Voltage sampling circuit

Abstract

The utility model discloses a voltage sampling circuit, which is coupled between a charging pile and a battery pack, and comprises a first sampling circuit, the first end of which is coupled to the positive end of the charging pile, the second end of which is coupled to the negative end of the charging pile, and the first sampling signal end of which provides a first sampling signal; the first end of the second sampling circuit is coupled to the positive end of the charging pile, the second end of the second sampling circuit is coupled to the negative end of the charging pile, the third end of the second sampling circuit is coupled to the positive end of the battery pack, the fourth end of the second sampling circuit is coupled to the negative end of the battery pack, and a second sampling signal end provides a second sampling signal; the first end of the third sampling circuit is coupled to the positive end of the charging pile, the second end of the third sampling circuit is coupled to the negative end of the charging pile, the third end of the third sampling circuit is coupled to the positive end of the battery pack, the fourth end of the third sampling circuit is coupled to the negative end of the battery pack, and a third sampling signal end provides a third sampling signal. The voltage sampling circuit can be compatible with voltage sampling of the charging pile port and the battery pack port, and the EMC performance of the whole vehicle is improved on the basis of reducing the production cost.

Description

Technical Field

[0001] This application relates to the field of voltage sampling circuit technology, and in particular to a voltage sampling circuit. Background Technology

[0002] With the development of new energy vehicles, electric vehicles with 800V high-voltage platforms have become the mainstream development trend of pure electric vehicles. However, existing charging piles are diverse and have different specifications, such as 500V, 750V, and 1000V. When the output voltage specifications of the charging pile do not match the voltage platform of the electric vehicle, the vehicle needs to obtain the type information of the charging pile and the accurate output voltage information.

[0003] If accurate output voltage information of the charging station cannot be obtained, the vehicle cannot trust whether the signal emitted by the charging station is genuine and reliable, which in turn leads to safety risks to the battery pack. Utility Model Content

[0004] The technical objective of this application is to provide a voltage sampling circuit to accurately detect the output voltage of a charging pile.

[0005] To achieve the above technical objectives, this application adopts the following technical solution.

[0006] According to a first aspect of this application, an embodiment of this application provides a voltage sampling circuit coupled between a charging pile and a battery pack, comprising: a first sampling circuit having a first terminal, a second terminal, and a first sampling signal terminal, wherein the first terminal is coupled to the positive terminal of the charging pile, the second terminal is coupled to the negative terminal of the charging pile, and the first sampling signal terminal provides a first sampling signal, wherein the first sampling signal characterizes the output voltage between the positive and negative terminals of the charging pile; and a second sampling circuit having a first terminal, a second terminal, a third terminal, a fourth terminal, and a second sampling signal terminal, wherein the first terminal is coupled to the positive terminal of the charging pile, and the second terminal is coupled to the negative terminal of the charging pile. The third sampling circuit has a first terminal, a second terminal, a third terminal, a fourth terminal, and a third sampling signal terminal, wherein the first terminal is coupled to the positive terminal of the charging pile, the second terminal is coupled to the negative terminal of the charging pile, the third terminal is coupled to the positive terminal of the battery pack, the fourth terminal is coupled to the negative terminal of the battery pack, and the third sampling signal terminal provides a third sampling signal, which represents the battery voltage of the battery pack when it is in a second charging mode.

[0007] Through one or more embodiments of the above embodiments of this application, at least the following technical effects can be achieved: In the embodiments of this application, the output voltage of the charging pile when the battery pack is not connected is obtained through a first sampling circuit, and the charging mode of the battery pack is determined based on the output voltage of the charging pile when the battery pack is not connected. When the output voltage of the charging pile is equal to the charging voltage of the battery pack, the battery pack is configured to charge in the first charging mode. The battery voltage of the battery pack in the first charging mode is obtained through a second sampling circuit. When the output voltage of the charging pile is less than the charging voltage of the battery pack, the battery pack is configured to charge in the second charging mode. The battery voltage of the battery pack in the second charging mode is obtained through a third sampling circuit. The battery sampling circuit of this application can detect the output voltage of the charging pile when the battery pack is not connected and when the charging pile is connected to the battery pack, and can also detect the charging voltage of the battery pack when the charging pile is connected to the battery pack, thus ensuring the accuracy of detecting the output voltage of the charging pile. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 A schematic diagram of a voltage sampling circuit according to an embodiment of this application is provided;

[0010] Figure 2 A schematic diagram of the circuit structure of a first sampling circuit according to an embodiment of this application is provided;

[0011] Figure 3 A schematic diagram of the circuit structure of a second sampling circuit according to an embodiment of this application is provided;

[0012] Figure 4 A schematic diagram of the circuit structure of a third sampling circuit according to an embodiment of this application is provided. Detailed Implementation

[0013] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0014] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0015] Figure 1 A schematic diagram of a voltage sampling circuit according to an embodiment of this application is provided. The voltage sampling circuit is coupled between the charging pile EVCS and the battery pack, and includes a first sampling circuit 10, a second sampling circuit 20 and a third sampling circuit 30.

[0016] The first sampling circuit 10 has a first terminal, a second terminal, and a first sampling signal V1 terminal, wherein the first terminal is coupled to the positive terminal HV+ of the charging pile EVCS, the second terminal is coupled to the negative terminal HV- of the charging pile EVCS, and the first sampling signal V1 terminal provides a first sampling signal V1, wherein the first sampling signal V1 represents the output voltage between the positive terminal HV+ and the negative terminal of the charging pile EVCS. The second sampling circuit 20 has a first terminal, a second terminal, a third terminal, a fourth terminal, and a second sampling signal V2 terminal, wherein the first terminal is coupled to the positive terminal HV+ of the charging pile EVCS, the second terminal is coupled to the negative terminal HV- of the charging pile EVCS, the third terminal is coupled to the positive terminal B+ of the battery pack, the fourth terminal is coupled to the negative terminal B- of the battery pack, and the second sampling signal V2 terminal provides a second sampling signal V2, wherein the second sampling signal V2 represents the battery voltage of the battery pack when it is in a first charging mode. The third sampling circuit 30 has a first terminal, a second terminal, a third terminal, a fourth terminal, and a third sampling signal V3 terminal. The first terminal is coupled to the positive terminal HV+ of the charging pile EVCS, the second terminal is coupled to the negative terminal HV- of the charging pile EVCS, the third terminal is coupled to the positive terminal B+ of the battery pack, and the fourth terminal is coupled to the negative terminal B- of the battery pack. The third sampling signal V3 terminal provides a third sampling signal V3, which represents the battery voltage of the battery pack when it is in the second charging mode.

[0017] In some embodiments, the first sampling circuit 10, the second sampling circuit 20, and the third sampling circuit 30 are electrically isolated from each other. The first sampling signal V1, the second sampling signal V2, and the third sampling signal V3 are all sent to the vehicle control unit (VCU). The vehicle control unit determines whether the rated output voltage of the charging pile EVCS matches the charging voltage of the battery pack based on the first sampling signal V1. For example, when the output voltage of the charging pile EVCS is equal to the charging voltage of the battery pack, the battery pack is configured to charge in the first charging mode, and the battery voltage of the battery pack in the first charging mode is obtained through the second sampling circuit 20. When the output voltage of the charging pile EVCS is less than the charging voltage of the battery pack, the battery pack is configured to charge in the second charging mode, and the battery voltage of the battery pack in the second charging mode is obtained through the third sampling circuit 30. The battery sampling circuit of this application can detect the output voltage of the charging pile EVCS when it is not connected to the battery pack for charging, and it can also detect the charging voltage of the battery pack when the charging pile EVCS is connected to the battery pack for charging. This ensures the accuracy of detecting the output voltage of the charging pile EVCS. At the same time, the various sampling circuits are electrically isolated from each other and do not interfere with each other, avoiding the electromagnetic interference problem of the sampling circuit in the prior art when detecting the output voltage of the charging pile EVCS. This improves the electromagnetic compatibility (EMC) of the whole vehicle while reducing costs.

[0018] Figure 2 A schematic diagram of the circuit structure of a first sampling circuit 10 according to an embodiment of this application is provided. The first sampling circuit 10 includes a first control module 11, a first resistor R1, and a second resistor R2. The first control module 11 has an input terminal and an output terminal, wherein the input terminal is coupled to the positive terminal HV+ of the charging pile EVCS. The first resistor R1 has a first end and a second end, wherein the first end is coupled to the output terminal of the first control module 11, and the second end is coupled to the first sampling signal V1 terminal. The second resistor R2 has a first end and a second end, wherein the first end is coupled to the first sampling signal V1 terminal, and the second end is coupled to the negative terminal HV- of the charging pile EVCS. The first control module 11 has a first resistor R1 and a second resistor R2 connected in series in the sampling circuit between the positive terminal HV+ and the negative terminal of the charging pile EVCS. The first control module 11 is used to keep the sampling circuit conducting under preset conditions. The output current of the charging pile EVCS flows through the first resistor R1 and the second resistor R2. The voltage divider terminal between the first resistor R1 and the second resistor R2 is the first sampling signal V1 terminal. The first sampling signal V1 is output from the first sampling signal V1 terminal. The output voltage between the positive terminal HV+ and the negative terminal of the charging pile EVCS is determined according to the voltage value of the first sampling signal V1.

[0019] exist Figure 2 In the illustrated embodiment, the first control module 11 includes a first switch S1, which has a first terminal and a second terminal. The first terminal is coupled to the positive terminal HV+ of the charging pile EVCS, and the second terminal is coupled to the first terminal of the first resistor R1. The first switch S1 receives a control signal from the VCU. When the VCU detects that the charging pile EVCS is connected to the vehicle, the control signal controls the first switch S1 to close, thereby opening the sampling circuit from the positive terminal HV+ of the charging pile EVCS through the first resistor R1 and the second resistor R2 to the negative terminal HV- of the charging pile EVCS, and outputting a first sampling signal V1.

[0020] In some embodiments, the first control module 11 may include at least one diode, which is connected in series between the input and output terminals of the first control module 11. The forward current in each diode flows from the input terminal to the output terminal of the first control module 11. When the charging pile EVCS is normally connected to the vehicle, its positive terminal is connected to the positive terminal of the diode, and the diode is in a forward conducting state. This makes the sampling circuit from the positive terminal HV+ of the charging pile EVCS through the first resistor R1 and the second resistor R2 to the negative terminal HV- of the charging pile EVCS conduct, and outputs the first sampling signal V1.

[0021] Figure 2 This illustrates a scenario where the first control module 11 includes a first diode D1 and a second diode D2 connected in the same direction. It should be noted that, although... Figure 2 The first switch S1 is shown in parallel with the first diode D1 and the second diode D2. However, in practical applications, the first control module 11 may include only the first switch S1 or only the first diode D1 and the second diode D2. When used alone, both can keep the sampling circuit on under preset conditions.

[0022] exist Figure 2In the illustrated embodiment, the first sampling circuit 10 further includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 has a first terminal and a second terminal, wherein the first terminal is coupled to the positive terminal HV+ of the charging pile EVCS. The second capacitor C2 has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the first capacitor C1, and the second terminal is coupled to the negative terminal HV- of the charging pile EVCS. Exemplarily, the first capacitor C1 and the second capacitor C2 can be safety Y capacitors. Signal transmission in the voltage sampling circuit is susceptible to external electromagnetic interference. Safety capacitors can effectively filter out high-frequency noise and voltage spikes in the power supply, preventing them from entering the sampling circuit, ensuring the purity of the sampling signal, and improving the stability and reliability of the circuit. Safety Y capacitors are used to suppress common-mode interference. In this application, the first capacitor C1 and the second capacitor C2 are connected between the output of the charging pile EVCS and the reference ground, which can prevent common-mode interference signals from entering the circuit, avoid interfering with the sampling signal, and ensure the normal operation of the voltage sampling circuit.

[0023] exist Figure 2 In the illustrated embodiment, the positive terminal HV+ of the charging pile EVCS is connected to a first connection line, and the negative terminal HV- of the charging pile EVCS is connected to a second connection line. The first sampling circuit 10 also includes a first magnetic ring, which surrounds the first and second connection lines. When the voltage sampling circuit operates, it may generate some electromagnetic interference. The first magnetic ring can limit these interference signals to a certain range, preventing interference to other surrounding electronic devices. It also avoids the influence of the external electromagnetic environment on the voltage sampling circuit, thereby improving the overall EMC of the vehicle and ensuring that all devices can work together normally.

[0024] In some embodiments, the first capacitor C1, the second capacitor C2, and the first magnetic ring can be set as needed according to the EMC performance of the voltage sampling circuit. The first capacitor C1, the second capacitor C2, and the first magnetic ring can be set simultaneously, or the first capacitor C1, the second capacitor C2, or the first magnetic ring can be set separately.

[0025] Figure 3A schematic diagram of the circuit structure of a second sampling circuit 20 according to an embodiment of this application is provided. The second sampling circuit 20 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, a second control module 21, and a first relay RY1. The third resistor R3 has a first terminal and a second terminal, wherein the first terminal is coupled to the positive terminal HV+ of the charging pile EVCS and the positive terminal B+ of the battery pack. The fourth resistor R4 has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the third resistor R3, and the second terminal is coupled to the second sampling signal V2 terminal. The fifth resistor R5 has a first terminal and a second terminal, wherein the first terminal is coupled to the second sampling signal V2 terminal, and the second terminal is coupled to the negative terminal HV- of the charging pile EVCS. The second control module 21 has an input terminal and an output terminal, wherein the input terminal is coupled to the first terminal of the fourth resistor R4, and the output terminal is coupled to the negative terminal B- of the battery pack. The first relay RY1 has an output terminal and an output terminal, wherein the input terminal is coupled to the negative terminal B- of the battery pack, and the output terminal is coupled to the negative terminal HV- of the charging pile EVCS.

[0026] exist Figure 3 In the illustrated embodiment, the second control module 21 includes a second switch S2. The second switch S2 has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the third resistor R3, and the second terminal is coupled to the negative terminal B- of the battery pack. The second switch S2 receives a control signal from the VCU. When the VCU detects that the charging pile EVCS is connected to the vehicle, the control signal controls the second switch S2 to close, outputting a second sampling signal V2. When the battery is connected to the charging pile for charging, the second sampling signal V2 is calculated by controlling the short-term closure of the second switch S2 to electrically connect the negative terminal B- of the battery pack and the negative terminal HV- of the charging pile as a reference potential.

[0027] In some embodiments, the second control module 21 may include at least one diode connected in series between the input and output terminals of the second control module 21, with the forward current in each diode flowing from the input terminal to the output terminal. When the charging pile EVCS is normally connected to the vehicle, the voltage at the positive terminal of the diode is higher than the voltage at the negative terminal, and the diode is in a forward conducting state.

[0028] Figure 3 This illustrates a second control module 21 comprising a third diode D3 and a fourth diode D4 connected in series in the same direction. It should be noted that, although... Figure 3 The second switch S2 is shown in parallel with the third diode D3 and the fourth diode D4. However, in practical applications, the second control module 21 may include only the second switch S2 or only the third diode D3 and the fourth diode D4. When used alone, both can keep the sampling circuit on under preset conditions.

[0029] In some embodiments, the first relay RY1 is a negative relay. The negative relay controls the negative path of the vehicle circuit. When the relay coil is energized, it connects the negative terminal HV- of the charging pile EVCS to the negative terminal B- of the battery pack, and the battery pack connects to the charging pile EVCS to begin charging. When the output voltage of the charging pile EVCS is equal to the charging voltage of the battery pack, the battery pack is configured to charge in the first charging mode.

[0030] Figure 4 A schematic diagram of the circuit structure of a third sampling circuit 30 according to an embodiment of this application is provided. The third sampling circuit 30 includes a sixth resistor R6, a third control module 31, a seventh resistor R7, a seventh diode D7, an eighth resistor R8, a second relay RY2, and an electric drive system. The sixth resistor R6 has a first terminal and a second terminal, wherein the first terminal is coupled to the positive terminal HV+ of the charging pile EVCS and the positive terminal B+ of the battery pack. The third control module 31 has an input terminal and an output terminal, wherein the input terminal is coupled to the second terminal of the sixth resistor R6. The seventh resistor R7 has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the third control module 31. The seventh diode D7 has a positive terminal and a negative terminal, wherein the positive terminal is coupled to the second terminal of the seventh resistor R7. The eighth resistor R8 has a first terminal and a second terminal, wherein the first terminal is coupled to the third sampling signal V3 terminal, and the second terminal is coupled to the negative terminal HV- of the charging pile EVCS. The second relay RY2 has an input terminal and an output terminal. The input terminal is coupled to the first end of the seventh resistor R7, and the output terminal is coupled to the negative terminal HV- of the charging pile EVCS. The electric drive system has an input terminal, a first output terminal, and a second output terminal. The input terminal is coupled to the first end of the seventh resistor R7. The first output terminal is coupled to the positive terminal B+ of the battery pack and the positive terminal HV+ of the charging pile EVCS. The second output terminal is coupled to the negative terminal B- of the battery pack. The electric drive system is used to regulate the voltage output by the charging pile EVCS. When the vehicle is in the second charging mode, since the rated output voltage of the charging pile EVCS is lower than the charging voltage of the battery pack, the electric drive system needs to raise the output voltage of the charging pile EVCS to the charging voltage of the battery pack so that the charging pile EVCS can charge the battery pack.

[0031] exist Figure 4 In the illustrated embodiment, the third control module 31 includes a third switch S3. The third switch S3 has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the sixth resistor R6, and the second terminal is coupled to the first terminal of the seventh resistor R7. The third switch S3 receives a control signal from the VCU. When the VCU detects that the charging pile EVCS is connected to the vehicle and has started charging in the second charging mode, the control signal controls the third switch S3 to close, thereby turning on the sampling circuit from the positive terminal HV+ of the charging pile EVCS to the negative terminal HV- of the charging pile EVCS, and outputting the third sampling signal V3.

[0032] In some embodiments, the third control module 31 may include at least one diode connected in series between the input and output terminals of the third control module 31, with the forward current in each diode flowing from the input terminal to the output terminal. When the charging pile EVCS is normally connected to the vehicle, the voltage at the positive terminal of the diode is greater than the voltage at the negative terminal, and the diode is in a forward conducting state, thus completing the sampling circuit from the positive terminal HV+ of the charging pile EVCS to the negative terminal HV- of the charging pile EVCS, and outputting the third sampling signal V3.

[0033] Figure 4 This illustrates the case where the third control module 31 includes a fifth diode D5 and a sixth diode D6 connected in series in the same direction. It should be noted that, although... Figure 4 The third switch S3 is shown in parallel with the fifth diode D5 and the sixth diode D6. However, in practical applications, the third control module 31 may include only the third switch S3 or only the fifth diode D5 and the sixth diode D6. Both can keep the sampling circuit on under preset conditions when used alone.

[0034] exist Figure 4 In the illustrated embodiment, the third sampling circuit 30 may further include a third capacitor C3, which has a first terminal and a second terminal. The first terminal is coupled to the first terminal of the seventh resistor R7, and the second terminal is coupled to a reference ground. Exemplarily, the third capacitor C3 may be a safety Y capacitor. Connecting the third capacitor C3 between the first terminal of the seventh resistor R7 and the reference ground prevents common-mode interference signals from entering the circuit, avoiding interference with the sampling signal and ensuring the normal operation of the voltage sampling circuit.

[0035] exist Figure 4 In the illustrated embodiment, the third sampling circuit 30 further includes a second magnetic ring that surrounds the connection line between the first end of the seventh resistor R7 and the electric drive system. The voltage sampling circuit may generate some electromagnetic interference during operation. The second magnetic ring can limit these interference signals to a certain range, preventing interference with other surrounding electronic devices. It also avoids the influence of the external electromagnetic environment on the voltage sampling circuit, thereby improving the overall EMC of the vehicle and ensuring that all devices can work together normally.

[0036] In some embodiments, the second relay RY2 is a negative relay. Specifically, the second relay RY2 is a boost negative relay. In addition to the basic on / off control function of a relay, the boost relay can also increase the voltage. When the vehicle is in the second charging mode, since the rated output voltage of the charging pile EVCS is less than the charging voltage of the battery pack, the second relay RY2 and the electric drive system boost the voltage to charge the battery pack.

[0037] exist Figure 4 In the embodiment shown, the third sampling circuit 30 further includes a seventh diode D7 and an eighth diode D8 to ensure the consistency of the current direction in the sampling loop.

[0038] In the embodiments of this application, the output voltage of the charging pile EVCS when it is not connected to the battery pack is obtained through the first sampling circuit 10. The charging mode of the battery pack is determined based on the output voltage of the charging pile EVCS when it is not connected to the battery pack. When the output voltage of the charging pile EVCS is equal to the charging voltage of the battery pack, the battery pack is configured to charge in the first charging mode. The battery voltage of the battery pack in the first charging mode is obtained through the second sampling circuit 20. When the output voltage of the charging pile EVCS is less than the charging voltage of the battery pack, the battery pack is configured to charge in the second charging mode. The battery voltage of the battery pack in the second charging mode is obtained through the third sampling circuit 30. The battery sampling circuit of this application can detect the output voltage of the charging pile EVCS when it is not connected to the battery pack and can also detect the charging voltage of the battery pack when the charging pile EVCS is connected to the battery pack and is charging, thus ensuring the accuracy of detecting the output voltage of the charging pile EVCS.

[0039] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.

Claims

1. A voltage sampling circuit, characterized in that, The voltage sampling circuit is coupled between the charging pile and the battery pack, and includes: A first sampling circuit has a first terminal, a second terminal, and a first sampling signal terminal, wherein the first terminal is coupled to the positive terminal of the charging pile, the second terminal is coupled to the negative terminal of the charging pile, and the first sampling signal terminal provides a first sampling signal, wherein the first sampling signal characterizes the output voltage between the positive and negative terminals of the charging pile. The second sampling circuit has a first terminal, a second terminal, a third terminal, a fourth terminal, and a second sampling signal terminal, wherein the first terminal is coupled to the positive terminal of the charging pile, the second terminal is coupled to the negative terminal of the charging pile, the third terminal is coupled to the positive terminal of the battery pack, the fourth terminal is coupled to the negative terminal of the battery pack, and the second sampling signal terminal provides a second sampling signal, which characterizes the battery voltage of the battery pack when it is in a first charging mode. The third sampling circuit has a first terminal, a second terminal, a third terminal, a fourth terminal, and a third sampling signal terminal. The first terminal is coupled to the positive terminal of the charging pile, the second terminal is coupled to the negative terminal of the charging pile, the third terminal is coupled to the positive terminal of the battery pack, the fourth terminal is coupled to the negative terminal of the battery pack, and the third sampling signal terminal provides a third sampling signal, which characterizes the battery voltage of the battery pack when it is in the second charging mode.

2. The voltage sampling circuit according to claim 1, characterized in that, When the output voltage between the positive and negative terminals of the charging pile is consistent with the charging voltage of the battery, the battery pack is in the first charging mode. When the output voltage between the positive and negative terminals of the charging pile is less than the charging voltage of the battery, the battery pack is in the second charging mode.

3. The voltage sampling circuit according to claim 1, characterized in that, The first sampling circuit includes: The first control module has an input terminal and an output terminal, wherein the input terminal is coupled to the positive terminal of the charging pile; The first resistor has a first end and a second end, wherein the first end is coupled to the output end of the first control module and the second end is coupled to the first sampling signal end; The second resistor has a first terminal and a second terminal, wherein the first terminal is coupled to the first sampling signal terminal and the second terminal is coupled to the negative terminal of the charging pile.

4. The voltage sampling circuit according to claim 3, characterized in that, The first control module includes: A first switch has a first terminal and a second terminal, wherein the first terminal is coupled to the positive terminal of the charging pile, and the second terminal is coupled to the first terminal of a first resistor.

5. The voltage sampling circuit according to claim 3, characterized in that, The first control module includes: At least one diode is connected in series between the input and output terminals of the first control module, and the forward current in each diode flows from the input terminal to the output terminal of the first control module.

6. The voltage sampling circuit according to claim 3, characterized in that, The first sampling circuit further includes: The first capacitor has a first terminal and a second terminal, wherein the first terminal is coupled to the positive terminal of the charging pile; The second capacitor has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the first capacitor and the second terminal is coupled to the negative terminal of the charging pile.

7. The voltage sampling circuit according to claim 3, characterized in that, The positive terminal of the charging pile has a first connection line, and the negative terminal of the charging pile has a second connection line. The first sampling circuit further includes: A first magnetic ring surrounds the first connecting line and the second connecting line.

8. The voltage sampling circuit according to claim 1, characterized in that, The second sampling circuit includes: The third resistor has a first terminal and a second terminal, wherein the first terminal is coupled to the positive terminal of the charging pile and the positive terminal of the battery pack. The fourth resistor has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the third resistor, and the second terminal is coupled to the second sampling signal terminal; The fifth resistor has a first terminal and a second terminal, wherein the first terminal is coupled to the second sampling signal terminal and the second terminal is coupled to the negative terminal of the charging pile; The second control module has an input terminal and an output terminal, wherein the input terminal is coupled to the first terminal of the fourth resistor and the output terminal is coupled to the negative terminal of the battery pack. The first relay has an input terminal coupled to the negative terminal of the battery pack and an output terminal coupled to the negative terminal of the charging pile.

9. The voltage sampling circuit according to claim 8, characterized in that, The second control module includes: The second switch has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the third resistor and the second terminal is coupled to the negative terminal of the battery pack.

10. The voltage sampling circuit according to claim 8, characterized in that, The second control module includes: At least one diode is connected in series between the input and output terminals of the second control module, and the forward current in each diode flows from the input terminal to the output terminal of the second control module.

11. The voltage sampling circuit according to claim 8, characterized in that, The first relay is a negative relay.

12. The voltage sampling circuit according to claim 1, characterized in that, The third sampling circuit includes: The sixth resistor has a first terminal and a second terminal, wherein the first terminal is coupled to the positive terminal of the charging pile and the positive terminal of the battery pack; The third control module has an input terminal and an output terminal, wherein the input terminal is coupled to the second terminal of the sixth resistor; The seventh resistor has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the third control module; The seventh diode has a positive terminal and a negative terminal, with the positive terminal coupled to the second end of the seventh resistor; The eighth resistor has a first terminal and a second terminal, wherein the first terminal is coupled to the third sampling signal terminal and the second terminal is coupled to the negative terminal of the charging pile; The second relay has an input terminal and an output terminal, wherein the input terminal is coupled to the first terminal of the seventh resistor and the output terminal is coupled to the negative terminal of the charging pile; An electric drive system has an input terminal, a first output terminal, and a second output terminal. The input terminal is coupled to the first end of a seventh resistor, the first output terminal is coupled to the positive terminal of the battery pack and the positive terminal of the charging pile, and the second output terminal is coupled to the negative terminal of the battery pack. The electric drive system is used to regulate the voltage output by the charging pile.

13. The voltage sampling circuit according to claim 12, characterized in that, The third control module includes: The third switch has a first terminal and a second terminal, wherein the first terminal is coupled to the second terminal of the sixth resistor and the second terminal is coupled to the first terminal of the seventh resistor.

14. The voltage sampling circuit according to claim 12, characterized in that, The third control module includes: At least one diode is connected in series between the input and output terminals of the third control module, and the forward current in each diode flows from the input terminal to the output terminal of the third control module.

15. The voltage sampling circuit according to claim 12, characterized in that, The third sampling circuit also includes: The third capacitor has a first terminal and a second terminal, wherein the first terminal is coupled to the first terminal of the seventh resistor and the second terminal is coupled to the reference ground.

16. The voltage sampling circuit according to claim 12, characterized in that, The third sampling circuit also includes: The second magnetic ring surrounds the connection line between the first end of the seventh resistor and the electric drive system.

17. The voltage sampling circuit according to claim 12, characterized in that, The second relay is a negative relay.

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