Voltage calibration method and device for battery management system

Abstract

The invention belongs to the technical field of battery detection (battery management), and provides a voltage calibration method and device of a battery management system in order to solve the problems that the charging and discharging time of a battery is long, the battery management system is affected by contact resistance, calibration parameters are difficult to adjust during testing, and batch testing is difficult to carry out. The method comprises the following steps: the battery management system comprises a plurality of ports, and each port is connected with a floating source; each port of the battery management system forms a channel, the channel is configured to be a preset voltage value, and a gain error and direct current offset are calculated according to a measurement result; and writing the calculated gain error and DC offset data into a corresponding register of the battery management system. The method is suitable for a mass production calibration scheme with controllable voltage monitoring precision of the battery management system BMS, the peripheral circuits are relatively few, the contact resistance is controllable, the floating source can provide voltage with higher precision for rapid and high-precision calibration, and mass production testing of the battery management system is achieved.

Description

Technical Field

[0001] This invention belongs to the field of battery testing (battery management) technology, and more specifically, relates to a voltage calibration method and apparatus for a battery management system. Background Technology

[0002] The Battery Management System (BMS), as an electronic component that performs real-time monitoring, automatic balancing, and intelligent charging and discharging, plays a crucial role in ensuring safety, extending lifespan, and estimating remaining capacity. It is an indispensable component in power and energy storage battery packs. When testing the BMS using battery packs, the long charging and discharging times and waiting times during test cycles, coupled with the increasing number of batch tests, can affect calibration accuracy due to the influence of contact resistance. This makes adjusting calibration parameters difficult and hinders batch testing. Summary of the Invention

[0003] To address the challenges of long battery charging and discharging times and the difficulty in adjusting calibration parameters during battery management system testing due to contact resistance, which hinders batch testing, this application provides a voltage calibration method and apparatus for a battery management system, enabling mass production testing of the battery management system.

[0004] In a first aspect, embodiments of this application provide a voltage calibration method for a battery management system, including: The battery management system includes multiple ports, each of which is connected to a floating source. Each port has two leads that are connected to the floating source. One of the two leads from each port is used for input / output, and the other is used to measure the voltage / current of the pin. Each port of the battery management system forms a channel, which is configured with a preset voltage value. The gain error and DC offset are calculated based on the measurement results. The calculated gain error and DC offset data are written into the corresponding registers of the battery management system.

[0005] The process of configuring the channel to a preset voltage value and calculating the gain error and DC offset based on the measurement results includes: configuring the channel voltage to 2V, measuring the first voltage of each port of the battery management system, configuring the channel voltage to 4V, measuring the second voltage of each port of the battery management system, and calculating the gain error and DC offset of each channel based on the first voltage and the second voltage.

[0006] The process of connecting each port to the floating source further includes: obtaining the contact impedance value through Kelvin testing, detecting whether the contact impedance value is within a preset range, and if it is, proceeding to subsequent testing steps; if the contact impedance value is not within the preset range, processing the contact impedance until the contact impedance is within the preset range before proceeding to subsequent testing steps.

[0007] The battery management system includes seven ports, each of which is connected to a floating source.

[0008] Secondly, this application provides a voltage calibration device for a battery management system, comprising: A connection unit is used to connect the floating source to the port of the battery management system. Each port of the battery management system has two wires leading out to connect to the floating source. One of the two wires leading out of each port is used for input / output, and the other is used to measure the voltage / current of the pin. The calculation unit is used to configure the channel to a preset voltage value and calculate the gain error and DC offset based on the measurement results. The write unit is used to write the calculated gain error and DC offset data into the corresponding registers of the battery management system.

[0009] The calculation unit is used to: configure the channel voltage to 2V, measure the first voltage of each port of the battery management system, configure the channel voltage to 4V, measure the second voltage of each port of the battery management system, and calculate the gain error and DC offset of each channel based on the first voltage and the second voltage.

[0010] It also includes a detection unit, used to: obtain a contact impedance value through Kelvin testing, detect whether the contact impedance value is within a preset range, and if so, proceed with subsequent testing steps; if the contact impedance value is not within the preset range, process the contact impedance until the contact impedance is within the preset range before proceeding with subsequent testing steps.

[0011] The battery management system includes seven ports, each of which is connected to a floating source.

[0012] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of any of the above methods.

[0013] Fourthly, this application provides a chip testing system, including a voltage calibration device for any of the aforementioned battery management systems.

[0014] The voltage calibration method and apparatus for the battery management system in this application have the following beneficial effects: This application presents a mass production calibration solution for battery management system (BMS) voltage monitoring with controllable accuracy. In this application, the external circuitry is relatively small, the contact resistance is controllable, and the floating source can provide higher-precision voltage for rapid and high-precision calibration, thus realizing mass production testing of the battery management system. Attached Figure Description

[0015] Figure 1 This is a schematic flowchart of the voltage calibration method for the battery management system according to an embodiment of this application; Figure 2 This is a circuit diagram of the voltage calibration device in the battery management system of this application embodiment; Figure 3 This is a schematic diagram of the voltage calibration device of the battery management system according to an embodiment of this application. Detailed Implementation

[0016] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0017] In the following description, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The following description provides multiple embodiments of the invention, which can be substituted or combined with each other. Therefore, this application can also be considered to include all possible combinations of the same and / or different embodiments described. Thus, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then this application should also be considered to include embodiments containing one or more other possible combinations of features A, B, C, and D, even if such embodiments are not explicitly described in the following text.

[0018] like Figure 1 As shown, a voltage calibration method for a battery management system according to this application includes: S101, the battery management system includes multiple ports, each port is connected to a floating source, and two lines are led out from each port and connected to the floating source. One of the two lines from each port is used for input / output, and the other is used to measure the voltage / current of the pin. S103, each port of the battery management system forms a channel, the channel is configured with a preset voltage value, and the gain error and DC offset are calculated based on the measurement results. S105, the calculated gain error and DC offset data are written into the corresponding register of the battery management system. These are described in detail below.

[0019] S101, the battery management system includes multiple ports, each of which is connected to a floating source. Each port has two leads that are connected to the floating source. One of the two leads from each port is used for input / output, and the other is used to measure the voltage / current of the pin.

[0020] like Figure 1-2As shown, the battery management system includes multiple ports, for example, seven: VC0, VC1, VC2, VC3, VC4, VC5, and VC6. Each of these seven ports is connected to a high-precision floating source, which is used to replace battery power for testing. Two lines are led out from each port and connected to the floating source. One of these two lines is used for input / output, and the other is used to measure the voltage / current of the pin. This employs the Kelvin dual-probe connection method, which involves leading two traces from the chip pin. These two traces are called the FORCE (transmission) terminal and the SENSE (measurement) terminal. The FORCE terminal is used for input or output, and the SENSE terminal is used to measure the current or voltage value of the pin.

[0021] In some embodiments, this step is followed by: obtaining a contact impedance value through a Kelvin test, detecting whether the contact impedance value is within a preset range, and if so, proceeding to subsequent test steps; if the contact impedance value is not within the preset range, processing the contact impedance until the contact impedance is within the preset range before proceeding to subsequent test steps.

[0022] Using the Kelvin dual-probe connection method, the two probes are connected to the Force and Sense resources of the Kelvin resource respectively. The contact impedance value is obtained through Kelvin testing. The contact impedance value is controlled within a certain range, so that if it exceeds the range, it fails and subsequent testing is not performed. After the contact impedance is properly addressed, testing can continue. This avoids problems such as the current calibration passing (PASS) due to contact impedance issues, but the actual calibration data being inaccurate, leading to risks in subsequent use.

[0023] like Figure 2 As shown, this application uses the ACCO STS8300 instrument, configured with an HPSM (High Precision Source Meter Module) board for high-precision floating voltage sources, and FXVI (Floating Voltage and Current Source Module) and other floating sources that can support Kelvin testing. The HPSM is used to simulate the power supply monitoring method of a single battery cell for high-precision calibration. The Kelvin dual-probe connection method is adopted, with the two probes connected to the FORCE and SENSE resource interfaces of the same group of the FXVI floating source, respectively. They are then connected to the corresponding pins of the socket with a dual-pin design through circuitry. After the chip is inserted, the corresponding pins of the chip will simultaneously contact the two pins of the socket to measure the contact impedance. If the detected contact impedance value exceeds the impedance parameter setting, the test is paused. After the contact impedance is corrected, the test continues, ensuring that the contact impedance is controlled within a certain range and preventing the actual calibration failure caused by contact impedance from flowing into subsequent processes.

[0024] S103, each port of the battery management system forms a channel, the channel is configured with a preset voltage value, and the gain error and DC offset are calculated based on the measurement results.

[0025] The channel voltage is configured to 2V, and the first voltage of each port of the battery management system is measured. Then the channel voltage is configured to 4V, and the second voltage of each port of the battery management system is measured. The gain error and DC offset of each channel are calculated based on the first voltage and the second voltage.

[0026] like Figure 1-2 As shown, ports VC0-VC6 of the battery management system are connected to a high-precision floating source. The required test voltage can be configured for each channel of VC0-VC6. For example, if each channel is configured with a voltage of 2V, the floating source accuracy can reach 50µV. The corresponding register voltage CODE is read. Similarly, other voltage values ​​can be configured to read the register code. The gain error for each channel is calculated according to the formula and adjusted. The DC offset is configured with a single value. The calculated fine-tuning data is written to the corresponding register. Each channel voltage can also be configured to 5V to confirm whether the measured voltage of each channel meets expectations.

[0027] Currently, the voltage of each cell (battery) channel is configured as U (e.g., 2000mV). The voltage code1 of each channel from VC0 to VC6 is measured. Then, the voltage of each channel is configured as Y (e.g., 4000mV), and the voltage code2 of each channel from VC0 to VC6 is measured. The gain error and DC offset are then calculated. Gain error: Cell_Gain = 2^16 * ( (Y * 10 - U * 10) * 1.0) / (( code2 - code1)) DC offset: Cell_Offset = (Cell_Gain * code2) / 2^16 - Y * 10 S105 writes the calculated gain error and DC offset data into the corresponding registers of the battery management system.

[0028] This application presents a mass production calibration solution for battery management system (BMS) voltage monitoring with controllable accuracy. In this application, the external circuitry is relatively small, the contact resistance is controllable, and the floating source can provide higher-precision voltage for rapid and high-precision calibration, thus realizing mass production testing of the battery management system.

[0029] like Figure 3As shown, this application provides a voltage calibration device for a battery management system. The device includes: a connection unit 201 for connecting a floating source to a port of the battery management system, wherein each port of the battery management system has two lines leading out to connect to the floating source, one of the two lines leading out of each port is used for input / output, and the other is used to measure the voltage / current of the pin; a calculation unit 202 for configuring the channel to a preset voltage value and calculating the gain error and DC offset based on the measurement results; and a writing unit 203 for writing the calculated gain error and DC offset data into the corresponding register of the battery management system.

[0030] In this application, the embodiments of the voltage calibration device for the battery management system are basically similar to the embodiments of the voltage calibration method for the battery management system. For relevant details, please refer to the description of the embodiments of the voltage calibration method for the battery management system.

[0031] This application also provides a chip testing system, including a voltage calibration device for any of the above-mentioned battery management systems.

[0032] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the voltage calibration method steps of the battery management system described above. The computer-readable storage medium may include, but is not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, microdrives, as well as magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0033] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed may be through some interfaces, indirect coupling or communication connection of devices or units, and may be electrical, mechanical, or other forms.

[0034] In the various embodiments of the present invention, all functional units can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A voltage calibration method of a battery management system, characterized by, The battery management system comprises a plurality of ports, each port is connected with a floating source, two lines are led out from each port and connected with the floating source, one of the two lines led out from each port is used for input / output, and the other is used for measuring voltage / current of a pin; Each port of the battery management system forms a channel, the channel is configured to a preset voltage value, gain error and DC offset are calculated according to a measurement result; Gain error and DC offset data calculated are written into a corresponding register of the battery management system. The channel is configured to a preset voltage value, gain error and DC offset are calculated according to a measurement result, which comprises:

2. The method of claim 1, wherein the voltage calibration of the battery management system is performed by a battery management system calibration device. The channel voltage is configured to 2V, a first voltage of each port of the battery management system is measured, then the channel voltage is configured to 4V, a second voltage of each port of the battery management system is measured, and gain error and DC offset of each channel are calculated according to the first voltage and the second voltage. After each port is connected with a floating source, the method further comprises:

3. The voltage calibration method of the battery management system according to claim 1 or 2, characterized in that, A contact impedance value is obtained through Kelvin test, whether the contact impedance value is in a preset range is detected, if yes, subsequent test steps are performed; if the contact impedance value is not in the preset range, the contact impedance is processed until the contact impedance is in the preset range, and then subsequent test steps are performed. The battery management system comprises seven ports, each port is connected with a floating source.

4. The voltage calibration method of the battery management system according to claim 1 or 2, characterized in that, The method comprises:

5. A voltage calibration apparatus of a battery management system, characterized by, A connecting unit is configured to connect a floating source with a port of a battery management system, two lines are led out from each port of the battery management system and connected with the floating source, one of the two lines led out from each port is used for input / output, and the other is used for measuring voltage / current of a pin; A calculating unit is configured to configure a channel to a preset voltage value, and calculate gain error and DC offset according to a measurement result; A writing unit is configured to write gain error and DC offset data calculated into a corresponding register of the battery management system. The calculating unit is configured to configure the channel voltage to 2V, measure a first voltage of each port of the battery management system, then configure the channel voltage to 4V, measure a second voltage of each port of the battery management system, and calculate gain error and DC offset of each channel according to the first voltage and the second voltage.

6. The voltage calibration apparatus of the battery management system according to claim 5, wherein, The method further comprises a detecting unit configured to obtain a contact impedance value through Kelvin test, detect whether the contact impedance value is in a preset range, if yes, perform subsequent test steps; if the contact impedance value is not in the preset range, process the contact impedance until the contact impedance is in the preset range, and then perform subsequent test steps.

7. The voltage calibration apparatus of the battery management system according to claim 5 or 6, wherein, The battery management system comprises seven ports, each port is connected with a floating source.

8. The voltage calibration apparatus of the battery management system according to claim 5 or 6, wherein, The program is executed by a processor to implement steps of the method in any one of claims 1-4.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The voltage calibration device comprises the battery management system in any one of claims 5-8.

10. A chip testing system, characterized by comprising: ​

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