Vehicle BMS high-voltage sampling system based on isolated high-voltage sampling

Abstract

The invention discloses a vehicle BMS high-voltage sampling system based on isolated high-voltage sampling, and the system comprises a voltage dividing module which is used for dividing the voltage collected by a BMS and then outputting the voltage, and an isolated operational amplifier module which is used for inputting the divided voltage to the isolated operational amplifier module, converting the input voltage from a differential-mode voltage to a common-mode voltage and then outputting the common-mode voltage, the isolation operational amplifier module inputs a common-mode voltage to the operational amplifier module, the operational amplifier module converts the input common-mode voltage into a differential-mode AD voltage value and outputs AD voltage value data, and the low-voltage control module is electrically connected with the operational amplifier module. The operational amplification module inputs AD voltage value data to the low-voltage control module, and the low-voltage control module collects an AD voltage value and sends the AD voltage value to a whole vehicle control unit of the vehicle; according to the invention, the architecture of the double-high-voltage sampling system is simplified, and the high-voltage sampling stability is improved; the use of high-low voltage isolation devices is reduced, and the high-low voltage electrical isolation capability is improved.

Description

Technical Field

[0001] The present application relates to the technical field of BMS sampling circuits, and in particular to a vehicle BMS high-voltage sampling system based on isolated high-voltage sampling. Background Art

[0002] The current high-voltage sampling of battery packs requires a specific high-voltage sampling MCU, which uploads the high-voltage sampling data to the low-voltage MCU through digital isolation. The sampling logic is complex and requires complex software strategies for parsing and sampling, resulting in relatively poor stability. It is not well suited for projects that only require a single or dual sampling loop, and the sampling port resources and hardware resources are wasted. Traditional high-voltage sampling circuits require a large number of isolation devices, occupy a large area of ​​PCB layout space, and have a high cost of use. Summary of the invention

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

[0004] In order to achieve the above objectives, the present application adopts the following technical solution: a vehicle BMS high-voltage sampling system based on isolated high-voltage sampling, comprising:

[0005] A voltage dividing module, which is electrically connected to the BMS voltage collection port and is used to divide the voltage collected by the BMS and then output it.

[0006] An isolation operational amplifier module, wherein the isolation module is electrically connected to the voltage divider module, the voltage divider module inputs the divided voltage to the isolation operational amplifier module, and the isolation operational amplifier module converts the input voltage from a differential mode voltage to a common mode voltage and then outputs it.

[0007] An operational amplifier module, the operational amplifier module is electrically connected to the isolation operational amplifier module, the isolation operational amplifier module inputs a common mode voltage to the operational amplifier module, the operational amplifier module converts the input common mode voltage into a differential mode AD voltage value, and outputs AD voltage value data,

[0008] A low voltage control module is electrically connected to the operational amplifier module, the operational amplifier module inputs AD voltage value data to the low voltage control module, and the low voltage control module collects the AD voltage value and sends it to the vehicle control unit of the vehicle.

[0009] Furthermore, the voltage divider module includes a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor. The voltage collected by the BMS passes through a voltage divider node of the first resistor, the second resistor, the third resistor, the fourth resistor and the fifth resistor and is input into the isolation operational amplifier module. The voltage divider node is electrically connected to the isolation operational amplifier module.

[0010] Furthermore, a sixth resistor is provided on the circuit connecting the voltage dividing node and the isolation operational amplifier module.

[0011] Furthermore, the isolation operational amplifier module includes an isolation operational amplifier chip, and the isolation operational amplifier chip includes a voltage divider input pin, a common mode voltage output pin 1, and a common mode voltage output pin 2, wherein the voltage divider input pin is electrically connected to the voltage divider node.

[0012] Further, the operational amplifier module includes an operational amplifier chip, and the operational amplifier chip includes a common mode voltage input pin 1, a common mode voltage input pin 2 and an AD voltage value output pin, wherein:

[0013] The common-mode voltage output pin 1 of the isolation operational amplifier chip is electrically connected to the common-mode voltage input pin 1 of the operational amplifier chip.

[0014] The common-mode voltage output pin 2 of the isolation operational amplifier chip is electrically connected to the common-mode voltage input pin 2 of the operational amplifier chip.

[0015] The AD voltage value output pin of the operational amplifier chip is electrically connected to the low voltage control module.

[0016] Furthermore, a seventh resistor is provided on the circuit connecting the common mode voltage output pin 1 of the isolation operational amplifier chip and the common mode voltage input pin 1 of the operational amplifier chip.

[0017] An eighth resistor is provided on the circuit connecting the common-mode voltage output pin 2 of the isolation operational amplifier chip and the common-mode voltage input pin 2 of the operational amplifier chip.

[0018] Furthermore, it also includes a low-voltage reference voltage source, which is electrically connected to a common-mode voltage input pin 1 of the operational amplifier chip, and a ninth resistor is arranged in the circuit connected between the two.

[0019] Furthermore, a tenth resistor is provided on the circuit connecting the AD voltage value output pin of the operational amplifier chip and the low voltage control module.

[0020] Furthermore, the low-voltage control module includes a low-voltage MCU chip, the low-voltage MCU chip includes an AD voltage value input pin, and the AD voltage value input pin is electrically connected to an AD voltage value output pin of the operational amplifier chip.

[0021] Furthermore, the high voltage sampling calculation formula is as follows:

[0022]

[0023] In the formula, HV is the voltage value of the BMS voltage acquisition port, AD is the AD voltage value collected by the low-voltage MCU chip, VERF_2.5 is the voltage value of the low-voltage reference voltage source, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, R4 is the resistance value of the fourth resistor, and R5 is the resistance value of the fifth resistor.

[0024] Beneficial Effects

[0025] The present application provides a vehicle BMS high-voltage sampling system based on isolated high-voltage sampling, which simplifies the dual high-voltage sampling system architecture and improves the stability of high-voltage sampling; reduces the use of high and low voltage isolation devices, improves the ability of high and low voltage electrical isolation and reduces the actual cost of use; supports single-channel high-voltage sampling, has strong compatibility and supports high voltage sampling systems that require dual grounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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.

[0027] Figure 1 This is the block diagram of the BMS high voltage sampling system for this application.

[0028] Figure 2 1 is a circuit diagram of a BMS high voltage sampling system in one embodiment of the present application. DETAILED DESCRIPTION

[0029] 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.

[0030] 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 before 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.

[0031] 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.

[0032] As described in the background technology, high-voltage sampling of battery packs requires a specific high-voltage sampling MCU, and the high-voltage sampling data is uploaded to the low-voltage MCU through digital isolation. The sampling logic is complex, and complex software strategies are required for parsing and sampling, and the stability of use is relatively poor; it is not very suitable for projects that only require single-channel or dual-channel sampling loops, and the sampling port resources and hardware resources are relatively wasted; traditional high-voltage sampling circuits require a large number of isolation devices, occupy a large area of ​​PCB layout space, and have a high cost of use.

[0033] In view of the above content, the inventor provides a vehicle BMS high-voltage sampling system based on isolated high-voltage sampling, such as Figure 1As shown, the sampling system includes a voltage divider module, which is electrically connected to the BMS voltage acquisition port and is used to divide the voltage collected by the BMS and then output it. It also includes an isolation amplifier module, which is electrically connected to the voltage divider module, and the voltage divider module inputs the divided voltage to the isolation amplifier module, and the isolation amplifier module converts the input voltage from a differential mode voltage to a common mode voltage and then outputs it. It also includes an operational amplifier module, which is electrically connected to the isolation amplifier module, and the isolation amplifier module inputs the common mode voltage to the operational amplifier module, and the operational amplifier module converts the input common mode voltage into a differential mode AD voltage value and outputs AD voltage value data. It also includes a low voltage control module, which is electrically connected to the operational amplifier module, and the operational amplifier module inputs the AD voltage value data to the low voltage control module, and the low voltage control module collects the AD voltage value and sends it to the vehicle control unit of the vehicle.

[0034] This application simplifies the dual high-voltage sampling system architecture and improves the stability of high-voltage sampling; reduces the use of high and low voltage isolation devices, improves the ability of high and low voltage electrical isolation and reduces the actual cost of use; supports single-channel high-voltage sampling, has strong compatibility and supports high-voltage sampling systems that require dual grounds.

[0035] Next, combine Figure 2 The present application is described exemplarily.

[0036] An embodiment of the present application provides a vehicle BMS high-voltage sampling system based on isolated high-voltage sampling, such as Figure 2 As shown, the high voltage sampling system includes:

[0037] A voltage dividing module, which is used to divide the voltage collected by the BMS and then output it. The voltage dividing module is composed of multiple voltage dividing resistors, and is output from the voltage dividing node after voltage division by multiple voltage dividing resistors. The voltage dividing module includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The voltage collected by the BMS passes through the voltage dividing node A of the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 and then inputs the isolation amplifier module. The voltage dividing node A is electrically connected to the isolation amplifier module, and a sixth resistor R6 is provided on the circuit connecting the voltage dividing node A and the isolation amplifier module, and the sixth resistor R is a current limiting resistor;

[0038] The isolation operational amplifier module, the voltage divider module inputs the voltage after voltage division to the isolation operational amplifier module, the isolation operational amplifier module converts the input voltage from the differential mode voltage to the common mode voltage and then outputs it, the isolation operational amplifier module includes an isolation operational amplifier chip U1, and the isolation operational amplifier chip U1 is provided with a voltage division input pin VI N, a common mode voltage output pin OUTPN and a common mode voltage output pin OUTP, wherein,

[0039] The voltage division input pin VI N is electrically connected to the voltage division node A, and the common mode voltage output pin 1 OUTPN and the common mode voltage output pin 2 OUTP are electrically connected to the operational amplifier module;

[0040] In addition, the isolation amplifier chip U1 is also provided with a pin VDD1, which is connected to HV-5V, the pin GND1 is grounded, the pin VDD2 is connected to the power supply, the DCDC isolation power supply is sampled, and the low voltage 5V is used to power the high voltage sampling module through the DCDC isolation chip, and the pin GND2 is grounded;

[0041] Operational amplifier module, the isolation operational amplifier module inputs the common mode voltage to the operational amplifier module, the operational amplifier module converts the input common mode voltage into a differential mode AD voltage value, and outputs the AD voltage value data.

[0042] The operational amplifier module includes an operational amplifier chip U2, which is provided with a common mode voltage input pin I N-2, a common mode voltage input pin I N+2, and an AD voltage value output pin OUT2, wherein:

[0043] The common mode voltage output pin OUTPN of the isolation operational amplifier chip U2 is electrically connected to the common mode voltage input pin I N-2 of the operational amplifier chip U3, and a seventh resistor R7 is provided on the circuit connecting the two. The common mode voltage output pin OUTP of the isolation operational amplifier chip is electrically connected to the common mode voltage input pin I N+2 of the operational amplifier chip U3, and an eighth resistor R8 is provided on the circuit connecting the two. The AD voltage value output pin OUT2 of the operational amplifier chip is electrically connected to the low voltage control module.

[0044] It also includes a low-voltage reference voltage source VERF_2.5V, which is electrically connected to the common-mode voltage input pin I N-2 of the operational amplifier chip, and a ninth resistor R9 is provided in the circuit connected between the two. The ninth resistor R9 pull-up resistor pulls up the input reference low of the U2 operational amplifier chip from 0V to 2.5V. When the input voltage is 0V, the output OUT voltage is 2.5V. When the input voltage is 2.5V, the input voltage is negative through the formula. The negative pressure sampling range can be adjusted by adjusting the voltage divider ratio of the high-voltage sampling voltage divider resistor.

[0045] The circuit connecting the AD voltage value output pin OUT2 of the operational amplifier chip U2 and the low-voltage control module is provided with a tenth resistor R10, which is a current limiting resistor. The low-voltage control module includes a low-voltage MCU chip U3.

[0046] The low voltage MCU chip U3 includes an AD voltage value input pin AD1, and the AD voltage value input pin AD1 is electrically connected to an AD voltage value output pin OUT2 of the operational amplifier chip;

[0047] A feedback circuit is also provided, one end of the feedback circuit is connected between R8 and IN+2, the other end of the feedback circuit is connected between OUT2 and R10, and an eleventh resistor R11 is provided on the feedback circuit.

[0048] The high voltage sampling calculation formula is as follows:

[0049]

[0050] Where:

[0051] HV is the voltage value of the BMS voltage acquisition port,

[0052] AD is the AD voltage value collected by the low-voltage MCU chip.

[0053] VERF_2.5 is the voltage value of the low voltage reference voltage source.

[0054] R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, R4 is the resistance value of the fourth resistor, and R5 is the resistance value of the fifth resistor.

[0055] The following table 1 is a high voltage acquisition calculation table:

[0056] AD acquisition value (V) Reference voltage (1.25V) High voltage acquisition voltage divider resistor ratio High voltage input value (V) 0 2.5 401 -1002.5 0.5 2.5 401 -802 1 2.5 401 -601.5 1.5 2.5 401 -401 2 2.5 401 -200.5 2.5 2.5 401 0 3 2.5 401 200.5 3.5 2.5 401 401 4 2.5 401 601.5 4.5 2.5 401 802 5 2.5 401 1002.5

[0057] Table 1

[0058] 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 vehicle BMS high-voltage sampling system based on isolated high-voltage sampling, characterized in that: include: A voltage dividing module, which is electrically connected to the BMS voltage collection port and is used to divide the voltage collected by the BMS and then output it. An isolation operational amplifier module, wherein the isolation module is electrically connected to the voltage divider module, the voltage divider module inputs the divided voltage to the isolation operational amplifier module, and the isolation operational amplifier module converts the input voltage from a differential mode voltage to a common mode voltage and then outputs it. An operational amplifier module, the operational amplifier module is electrically connected to the isolation operational amplifier module, the isolation operational amplifier module inputs a common mode voltage to the operational amplifier module, the operational amplifier module converts the input common mode voltage into a differential mode AD voltage value, and outputs AD voltage value data, A low voltage control module is electrically connected to the operational amplifier module, the operational amplifier module inputs AD voltage value data to the low voltage control module, and the low voltage control module collects the AD voltage value and sends it to the vehicle control unit of the vehicle.

2. The vehicle BMS high-voltage sampling system based on isolated high-voltage sampling as claimed in claim 1, characterized in that: The voltage divider module includes a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor. The voltage collected by the BMS passes through a voltage divider node of the first resistor, the second resistor, the third resistor, the fourth resistor and the fifth resistor and is input into the isolation operational amplifier module. The voltage divider node is electrically connected to the isolation operational amplifier module.

3. The vehicle BMS high-voltage sampling system based on isolated high-voltage sampling as claimed in claim 2, characterized in that: A sixth resistor is provided on the circuit connecting the voltage dividing node and the isolation operational amplifier module.

4. The vehicle BMS high-voltage sampling system based on isolated high-voltage sampling as claimed in claim 2, characterized in that: The isolation operational amplifier module includes an isolation operational amplifier chip, and the isolation operational amplifier chip includes a voltage divider input pin, a common mode voltage output pin 1, and a common mode voltage output pin 2, wherein the voltage divider input pin is electrically connected to the voltage divider node.

5. The vehicle BMS high-voltage sampling system based on isolated high-voltage sampling as claimed in claim 4, characterized in that: The operational amplifier module includes an operational amplifier chip, and the operational amplifier chip includes a common mode voltage input pin 1, a common mode voltage input pin 2, and an AD voltage value output pin, wherein: The common-mode voltage output pin 1 of the isolation operational amplifier chip is electrically connected to the common-mode voltage input pin 1 of the operational amplifier chip. The common mode voltage output pin 2 of the isolation operational amplifier chip is electrically connected to the common mode voltage input pin 2 of the operational amplifier chip. The AD voltage value output pin of the operational amplifier chip is electrically connected to the low voltage control module.

6. The vehicle BMS high-voltage sampling system based on isolated high-voltage sampling as claimed in claim 5, characterized in that: A seventh resistor is provided on the circuit connecting the common mode voltage output pin 1 of the isolation operational amplifier chip and the common mode voltage input pin 1 of the operational amplifier chip. An eighth resistor is provided on the circuit connecting the common-mode voltage output pin 2 of the isolation operational amplifier chip and the common-mode voltage input pin 2 of the operational amplifier chip.

7. The vehicle BMS high-voltage sampling system based on isolated high-voltage sampling as claimed in claim 6, characterized in that: It also includes a low voltage reference voltage source, which is electrically connected to a common mode voltage input pin of the operational amplifier chip, and a ninth resistor is arranged on the circuit connected between the two.

8. The vehicle BMS high-voltage sampling system based on isolated high-voltage sampling as claimed in claim 5, characterized in that: A tenth resistor is provided on the circuit connecting the AD voltage value output pin of the operational amplifier chip and the low voltage control module.

9. The vehicle BMS high-voltage sampling system based on isolated high-voltage sampling as claimed in claim 5, characterized in that: The low-voltage control module includes a low-voltage MCU chip, and the low-voltage MCU chip includes an AD voltage value input pin, and the AD voltage value input pin is electrically connected to the AD voltage value output pin of the operational amplifier chip.

10. The vehicle BMS high-voltage sampling system based on isolated high-voltage sampling as claimed in claim 7, characterized in that: The high voltage sampling calculation formula is as follows: Wherein, HV is the voltage value of the BMS voltage acquisition port, AD is the AD voltage value collected by the low-voltage MCU chip, VERF_2.5 is the voltage value of the low-voltage reference voltage source, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, R3 is the resistance value of the third resistor, R4 is the resistance value of the fourth resistor, and R5 is the resistance value of the fifth resistor.

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