A strong anti-interference battery cell voltage sampling circuit and a battery management system

Abstract

The utility model discloses a kind of strong anti-interference's battery cell voltage sampling circuit and battery management system, the circuit includes: microprocessor and multiple groups of sampling circuit;Each group of sampling circuit includes: analog front-end chip, for collecting multiple battery cell voltage, and transmit to microprocessor;Isolation driving circuit, for the control and communication connection of microprocessor and analog front-end chip;Isolation power supply, for the power supply of the analog front-end chip and isolation driving circuit in the sampling circuit independently.This circuit is configured with independent isolation power supply and isolation driving circuit for each analog front-end chip, effectively guarantees the collection stability and anti-interference ability of battery cell voltage, battery cell temperature and the like data.

Description

Technical Field

[0001] This utility model relates to the field of energy storage battery management, and in particular to a cell voltage sampling circuit with strong anti-interference and a battery management system. Background Technology

[0002] Most commercially available Battery Management System (BMS) architectures employ analog front-end chips to collect cell voltage and temperature data. The collected digital signals are then transmitted to the main control chip for processing via a daisy-chain configuration or IIC communication protocol. While this communication method is convenient and feasible in static environments, it becomes highly susceptible to interference in complex and disruptive environments. In some cases, the cell voltage data collected by the main control chip may even be entirely garbled. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a cell voltage sampling circuit with strong anti-interference capabilities. The technical solution is as follows:

[0004] A cell voltage sampling circuit with strong anti-interference capability, comprising:

[0005] The microprocessor and multiple sampling circuits; each sampling circuit includes:

[0006] The analog front-end chip is used to collect the voltage of multiple battery cells and transmit it to the microprocessor;

[0007] Isolated driver circuits are used for control and communication connections between microprocessors and analog front-end chips;

[0008] An isolated power supply is used to independently power the analog front-end chip and isolated drive circuit in the sampling circuit.

[0009] Furthermore, the isolation drive circuit includes:

[0010] A control signal driving circuit is used for the microprocessor to send acquisition commands to the analog front-end chip;

[0011] A communication interface driver circuit is used to transmit data collected by the analog front-end chip back to the microprocessor.

[0012] Furthermore, the core component of the control signal driving circuit is an optocoupler.

[0013] Furthermore, the communication interface adopts an SPI interface, and the core component of the communication interface driver circuit is a four-channel digital isolation chip with three transmitters and one receiver.

[0014] Furthermore, the analog chip is equipped with 18 cell voltage acquisition interfaces.

[0015] Furthermore, the analog front-end chip is also equipped with 9 cell temperature acquisition interfaces.

[0016] Furthermore, the voltage of the isolation power supply is 5V.

[0017] Furthermore, the number of sampling circuit groups is 3.

[0018] This utility model also provides a battery management system, including the cell voltage sampling circuit with strong anti-interference as described above.

[0019] Compared with the prior art, the significant features of this utility model are:

[0020] This circuit configures an independent isolated power supply and isolated drive circuit for each analog front-end chip, effectively ensuring the stability and anti-interference capability of data acquisition such as cell voltage and cell temperature. Attached Figure Description

[0021] Figure 1 This is a system block diagram of the battery parameter acquisition section of the BMS;

[0022] Figure 2 This is a system block diagram of the isolated analog front-end of the BMS system of this utility model;

[0023] Figure 3 This is the schematic diagram of an isolated power supply;

[0024] Figure 4 This is the schematic diagram of an isolated drive circuit;

[0025] Figure 5 It is a schematic diagram of the analog front-end chip and its peripheral circuits;

[0026] Figure 6 This is a schematic diagram of the MCU and its peripheral circuits. Detailed Implementation

[0027] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0028] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] like Figure 1As shown, this invention provides a cell voltage sampling circuit with strong anti-interference capability for a battery management system (BMS). The BMS uses this cell voltage sampling circuit to collect data from 54 cells. To ensure the accuracy and timeliness of the cell voltage data acquisition, the circuit employs three isolated analog front-ends (2a, 2b, 2c) for acquisition, each capable of processing the voltage values ​​of 18 cells. An MCU connects to these three isolated analog front-end circuits via three independent I / O ports, controlling their on / off states to flexibly adjust the number of cells collected, ensuring timely and consistent data transmission. The MCU also connects to these three isolated analog front-ends via three independent communication interfaces to receive cell data such as cell voltage and temperature collected by the isolated analog front-ends.

[0031] like Figure 2 As shown, each isolated analog front-end (2a, 2b, 2c) includes an analog front-end chip 21, an isolated power supply 22, and an isolated driver circuit 23. The isolated power supply 22 and the isolated driver circuit 23 ensure independent control of each analog front-end chip 21, while the isolated driver circuit 23 is responsible for controlling signal transmission and data feedback, ensuring signal integrity and system stability. During the design process, special consideration was given to power supply isolation and stability to avoid the impact of external interference on system performance. Compared to the traditional daisy-chain communication method, the system exhibits stronger anti-interference capabilities and data transmission stability.

[0032] Example 2

[0033] Figures 3-6 An embodiment of the cell voltage sampling circuit with strong anti-interference capability is given.

[0034] Isolated power supply: such as Figure 3 As shown, the isolated power supply 22 converts the VCCC_5V power supply into an isolated +5V_A power supply through the power management chip U6 and transformer T4, powering the analog front-end chip 21 and the isolated drive circuit 23. The analog front-end chip 21 uses a 5V power supply and features high precision and low noise characteristics to ensure the accuracy of the acquired cell voltage and temperature data. This chip converts analog signals into digital signals through its internal ADC (analog-to-digital converter) for further processing by the MCU.

[0035] Isolated drivers: such as Figure 4As shown, the control signal drive circuit uses optocouplers for isolated driving. The control signal PA4_ISO_ENA_CTR output by the MCU is isolated by optocoupler OC3 and output as ISO_EN_A, controlling the analog front-end circuit. Optocoupler OC3 also performs level conversion / matching functions. Its chip side is powered by VCC_3V3, consistent with the MCU's operating voltage; the device side is powered by +5V_A, provided by isolated power supply 22. Higher voltage helps improve anti-interference capability.

[0036] The communication interface uses a four-wire SPI interface, and the communication interface driver circuit uses a four-channel digital isolation chip U7 with three transmitters and one receiver for isolation driving. The digital isolation chip U7 also has level conversion / matching functions. Its chip side is powered by VCC_3V3, which is consistent with the MCU's operating voltage; the device side is powered by +5V_A, provided by the isolation power supply 22.

[0037] Analog front-end chips: such as Figure 5 As shown, the operating power supply VREG_A of the analog front-end chip U5 is connected to +5V_A, that is, it is powered by +5V_A, providing 18 voltage sampling channels (C00_A~C18_A, S01_A~S18_A) and 9 temperature acquisition channels (NTC0_CA~NTC8_CA).

[0038] MCU and its peripheral circuits: such as Figure 6 As shown, U3 is the MCU.

[0039] This invention provides power to the analog front-end circuit and the isolated communication circuit through an isolated power supply, effectively ensuring the stability and anti-interference capability of data acquisition such as cell voltage and cell temperature.

[0040] Although the present invention has been shown in detail with reference to preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall fall within the protection scope of the present invention.

Claims

1. A cell voltage sampling circuit with strong anti-interference capability, used in a battery management system, characterized in that, include: Microprocessor and multiple sampling circuits; Each sampling circuit includes: The analog front-end chip is used to collect the voltage of multiple battery cells and transmit it to the microprocessor; Isolated driver circuits are used for control and communication connections between microprocessors and analog front-end chips; An isolated power supply is used to independently power the analog front-end chip and isolated drive circuit in the sampling circuit.

2. The cell voltage sampling circuit with strong anti-interference capability as described in claim 1, characterized in that, The isolation drive circuit includes: A control signal driving circuit is used for the microprocessor to send acquisition commands to the analog front-end chip; A communication interface driver circuit is used to transmit data collected by the analog front-end chip back to the microprocessor.

3. The cell voltage sampling circuit with strong anti-interference capability as described in claim 2, characterized in that, The core component of the control signal drive circuit is an optocoupler.

4. The cell voltage sampling circuit with strong anti-interference capability as described in claim 2, characterized in that, The core component of the communication interface driver circuit is a four-channel digital isolation chip with three transmitters and one receiver.

5. The cell voltage sampling circuit with strong anti-interference capability as described in claim 1, characterized in that, The analog front-end chip is equipped with 18 cell voltage acquisition interfaces.

6. The cell voltage sampling circuit with strong anti-interference capability as described in claim 5, characterized in that, The analog front-end chip is also equipped with 9 cell temperature acquisition interfaces.

7. The cell voltage sampling circuit with strong anti-interference capability as described in claim 5, characterized in that, The voltage of the isolation power supply is 5V.

8. The cell voltage sampling circuit with strong anti-interference capability as described in claim 1, characterized in that, The number of sampling circuits is 3.

9. A battery management system, characterized in that, Includes the cell voltage sampling circuit with strong anti-interference as described in any one of claims 1-8.

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