second current sampling device 202 .

[0074] The upper end of the power battery 22 can be the positive electrode of the battery, and the lower end of the power battery 22 can be the negative electrode of the battery. The power battery 22 on the vehicle can output high voltage electricity, and the corresponding power consumption equipment 21 is a high voltage power consumption equipment. In other words, a series closed high voltage loop can be formed between the current sampling system 20, the power consumption equipment 21 and the power battery 22.

[0075] like Figure 2As shown, the positive electrode of the power battery 22 can be connected to the current input terminal of the power device 21 (the upper end of the power device 21), the current output terminal of the power device 21 (the lower end of the power device 21) can be connected to the current input terminal of the second current sampling device 202 (the right side of the second current sampling device 202), the current output terminal of the second current sampling device 202 (the left side of the second current sampling device 202) can be connected to the current input terminal of the first current sampling device 201 (the right side of the first current sampling device 201), and the current output terminal of the first current sampling device 201 (the left side of the first current sampling device 201) can be connected to the negative electrode of the power battery 22.

[0076] The first current sampling device 201 and the second current sampling device 202 are connected in series to the power supply circuit of the power battery 22 and the power device 21, and are located downstream of the power device 21. That is to say, after the first current sampling device 201 and the second current sampling device 202 are connected in series, they are connected to the current output end of the power device 21 and the negative electrode of the power battery 22.

[0077] The battery management system 203 is connected to the first current sampling device 201 and the second current sampling device 202, and is used to determine the remaining discharge capacity according to the current of the power battery 22 collected by the first current sampling device 201 if the power usage scenario of the vehicle is determined to be a preset high-current power usage scenario; if the power usage scenario of the vehicle is determined to be a preset low-current power usage scenario, the remaining discharge capacity is determined according to the current of the power battery 22 collected by the second current sampling device 202.

[0078] The sampling bandwidth corresponding to the first current sampling device 201 is greater than the sampling bandwidth corresponding to the second current sampling device 202 .

[0079] The current sampling devices with different sampling bandwidths have different current accuracies. In this way, the battery management system 203 can determine the remaining discharge capacity according to the current of the power battery 22 collected by different current sampling devices in power usage scenarios corresponding to different current sizes, thereby meeting the requirements of the battery management system 203 for the current sampling accuracy of the power battery 22 in different power usage scenarios, thereby improving the estimation accuracy of the remaining discharge capacity of the power battery.

[0080] Figure 3 FIG. 1 is a block diagram of a current sampling system provided by an exemplary embodiment of the present disclosure. Figure 3 As shown, the current sampling system 20 may further include a first switch 204 .

[0081] The battery management system 203 is also connected to the second current sampling device 202 via the first switch 204;

[0082] The battery management system 203 is further configured to control the first switch 204 to close if it is determined that the power usage scenario of the vehicle is a preset low current power usage scenario;

[0083] The battery management system 203 is further configured to control the first switch 204 to be disconnected if it is determined that the power usage scenario of the vehicle is a preset high current power usage scenario;

[0084] The second current sampling device 202 is used to collect the current of the power battery 22 when the first switch 204 is closed.

[0085] In this way, the current sampling accuracy can be improved by the second current sampling device 202, and the energy consumption of the current sampling system 20 can be reduced in a high current power usage scenario by controlling the first switch 204. In addition, in a high current power usage scenario, the current can be prevented from exceeding the sampling range of the second current sampling device 202.

[0086] Optionally, a second switch may be provided between the first current sampling device 201 and the battery management system 203. The battery management system 203 is further used to control the second switch between the first current sampling device 201 and the battery management system 203 to close if the vehicle's power usage scenario is determined to be a preset high-current power usage scenario, and obtain the current of the power battery 22 collected by the first current sampling device 201; if the vehicle's power usage scenario is determined to be a preset low-current power usage scenario, the second switch between the first current sampling device 201 and the battery management system 203 is controlled to open. In this way, the energy consumed by the first current sampling device 201 to achieve information transmission in a low-current scenario can be reduced.

[0087] Optionally, the second switch may not be provided between the first current sampling device 201 and the battery management system 203. In this way, the structure of the current sampling system 20 may be simplified, and the battery management system 203 may determine whether the current of the power battery 22 collected by the first current sampling device 201 is applied to the calculation of the SOC.

[0088] The specific manner in which the battery management system 203 performs the operation has been described in detail in the embodiment of the method for determining the remaining discharge capacity, and will not be elaborated on here.

[0089] Optionally, the battery management system 203 includes a power source;

[0090] The power supply is connected to the second current sampling device 202 via the first switch 204 , and is used to provide power to the second current sampling device 202 .

[0091] Alternatively, if Figure 4As shown, the current sampling system 20 may further include a first filter 205 , and the battery management system 203 is connected to the first current sampling device 201 via the first filter 205 .

[0092] In this way, interference noise can be filtered out by the first filter 205, so that the value of the current of the power battery 22 collected by the first current sampling device 201 and obtained by the battery management system 203 is more accurate, thereby improving the accuracy of the determined SOC.

[0093] Alternatively, if Figure 2 As shown, the current sampling system 20 may further include a second filter 206.

[0094] The battery management system 203 is connected to the first switch 204 via the second filter 206 ; or, the first switch 204 is connected to the second current sampling device 202 via the second filter 206 .

[0095] In this way, the second filter 206 can filter out interference noise, so that the value of the current of the power battery 22 collected by the second current sampling device 202 and acquired by the battery management system 203 is more accurate, thereby improving the accuracy of the determined SOC.

[0096] The first filter 205 and the second filter 206 may include a high-pass filter and a low-pass filter.

[0097] Figure 4 is a block diagram of a vehicle provided by an exemplary embodiment of the present disclosure. Figure 4 As shown, the vehicle provided by the present disclosure includes a current sampling system 20 , an electrical device 21 , a power battery 22 , and an information prompting unit 23 .

[0098] The power battery 22 is connected to the power-consuming device 21 and is used to supply power to the power-consuming device 21 .

[0099] The current sampling system 20 is the current sampling system 20 described in any of the above embodiments.

[0100] The information prompting unit 23 is connected to the battery management system 203 and is used to display the remaining discharge capacity of the power battery 22 .

[0101] For example, the information prompting unit 23 may be a meter display screen. The current sampling system 20 may send the determined remaining discharge capacity to the meter display screen, and display the remaining discharge capacity to the user through the meter display screen, so that the user can know the remaining power of the vehicle in time.

[0102] In this way, the battery management system 203 can determine the remaining discharge capacity according to the current of the power battery 22 collected by different current sampling devices in power usage scenarios corresponding to different current sizes, and meet the requirements of the battery management system 203 for the current sampling accuracy of the power battery 22 in different power usage scenarios, thereby improving the estimation accuracy of the remaining discharge capacity of the power battery. The remaining discharge capacity of the power battery 22 can be displayed through the information prompt unit 23, so that the user can know the remaining power of the vehicle in time.

[0103] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0104] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0105] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for determining a remaining discharge capacity, characterized in that: Applicable to a battery management system (203), comprising: If it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario, the remaining discharge capacity is determined based on the current of the power battery (22) collected by the first current sampling device (201); If it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario, the remaining discharge capacity is determined based on the current of the power battery (22) collected by the second current sampling device (202); The sampling bandwidth corresponding to the first current sampling device (201) is greater than the sampling bandwidth corresponding to the second current sampling device (202).

2. The method according to claim 1, characterized in that The method further comprises: If it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario, controlling the first switch (204) between the second current sampling device (202) and the battery management system (203) to be closed, so that the power supply in the battery management system (203) provides power to the second current sampling device (202); The second current sampling device (202) is used to collect the current of the power battery (22).

3. The method according to claim 1, characterized in that The method further comprises: If it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario, the first switch (204) between the second current sampling device (202) and the battery management system (203) is controlled to be disconnected.

4. A current sampling system (20), characterized in that: include: A first current sampling device (201) and a second current sampling device (202) connected in series with the first current sampling device (201), wherein the first current sampling device (201) and the second current sampling device (202) are connected in series on a power supply circuit between a power battery (22) and an electrical device (21); A battery management system (203) is connected to the first current sampling device (201) and the second current sampling device (202) and is used to determine the remaining discharge capacity according to the current of the power battery (22) collected by the first current sampling device (201) if it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario; If it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario, determining the remaining discharge capacity according to the current of the power battery (22) collected by the second current sampling device (202); The sampling bandwidth corresponding to the first current sampling device (201) is greater than the sampling bandwidth corresponding to the second current sampling device (202).

5. The current sampling system (20) according to claim 4, characterized in that: The current sampling system (20) further includes: A first switch (204), wherein the battery management system (203) is also connected to the second current sampling device (202) via the first switch (204); The battery management system (203) is further configured to control the first switch (204) to close if it is determined that the power usage scenario of the vehicle is a preset low-current power usage scenario; The second current sampling device (202) is used to collect the current of the power battery (22) when the first switch (204) is closed.

6. The current sampling system (20) according to claim 5, characterized in that: The battery management system (203) is further configured to control the first switch (204) to be disconnected if it is determined that the power usage scenario of the vehicle is a preset high-current power usage scenario.

7. The current sampling system (20) according to claim 5, characterized in that: The battery management system (203) comprises a power source; The power supply is connected to the second current sampling device (202) via the first switch (204) and is used to provide electrical energy to the second current sampling device (202).

8. The current sampling system (20) according to claim 5, characterized in that: The first current sampling device (201) is a resistive shunt; The second current sampling device (202) is a Hall-type current sensor.

9. The current sampling system (20) according to claim 5, characterized in that: The current sampling system (20) further includes: A first filter (205); The battery management system (203) is connected to the first current sampling device (201) via the first filter (205).

10. The current sampling system (20) according to claim 5, characterized in that: The current sampling system (20) further includes: a second filter (206); The battery management system (203) is connected to the first switch (204) via the second filter (206); or the first switch (204) is connected to the second current sampling device (202) via the second filter (206).

11. A vehicle, characterized in that: The vehicle comprises: Electrical equipment (21); A power battery (22), connected to the power-consuming device (21), and used to supply power to the power-consuming device (21); A current sampling system (20), wherein the current sampling system (20) is the current sampling system (20) according to any one of claims 4 to 10.

12. The vehicle according to claim 11, characterized in that The vehicle also includes an information prompting unit (23) connected to the battery management system (203) and used for displaying the remaining discharge capacity of the power battery (22).

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