CN220120961U - High-voltage sampling circuit, battery management system and power utilization device - Google Patents

Abstract

The application discloses a high-voltage sampling circuit, a battery management system and an electricity utilization device, and relates to the technical field of batteries. The high voltage sampling circuit includes: the device comprises a first sampling module, a second sampling module, a first signal transmission module, a second signal transmission module, a bias power supply and a processor; the first sampling module is connected with the positive electrode of the battery pack to be tested, the bias power supply and the first signal transmission module; the second sampling module is connected with a bias power supply, the negative electrode of the battery pack to be tested and the second signal transmission module; the processor is used for obtaining the high-voltage loop voltage of the battery pack to be tested according to the difference value of the first voltage signal and the second voltage signal; at least one of the first signal transmission module and the second signal transmission module includes a voltage follower. According to the embodiment of the application, the cost of the high-voltage sampling circuit is reduced.

Description

High-voltage sampling circuit, battery management system and electrical device

Technical field

The present application relates to the field of battery technology, and in particular to a high-voltage sampling circuit, a battery management system and an electrical device.

Background technique

With the continuous development of battery technology, people have higher and higher requirements for batteries.

In the related art, a high-voltage sampling circuit is provided for the power battery to monitor the voltage state of the power battery. However, the high-voltage sampling circuit in the related art has the problem of high cost.

Utility model content

This application provides a high-voltage sampling circuit, a battery management system and an electrical device, which helps to reduce the cost of the high-voltage sampling circuit.

In a first aspect, the application provides a high-voltage sampling circuit, including a first sampling module, a second sampling module, a first signal transmission module, a second signal transmission module, a bias power supply and a processor; wherein,

The first sampling module is connected to the positive electrode of the battery pack to be tested, the bias power supply, and the first signal transmission module. The first signal transmission module is used to transmit the first voltage signal collected by the first sampling module to the processor;

The second sampling module is connected to the bias power supply, the negative electrode of the battery pack to be tested, and the second signal transmission module. The second signal transmission module is used to transmit the second voltage signal collected by the second sampling module to the processor;

The processor is configured to obtain the high-voltage circuit voltage of the battery pack to be tested based on the difference between the first voltage signal and the second voltage signal;

At least one of the first signal transmission module and the second signal transmission module includes a voltage follower.

In a possible implementation of the first aspect, the first signal transmission module includes a first voltage follower, the non-inverting input end of the first voltage follower is connected to the first sampling module, and the inverting input end of the first voltage follower is connected to The output terminal of the first voltage follower is connected to the processor.

In a possible implementation of the first aspect, the first sampling module includes a first resistor and a second resistor;

The first end of the first resistor is connected to the positive electrode of the battery pack to be tested, and the second end of the first resistor is connected to the first end of the second resistor and the first signal transmission module;

The second terminal of the second resistor is connected to the bias power supply.

In a possible implementation of the first aspect, the second signal transmission module includes a second voltage follower, the non-inverting input end of the second voltage follower is connected to the second sampling module, and the inverting input end of the second voltage follower is connected The output terminal of the second voltage follower is connected to the processor.

In a possible implementation of the first aspect, the second sampling module includes a third resistor and a fourth resistor;

The first end of the third resistor is connected to the negative electrode of the battery pack to be tested, and the second end of the third resistor is connected to the first end of the fourth resistor and the second signal transmission module;

The second end of the fourth resistor is connected to the bias power supply.

In a possible implementation of the first aspect, the voltage of the bias power supply is greater than 0.

In a possible implementation of the first aspect, the processor includes an analog-to-digital conversion module, the reference voltage of the analog-to-digital conversion module is Vref, and the voltage of the bias power supply is Voffset, Vref/3≤Voffset≤Vref*3/4.

In a possible implementation of the first aspect, the processor includes an analog-to-digital conversion module, the reference voltage of the analog-to-digital conversion module is Vref, and the voltage of the bias power supply is Voffset, and Voffset=Vref/2.

In a possible implementation of the first aspect, the bias power supply is connected to the processor, and the processor is also used to:

According to the voltage of the bias power supply, detect whether the bias power supply is abnormal;

And/or, the processor includes an analog-to-digital conversion module, and the processor is also used to detect whether the analog-to-digital conversion module is abnormal based on the voltage of the bias power supply.

In a possible implementation of the first aspect, the high-voltage sampling circuit further includes a first switch module, a second switch module, a third sampling module, a fourth sampling module, a third signal transmission module and a fourth signal transmission module;

The first end of the first switch module is connected to the positive electrode of the battery pack to be tested and the first sampling module;

The first end of the second switch module is connected to the negative electrode of the battery pack to be tested and the second sampling module;

The third sampling module is connected to the second end of the first switch module, the bias power supply and the third signal transmission module. The third signal transmission module is used to transmit the third voltage signal collected by the third sampling module to the processor;

The fourth sampling module is connected to the bias power supply, the second end of the second switch module and the fourth signal transmission module. The fourth signal transmission module is used to transmit the fourth voltage signal collected by the fourth sampling module to the processor;

At least one of the third signal transmission module and the fourth signal transmission module includes a voltage follower;

The processor is also used for:

Calculate a first difference between the first voltage signal and the second voltage signal, and a second difference between the third voltage signal and the second voltage signal;

Obtain the status of the first switch module according to the comparison result between the first difference value and the second difference value;

And/or, calculate a first difference between the first voltage signal and the second voltage signal, and a third difference between the first voltage signal and the fourth voltage signal;

According to the comparison result between the first difference value and the third difference value, the state of the second switch module is obtained.

In a possible implementation of the first aspect, the third signal transmission module includes a third voltage follower, the non-inverting input end of the third voltage follower is connected to the third sampling module, and the inverting input end of the third voltage follower is connected The output terminal of the third voltage follower is connected to the processor.

In a possible implementation of the first aspect, the third sampling module includes a fifth resistor and a sixth resistor;

The first end of the fifth resistor is connected to the second end of the first switch module, and the second end of the fifth resistor is connected to the first end of the sixth resistor and the third signal transmission module;

The second terminal of the sixth resistor is connected to the bias power supply.

In a possible implementation of the first aspect, the fourth signal transmission module includes a fourth voltage follower, the non-inverting input end of the fourth voltage follower is connected to the fourth sampling module, and the inverting input end of the fourth voltage follower is connected The output terminal of the fourth voltage follower is connected to the processor.

In a possible implementation of the first aspect, the fourth sampling module includes a seventh resistor and an eighth resistor;

The first end of the seventh resistor is connected to the second end of the second switch module, and the second end of the seventh resistor is connected to the first end of the eighth resistor and the fourth signal transmission module;

The second end of the eighth resistor is connected to the bias power supply.

Based on the same inventive concept, in a second aspect, an embodiment of the present application provides a battery management system, including a high-voltage sampling circuit as described in any embodiment of the first aspect.

Based on the same inventive concept, in a third aspect, an embodiment of the present application provides an electrical device, including the battery management system as described in any embodiment of the first aspect.

According to the high-voltage sampling circuit, battery management system and power device provided by the embodiment of the present application, the first voltage signal collected by the first sampling module is transmitted to the processor through the first signal transmission module, and the first voltage signal collected by the first sampling module is transmitted to the processor through the second signal transmission module. The second voltage signal collected by the second sampling module is transmitted to the processor. At least one of the first signal transmission module and the second signal transmission module includes a voltage follower. Since the voltage follower has an isolation effect, the voltage follower can By performing high and low voltage isolation, high-voltage sampling can be achieved without the need for independent analog-to-digital conversion modules, isolated communication chips, and isolated power supplies, thereby helping to reduce the cost of high-voltage sampling circuits.

Description of the drawings

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

Figure 1 is a schematic structural diagram of a high-voltage sampling circuit in the related art;

Figure 2 is a schematic structural diagram of a high-voltage sampling circuit according to an embodiment of the present application;

Figure 3 is a schematic structural diagram of a high-voltage sampling circuit according to another embodiment of the present application;

Figure 4 is a schematic structural diagram of a high-voltage sampling circuit according to another embodiment of the present application;

FIG. 5 is a schematic structural diagram of a high-voltage sampling circuit according to yet another embodiment of the present application.

Explanation of reference symbols:

100. High voltage sampling circuit;

11. The first sampling module; 12. The second sampling module;

13. The first signal transmission module; 131. The first voltage follower;

14. Second signal transmission module; 141. Second voltage follower;

15. Bias power supply; 16. Processor;

17. The first switch module; 18. The second switch module;

19. The third sampling module; 20. The fourth sampling module;

21. The third signal transmission module; 211. The third voltage follower;

22. The fourth signal transmission module; 221. The fourth voltage follower.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments These are part of the embodiments of this application, but not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of this application.

Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the technical field of this application; the terms used in the specification of this application are only for describing specific implementations. The purpose of the examples is not intended to limit the application; the terms "including" and "having" and any variations thereof in the description and claims of the application and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or priority relationship.

In the description of this application, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection", "connection" and "attachment" should be understood in a broad sense. For example, it can be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

As shown in Figure 1, the high-voltage sampling circuit in the related art can be provided with a first resistor Ra, a second resistor Rb, a switching element Ka, a switching element Kb, an independent analog-to-digital conversion module A, an isolated communication chip B, and an isolated power supply C. and controller D, there is a problem of high cost. Among them, the independent analog-to-digital conversion module A can be used to convert analog signals into data signals; the isolation communication chip B is used to transmit the output signal of the analog-to-digital conversion module A to the controller D. The isolation communication chip B can also be used to isolate multiple signals at the same time. circuit voltage or analog signal to prevent cross coupling; the isolated power supply C can be used to power the independent analog-to-digital conversion module A and/or the isolated communication chip B.

It can be seen that the high-voltage sampling circuit in the related technology requires an independent analog-to-digital conversion module A and an isolated communication chip B, which has a high cost problem.

In order to solve the above technical problems, embodiments of the present application provide a high-voltage sampling circuit, a battery management system and an electrical device. The high-voltage sampling circuit, battery management system and electrical device provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings. introduce.

The following first introduces the high-voltage sampling circuit provided in the application embodiment.

As shown in FIG. 2 , the high-voltage sampling circuit 100 may include a first sampling module 11 , a second sampling module 12 , a first signal transmission module 13 , a second signal transmission module 14 , a bias power supply 15 and a processor 16 .

The first sampling module 11 can be connected to the positive electrode B+ of the battery pack to be tested, the bias power supply 15 and the first signal transmission module 13 . For example, the first end of the first sampling module 11 can be connected to the positive electrode B+ of the battery pack to be tested, the second end of the first sampling module 11 can be connected to the bias power supply 15, and the third end of the first sampling module 11 can be connected to The first end of the first signal transmission module 13 . The second end of the first signal transmission module 13 can be connected to the first end of the processor 16 . The first sampling module 11 can be used to collect the first voltage signal; the first signal transmission module 13 can be used to transmit the first voltage signal collected by the first sampling module 11 to the processor 16 .

The second sampling module 12 can be connected to the bias power supply 15, the negative electrode B- of the battery pack to be tested, and the second signal transmission module 14. For example, the first end of the second sampling module 12 can be connected to the bias power supply 15, the second end of the second sampling module 12 can be connected to the negative electrode B- of the battery pack to be tested, and the third end of the second sampling module 12 can be connected to the bias power supply 15. The first end of the second signal transmission module 14 is connected, and the second end of the second signal transmission module 14 can be connected to the second end of the processor 16 . The second sampling module 12 can be used to collect the second voltage signal; the second signal transmission module 14 can be used to transmit the second voltage signal collected by the second sampling module 12 to the processor 16 .

The processor 16 may be configured to obtain the high-voltage circuit voltage of the battery pack to be tested based on the difference between the first voltage signal and the second voltage signal.

At least one of the first signal transmission module 13 and the second signal transmission module 14 may include a voltage follower. In other words, the first signal transmission module 13 may include a voltage follower, or the second signal transmission module 14 may include a voltage follower, or both the first signal transmission module 13 and the second signal transmission module 14 may include a voltage follower. follower.

A voltage follower can be a type of electronic component that realizes the transformation of the output voltage to follow the input voltage. The voltage follower has the characteristics of high input impedance and low output impedance, so the voltage follower can play an isolation role. In the embodiment of the present application, the first voltage signal collected by the first sampling module is transmitted to the processor through the first signal transmission module, and the second voltage signal collected by the second sampling module is transmitted to the processor through the second signal transmission module. At least one of the processor, the first signal transmission module and the second signal transmission module includes a voltage follower. Since the voltage follower has an isolation function, the voltage follower can perform high and low voltage isolation, so that there is no need to set an independent module. With the conversion module, isolated communication chip and isolated power supply, high-voltage sampling can be achieved, which in turn helps reduce the cost of the high-voltage sampling circuit.

Illustratively, bias power supply 15 may be used to provide voltage. For example, bias power supply 15 may be used to provide a fixed voltage. Anything that can provide voltage can be used as the bias power supply 15. The embodiment of the present application does not limit the specific structure of the bias power supply 15.

Since the second end of the first sampling module 11 is connected to the bias power supply 15 and the first end of the second sampling module 12 is connected to the bias power supply 15, the second end of the first sampling module 11 and the first end of the second sampling module 12 The potentials of the terminals are equal to the potential of the bias power supply 15. Therefore, the voltage magnitude of the bias power supply 15 affects the voltage magnitudes of the first voltage signal and the second voltage signal. For example, the voltage value range of the bias power supply 15 can be set to correct the voltages of the first voltage signal and the second voltage signal.

The processor 16 may include a microcontroller unit (MCU).

In some optional implementations, as shown in FIGS. 3 to 5 , the first signal transmission module 13 may include a first voltage follower 131 , and the non-inverting input terminal + of the first voltage follower 131 may be connected to the first sampling module. 11. The inverting input terminal of the first voltage follower 131 can be connected to the output terminal of the first voltage follower 131 , and the output terminal of the first voltage follower 131 can be connected to the processor 16 .

For example, the non-inverting input terminal + of the first voltage follower 131 can be connected to the third terminal of the first sampling module 11 , and the output terminal of the first voltage follower 131 can be connected to the first terminal of the processor 16 . That is to say, the first terminal of the first signal transmission module 13 may be the non-inverting input terminal + of the first voltage follower 131 , and the second terminal of the first signal transmission module 13 may be the output terminal of the first voltage follower 131 .

Optionally, the first voltage follower 131 may also include a first voltage terminal V+ and a second voltage terminal GND. Among them, the first voltage terminal V+ can be connected to a low-voltage power supply inside the battery management unit (Battery Management Unit, BMU). The low-voltage power supply can be used to provide a positive voltage. The positive voltage can be greater than the reference voltage Vref of the analog-to-digital conversion module in the processor 16 ;The second voltage terminal GND can be grounded.

In this embodiment, by setting the first voltage follower 131 between the first sampling module 11 and the processor 16, it is possible to avoid setting an independent analog-to-digital conversion module between the first sampling module 11 and the processor 16. Isolating communication modules, etc., thereby helping to reduce the cost of high-voltage sampling circuits.

In some optional implementations, as shown in FIGS. 3 to 5 , the first sampling module 11 may include a first resistor RP1 and a second resistor RP2. The first end of the first resistor RP1 can be connected to the positive electrode B+ of the battery pack to be tested, and the second end of the first resistor RP1 can be connected to the first end of the second resistor RP2 and the first signal transmission module 13 . The second terminal of the second resistor RP2 can be connected to the bias power supply 15 . For example, the second terminal of the first resistor RP1 may be connected to the first terminal of the second resistor RP2 and the non-inverting input terminal + of the first voltage follower 131 .

The first terminal of the first sampling module 11 may be the first terminal of the first resistor RP1, the second terminal of the first sampling module 11 may be the second terminal of the second resistor RP2, and the third terminal of the first sampling module 11 may be Disposed between the second end of the first resistor RP1 and the first end of the second resistor RP2. The third end of the first sampling module 11 is the first sampling point.

The first voltage signal is the voltage signal of the third terminal of the first sampling module 11 .

The resistance of the first resistor RP1 may be in the megohm level. For example, the resistance of the first resistor RP1 may be 25 MΩ. For example, when the resistance of the first resistor RP1 is 25 MΩ, the first resistor RP1 may be a set of five 5 MΩ resistors connected in series.

The resistance of the second resistor RP2 may be in the kiloohm level. For example, the resistance of the second resistor RP2 may range from several thousand ohms to more than ten kiloohms.

Both the first resistor RP1 and the second resistor RP2 can play a voltage dividing role.

Optionally, the first sampling module 11 may also include a third switch (not shown in the figure). The position of the third switch is adjustable, as long as the third switch, the first resistor RP1 and the second resistor RP2 are connected in series to the battery to be tested. It can be between the positive electrode B+ of the group and the bias power supply 15. For example, the third switch may be connected between the first resistor RP1 and the second resistor RP2. The third switch can be used to cooperatively provide the first voltage signal. For example, when the third switch is closed, the first voltage signal can be provided, but when the third switch is open, the first voltage signal cannot be provided.

The third switch, as well as the first switch, the second switch, the fourth switch, the fifth switch and the sixth switch below, may be a pneumatic relay (Pressure Operated Switch, POS), MOS (Metal Oxide Semiconductor Field Effect Transistor, Metal Oxide Controllable switches such as physical semiconductor field effect) tubes, optical coupling switches, and magnetic isolators can also be other types of switches, which are not limited here.

In some optional implementations, as shown in FIGS. 3 to 5 , the second signal transmission module 14 may include a second voltage follower 141 , and the non-inverting input terminal + of the second voltage follower 141 may be connected to the second sampling module. 12. The inverting input terminal of the second voltage follower 141 can be connected to the output terminal of the second voltage follower 141 , and the output terminal of the second voltage follower 141 can be connected to the processor 16 .

For example, the non-inverting input terminal + of the second voltage follower 141 may be connected to the third terminal of the second sampling module 12 , and the output terminal of the second voltage follower 141 may be connected to the first terminal of the processor 16 . That is to say, the first terminal of the second signal transmission module 14 may be the non-inverting input terminal + of the second voltage follower 141 , and the second terminal of the second signal transmission module 14 may be the output terminal of the second voltage follower 141 .

Optionally, the second voltage follower 141 may also include a first voltage terminal V+ and a second voltage terminal GND. Among them, the first voltage terminal V+ can be connected to a low-voltage power supply inside the battery management unit, and the low-voltage power supply can be used to provide a positive voltage, which can be greater than the reference voltage Vref of the analog-to-digital conversion module in the processor 16; the second voltage terminal GND can be Ground.

In this embodiment, by setting the second voltage follower 141 between the second sampling module 12 and the processor 16, it is possible to avoid setting an independent analog-to-digital conversion module between the second sampling module 12 and the processor 16. Isolating communication modules, etc., thereby helping to reduce the cost of high-voltage sampling circuits.

In some optional implementations, as shown in FIGS. 3 to 5 , the second sampling module 12 may include a third resistor RN1 and a fourth resistor RN2. The first end of the third resistor RN1 can be connected to the negative electrode B- of the battery pack to be tested, and the second end of the third resistor RN1 can be connected to the first end of the fourth resistor RN2 and the second signal transmission module 14 . The second end of the fourth resistor RN2 can be connected to the bias power supply 15 .

The first terminal of the second sampling module 12 may be the first terminal of the third resistor RN1 , the second terminal of the second sampling module 12 may be the second terminal of the fourth resistor RN2 , and the third terminal of the second sampling module 12 may be Disposed between the second end of the third resistor RN1 and the first end of the fourth resistor RN2. The third end of the second sampling module 12 is the second sampling point.

The second voltage signal is the voltage signal of the third terminal of the second sampling module 12 .

For example, the resistance value of the third resistor RN1 may be equal to the resistance value of the first resistor RP1, and the resistance value of the fourth resistor RN2 may be equal to the resistance value of the second resistor RP2.

The resistance of the third resistor RN1 may be in the megohm level. For example, the resistance of the third resistor RN1 may be 25 MΩ. When the resistance of the third resistor RN1 is 25MΩ, the third resistor RN1 may be a set of five 5MΩ resistors connected in series.

The resistance of the fourth resistor RN2 may be in the kiloohm level. For example, the resistance of the fourth resistor RN2 may range from several thousand ohms to more than ten thousand ohms.

Both the third resistor RN1 and the fourth resistor RN2 can play a voltage dividing role.

Optionally, the second sampling module 12 may also include a fourth switch (not shown in the figure). The position of the fourth switch is adjustable, as long as the fourth switch, the third resistor RN1 and the fourth resistor RN2 are connected in series to the battery to be tested. It can be between the negative electrode B- of the group and the bias power supply 15. For example, the fourth switch may be connected between the third resistor RN1 and the fourth resistor RN2. The fourth switch can be used to cooperatively provide the second voltage signal. For example, when the fourth switch is closed, the second voltage signal can be provided, but when the fourth switch is open, the second voltage signal cannot be provided.

For the convenience of description, the voltage of the first voltage signal is marked as AI_U1P, the voltage of the second voltage signal is marked as AI_U1N, the voltage of the positive electrode B+ of the battery pack to be tested is marked as U1, and the voltage of the negative electrode B- of the battery pack to be tested is marked as U00. In order to simplify the calculation process, in the embodiment of the present application, the resistance values of the first resistor RP1 and the third resistor RN1 are both r1, and the resistance values of the second resistor RP2 and the fourth resistor RN2 are both r2. The processor 16 can use the formula (1) Calculate the high-voltage circuit voltage U1-U00 of the battery pack to be tested.

Among them, r1 and r2 are both known values.

For convenience of description, the divided voltage of the second resistor RP2 is denoted as Vrp2, the divided voltage of the fourth resistor RN2 is denoted as Vrn2, and the voltage of the bias power supply 15 is denoted as Voffset. AI_U1P can be calculated by formula (2), and AI_U1N can be calculated by formula (3).

Through formula (2) to formula (3), formula (4) for calculating the difference between the first voltage signal and the second voltage signal can be obtained.

It can be seen that since the sampling of the first voltage signal and the sampling of the second voltage signal both include the voltage of the bias power supply 15, the processor 16 obtains the high voltage of the battery pack to be tested by calculating the difference between the first voltage signal and the second voltage signal. The loop voltage can eliminate the voltage of the bias power supply 15, thereby helping to improve the detection accuracy of the high-voltage loop voltage.

It should be noted that in other embodiments of the present application, the resistance values of the first resistor RP1 and the third resistor RN1 may be unequal, and the resistance values of the second resistor RP2 and the fourth resistor RN2 may be unequal.

In some optional implementations, the voltage of the bias power supply 15 is greater than 0. In this way, both the voltage value of the first voltage signal and the voltage value of the second voltage signal can be greater than 0. The processor usually only collects positive voltage and cannot directly collect the first voltage signal and the second voltage signal. By setting the bias power supply, the first voltage signal and the second voltage signal can be both greater than 0, thus enabling the processor to The first voltage signal and the second voltage signal are collected simultaneously. This setting method does not require additional modules such as inverting modules, which helps to simplify the structure of the high-voltage sampling circuit and reduce the cost of the high-voltage sampling circuit.

In some optional implementations, as shown in FIG. 3 , the processor 16 may include an analog-to-digital conversion module 161 , and the reference voltage of the analog-to-digital conversion module 161 is Vref. The first voltage signal AI_U1P and the second voltage signal AI_U1N may be analog voltage signals. For example, the analog-to-digital conversion module 161 may be a single-channel module, and the processor 16 may include two analog-to-digital conversion modules 161, one for converting the analog voltage signal AI_U1P into a digital voltage signal, and the other for analog-to-digital conversion. Module 161 is used to convert the analog voltage signal AI_U1N into a digital voltage signal. For another example, the analog-to-digital conversion module 161 may be multi-channel, and the analog-to-digital conversion module 161 may convert the collected analog voltage signals AI_U1P and AI_U1N into digital voltage signals based on the reference voltage Vref.

The voltage of the bias power supply 15 is Voffset, Vref/3≤Voffset≤Vref*3/4. That is, the voltage of the bias power supply 15 may be greater than or equal to one-third of the reference voltage Vref of the analog-to-digital conversion module 161 , and may be less than or equal to three-quarters of the reference voltage Vref of the analog-to-digital conversion module 161 . In this way, the voltage Voffset of the bias power supply 15 can be adjusted according to the reference voltage Vref of the analog-to-digital conversion module 161, which helps ensure that the analog-to-digital conversion module 161 has better resolution.

It can be understood that the analog-to-digital conversion module 161 can offset errors when two samples have the same offset.

For example, Voffset=Vref/2. That is to say, the voltage Voffset of the bias power supply 15 can be half of the reference voltage Vref of the analog-to-digital conversion module 16, which further helps to ensure that the analog-to-digital conversion module 161 has better resolution.

As an example, Vref is 3.3V and Voffset can be 1.6V.

As another example, Vref is 5V and Voffset can be 2.5V.

In some optional implementations, the bias power supply 15 can be connected to the processor 16, and the processor 16 can also be used for:

According to the voltage of the bias power supply 15, detect whether the bias power supply 15 is abnormal;

And/or, the processor 16 may also include an analog-to-digital conversion module 161 , and the processor 16 is further configured to detect whether the analog-to-digital conversion module 161 is abnormal based on the voltage of the bias power supply 15 .

The bias power supply 15 may also be connected to the third terminal of the processor 16 .

In this embodiment, the processor can be used to accurately determine whether the bias power supply 15 is abnormal, thereby improving the accuracy of high-voltage sampling.

The processor 16 collects the voltage of the bias power supply 15. For convenience of description, the voltage of the bias power supply 15 collected by the processor 16 is recorded as AI_offset.

When AI_offset is within the first preset voltage range, it is determined that the bias power supply 15 is normal; when AI_offset is not within the first preset voltage range, it is determined that the bias power supply 15 is abnormal. The first preset voltage range can be set according to actual conditions. For example, when Voffset is 1.6V, the first preset voltage range may be [1.5, 1.7]V.

The processor 16 can use AI_offset as the input of the analog-to-digital conversion module 161 to obtain the output of the analog-to-digital conversion module 161. When the output of the analog-to-digital conversion module 161 is within the second preset voltage range, determine the analog-to-digital conversion module 161 Normal; when the output of the analog-to-digital conversion module 161 is not within the second preset voltage range, it is determined that the analog-to-digital conversion module 161 is abnormal. The second preset voltage range can be set according to actual conditions. The first preset voltage range and the second preset voltage range may be the same or different, and are not limited here.

In some optional implementations, as shown in FIG. 4 , the high-voltage sampling circuit 100 may also include a first switch module 17 , a second switch module 18 , a third sampling module 19 , a fourth sampling module 20 , and a third signal transmission module. module 21 and the fourth signal transmission module 22.

The first end of the first switch module 17 can be connected to the positive electrode B+ of the battery pack to be tested and the first sampling module 11 . For example, the first end of the first switch module 17 may be connected to the positive electrode B+ of the battery pack to be tested and the first end of the first sampling module 11 .

The first end of the second switch module 18 can be connected to the negative electrode B- of the battery pack to be tested and the second sampling module 12 . For example, the first end of the second switch module 18 may be connected to the negative electrode B- of the battery pack to be tested and the second end of the second sampling module 12 .

The third sampling module 19 can be connected to the second end of the first switch module 17 , the bias power supply 15 and the third signal transmission module 21 . For example, the first end of the third sampling module 19 can be connected to the second end of the first switch module 17 , the second end of the third sampling module 19 can be connected to the bias power supply 15 , and the third end of the third sampling module 19 The first end of the third signal transmission module 21 can be connected. The second end of the third signal transmission module 21 can be connected to the processor 16 . The third sampling module 19 can be used to collect the third voltage signal. The third signal transmission module 21 may be used to transmit the third voltage signal collected by the third sampling module 19 to the processor 16 .

The fourth sampling module 20 can be connected to the bias power supply 15 , the second end of the second switch module 18 and the fourth signal transmission module 22 . For example, the first end of the fourth sampling module 20 can be connected to the bias power supply 15 , the second end of the fourth sampling module 20 can be connected to the second end of the second switch module 18 , and the third end of the fourth sampling module 20 The first end of the fourth signal transmission module 22 can be connected. The second end of the fourth signal transmission module 22 can be connected to the processor 16 . The fourth sampling module 20 can be used to collect the fourth voltage signal. The fourth signal transmission module 22 may be used to transmit the fourth voltage signal collected by the fourth sampling module 20 to the processor 16 .

At least one of the third signal transmission module 21 and the fourth signal transmission module 22 may include a voltage follower. In other words, the third signal transmission module 21 may include a voltage follower, or the fourth signal transmission module 22 may include a voltage follower, or both the third signal transmission module 21 and the fourth signal transmission module 22 may include a voltage follower. follower.

The processor 16 may also be configured to: calculate a first difference between the first voltage signal and the second voltage signal, and a second difference between the third voltage signal and the second voltage signal; Compare the results to obtain the state of the first switch module; and/or calculate the first difference between the first voltage signal and the second voltage signal, and the third difference between the first voltage signal and the fourth voltage signal; according to the first The comparison result between the difference value and the third difference value is used to obtain the status of the second switch module.

In this embodiment, the status of the first switch module and the second switch module can be accurately determined based on the first voltage signal, the second voltage signal, the third voltage signal and the fourth voltage signal, which in turn can help determine the third voltage signal. Check whether the first switch module and the second switch module are faulty.

Obtaining the status of the first switch module according to the comparison result between the first difference value and the second difference value may include: when the comparison result between the first difference value and the second difference value is that the first difference value is equal to the second difference value , determine that the state of the first switch module is closed; when the comparison result between the first difference and the second difference is that the first difference is not equal to the second difference, determine that the state of the first switch module is open .

Obtaining the status of the second switch module according to the comparison result between the first difference value and the third difference value may include: when the comparison result between the first difference value and the third difference value is that the first difference value is equal to the third difference value , determine that the state of the second switch module is closed; when the comparison result between the first difference and the third difference is that the first difference is not equal to the third difference, determine that the state of the second switch module is open .

In some optional implementations, as shown in FIG. 5 , the third signal transmission module 21 may include a third voltage follower 211 , and the non-inverting input terminal + of the third voltage follower 211 may be connected to the third sampling module 19 . The inverting input terminal of the three voltage follower 211 can be connected to the output terminal of the third voltage follower 211 , and the output terminal of the third voltage follower 211 can be connected to the processor 16 .

For example, the non-inverting input terminal + of the third voltage follower 211 may be connected to the third terminal of the third sampling module 19 , and the output terminal of the third voltage follower 211 may be connected to the fourth terminal of the processor 16 . That is to say, the first terminal of the third signal transmission module 21 may be the non-inverting input terminal + of the third voltage follower 211 , and the second terminal of the third signal transmission module 21 may be the output terminal of the third voltage follower 211 .

Optionally, the third voltage follower 211 may also include a first voltage terminal V+ and a second voltage terminal GND. The first voltage terminal V+ can be connected to a low-voltage power supply inside the battery management unit (BMU). The low-voltage power supply can be used to provide a positive voltage, and the positive voltage can be greater than the reference voltage Vref of the analog-to-digital conversion module 161 in the processor 16; the second voltage terminal V+ can be connected to a low-voltage power supply inside the battery management unit (BMU). The voltage terminal GND can be connected to ground.

In this embodiment, by setting the third voltage follower 211 between the third sampling module 19 and the processor 16, it is possible to avoid setting an independent analog-to-digital conversion module between the third sampling module 19 and the processor 16. Isolating communication modules, etc., thereby helping to reduce the cost of high-voltage sampling circuits.

In some optional implementations, as shown in FIG. 5 , the third sampling module 19 may include a fifth resistor RP3 and a sixth resistor RP4. The first end of the fifth resistor RP3 may be connected to the second end of the first switch module 17 . terminal, the second terminal of the fifth resistor RP3 can be connected to the first terminal of the sixth resistor RP4 and the third signal transmission module 21 , and the second terminal of the sixth resistor RP4 can be connected to the bias power supply 15 . For example, the second terminal of the fifth resistor RP3 may be connected to the first terminal of the sixth resistor RP4 and the non-inverting input terminal + of the third voltage follower 211 .

The first terminal of the third sampling module 19 may be the first terminal of the fifth resistor RP3, the second terminal of the third sampling module 19 may be the second terminal of the sixth resistor RP4, and the third terminal of the third sampling module 19 may be Disposed between the second end of the fifth resistor RP3 and the first end of the sixth resistor RP4. The third end of the third sampling module 19 is the third sampling point.

The third voltage signal may be the voltage signal of the third terminal of the third sampling module 19 .

The resistance of the fifth resistor RP3 may be in the megohm level. For example, the resistance of the fifth resistor RP3 may be 25 MΩ. For example, when the resistance of the fifth resistor RP3 is 25 MΩ, the fifth resistor RP3 may be a set of five 5 MΩ resistors connected in series.

The resistance of the sixth resistor RP4 may be in the kiloohm level. For example, the resistance of the sixth resistor RP4 may range from several thousand ohms to more than ten thousand ohms.

Both the fifth resistor RP3 and the sixth resistor RP4 can play a voltage dividing role.

Optionally, the third sampling module 19 may also include a fifth switch (not shown in the figure). The position of the fifth switch is adjustable, as long as the fifth switch, the fifth resistor RP3 and the sixth resistor RP4 are connected in series to the battery to be tested. It can be between the positive electrode B+ of the group and the bias power supply 15. For example, the fifth switch may be connected between the fifth resistor RP3 and the sixth resistor RP4. The fifth switch can be used to provide a third voltage signal. For example, when the fifth switch is closed, the third voltage signal can be provided, but when the fifth switch is open, the third voltage signal cannot be provided.

In some optional implementations, as shown in FIG. 5 , the fourth signal transmission module 22 may include a fourth voltage follower 221 , and the non-inverting input terminal + of the fourth voltage follower 221 may be connected to the fourth sampling module 20 . The inverting input terminal of the four-voltage follower 221 can be connected to the output terminal of the fourth voltage follower 221 , and the output terminal of the fourth voltage follower 221 can be connected to the processor 16 .

For example, the non-inverting input terminal + of the fourth voltage follower 221 may be connected to the third terminal of the fourth sampling module 20 , and the output terminal of the fourth voltage follower 221 may be connected to the first terminal of the processor 16 . That is to say, the first terminal of the fourth signal transmission module 22 may be the non-inverting input terminal + of the fourth voltage follower 221 , and the second terminal of the fourth signal transmission module 22 may be the output terminal of the fourth voltage follower 221 .

Optionally, the fourth voltage follower 221 may also include a first voltage terminal V+ and a second voltage terminal GND. Among them, the first voltage terminal V+ can be connected to a low-voltage power supply inside the battery management unit (BMU). The low-voltage power supply can be used to provide a positive voltage, and the positive voltage can be greater than the reference voltage Vref of the analog-to-digital conversion module in the processor 16; the second voltage Terminal GND can be grounded.

In this embodiment, by setting the fourth voltage follower 221 between the fourth sampling module 20 and the processor 16, it is possible to avoid setting an independent analog-to-digital conversion module between the fourth sampling module 20 and the processor 16. Isolating communication modules, etc., thereby helping to reduce the cost of high-voltage sampling circuits.

In some optional implementations, as shown in FIG. 5 , the fourth sampling module 20 includes a seventh resistor RN3 and an eighth resistor RN4; the first end of the seventh resistor RN3 is connected to the second end of the second switch module 18, The second end of the seventh resistor RN3 is connected to the first end of the eighth resistor RN4 and the fourth signal transmission module 22 ; the second end of the eighth resistor RN4 is connected to the bias power supply 15 . For example, the second terminal of the seventh resistor RN3 may be connected to the first terminal of the eighth resistor RN4 and the non-inverting input terminal + of the fourth voltage follower 221 .

The first terminal of the fourth sampling module 20 may be the first terminal of the seventh resistor RN3, the second terminal of the fourth sampling module 20 may be the second terminal of the eighth resistor RN4, and the third terminal of the fourth sampling module 20 may be Disposed between the second end of the seventh resistor RN3 and the first end of the eighth resistor RN4. The third end of the fourth sampling module 20 is the fourth sampling point.

The fourth voltage signal may be the voltage signal of the third terminal of the fourth sampling module 20 .

For example, the resistance value of the seventh resistor RN3 may be equal to the resistance value of the fifth resistor RP3, and the resistance value of the eighth resistor RN4 may be equal to the resistance value of the sixth resistor RP4.

The resistance of the seventh resistor RN3 may be in the megohm level. For example, the resistance of the seventh resistor RN3 may be 25 MΩ. For example, when the resistance of the seventh resistor RN3 is 25 MΩ, the seventh resistor RN3 may be a set of five 5 MΩ resistors connected in series.

The resistance of the eighth resistor RN4 may be in the kiloohm level. For example, the resistance of the eighth resistor RN4 may range from several thousand ohms to more than ten thousand ohms.

Both the seventh resistor RN3 and the eighth resistor RN4 can play a voltage dividing role.

Optionally, the fourth sampling module 20 may also include a sixth switch (not shown in the figure). The position of the sixth switch is adjustable, as long as the sixth switch, the seventh resistor RN3 and the eighth resistor RN4 are connected in series to the battery to be tested. It can be between the negative electrode B- of the group and the bias power supply 15. For example, the sixth switch may be connected between the seventh resistor RN3 and the eighth resistor RN4. The sixth switch can be used to cooperatively provide a fourth voltage signal. For example, when the sixth switch is closed, the fourth voltage signal can be provided, but when the sixth switch is open, the fourth voltage signal cannot be provided.

For example, the first switch module 17 may include a relay K1, and the second switch module may include a relay K2.

For example, any one of the first switch module and the second switch module may also be a composite circuit module composed of a switch and other protection devices connected.

Based on the same inventive concept, embodiments of the present application also provide a battery management system, including the high-voltage sampling circuit in any of the above embodiments. It can be understood that the battery management system has the beneficial effects of the high-voltage sampling circuit provided by the embodiments of the present application. For details, reference can be made to the specific descriptions of the high-voltage sampling circuit in the above embodiments, which will not be described again in this embodiment.

Based on the same inventive concept, this application also provides an electrical device. The power-consuming device includes a battery management system, and the battery management system includes the high-voltage sampling circuit in any of the above embodiments. It can be understood that the electrical device has the beneficial effects of the high-voltage sampling circuit provided by the embodiments of the present application. For details, reference can be made to the specific description of the high-voltage sampling circuit in the above embodiments, which will not be described again in this embodiment.

It should be noted that in the embodiments shown in the above figures, the resistor is in the form of a single resistor. In other embodiments, the resistor may also be an integration of series, parallel or mixed resistors. The specific parameters of each device can be set according to actual needs, and this application does not limit this.

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other.

Although the application has been described with reference to preferred embodiments, various modifications may be made and equivalents may be substituted for parts thereof without departing from the scope of the application, in particular provided that no structural conflicts exist , the technical features mentioned in each embodiment can be combined in any way. The application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims (16)

1. The high-voltage sampling circuit is characterized by comprising a first sampling module, a second sampling module, a first signal transmission module, a second signal transmission module, a bias power supply and a processor; wherein,

the first sampling module is connected with the anode of the battery pack to be tested, the bias power supply and the first signal transmission module, and the first signal transmission module is used for transmitting the first voltage signal acquired by the first sampling module to the processor;

the second sampling module is connected with the bias power supply, the negative electrode of the battery pack to be tested and the second signal transmission module, and the second signal transmission module is used for transmitting the second voltage signal acquired by the second sampling module to the processor;

The processor is used for obtaining the high-voltage loop voltage of the battery pack to be tested according to the difference value of the first voltage signal and the second voltage signal;

at least one of the first signal transmission module and the second signal transmission module includes a voltage follower.

2. The high voltage sampling circuit of claim 1, wherein the first signal transmission module comprises a first voltage follower, wherein a non-inverting input of the first voltage follower is connected to the first sampling module, wherein an inverting input of the first voltage follower is connected to an output of the first voltage follower, and wherein an output of the first voltage follower is connected to the processor.

3. The high voltage sampling circuit of claim 1, wherein the first sampling module comprises a first resistor and a second resistor;

the first end of the first resistor is connected with the positive electrode of the battery pack to be tested, and the second end of the first resistor is connected with the first end of the second resistor and the first signal transmission module;

the second end of the second resistor is connected with the bias power supply.

4. The high voltage sampling circuit of claim 1, wherein the second signal transmission module comprises a second voltage follower, wherein a non-inverting input terminal of the second voltage follower is connected to the second sampling module, wherein an inverting input terminal of the second voltage follower is connected to an output terminal of the second voltage follower, and wherein an output terminal of the second voltage follower is connected to the processor.

5. The high voltage sampling circuit of claim 1, wherein the second sampling module comprises a third resistor and a fourth resistor;

the first end of the third resistor is connected with the negative electrode of the battery pack to be tested, and the second end of the third resistor is connected with the first end of the fourth resistor and the second signal transmission module;

and the second end of the fourth resistor is connected with the bias power supply.

6. The high voltage sampling circuit of any one of claims 1 to 5, wherein the voltage of the bias power supply is greater than 0.

7. The high voltage sampling circuit of claim 1, wherein the processor comprises an analog-to-digital conversion module, the reference voltage of the analog-to-digital conversion module is Vref, the voltage of the bias power supply is Voffset, and Vref/3 is equal to or less than Voffset is equal to or less than Vref by 3/4.

8. The high voltage sampling circuit of claim 1, wherein the processor comprises an analog-to-digital conversion block having a reference voltage Vref and the bias power supply has a voltage Voffset, voffset = Vref/2.

9. The high voltage sampling circuit of any one of claims 1-5, wherein the bias power supply is coupled to the processor, the processor further configured to:

Detecting whether the bias power supply is abnormal or not according to the voltage of the bias power supply;

and/or the processor comprises an analog-to-digital conversion module, and the processor is further used for detecting whether the analog-to-digital conversion module is abnormal according to the voltage of the bias power supply.

10. The high voltage sampling circuit of any one of claims 1 to 5, further comprising a first switch module, a second switch module, a third sampling module, a fourth sampling module, a third signal transmission module, and a fourth signal transmission module;

the first end of the first switch module is connected with the positive electrode of the battery pack to be tested and the first sampling module;

the first end of the second switch module is connected with the negative electrode of the battery pack to be tested and the second sampling module;

the third sampling module is connected with the second end of the first switch module, the bias power supply and the third signal transmission module, and the third signal transmission module is used for transmitting the third voltage signal acquired by the third sampling module to the processor;

the fourth sampling module is connected with the bias power supply, the second end of the second switch module and the fourth signal transmission module, and the fourth signal transmission module is used for transmitting a fourth voltage signal acquired by the fourth sampling module to the processor;

At least one of the third signal transmission module and the fourth signal transmission module includes a voltage follower;

the processor is further configured to:

calculating a first difference of the first voltage signal and the second voltage signal, and a second difference of the third voltage signal and the second voltage signal;

obtaining the state of the first switch module according to the comparison result of the first difference value and the second difference value;

and/or calculating a first difference of the first voltage signal and the second voltage signal, and a third difference of the first voltage signal and the fourth voltage signal;

and obtaining the state of the second switch module according to the comparison result of the first difference value and the third difference value.

11. The high voltage sampling circuit of claim 10, wherein the high voltage sampling circuit comprises a high voltage circuit,

the third signal transmission module comprises a third voltage follower, the non-inverting input end of the third voltage follower is connected with the third sampling module, the inverting input end of the third voltage follower is connected with the output end of the third voltage follower, and the output end of the third voltage follower is connected with the processor.

12. The high voltage sampling circuit of claim 10, wherein the high voltage sampling circuit comprises a high voltage circuit,

The third sampling module comprises a fifth resistor and a sixth resistor;

the first end of the fifth resistor is connected with the second end of the first switch module, and the second end of the fifth resistor is connected with the first end of the sixth resistor and the third signal transmission module;

the second end of the sixth resistor is connected with the bias power supply.

13. The high voltage sampling circuit of claim 10, wherein the high voltage sampling circuit comprises a high voltage circuit,

the fourth signal transmission module comprises a fourth voltage follower, the non-inverting input end of the fourth voltage follower is connected with the fourth sampling module, the inverting input end of the fourth voltage follower is connected with the output end of the fourth voltage follower, and the output end of the fourth voltage follower is connected with the processor.

14. The high voltage sampling circuit of claim 10, wherein the fourth sampling module comprises a seventh resistor and an eighth resistor;

the first end of the seventh resistor is connected with the second end of the second switch module, and the second end of the seventh resistor is connected with the first end of the eighth resistor and the fourth signal transmission module;

and the second end of the eighth resistor is connected with the bias power supply.

15. A battery management system comprising a high voltage sampling circuit according to any one of claims 1 to 14.

16. An electrical consumer comprising the battery management system of claim 15.