A protection board micro-current acquisition system and method

Abstract

The present invention provides a micro-current acquisition system and method for a protection board in the technical field of lithium battery protection board testing. The system includes a high-speed acquisition box, a host computer, and a protection board tester; the high-speed acquisition box includes an MCU, a high-speed ADC chip, a current acquisition circuit, a power supply reference chip, a first isolated power supply, a second isolated power supply, a relay, an Ethernet communication module, and an IO interface; the MCU is respectively connected to the high-speed ADC chip, the power supply reference chip, the first isolated power supply, the Ethernet communication module, and the relay; the relay is respectively connected to the second isolated power supply and the IO interface; one end of the high-speed ADC chip is connected to the current acquisition circuit, and the other end is connected to the power supply reference chip; one end of the host computer is connected to the protection board tester, and the other end is connected to the Ethernet communication module; the protection board tester is connected to the IO interface. The advantages of the present invention are: greatly improving the speed, accuracy, and traceability of micro-current acquisition for the protection board.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery protection board testing, and particularly to a protection board micro-current acquisition system and method. Background Art

[0002] After the production of lithium batteries, a series of tests need to be carried out on them, including collecting the static current and power-off current of the protection board of the lithium battery through a protection board tester. Since the static current and power-off current are at the levels of μA and nA, belonging to micro-currents, and it is required to continuously collect micro-current data at a speed of more than 100Khz for 10S. However, the acquisition speed of traditional protection board testers cannot meet the requirements, and there is also interference from the antenna effect of other test lines, which affects the acquisition accuracy. Moreover, the data volume of continuously collecting 10S of micro-current data is too large, there is no space for storage, and it needs to be cyclically updated and stored, which affects the subsequent traceability.

[0003] Therefore, how to provide a protection board micro-current acquisition system and method to improve the acquisition speed, accuracy, and traceability of the protection board micro-current has become an urgent technical problem to be solved. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a protection board micro-current acquisition system and method to improve the acquisition speed, accuracy, and traceability of the protection board micro-current.

[0005] In a first aspect, the present invention provides a protection board micro-current acquisition system, including a high-speed acquisition box, a host computer, and a protection board tester;

[0006] The high-speed acquisition box includes an MCU, a high-speed ADC chip, a current acquisition circuit, a power reference chip, a first isolated power supply, a second isolated power supply, a relay, an Ethernet communication module, and an IO interface;

[0007] The MCU is respectively connected to the high-speed ADC chip, the power reference chip, the first isolated power supply, the Ethernet communication module, and the relay; the relay is respectively connected to the second isolated power supply and the IO interface; one end of the high-speed ADC chip is connected to the current acquisition circuit, and the other end is connected to the power reference chip;

[0008] One end of the host computer is connected to the protection board tester, and the other end is connected to the Ethernet communication module; the protection board tester is connected to the IO interface.

[0009] Further, the Ethernet communication module is a gigabit Ethernet communication module.

[0010] Further, it further includes a memory connected to the host computer.

[0011] Further, it further includes a protection board, which is connected to the current acquisition circuit and the relay.

[0012] In a second aspect, the present invention provides a method for collecting micro-current of a protection board, including the following steps:

[0013] Step S1: The host computer sends a start test instruction to the protection board tester and the MCU.

[0014] Step S2: The protection board tester and the MCU are initialized based on the received start test instruction.

[0015] Step S3: The MCU starts the current acquisition circuit to collect the current value of the protection board in real time.

[0016] Step S4: The MCU sets the acquisition frequency of the high-speed ADC chip, collects the current data of the current acquisition circuit for a preset duration through the acquisition frequency, and sends the current data to the host computer.

[0017] Step S5: The host computer calculates the micro-current value based on the received current data, and stores the current data and the micro-current value.

[0018] Further, in the step S1, the start test instruction carries the acquisition frequency.

[0019] Further, the step S2 is specifically as follows:

[0020] The protection board tester controls the protection board to charge and discharge through the high-speed acquisition box based on the received start test instruction; the MCU enters the micro-current acquisition mode based on the received start test instruction and disconnects the relay.

[0021] Further, the step S4 is specifically as follows:

[0022] The MCU analyzes the start test instruction to obtain the acquisition frequency, sets the high-speed ADC chip based on the acquisition frequency, the high-speed ADC chip collects the current data of the current acquisition circuit for a preset duration through the acquisition frequency, and sends the current data to the host computer in real time through the Ethernet communication module.

[0023] Further, the step S5 is specifically as follows:

[0024] The host computer calculates the average value of the current data for the preset duration to obtain the micro-current value, and stores the current data and the micro-current value in the memory.

[0025] The advantages of the present invention are as follows:

[0026] By setting up a high-speed acquisition box to connect to the host computer, the protection board tester, and the protection board, the high-speed acquisition box is equipped with a high-speed ADC chip for high-speed sampling of the current acquisition circuit, meeting an acquisition speed (acquisition frequency) above 100Khz; by setting up the relay of the high-speed acquisition box to connect to the MCU and the second isolated power supply, when the MCU enters the micro-current acquisition mode, disconnecting the relay can eliminate the interference brought by the relay and also eliminate other signal lines connected by the relay to reduce line length interference and improve the signal-to-noise ratio; the MCU sends the acquired current data to the host computer in real time through the Ethernet communication module, and the host computer calculates the micro-current value based on the received current data and stores the current data and the micro-current value in the memory to overcome the problem of the too small storage capacity of the protection board tester, ultimately greatly improving the speed, accuracy, and traceability of the micro-current acquisition of the protection board. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below with reference to the accompanying drawings in conjunction with the embodiments.

[0028] Figure 1 It is a circuit principle block diagram of a micro-current acquisition system for a protection board according to the present invention.

[0029] Figure 2 It is a flowchart of a method for acquiring micro-current of a protection board according to the present invention.

[0030] MARKING DESCRIPTION:

[0031] 100 - A micro-current acquisition system for a protection board, 1 - High-speed acquisition box, 2 - Host computer, 3 - Protection board tester, 4 - Memory, 5 - Protection board, 11 - MCU, 12 - High-speed ADC chip, 13 - Current acquisition circuit, 14 - Power reference chip, 15 - First isolated power supply, 16 - Second isolated power supply, 17 - Relay, 18 - Ethernet communication module, 19 - IO interface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The overall idea of the technical solution in the embodiments of the present application is as follows: By setting up a high-speed ADC chip for high-speed sampling of the current acquisition circuit to improve the speed of micro-current acquisition of the protection board; by setting up a relay to connect to the MCU and the second isolated power supply and disconnecting the relay to isolate interference when entering the micro-current acquisition mode to improve the accuracy of micro-current acquisition of the protection board; by sending the current data to the host computer, the host computer calculates the micro-current value based on the received current data and stores the current data and the micro-current value in the memory to improve the traceability of micro-current acquisition of the protection board.

[0033] Please refer to Figures 1 to 2As shown in the figure, a preferred embodiment of a protection board micro-current acquisition system 100 of the present invention includes a high-speed acquisition box 1, a host computer 2, and a protection board tester 3; the high-speed acquisition box 1 is used for high-speed acquisition of the micro-current of the protection board 5; the host computer 2 is used to control the operation of the acquisition system 100; by connecting the high-speed acquisition box 1 to the host computer 2 and the protection board tester 3, one-stop testing (acquisition) is realized, without adding a data storage chip to the protection board tester 3, improving the space utilization rate, and thus reducing the cost;

[0034] The high-speed acquisition box 1 includes an MCU 11, a high-speed ADC chip 12, a current acquisition circuit 13, a power reference chip 14, a first isolated power supply 15, a second isolated power supply 16, a relay 17, an Ethernet communication module 18, and an IO interface 19; the MCU 11 is used to control the operation of the high-speed acquisition box 1; the high-speed ADC chip 12 is used for high-speed analog-to-digital conversion, that is, high-speed sampling of the micro-current, supporting an acquisition frequency above 100Khz; the current acquisition circuit 13 is used to acquire the model signal of the current value of the protection board 5; the power reference chip 14 is used to provide a clock reference signal for the MCU 11 and the high-speed ADC chip 12; the relay 17 is used to connect the remaining signal lines (not shown) on the protection board 5. When the MCU 11 receives the start test instruction from the host computer 2, the relay 17 is disconnected, so that the relay 17 is in a power-off state to reduce interference and improve the signal-to-noise ratio. And the length of the signal line is generally about 2.5 meters. When not in use, it is connected to the protection board 5, which is equivalent to an antenna and is easily interfered with when acquiring micro-current. Disconnecting the relay 17 can also isolate the interference of the antenna; the Ethernet communication module 18 is used for communication between the host computer 2 and the MCU 11; the IO interface 19 is used for communication between the protection board tester 3 and the MCU 11;

[0035] The MCU 11 is respectively connected to the high-speed ADC chip 12, the power reference chip 14, the first isolated power supply 15, the Ethernet communication module 18, and the relay 17; the relay 17 is respectively connected to the second isolated power supply 16 and the IO interface 19; one end of the high-speed ADC chip 12 is connected to the current acquisition circuit 13, and the other end is connected to the power reference chip 14;

[0036] One end of the host computer 2 is connected to the protection board tester 3 through Ethernet, and the other end is connected to the Ethernet communication module 18; the protection board tester 3 is connected to the IO interface 19.

[0037] The Ethernet communication module 18 is a gigabit Ethernet communication module, which greatly improves the communication rate and thus greatly improves the timeliness of data transmission.

[0038] It further includes a memory 4, connected to the host computer 2, for storing relevant collected data.

[0039] It further includes a protection board (BMS) 5, connected to the current acquisition circuit 13 and the relay 17.

[0040] A preferred embodiment of the method for collecting micro-current of the protection board in the present invention includes the following steps:

[0041] Step S1: The host computer sends a start test instruction to the protection board tester and the MCU.

[0042] Step S2: The protection board tester and the MCU are initialized based on the received start test instruction.

[0043] Step S3: The MCU starts the current acquisition circuit to collect the current value of the protection board in real time.

[0044] Step S4: The MCU sets the acquisition frequency of the high-speed ADC chip, acquires the current data of the current acquisition circuit for a preset duration through the acquisition frequency, and sends the current data to the host computer; the preset duration is preferably 10S; that is, the MCU does not perform calculation processing on the collected current data, but sends it to the host computer for calculation processing, making full use of the powerful computing power of the host computer.

[0045] Step S5: The host computer calculates the micro-current value based on the received current data, and stores the current data and the micro-current value for later traceability.

[0046] In the step S1, the start test instruction carries the acquisition frequency.

[0047] The specific content of the step S2 is as follows:

[0048] Based on the received start test instruction, the protection board tester controls the protection board to charge and discharge through the high-speed acquisition box; the MCU enters the micro-current acquisition mode based on the received start test instruction and disconnects the relay.

[0049] The specific content of the step S4 is as follows:

[0050] The MCU parses the start test instruction to obtain the acquisition frequency, sets the high-speed ADC chip based on the acquisition frequency, the high-speed ADC chip acquires the current data of the current acquisition circuit for a preset duration through the acquisition frequency, and sends the current data to the host computer in real time through the Ethernet communication module.

[0051] The specific content of the step S5 is as follows:

[0052] The host computer calculates the average value of the current data for the preset duration, thereby obtaining the micro-current value, and stores the current data and the micro-current value in the memory.

[0053] In summary, the advantages of the present invention are as follows:

[0054] By setting a high-speed acquisition box to connect to the host computer, the protection board tester, and the protection board, and setting a high-speed ADC chip in the high-speed acquisition box for high-speed sampling of the current acquisition circuit to meet the acquisition speed (acquisition frequency) above 100Khz; by setting the relay of the high-speed acquisition box to connect to the MCU and the second isolated power supply, when the MCU enters the micro-current acquisition mode, disconnecting the relay can eliminate the interference brought by the relay and also eliminate other signal lines connected by the relay to reduce the line length interference and improve the signal-to-noise ratio; by the MCU, the acquired current data is sent to the host computer in real time through the Ethernet communication module, and the host computer calculates the micro-current value based on the received current data and stores the current data and the micro-current value in the memory to overcome the problem of too small storage capacity of the protection board tester, and ultimately greatly improves the speed, accuracy, and traceability of the micro-current acquisition of the protection board.

[0055] Although the specific embodiments of the present invention have been described above, those skilled in the art of this technology should understand that the specific embodiments we described are illustrative rather than used to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be covered by the scope protected by the claims of the present invention.

Claims

1. A method for collecting micro-current of a protection board, characterized in that: The method needs to use a protection board micro-current acquisition system as follows, including a high-speed acquisition box, a host computer, and a protection board tester; The high-speed acquisition box includes an MCU, a high-speed ADC chip, a current acquisition circuit, a power reference chip, a first isolated power supply, a second isolated power supply, a relay, an Ethernet communication module, and an IO interface; The MCU is respectively connected to the high-speed ADC chip, the power reference chip, the first isolated power supply, the Ethernet communication module, and the relay; the relay is respectively connected to the second isolated power supply and the IO interface; one end of the high-speed ADC chip is connected to the current acquisition circuit, and the other end is connected to the power reference chip; One end of the host computer is connected to the protection board tester, and the other end is connected to the Ethernet communication module; the protection board tester is connected to the IO interface; The Ethernet communication module is a gigabit Ethernet communication module; It further includes a memory connected to the host computer; It further includes a protection board connected to the current acquisition circuit and the relay; The method includes the following steps: Step S1, the host computer sends a start test instruction to the protection board tester and the MCU; Step S2, the protection board tester and the MCU are initialized based on the received start test instruction; Step S3, the MCU starts the current acquisition circuit to collect the current value of the protection board in real time; Step S4, the MCU sets the acquisition frequency of the high-speed ADC chip, collects the current data of the current acquisition circuit for a preset duration through the acquisition frequency, and sends the current data to the host computer; Step S5, the host computer calculates the micro-current value based on the received current data, and stores the current data and the micro-current value.

2. The method for collecting micro-current of a protection board according to claim 1, characterized in that: In the step S1, the start test instruction carries the acquisition frequency.

3. The method for collecting micro-current of a protection board according to claim 1, characterized in that: The step S2 is specifically: The protection board tester controls the protection board to charge and discharge through the high-speed acquisition box based on the received start test instruction; the MCU enters the micro-current acquisition mode based on the received start test instruction and disconnects the relay.

4. The method for collecting micro-current of a protection board according to claim 1, characterized in that: The step S4 is specifically: The MCU analyzes the start test instruction to obtain the acquisition frequency, sets the high-speed ADC chip based on the acquisition frequency, the high-speed ADC chip collects the current data of the current acquisition circuit for a preset duration through the acquisition frequency, and sends the current data to the host computer in real time through the Ethernet communication module.

5. The method for collecting micro-current of a protection board according to claim 1, characterized in that: The step S5 is specifically: The host computer calculates the average value of the current data for a preset duration to obtain the micro-current value, and stores the current data and the micro-current value in the memory.

Images