Voltage calibration device for DC-DC power supply control module

Abstract

The utility model aims to provide the DC-DC power supply control module voltage calibration device which is good in test compatibility and high in precision. The device comprises an upper computer, a switch, a middle computer, a universal meter, a control module and a board to be tested, the upper computer is in communication connection with the board to be tested through the switch and the middle computer in sequence, and the board to be tested is connected with the switch and the universal meter through the control module. The control module comprises a voltage acquisition port switching module and a programmable standard voltage source, the programmable standard voltage source is connected with the voltage acquisition port switching module, the switch and the universal meter, and the voltage acquisition port switching module is connected with the tested board. The device is applied to the technical field of formation and capacity grading detection equipment.

Description

Technical Field

[0001] The utility model is applied to the technical field of chemical component capacity detection equipment, and particularly relates to a DC-DC power supply control module voltage calibration device. Background Art

[0002] With the rapid development of mobile phones, smart wireless devices and electric vehicles, the market demand for lithium batteries is becoming more and more extensive, and as a result, the demand for lithium battery composition and capacity testing equipment is also increasing, and the testing requirements for production and manufacturing are becoming higher and higher.

[0003] Formation refers to the electrochemical process in which a certain current is supplied to the lithium battery after the battery is assembled, so that the active materials at the positive and negative electrodes of the lithium battery are stimulated, and finally the battery has the ability to discharge. Factors affecting formation include formation current, SOC, aging time and temperature, and the battery material system and production capacity requirements must also be considered. Therefore, formation is not just a simple charging and discharging process, but a comprehensive measure of the impact of different parameters on battery performance, which requires the use of instruments and equipment to conduct a large amount of accurate data testing and research and verification.

[0004] Capacity grading is to charge and discharge the formed battery. The charge and discharge currents of different types of batteries are slightly different, so that the battery capacity, charging constant current ratio, discharge platform voltage, internal resistance, etc. can be statistically distinguished, and the monomers with the same indicators can be screened out for grading and grouping. Only those with very similar performance can form a battery pack. On the other hand, the poor consistency of single cells may also lead to reduced safety of the battery pack. For example, in order to meet the energy needs of electric vehicles, power battery packs often require dozens to thousands of batteries. Affected by the complexity of the system, the behavior of the battery pack is unique, and the performance of the battery pack cannot be obtained by simply adding and subtracting single cells.

[0005] In order to improve the electrochemical properties of batteries, such as cycle life, stability, self-discharge, and safety, the consistency of batteries must be strictly controlled and the battery grade must be accurately assessed. This places high demands on the current and voltage measurement accuracy of chemical composition and capacity detection equipment, and also helps battery manufacturers and test equipment providers expand battery production and improve efficiency, and seize the key opportunity of production and sales explosion in the electric vehicle market. Limited by the chip acquisition accuracy, and in order to reduce battery costs, manufacturers need to take a comprehensive approach and use the supplier's system-level expertise to reduce the overall battery test circuit area size while increasing the number of channels. They must also maintain the accuracy, reliability, and speed of test measurements, and achieve an accuracy of more than ±0.05% even under harsh factory conditions.

[0006] The chemical composition and capacity detection equipment of lithium batteries is mainly composed of a charging power supply unit, a needle bed unit, a temperature control unit and background monitoring software. The core unit is the charging and discharging power supply unit, which is composed of a bidirectional AC / DC power supply, a mid-position machine, a DC-DC power supply control module and a DC-DC power supply. It is necessary to purchase a standard voltage source additionally, which is expensive. Separately designed modules need to be controlled separately. Therefore, it is necessary to provide a DC-DC power supply control module voltage calibration device with good test compatibility and high accuracy. Utility Model Content

[0007] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a DC-DC power supply control module voltage calibration device with good test compatibility and high precision.

[0008] The technical solution adopted by the utility model is: the utility model includes a host computer, a switch, a middle computer, a multimeter, a control module and a tested board, the host computer is sequentially connected to the tested board through the switch and the middle computer, the tested board is connected to the switch and the multimeter through the control module, the control module includes a voltage acquisition port switching module and a programmable standard voltage source, the programmable standard voltage source is connected to the voltage acquisition port switching module, the switch and the multimeter, and the voltage acquisition port switching module is connected to the tested board.

[0009] It can be seen from the above scheme that this application uses a 16-bit high-precision DAC chip to design a programmable standard voltage source, which is integrated into the MCU control module. The standard voltage source has a programmable output of 0-5V, and a single module voltage acquisition port is designed as 16 channels, which can basically cover the product testing needs on the market, can be reused in other projects, and integrated into the MCU control module. It is cheap and suitable for mass applications.

[0010] A preferred solution is that the positive pole and the negative pole of the voltage acquisition port switching module are respectively selected from two groups of 16-way electronic switches, and the four electronic switches include a first switch, a second switch, a third switch, and a fourth switch.

[0011] A preferred solution is that the programmable standard voltage source includes a digital-to-analog converter, an operational amplifier, a relay and a connector connected in sequence, the control module controls the digital-to-analog converter to output 0-2.5V through the I2C bus, and after amplification by the operational amplifier, the analog output standard voltage source is output, and the connector is connected to the multimeter.

[0012] A preferred solution is that the DC-DC power supply control module voltage calibration device further includes a programmable read-only memory, and the control module is connected to the programmable read-only memory via an I2C bus. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural block diagram of the utility model;

[0014] Figure 2 is a circuit schematic diagram of the programmable standard voltage source;

[0015] Figure 3 is a circuit schematic diagram of the voltage acquisition port switching module;

[0016] Figure 4 It is a circuit schematic diagram of the programmable read-only memory. DETAILED DESCRIPTION

[0017] like Figure 1 As shown, in this embodiment, the utility model includes a host computer 1, a switch 2, a middle computer 3, a multimeter 4, a control module 5 and a tested board 6. The host computer 1 is sequentially connected to the tested board 6 through the switch 2 and the middle computer 3, and the tested board 6 is connected to the switch 2 and the multimeter 4 through the control module 5. The control module 5 includes a voltage acquisition port switching module and a programmable standard voltage source. The programmable standard voltage source is connected to the voltage acquisition port switching module, the switch 2, and the multimeter 4, and the voltage acquisition port switching module is connected to the tested board 6.

[0018] The host computer 1 is used to run the program; the switch 2 is used to complete the information exchange between the instrument and the host computer 1; the tested board 6 includes a DC-DC power supply control module, and the intermediate computer 3 is used to forward the communication data between the host computer 1 and the DC-DC power supply control module; the multimeter 4 adopts a six-and-a-half-digit desktop digital multimeter with model 34465A, which is used to measure the voltage of the voltage source; the control module 5 communicates with the host computer 1 through the network port.

[0019] like Figure 3 As shown, in this embodiment, Figure 1 As shown, in this embodiment, the positive and negative poles of the voltage acquisition port switching module are respectively selected from two groups of 16-way electronic switches, and the four electronic switches include a first switch U1000, a second switch U1001, a third switch U1002, and a fourth switch U1003. The models of the four electronic switches are all ADG1406BRUZ-REEL7. The electronic switches are switched independently, which can ensure that each voltage path is independently controlled, thereby performing independent calibration and ensuring measurement accuracy.

[0020] like Figure 2As shown, in this embodiment, the programmable standard voltage source includes a digital-to-analog converter U1201, an operational amplifier U1200, a relay K1200 and a connector J1200 connected in sequence, and the control module 5 controls the digital-to-analog converter U1201 to output 0-2.5V through the I2C bus, and after amplification by the operational amplifier U1200, the analog output standard voltage source is output, and the connector J1200 is connected to the multimeter 4. The operational amplifier U1200 uses a 16-bit high-precision DAC chip AD5667RBRMZ-1REEL7, which belongs to the nanoDAC series, is a low-power, dual-channel, 16-bit buffered voltage output digital-to-analog converter (DAC), with or without an on-chip reference voltage source, powered by a single power supply of 2.7 V to 5.5 V, monotonicity is guaranteed by design, and there is also an I2C compatible serial interface; a power-on reset circuit is built in to ensure that the DAC output is powered on to 0 V and maintains this level until a valid write operation is performed. In addition, it has independent power saving features for each channel. In power saving mode, the power consumption of the device is reduced to 480 nA at 5 V, and software-selectable output loads are provided. In normal working mode, the device has low power consumption characteristics and is very suitable for portable battery-powered devices. It has a built-in on-chip precision output amplifier that can achieve rail-to-rail output swing; it uses a two-wire I2C-compatible serial interface and can operate in three modes: standard (100kHz), fast (400 kHz) and high-speed (3.4 MHz). The model of the operational amplifier U1200 is OPA2196IDGKR.

[0021] like Figure 4 As shown, in this embodiment, the DC-DC power supply control module voltage calibration device further includes a programmable read-only memory U1203, and the control module 5 is connected to the programmable read-only memory U1203 via an I2C bus. The model of the programmable read-only memory U1203 is CAT24C32YI-GT3.

[0022] In this embodiment, the DC-DC power supply control module voltage calibration steps are:

[0023] A. The control module 5 controls the digital-to-analog converter U1201 to output 0-2.5V through the I2C bus, and after being amplified by the operational amplifier U1200 by 2 times, it simulates and outputs a 0-5V standard voltage source;

[0024] B. The control module 5 controls the relay K1200 to close through the I2C bus, and connects the standard voltage source signal to the multimeter 4;

[0025] C. The host computer 1 sends instructions to control the multimeter 4 to read the voltage value and generate a test record;

[0026] D. The control module 5 controls the corresponding channels of the electronic switches through the I2C bus (U1000, U1001 closed, U1002, U10003) to be disconnected or (U1000, U1001 disconnected, U1002, U10003) to be closed;

[0027] E. The host computer 1 sends instructions to control the bidirectional DC-DC power supply control module to read the voltages of the two groups of 16 voltage acquisition ports respectively, and generate test records;

[0028] F. Analyze the measurement results:

[0029] a. Compare the voltage read by the multimeter 4 with the voltage read by the bidirectional DC-DC power supply control module and calculate the calibration coefficient;

[0030] b. The control module 5 writes the calibration coefficient into the PROM U1203 via the I2C bus.

Claims

1. A DC-DC power supply control module voltage calibration device, characterized in that: The device comprises a host computer (1), a switch (2), a middle computer (3), a multimeter (4), a control module (5) and a board under test (6); the host computer (1) is sequentially connected to the board under test (6) through the switch (2) and the middle computer (3); the board under test (6) is connected to the switch (2) and the multimeter (4) through the control module (5); the control module (5) comprises a voltage acquisition port switching module and a programmable standard voltage source; the programmable standard voltage source is connected to the voltage acquisition port switching module, the switch (2) and the multimeter (4); and the voltage acquisition port switching module is connected to the board under test (6).

2. A DC-DC power supply control module voltage calibration device according to claim 1, characterized in that: The positive and negative poles of the voltage acquisition port switching module are respectively selected from two groups of 16-way electronic switches, and the four electronic switches include a first switch (U1000), a second switch (U1001), a third switch (U1002), and a fourth switch (U1003).

3. A DC-DC power supply control module voltage calibration device according to claim 1, characterized in that: The programmable standard voltage source comprises a digital-to-analog converter (U1201), an operational amplifier (U1200), a relay (K1200) and a connector (J1200) which are connected in sequence. The control module (5) controls the digital-to-analog converter (U1201) to output 0-2.5V through an I2C bus. After amplification by the operational amplifier (U1200), the analog output standard voltage source is output. The connector (J1200) is connected to the multimeter (4).

4. A DC-DC power supply control module voltage calibration device according to claim 1, characterized in that: The DC-DC power supply control module voltage calibration device also includes a programmable read-only memory (U1203), and the control module (5) is connected to the programmable read-only memory (U1203) via an I2C bus.

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