BMS high-voltage sampling circuit

Abstract

The invention discloses a BMS high-voltage sampling circuit which comprises a high-voltage side sampling port, a voltage dividing module and an isolation operational amplifier module, the high-voltage side sampling port inputs a first voltage to the voltage dividing module, the voltage dividing module is used for dividing the collected first voltage to output a second voltage, the voltage dividing module inputs the second voltage to the isolation operational amplifier module, and the isolation operational amplifier module is used for outputting the second voltage. The isolation operational amplifier module is used for inputting the third voltage to the bias operational amplifier module, the bias operational amplifier module is used for enabling the third voltage to generate bias gain so as to output a fourth voltage, and the low-voltage side sampling port is used for receiving the fourth voltage. The bias operational amplifier module inputs a fourth voltage to a low-voltage side sampling port, and the low-voltage side sampling port is used for collecting the fourth voltage as a sampling voltage; during high-voltage sampling, isolation communication between high voltage and low voltage is not needed, an isolation power supply module does not need to be arranged, a sampling chip does not need to be arranged on the high-voltage side, the circuit is simple and high in reliability, and the sampling circuit can collect negative voltage.

Description

Technical Field

[0001] The present application relates to the technical field of sampling circuit structures, and in particular to a BMS high-voltage sampling circuit. Background Art

[0002] When the traditional BMS high-voltage sampling circuit performs sampling, it is necessary to set up isolated communication between high and low voltages, set up isolated power supply between high and low voltages, and set up an ADC sampling chip on the high-voltage side. The circuit structure is complex, the stability is poor, and negative pressure cannot be collected. Summary of the invention

[0003] In order to overcome the above shortcomings, the purpose of this application is to provide a BMS high-voltage sampling circuit, thereby effectively solving the above technical problems.

[0004] In order to achieve the above objectives, this application adopts the following technical solutions:

[0005] The present application provides a BMS high voltage sampling circuit, comprising:

[0006] High-voltage side sampling port, used for BMS high-voltage sampling,

[0007] A voltage dividing module, the voltage dividing module is electrically connected to the high-voltage side sampling port, the high-voltage side sampling port inputs a first voltage to the voltage dividing module, and the voltage dividing module is used to divide the collected first voltage to output a second voltage,

[0008] an isolation operational amplifier module, the isolation operational amplifier module is electrically connected to the voltage divider module, the voltage divider module inputs the second voltage to the isolation operational amplifier module, and the voltage divider module is used to isolate and gain the second voltage to output a third voltage,

[0009] a bias operational amplifier module, the bias operational amplifier module is electrically connected to the isolation operational amplifier module, the isolation operational amplifier module inputs the third voltage to the bias operational amplifier module, and the bias operational amplifier module is used to make the third voltage generate a bias gain to output a fourth voltage,

[0010] A low-voltage side sampling port, wherein the low-voltage side sampling port is electrically connected to the bias operational amplifier module, the bias operational amplifier module inputs the fourth voltage to the low-voltage side sampling port, and the low-voltage side sampling port is used to collect the fourth voltage as a sampling voltage.

[0011] Furthermore, the voltage dividing module includes a first resistor, a second resistor and a first ground terminal.

[0012] The isolation operational amplifier module comprises a first input terminal and a second input terminal, wherein:

[0013] The first end of the first resistor is electrically connected to the high-voltage side sampling port, the second end of the first resistor is electrically connected to the first input end of the isolation operational amplifier module, the first end of the second resistor is electrically connected to the circuit in which the second end of the first resistor is connected to the first input end of the isolation operational amplifier module, the second end of the second resistor is electrically connected to the first ground end, and the second input end of the isolation operational amplifier module is electrically connected to the circuit in which the second end of the second resistor is connected to the first ground end.

[0014] Further, the resistance of the first resistor is 200 times the resistance of the second resistor, the voltage divider module is a 1 / 200 voltage divider module, and the first voltage and the second voltage are calculated as follows:

[0015]

[0016] In the formula, U1 is the voltage value of the first voltage, and U2 is the voltage value of the second voltage.

[0017] Furthermore, the isolation operational amplifier module further includes a first output terminal and a second output terminal.

[0018] The bias amplifier module includes a third input terminal and a fourth input terminal, wherein:

[0019] The first output terminal of the isolation operational amplifier module is electrically connected to the third input terminal of the bias operational amplifier module, and the second output terminal of the isolation operational amplifier module is electrically connected to the fourth input terminal of the bias operational amplifier module.

[0020] Furthermore, a third resistor is provided on the circuit connecting the first output end of the isolation operational amplifier module and the third input end of the bias operational amplifier module, and a fourth resistor is provided on the circuit connecting the second output end of the isolation operational amplifier module and the fourth input end of the bias operational amplifier module.

[0021] Further, the output gain of the isolation amplifier module is 0.4 times, and the second voltage and the third voltage are calculated as follows:

[0022] U3=0.4*U2

[0023] In the formula, U2 is the voltage value of the second voltage, and U3 is the voltage value of the third voltage.

[0024] Furthermore, the bias op amp module also includes a first voltage source and a second voltage source, the first voltage source is electrically connected to the third input terminal of the bias op amp module, and a fifth resistor is arranged on the circuit connecting the first voltage source and the third input terminal of the bias op amp module, and the second voltage source is electrically connected to the voltage terminal of the bias op amp module.

[0025] Furthermore, the bias op amp module also includes a third output terminal, the third output terminal of the bias op amp module is electrically connected to the low-voltage side sampling port, a first connection node is provided on the circuit connecting the third output terminal of the bias op amp module to the low-voltage side sampling port, a second connection node is provided on the circuit connecting the fourth resistor to the fourth input terminal of the bias op amp module, the first connection node is electrically connected to the second connection node, and a sixth resistor is provided on the circuit connecting the two nodes.

[0026] Furthermore, a seventh resistor is provided on the circuit connecting the third output terminal of the bias operational amplifier module and the low-voltage side sampling port, and the seventh resistor is located between the first connection node and the low-voltage side sampling port.

[0027] Further, the voltage value of the first voltage source is 2.5V, the voltage value of the second voltage source is 5V, the bias gain of the bias amplifier module is 1 times, and the third voltage and the fourth voltage are calculated as follows:

[0028] U4=2.5+U3

[0029] In the formula, U3 is the voltage value of the third voltage, and U4 is the voltage value of the fourth voltage.

[0030] Beneficial Effects

[0031] The present application provides a BMS high-voltage sampling circuit. When high-voltage sampling is performed, no isolated communication is required between high and low voltages, no isolated power supply module is required, and no sampling chip is required on the high-voltage side. The circuit is simple and reliable, and the sampling circuit can collect negative pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide an understanding of the technical solution of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solution of the present disclosure and do not constitute a limitation on the technical solution of the present disclosure. The shapes and sizes of the components in the accompanying drawings do not reflect the actual proportions and are only intended to illustrate the content of the present application.

[0033] Figure 1 This is the schematic diagram of the BMS high-voltage sampling circuit module for this application.

[0034] Figure 2 This is a schematic diagram of the structure of a BMS high-voltage sampling circuit disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The above scheme is further described below in conjunction with specific examples. It should be understood that these examples are used to illustrate the present application and are not limited to the scope of the present application. The implementation conditions adopted in the examples can be further adjusted as the conditions of the specific manufacturer, and the unspecified implementation conditions are usually the conditions in conventional experiments.

[0036] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connecting" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. In this article, "electrical connection" includes the situation where the constituent elements are connected together through an element with some electrical function. "Elements with some electrical function" are not particularly limited as long as they can transfer electrical signals between the connected constituent elements. "Elements with some electrical function" can be, for example, electrodes or wiring, or switching elements such as transistors, or other functional elements such as resistors, inductors or capacitors. "Up", "down", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0037] In this application, the directions or positional relationships indicated by the terms "upper", "lower", "inner", "middle", etc. are based on the directions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction.

[0038] As described in the background technology, when the traditional BMS high-voltage sampling circuit performs sampling, it is necessary to set up isolated communication between high and low voltages, set up isolated power supply between high and low voltages, and set up an ADC sampling chip on the high voltage side. The circuit structure is complex, the stability is poor, and negative pressure cannot be collected.

[0039] In view of the above problems, the inventor provides a BMS high voltage sampling circuit, such as Figure 1As shown, the high-voltage sampling circuit includes a high-voltage side sampling port HV, which is used for BMS high-voltage sampling, and also includes a voltage dividing module FY, which is electrically connected to the high-voltage side sampling port HV, and the high-voltage side sampling port HV inputs a first voltage to the voltage dividing module FY, and the voltage dividing module FY is used to divide the collected first voltage to output a second voltage, and also includes an isolation amplifier module GQ, which is electrically connected to the voltage dividing module FY, and the voltage dividing module FY inputs a second voltage to the isolation amplifier module GQ, and the voltage dividing module FY is used to isolate the second voltage and The bias amplifier module PQ is electrically connected to the isolation amplifier module GQ, the isolation amplifier module GQ inputs the third voltage to the bias amplifier module PQ, the bias amplifier module PQ is used to make the third voltage generate a bias gain to output a fourth voltage, and also includes a low-voltage side sampling port ADC, the low-voltage side sampling port ADC is electrically connected to the bias amplifier module PQ, the bias amplifier module PQ inputs the fourth voltage to the low-voltage side sampling port ADC, and the low-voltage side sampling port ADC is used to collect the fourth voltage as the sampling voltage.

[0040] This application does not require isolated communication between high and low voltages during high-voltage sampling, does not require an isolated power supply module, and does not require a sampling chip on the high-voltage side. The circuit is simple and reliable, and the sampling circuit can collect negative pressure.

[0041] Next, combine Figure 2 The present application is described exemplarily.

[0042] An embodiment of the present application provides a BMS high voltage sampling circuit, such as Figure 2 As shown, the BMS high voltage sampling circuit includes:

[0043] High-voltage side sampling port HV, HV is used for BMS high-voltage sampling, and the collected voltage is the first voltage U1,

[0044] The voltage dividing module includes a first resistor R1, a second resistor R2 and a first ground terminal GND1. The voltage dividing module is electrically connected to the high-voltage side sampling port HV. The high-voltage side sampling port HV inputs a first voltage U1 to the voltage dividing module. The voltage dividing module is used to divide the collected first voltage U1 to output a second voltage U2

[0045] The resistance of the first resistor R1 is 4000K, and the resistance of the second resistor R2 is 20K. Therefore, the resistance of the first resistor R1 is 200 times that of the second resistor R2. The voltage divider module is a 1 / 200 voltage divider module. The calculation method of the first voltage U1 and the second voltage U2 is:

[0046]

[0047] It also includes an isolation amplifier module, which is electrically connected to the voltage divider module. The voltage divider module inputs the second voltage U2 to the isolation amplifier module. The voltage divider module is used to isolate and gain the second voltage to output a third voltage.

[0048] The isolation amplifier module uses an isolation amplifier with the signal AMC1350-Q1. The characteristic of the isolation amplifier is that the input signal and the output signal can be isolated. The chip integrates an isolation power supply module. When the output is isolated, the signal will have an output gain of 0.4 times (the output signal is 0.4 times the input signal). Because this module integrates the isolation function, the high-voltage side does not need to set up a separate ADC sampling chip, so the signal on the high-voltage side does not need to be transmitted directly to the ADC module of the low-voltage side MCU through isolation communication. The isolation amplifier module includes a first input terminal I NP, a second input terminal I NN, a first output terminal OUTP, and a second output terminal OUTN. The output gain of the isolation amplifier module is 0.4 times. The calculation method of the second voltage U2 and the third voltage U3 is:

[0049] U3=0.4*U2 (Formula 2)

[0050] It also includes a bias op amp module, which is electrically connected to the isolation op amp module. The isolation op amp module inputs a third voltage U3 to the bias op amp module. The bias op amp module is used to make the third voltage U3 generate a bias gain to output a fourth voltage U4. This module is an op amp output circuit with a bias gain of 1 times with 2.5V. The output signal directly enters the ADC sampling pin of the low-voltage side MCU for sampling. Because of the bias, this circuit can collect negative voltage. The lowest input voltage of this module is -2.5V, the highest input voltage is 2.5V, and the output range is 0V~5V. The bias op amp module includes a third input terminal V-, a fourth input terminal V+, and a third output terminal VO. The bias op amp module also includes a first voltage source V1, V1=2.5V, a second voltage source V2, V2=5V, and the bias gain of the bias op amp module is 1 times. The calculation method of the third voltage U3 and the fourth voltage U4 is as follows:

[0051] U4=2.5+U3 (Formula 3)

[0052] It also includes a low-voltage side sampling port ADC, which is electrically connected to the bias amplifier module. The bias amplifier module inputs the fourth voltage U4 to the low-voltage side sampling port ADC, and the low-voltage side sampling port ADC is used to collect the fourth voltage U4 as a sampling voltage.

[0053] like Figure 2 As shown, the connection structure of the BMS high voltage sampling circuit is as follows:

[0054] One end of the first resistor R1 is electrically connected to the high-voltage side sampling port HV, the other end of the first resistor R2 is electrically connected to the first input terminal INP of the isolation operational amplifier module, one end of the second resistor R2 is electrically connected to the circuit in which the first resistor R1 is connected to the first input terminal INP of the isolation operational amplifier module, the other end of the second resistor R2 is electrically connected to the first ground terminal GND1, and the second input terminal I NN of the isolation operational amplifier module is electrically connected to the circuit in which the second resistor R2 is connected to the first ground terminal GND1;

[0055] The first output terminal OUTP of the isolation operational amplifier module is electrically connected to the third input terminal V- of the bias operational amplifier module, the second output terminal OUTN of the isolation operational amplifier module is electrically connected to the fourth input terminal V+ of the bias operational amplifier module, a third resistor R3 is provided on the circuit connecting the first output terminal OUTP of the isolation operational amplifier module to the third input terminal V- of the bias operational amplifier module, and a fourth resistor R4 is provided on the circuit connecting the second output terminal OUTN of the isolation operational amplifier module to the fourth input terminal V+ of the bias operational amplifier module;

[0056] The first voltage source V1 is electrically connected to the third input terminal of the bias amplifier module, and a fifth resistor R5 is provided on the circuit in which the first voltage source is connected to the third input terminal V- of the bias amplifier module, the second voltage source V2 is electrically connected to the voltage terminal VSS of the bias amplifier module, the third output terminal V0 of the bias amplifier module is electrically connected to the low-voltage side sampling port ADC, a first connection node P is provided on the circuit in which the third output terminal v0 of the bias amplifier module is connected to the low-voltage side sampling port ADC, a second connection node Q is provided on the circuit in which the fourth resistor R4 is connected to the fourth input terminal V+ of the bias amplifier module, the first connection node P is electrically connected to the second connection node Q, and a sixth resistor R6 is provided on the circuit in which the two nodes are connected;

[0057] A seventh resistor R7 is provided on the circuit connecting the third output terminal V0 of the bias amplifier module and the low-voltage side sampling port ADC. The seventh resistor R7 is located between the first connection node P and the low-voltage side sampling port ADC.

[0058] According to the above formulas 1, 2 and 3,

[0059] Formula 1:

[0060] Formula 2: U3=0.4*U2

[0061] Formula 3: U3=0.4*U2

[0062] Therefore:

[0063] Therefore, the output range of U4 is 0V~5V, and the formula is:

[0064] When U4 = 0V, HV = -1250V;

[0065] When U4=5V, HV=1250V;

[0066] Therefore, the voltage acquisition range of this circuit is -1250V~+1250V.

[0067] The above embodiments are only for illustrating the technical concept and features of the present application, and their purpose is to enable people familiar with the technology to understand the content of the present application and implement it accordingly, and they cannot be used to limit the protection scope of the present application. Any equivalent transformation or modification made according to the spirit of the present application shall be included in the protection scope of the present application.

Claims

1. A BMS high voltage sampling circuit, characterized in that: include: High-voltage side sampling port, used for BMS high-voltage sampling, A voltage dividing module, the voltage dividing module is electrically connected to the high-voltage side sampling port, the high-voltage side sampling port inputs a first voltage to the voltage dividing module, and the voltage dividing module is used to divide the collected first voltage to output a second voltage, an isolation operational amplifier module, the isolation operational amplifier module is electrically connected to the voltage divider module, the voltage divider module inputs the second voltage to the isolation operational amplifier module, and the voltage divider module is used to isolate and gain the second voltage to output a third voltage, a bias operational amplifier module, the bias operational amplifier module is electrically connected to the isolation operational amplifier module, the isolation operational amplifier module inputs the third voltage to the bias operational amplifier module, and the bias operational amplifier module is used to make the third voltage generate a bias gain to output a fourth voltage, A low-voltage side sampling port, wherein the low-voltage side sampling port is electrically connected to the bias operational amplifier module, the bias operational amplifier module inputs the fourth voltage to the low-voltage side sampling port, and the low-voltage side sampling port is used to collect the fourth voltage as a sampling voltage.

2. The BMS high voltage sampling circuit according to claim 1, characterized in that: The voltage dividing module includes a first resistor, a second resistor and a first ground terminal. The isolation operational amplifier module comprises a first input terminal and a second input terminal, wherein: The first end of the first resistor is electrically connected to the high-voltage side sampling port, the second end of the first resistor is electrically connected to the first input end of the isolation operational amplifier module, the first end of the second resistor is electrically connected to the circuit in which the second end of the first resistor is connected to the first input end of the isolation operational amplifier module, the second end of the second resistor is electrically connected to the first ground end, and the second input end of the isolation operational amplifier module is electrically connected to the circuit in which the second end of the second resistor is connected to the first ground end.

3. The BMS high voltage sampling circuit according to claim 2, characterized in that: The resistance of the first resistor is 200 times the resistance of the second resistor, the voltage divider module is a 1 / 200 voltage divider module, and the first voltage and the second voltage are calculated as follows: In the formula, U1 is the voltage value of the first voltage, and U2 is the voltage value of the second voltage.

4. The BMS high voltage sampling circuit according to claim 1, characterized in that: The isolation operational amplifier module further includes a first output terminal and a second output terminal. The bias amplifier module includes a third input terminal and a fourth input terminal, wherein: The first output terminal of the isolation operational amplifier module is electrically connected to the third input terminal of the bias operational amplifier module, and the second output terminal of the isolation operational amplifier module is electrically connected to the fourth input terminal of the bias operational amplifier module.

5. The BMS high voltage sampling circuit according to claim 4, characterized in that: A third resistor is provided on the circuit connecting the first output end of the isolation operational amplifier module and the third input end of the bias operational amplifier module, and a fourth resistor is provided on the circuit connecting the second output end of the isolation operational amplifier module and the fourth input end of the bias operational amplifier module.

6. The BMS high voltage sampling circuit according to claim 1, characterized in that: The output gain of the isolation amplifier module is 0.4 times, and the second voltage and the third voltage are calculated as follows: U3=0.4*U2 In the formula, U2 is the voltage value of the second voltage, and U3 is the voltage value of the third voltage.

7. The BMS high voltage sampling circuit according to claim 5, characterized in that: The bias op amp module also includes a first voltage source and a second voltage source, the first voltage source is electrically connected to the third input terminal of the bias op amp module, and a fifth resistor is arranged on the circuit connecting the first voltage source and the third input terminal of the bias op amp module, and the second voltage source is electrically connected to the voltage terminal of the bias op amp module.

8. The BMS high voltage sampling circuit according to claim 7, characterized in that: The bias op amp module also includes a third output terminal, the third output terminal of the bias op amp module is electrically connected to the low-voltage side sampling port, a first connection node is provided on the circuit connecting the third output terminal of the bias op amp module to the low-voltage side sampling port, a second connection node is provided on the circuit connecting the fourth resistor to the fourth input terminal of the bias op amp module, the first connection node is electrically connected to the second connection node, and a sixth resistor is provided on the circuit connecting the two nodes.

9. The BMS high voltage sampling circuit according to claim 8, characterized in that: A seventh resistor is provided on the circuit connecting the third output terminal of the bias operational amplifier module and the low-voltage side sampling port, and the seventh resistor is located between the first connection node and the low-voltage side sampling port.

10. The BMS high voltage sampling circuit according to claim 9, characterized in that: The voltage value of the first voltage source is 2.5V, the voltage value of the second voltage source is 5V, the bias gain of the bias amplifier module is 1 times, and the third voltage and the fourth voltage are calculated as follows: U4=2.5+U3 In the formula, U3 is the voltage value of the third voltage, and U4 is the voltage value of the fourth voltage.

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