BMS sampling circuit, sampling method, equipment and storage medium

Abstract

The invention relates to the technical field of battery management, in particular to a BMS sampling circuit, a sampling method, equipment and a storage medium. In a current sampling module of the BMS sampling circuit, a diverter is connected with a battery pack in series, a current detection amplifier is connected with the diverter in parallel to obtain a first voltage signal, one AFE branch of an AFE module is used for collecting the first voltage signal, and other AFE branches are used for collecting temperature information, second voltage signals and balance control information of battery cells of the battery pack respectively. An isolation communication interface of a high-voltage side of the isolation communication module is connected with the AFE module, an isolation communication interface of a low-voltage side of the isolation communication module is connected with the MCU module, and the isolation communication module is used for sending the first voltage signal collected by the AFE module, the temperature information of each battery cell, the second voltage signal and the balance control information to the MCU module. The isolation communication module configured by the multiplexing AFE module and the MCU module perform isolation bidirectional communication, so that the circuit integration function is enhanced, and the cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to a BMS sampling circuit, a sampling method, a device, and a storage medium. Background Art

[0002] The Battery Management System (BMS) is commonly known as the battery nanny or battery steward, mainly used for intelligent management and maintenance of each battery unit, preventing the battery from overcharging and over-discharging, extending the service life of the battery, and monitoring the state of the battery.

[0003] The Analog Front End (AFE) is at the forefront of the processing chain, that is, the input end, and is the connection point between the analog signal sensor and the digital signal processor. It can be widely used in various high-precision measurement fields. In the BMS system, the AFE specifically refers to the battery sampling chip, which realizes high-precision measurement and equalization management of the battery voltage and temperature. For the current to be collected, generally, the current is collected by the analog-to-digital conversion circuit ADC and then transmitted to the controller MCU. And because the communication between the high-voltage circuit and the low-voltage circuit in the BMS system requires the use of an isolation circuit to ensure the safe transmission of the high-voltage sampling result to the controller MCU, the structure of the BMS sampling circuit is relatively complex and the cost is relatively high. Summary of the Invention

[0004] The purpose of the present invention is to provide a BMS sampling circuit, a sampling method, a device, and a storage medium with a simple structure and low cost.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A BMS sampling circuit includes: a current sampling module, an analog front end AFE module, an isolation communication module, and an MCU module;

[0007] The current sampling module includes a shunt resistor and a current detection amplifier. The shunt resistor is connected in series with the battery pack, and the current detection amplifier is connected in parallel with the shunt resistor. The current detection amplifier is used to obtain the first voltage signal generated across the shunt resistor;

[0008] The analog front end AFE module includes multiple analog front end AFE branches. One of the analog front end AFE branches is connected to the current detection amplifier for collecting the first voltage signal, and the other analog front end AFE branches are respectively used for collecting the temperature information, the second voltage signal, and the equalization control information of each battery cell of the battery pack;

[0009] The isolation communication module is connected to the analog front-end AFE module through the isolation communication interface on the high-voltage side and to the MCU module through the isolation communication interface on the low-voltage side, and is used to send the first voltage signal collected by the analog front-end AFE module, the temperature information of each battery cell, the second voltage signal, and the equalization control information to the MCU module.

[0010] Further, the positive and negative input pins of the current detection amplifier are respectively connected to both ends of the shunt resistor, and its output pin is connected to the first GPIO interface of the analog front-end AFE module, and is used to output the first voltage signal to the analog front-end AFE module.

[0011] The positive power supply VCC interface of the current detection amplifier is connected to the positive power supply VCC interface of the analog front-end AFE module.

[0012] Further, several other analog front-end AFE branches are configured with temperature acquisition channels, which are used to collect the temperature information of the battery cells by using temperature sensors connected to the battery cells, and input the collected temperature information of the battery cells into the second GPIO interface of the analog front-end AFE module.

[0013] Further, several other analog front-end AFE branches are configured with voltage acquisition channels or equalization control units, which are used to input the collected second voltage signals or equalization control information of the battery cells into the corresponding CB interfaces of the analog front-end AFE module respectively.

[0014] Further, the isolation communication interface of the isolation communication module is one of a UART isolation communication interface, an SPI isolation communication interface, and an I2C isolation communication interface.

[0015] The present invention also provides a BMS sampling method based on the above BMS sampling circuit, including:

[0016] Obtaining a first voltage signal generated at both ends of a shunt resistor connected in series with the battery pack by using a current detection amplifier;

[0017] Collecting the first voltage signal by using one analog front-end AFE branch of the analog front-end AFE module;

[0018] Collecting the temperature information, the second voltage signal, and the equalization control information of each battery cell of the battery pack respectively by using other analog front-end AFE branches of the analog front-end AFE module;

[0019] Inputting the first voltage signal, the temperature information of each battery cell, the second voltage signal, and the equalization control information from the isolation communication interface on the high-voltage side of the isolation communication module, and outputting them from the isolation communication interface on the low-voltage side of the isolation communication module to the MCU module.

[0020] Further, temperature acquisition channels are configured for several other analog front-end AFE branches of the analog front-end AFE module, and the cell temperature information is acquired by using a temperature sensor connected to the cell.

[0021] Further, voltage acquisition channels or balancing control units are configured for several other analog front-end AFE branches of the analog front-end AFE module to acquire the cell voltage or balancing control information.

[0022] Based on the same inventive concept, the present invention also provides an electronic device including the above-mentioned BMS sampling circuit.

[0023] Based on the same inventive concept, the present invention also provides a computer-readable storage medium storing computer-executable instructions, and when the computer-executable instructions are executed, the above-mentioned BMS sampling method is implemented.

[0024] Technical effects and advantages of the present invention:

[0025] (1) The BMS sampling circuit acquires the first voltage across the shunt through the AFE module, transmits it to the MCU to be converted into the battery pack working current, and acquires the second voltage, temperature information and balancing control information of the cell, so as to realize battery state monitoring and charge and discharge balancing control;

[0026] (2) When the BMS sampling circuit acquires the current, voltage, temperature and balancing control information of the battery pack, it shares one AFE module and one isolation communication module, which greatly saves the sampling cost and simplifies the circuit structure.

[0027] Other features and advantages of the present invention will be described in the subsequent specification, and some of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification, claims and drawings. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a schematic structural diagram of the BMS sampling circuit provided by the embodiment of the present invention;

[0030] Figure 2 It is a schematic principle diagram of the current detection amplifier provided by the embodiment of the present invention;

[0031] Figure 3 This is a schematic flowchart of the BMS sampling method provided by an embodiment of the present invention. Specific embodiments

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] To solve the deficiencies of the prior art, an embodiment of the present invention discloses a BMS sampling circuit, as Figure 1 shown. The BMS sampling circuit includes: a current sampling module, an analog front end AFE module, an isolation communication module, and an MCU module.

[0034] The current sampling module includes a shunt U1 and a current detection amplifier. The shunt U1 is connected in series with the battery pack, and the current detection amplifier is connected in parallel with the shunt U1 for obtaining a first voltage signal generated across the shunt U1.

[0035] The battery pack includes a plurality of series-connected battery cells. The analog front end AFE module includes a plurality of analog front end AFE branches. One of the analog front end AFE branches is connected to the current detection amplifier for collecting the first voltage signal, and the other analog front end AFE branches are respectively used for collecting the temperature information, second voltage signal, and equalization control information of each battery cell of the battery pack.

[0036] The isolation communication module has an isolation communication interface on the high-voltage side connected to the analog front end AFE module, and its isolation communication interface on the low-voltage side is connected to the MCU module for sending the first voltage signal collected by the analog front end AFE module, as well as the temperature information, second voltage signal, and equalization control information of each battery cell to the MCU module.

[0037] In an embodiment of the present invention, multiple analog front-end (AFE) branches of the AFE module respectively collect the first voltage signal generated at both ends of the shunt, the temperature information of each battery cell, the second voltage signal, and the equalization control information. Among them, the first voltage signal can be converted into the working current of the battery pack, and the second voltage signal corresponds to the voltage of each battery cell in the battery pack. An isolation communication module is provided between the AFE module on the high-voltage side and the MCU module on the low-voltage side to provide a two-way data transmission channel required for isolation communication. The MCU module periodically reads the first voltage signal from the AFE module through the isolation communication module and converts it into the working current of the battery pack, and synchronously reads the battery cell temperature information, the battery cell voltage, and the battery cell equalization control information. The MCU module analyzes and processes the sampled data read, such as calculating the state of charge (SOC) and state of health (SOH) of the battery pack, etc., so as to monitor the battery state and perform charge and discharge equalization control of the battery pack according to a preset strategy.

[0038] In the BMS sampling circuit provided by the embodiment of the present invention, the MCU module uses multiple analog front-end (AFE) branches integrated in the AFE module to synchronously collect the working current of the battery pack, the battery cell temperature information, the battery cell voltage, and the equalization control information, improving the information collection efficiency. And because the already configured isolation communication module of the AFE module is reused for two-way communication with the MCU module, there is no need to additionally set an isolation communication mechanism for collecting the battery current, strengthening the circuit integration function, greatly saving the sampling cost, and also simplifying the circuit structure.

[0039] Different types of current detection amplifiers use different principles for current detection and amplification. In an embodiment of the present invention, a resistive current detection amplifier is used to detect the voltage at both ends of the shunt to monitor the working current of the battery pack. The current detection amplifier described in the embodiment of the present invention is based on Ampere's law and Ohm's law, that is, there is a linear relationship between current and voltage. When current passes through a resistor, a voltage signal of a certain magnitude will be generated at both ends of the resistor. The MCU module can obtain an accurate current value by collecting and processing this voltage signal. In other embodiments, current detection amplifiers based on other principles can also be used. For example, a Hall current detection amplifier uses the influence of a magnetic field on a Hall element to achieve current monitoring, or a mutual inductance current detection amplifier uses the magnetic field change caused by current in a mutual inductor to achieve current detection, and so on.

[0040] According to an embodiment of the present invention, when measuring the working current of a battery pack, a small resistor (i.e., a shunt) is inserted in series with the battery pack to be measured. The current detection amplifier is a special-purpose integrated circuit differential amplifier used to detect and amplify the current or voltage generated across the shunt. In the embodiment of the present invention, the working current of the battery pack is detected by detecting the first voltage signal and converting it. The voltage across the shunt is typically in the range of 1 to 100 mV, but may depend on the nominal bus voltage potential. The current detection amplifier is designed with a high common-mode rejection ratio (CMRR) to eliminate the bus voltage in the output voltage and process common-mode voltages that exceed its own power supply voltage.

[0041] In practical applications, the selection of the shunt must consider resistor accuracy, the temperature coefficient of resistance TCR, and the rated power. For a given current value, the resistance value determines the voltage drop across the shunt and the power consumption of the resistor. Generally speaking, the resistance value of the shunt is much less than 1 Ω. There are dedicated resistors on the market that use metal elements in the form of plates, foils, or films, or use deposited thin-film or thick-film hybrid elements as shunts. One example of a surface-mounted metal shunt resistor is the MCS3264R005FEZR current-sensing resistor, which is a two-terminal, 5 mΩ resistor with a rated power of 2 W and a temperature coefficient of resistance TCR of 50 ppm / °C.

[0042] Figure 2 It is a schematic diagram of the principle of the current detection amplifier, showing a typical differential amplifier with inverting and non-inverting inputs and a single output. Among them, R1 = R3, R2 = R4, and the gain is set by the ratio of resistor R2 to R1 and R4 to R3. According to a specific embodiment, a typical current detection amplifier INA210CIDCKR, where R2 and R4 are 1 MΩ, and R1 and R3 are 5 kΩ, so the gain is 200 V / V, and the gain accuracy of this current detection amplifier is 0.5%.

[0043] The current detection amplifier is also used to convert weak current signals or voltage signals into standard analog or digital signals, so as to achieve precise monitoring and control of current or voltage. According to a preferred embodiment of the present invention, the positive and negative input pins (IN+ and IN-) of the current detection amplifier are respectively connected to both ends of the shunt U1, and its output pin OUT is connected to the first GPIO interface (such as the GPIO1 interface) of the analog front-end AFE module, for outputting the first voltage signal to the analog front-end AFE module. The positive power supply VCC interface of the current detection amplifier is connected to the positive power supply VCC interface of the analog front-end AFE module.

[0044] The AFE chip is one of the core components of the BMS, and it can accurately measure various parameters of the battery. Common AFE chips include the BQ769X series, MAX178XX series, etc. These chips feature high precision and multi-channel measurement. Common MCUs include the ARM Cortex-M series, such as the STM32 series, which have high performance, low power consumption, and rich peripheral interfaces.

[0045] The operating principle of the AFE chip can be divided into the following steps:

[0046] 1. Sampling: The analog signal collected by the sensor is converted into a digital signal through the built-in analog-to-digital converter (ADC). The higher the sampling rate adopted by the ADC, the higher the accuracy of the converted digital signal.

[0047] 2. Filtering: Since the analog signal collected by the sensor may contain some unnecessary noise and interference, the AFE chip filters the digital signal through the built-in filter to improve the signal-to-noise ratio of the digital signal.

[0048] 3. Amplification: The digital signal is amplified to improve the sensitivity and resolution of the digital signal.

[0049] 4. Digital processing: The digital signal is sent to the processor for digital signal processing. The processor can perform various algorithmic processes on the digital signal, such as filtering, FFT (Fast Fourier Transform), signal analysis, etc.

[0050] 5. Output: The processed digital signal can be output in various ways, such as serial output, parallel output, Ethernet output, etc.

[0051] In an embodiment of the present invention, the analog front-end AFE module integrates multiple analog front-end AFE branches. One of the analog front-end AFE branches is connected to the current detection amplifier and is used to collect a first voltage signal. The first voltage signal is the voltage generated across the shunt resistor and is amplified. After being transmitted to the MCU module, it is converted into the working current of the battery pack. The other analog front-end AFE branches are respectively used to collect the temperature information of each battery cell in the battery pack, the cell voltage, and the cell equalization control information. Among them, several other analog front-end AFE branches for collecting the cell temperature information are configured with temperature acquisition channels, and the temperature sensors (NTC) connected to the battery cells are used to collect the cell temperature information, and the collected cell temperature information is input into the second GPIO interface (such as GPIO2-5 interfaces) of the analog front-end AFE module; several other analog front-end AFE branches for collecting the cell voltage are configured with voltage acquisition channels, and several other analog front-end AFE branches for collecting the equalization control information are configured with equalization control units. The cell voltage and the equalization control information are respectively input into the corresponding CB interfaces (such as CB0, CB1, CB12, CB13 interfaces) of the analog front-end AFE module.

[0052] The function of equalization control is to improve the battery endurance time and cycle life. Battery imbalance is manifested as the unequal voltages of each battery cell when multiple battery cells are connected in series, especially obvious at the end of charging and discharging. When battery packs with different full charge capacities are connected in series, the series charging current is the same, but the battery cell with a smaller full charge capacity will be charged to a higher voltage first, resulting in unequal voltages of each battery cell. Even when the full charge capacities are the same, but battery packs with different SOCs are connected in series, the voltage of the battery cell with a higher SOC is relatively high, resulting in unequal voltages of each battery cell. Even when the full charge capacities are the same, the SOCs are the same, but the internal resistances of each battery cell are different, and the voltage differences during charge and discharge are different, which will also cause different battery terminal voltages. In addition, some external factors (such as local temperature of the battery pack or thermal imbalance between individual battery cells) will also cause different aging rates of individual battery cells, resulting in internal resistance imbalance, and ultimately may all be manifested as unequal voltages of each battery cell. The equalization circuit mainly includes active equalization and passive equalization. Active equalization is to transfer the extra power of the battery cell with the most power to the battery cell with the least power, or transfer it to the entire battery pack to achieve energy recovery. Passive equalization is to consume the extra power of the battery cell with the most power by heating through a resistor.

[0053] Since one-time over-discharge will cause permanent damage to the battery, in extreme cases, overheating or overcharging of the battery will lead to thermal runaway, battery rupture, and even explosion. Therefore, in the BMS system, the MCU module protects the battery from overcharging and over-discharging by monitoring the equalization control information of each battery cell, balances the power of each battery cell in the battery pack, and analyzes and calculates the power of the battery pack and converts it into understandable endurance information to ensure the safe operation of the power battery.

[0054] Communication isolation is to protect the system from high voltage and noise, while ensuring signal integrity and system security. In the embodiment of the present invention, the AFE module is in the high-voltage domain, the MCU module is in the low-voltage domain, and an isolation communication module is provided between the AFE module and the MCU module. The isolation communication module provides a reliable and secure two-way communication channel between the two. The isolation communication module is preferably a digital isolator, and its isolation communication interface is one of UART isolation communication interface, SPI isolation communication interface, and I2C isolation communication interface.

[0055] Exemplarily, the isolator LTC6820 can achieve the two-way data transmission required for SPI communication between two completely electrically isolated devices. It encodes the SPI signal from the AFE chip into a differential signal with a maximum rate of 1 Mbps, and then transmits it through the electrical isolation gate and twisted pair to the other end. After that, the differential signal is received by the LTC6820 again and decoded into an SPI signal, and then routed to the MCU module. The LTC6820 also provides the current required to drive the signal through the isolation gate. These currents are adjusted to meet the system requirements through external resistors, such as the required cable length, signal-to-noise ratio SNR, and immunity. The LTC6820 can also easily implement a daisy-chain application (one master controller controls multiple slave controllers), which is applied to the battery monitoring system to implement electrically isolated communication for some charging units (such as lithium-ion batteries) that may pose an explosion risk.

[0056] In the embodiment of the present invention, when the BMS sampling circuit collects the working current, voltage, temperature, and equalization control information of the battery pack, it shares one AFE module and one isolation communication module, and performs two-way communication with the MCU module through the multiplexed isolation communication module configured in the AFE module. The MCU module periodically reads the first voltage signal from the AFE module and converts it into the working current of the battery pack, synchronously reads the cell temperature, cell voltage, and equalization control information, and then analyzes and processes the sampled data read, such as calculating the SOC (state of charge) and SOH (state of health) of the battery pack, monitoring the battery state, and performing charge and discharge equalization control of the battery pack according to the preset strategy. Since there is no need to additionally set an isolation communication mechanism for collecting battery current, the circuit integration function is strengthened, the circuit structure is simplified, and the equipment cost is reduced.

[0057] The second embodiment of the present invention provides a BMS sampling method, as Figure 2 shown, the BMS sampling method is implemented based on the above BMS sampling circuit, and the method includes:

[0058] S1. Use a current detection amplifier to collect the first voltage signal generated at both ends of the shunt resistor connected in series with the battery pack;

[0059] S2. Use one AFE branch of the AFE module to collect the first voltage signal;

[0060] S3. Use other AFE branches of the AFE module to collect the temperature information, second voltage signal, and equalization control information of each battery cell of the battery pack respectively;

[0061] S4. Input the first voltage signal, the temperature information, second voltage signal, and equalization control information of each battery cell from the isolation communication interface on the high-voltage side of the isolation communication module, and output them from the isolation communication interface on the low-voltage side of the isolation communication module to the MCU module.

[0062] In the embodiment of the present invention, the analog front-end AFE module integrates multiple analog front-end AFE branches. One of the analog front-end AFE branches is used to measure the working current of the battery pack. Specifically, a small resistor (i.e., a shunt) is inserted in series with the battery pack to be measured, and the current detection amplifier is connected in parallel with the shunt U1. The current detection amplifier is a special-purpose integrated circuit differential amplifier, which is used to detect the current or voltage generated across the shunt and amplify it. In the embodiment of the present invention, the working current of the battery pack is detected by detecting the first voltage signal and converting it. The positive and negative input pins of the current detection amplifier are respectively connected to both ends of the shunt, and its output pin is connected to the first GPIO interface of the analog front-end AFE module, which is used to output the first voltage signal to the analog front-end AFE module. After the first voltage signal is transmitted to the MCU module, it is converted into the working current of the battery pack.

[0063] The other analog front-end AFE branches of the AFE module are respectively used to collect the temperature information, second voltage (cell voltage), and equalization control information of each battery cell of the battery pack. Among them, the analog front-end AFE branch for collecting the cell temperature is configured with a temperature acquisition channel, and the cell temperature information is collected by using a temperature sensor connected to the cell and input to the second GPIO interface of the analog front-end AFE module. The analog front-end AFE branch for collecting the cell voltage is configured with a voltage acquisition channel, and the analog front-end AFE branch for collecting the equalization control information is configured with an equalization control unit. The cell voltage and equalization control information are respectively input to the corresponding CB interface of the analog front-end AFE module.

[0064] Each analog front-end AFE branch integrated in the AFE module is used to collect the first voltage, cell temperature, cell voltage, and equalization control information. First, the analog signals collected by the sensors are converted into digital signals through the built-in analog-to-digital converter ADC. The higher the sampling rate adopted by the ADC, the higher the accuracy of the converted digital signals. Since the analog signals collected by the sensors may contain some unnecessary noise and interference, the AFE chip will filter the digital signals through the built-in filter to improve the signal-to-noise ratio of the digital signals. Then, the digital signals are amplified to improve the sensitivity and resolution of the digital signals. Next, the digital signals are sent to the processor for digital signal processing. The processor can perform various algorithmic processes on the digital signals, such as filtering, FFT (Fast Fourier Transform), signal analysis, etc. The processed digital signals can be output in various ways, such as serial port output, parallel port output, Ethernet output, etc.

[0065] In the embodiment of the present invention, since the AFE module is in the high-voltage domain and the MCU module is in the low-voltage domain, an isolation communication module is provided between the AFE module and the MCU module. The isolation communication module provides a reliable and secure bidirectional communication channel for the two. The isolation communication interface of the isolation communication module is one of the UART isolation communication interface, SPI isolation communication interface, and I2C isolation communication interface.

[0066] Exemplarily, the isolator LTC6820 can achieve the bidirectional data transmission required for SPI communication between two completely electrically isolated devices. It encodes the SPI signals from the AFE chip into differential signals with a maximum rate of 1 Mbps, and then after transmission through the electrical isolation barrier and twisted pair to the other end, the differential signals are received by the LTC6820 again and decoded into SPI signals, and then routed to the MCU module. The LTC6820 also provides the current required to drive the signals through the isolation barrier. These currents are adjusted to the values that meet the system requirements through external resistors, such as the required cable length, signal-to-noise ratio SNR, and immunity. The LTC6820 can also easily implement daisy-chain applications (one master controller controls multiple slave controllers), which are applied to the battery monitoring system to implement electrically isolated communication for some charging units that may pose an explosion risk (for example, lithium-ion batteries).

[0067] In an embodiment of the present invention, when the BMS circuit samples, a single AFE module and a single isolated communication module are shared to synchronously collect current, voltage, temperature, and equalization control information. Bidirectional communication is carried out between the MCU module and the configured isolated communication module of the AFE module. The MCU module periodically reads the first voltage signal from the AFE module and converts it into the working current of the battery pack, and synchronously reads the cell temperature, cell voltage, and equalization control information. Since there is no need to additionally set up an isolated communication mechanism for collecting battery current, the circuit integration function is enhanced, the sampling cost is greatly saved, and the circuit structure is simplified. The MCU module analyzes and processes the sampled data read, such as calculating the SOC (state of charge) and SOH (state of health) of the battery pack, monitoring the battery state, and performing charge and discharge equalization control of the battery pack according to a preset strategy.

[0068] It should be noted that, for the foregoing method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0069] In the above embodiments, the descriptions of the various embodiments have their own emphases. For parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A BMS sampling circuit, characterized in that, The BMS sampling circuit includes: a current sampling module, an analog front end AFE module, an isolation communication module, and an MCU module; The current sampling module includes a shunt and a current detection amplifier, and the shunt is connected in series with the battery pack; The current detection amplifier is connected in parallel with the shunt, and the current detection amplifier is used to obtain a first voltage signal generated across the shunt; The analog front end AFE module includes a plurality of analog front end AFE branches. One of the analog front end AFE branches is connected to the current detection amplifier for collecting the first voltage signal, and the other analog front end AFE branches are respectively used for collecting the temperature information, second voltage signal, and equalization control information of each battery cell of the battery pack; The isolation communication module is connected to the analog front end AFE module at the isolation communication interface on the high voltage side and is connected to the MCU module at the isolation communication interface on the low voltage side, and is used to send the first voltage signal, the temperature information, second voltage signal, and equalization control information of each battery cell collected by the analog front end AFE module to the MCU module.

2. The BMS sampling circuit according to claim 1, characterized in that The positive and negative input pins of the current detection amplifier are respectively connected to both ends of the shunt, and its output pin is connected to the first GPIO interface of the analog front end AFE module for outputting the first voltage signal to the analog front end AFE module; The power supply positive VCC interface of the current detection amplifier is connected to the power supply positive VCC interface of the analog front end AFE module.

3. The BMS sampling circuit according to claim 1, characterized in that, A plurality of the other analog front end AFE branches are configured with temperature acquisition channels for using temperature sensors connected to the battery cells to collect the temperature information of the battery cells and inputting the collected temperature information of the battery cells into the second GPIO interface of the analog front end AFE module.

4. The BMS sampling circuit according to claim 1, wherein A plurality of the other analog front end AFE branches are configured with voltage acquisition channels or equalization control units for respectively inputting the collected second voltage signals or equalization control information of the battery cells into the corresponding CB interfaces of the analog front end AFE module.

5. The BMS sampling circuit according to claim 1, wherein The isolation communication interface of the isolation communication module is one of a UART isolation communication interface, an SPI isolation communication interface, and an I2C isolation communication interface.

6. The BMS sampling method based on the BMS sampling circuit according to any one of claims 1 to 5, characterized in that, The BMS sampling method includes: Using a current detection amplifier to obtain a first voltage signal generated across a shunt connected in series with the battery pack; Using one of the analog front end AFE branches of the analog front end AFE module to collect the first voltage signal; Using the other analog front end AFE branches of the analog front end AFE module to respectively collect the temperature information, second voltage signal, and equalization control information of each battery cell of the battery pack; Inputting the first voltage signal, the temperature information, second voltage signal, and equalization control information of each battery cell from the isolation communication interface on the high voltage side of the isolation communication module and outputting them from the isolation communication interface on the low voltage side of the isolation communication module to the MCU module.

7. The BMS sampling method according to claim 6, wherein Configuring temperature acquisition channels for a plurality of the other analog front end AFE branches of the analog front end AFE module and using temperature sensors connected to the battery cells to collect the temperature information of the battery cells.

8. The BMS sampling method according to claim 6, wherein Configure voltage acquisition channels or equalization control units for several other analog front-end AFE branches of the analog front-end AFE module to acquire the second voltage signal or equalization control information of the battery cells.

9. An electronic device, characterized in that, Including the BMS sampling circuit according to any one of claims 1-5.

10. A computer-readable storage medium, characterized in that, Computer-executable instructions are stored in the computer-readable storage medium, and when the computer-executable instructions are executed, the BMS sampling method according to any one of claims 6-8 is implemented.

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