BMS-based function test circuit and method

Abstract

The invention aims to provide a BMS-based function test circuit and method. The circuit comprises a BMS battery management system, a first direct-current power supply, a super capacitor module and a second direct-current power supply, the first direct current power supply is connected with the BMS battery management system; the super capacitor module is connected with the BMS battery management system; the second direct-current power supply is connected with the super-capacitor module and controls charging and discharging of the super-capacitor module; and the second direct current power supply is connected with the BMS battery management system so as to realize a reverse overvoltage test. Therefore, the defect that the cell simulator cannot realize large-current power supply is overcome, and the test flexibility and the test coverage rate are improved; and the cost of the device is reduced, and the control of the production cost is facilitated.

Description

Technical Field

[0001] This application relates to the field of circuit testing, and particularly to a function test circuit and method based on a BMS. Background Art

[0002] Functional test (FCT) generally refers to the test after the power-on of a populated printed circuit board (PCBA), mainly including test items such as voltage, current, frequency, duty cycle, temperature, resistance, FLASH and EEPROM programming, etc. It is mainly to discover the defects that may be introduced by equipment status and human operation factors during the mass production of populated printed circuit boards of various electronic products. The traditional 12V BMS test solution uses a cell simulator to achieve the simulated power supply for the cells in the BMS, so as to complete function tests such as voltage accuracy, current accuracy, and balancing. However, for high-current output, due to the limited current output capacity of the cell simulator, the corresponding module function verification cannot be completed. If a related circuit fault occurs after the battery pack is assembled, the troubleshooting difficulty increases linearly; in addition, the use of the cell simulator has a high cost, which also greatly increases the production cost. Summary of the Invention

[0003] An object of this application is to provide a function test circuit and method based on a BMS, which solves the problems in the prior art that the corresponding module function verification cannot be completed for high-current output, the troubleshooting difficulty is high when a circuit fault occurs, and the production cost of the used devices is relatively high.

[0004] According to one aspect of this application, a function test circuit based on a BMS is provided. The circuit includes: a BMS battery management system, a first DC power supply, a supercapacitor module, and a second DC power supply;

[0005] The first DC power supply is connected to the BMS battery management system;

[0006] The supercapacitor module is connected to the BMS battery management system;

[0007] The second DC power supply is connected to the supercapacitor module and controls the charging and discharging of the supercapacitor module;

[0008] The second DC power supply is connected to the BMS battery management system to achieve reverse overvoltage testing.

[0009] Optionally, the circuit includes a multimeter module, a constant current source, and a load module. The multimeter module is connected to the first DC power supply and the BMS battery management system. The constant current source is connected to the BMS battery management system for current accuracy testing and calibration. The load module is connected to the supercapacitor module and the BMS battery management system to test the output capacity of the BMS battery management system.

[0010] Optionally, the circuit includes a switch module, the switch module includes a first switch, a second switch, and a third switch, and the BMS battery management system includes a first output port and a second output port;

[0011] The second DC power supply is connected to the first output port through the first switch and the third switch. When the first switch and the third switch are closed, a reverse overvoltage test is performed on the first output port;

[0012] The second DC power supply is connected to the second output port through the second switch and the third switch. When the second switch and the third switch are closed, a reverse overvoltage test is performed on the second output port.

[0013] Optionally, the switch module includes a fourth switch, and the fourth switch is connected in parallel with the third switch and is used to control the charging and discharging of the supercapacitor module.

[0014] Optionally, the switch module includes a fifth switch and a sixth switch. One end of the sixth switch is connected to the battery cell in the BMS battery management system, the other end is connected to one end of the fifth switch, and the other end of the fifth switch is connected to the third switch.

[0015] Optionally, the switch module includes a seventh switch, an eighth switch, a ninth switch, and a tenth switch. The eighth switch and the ninth switch are respectively connected to the positive electrode of the constant current source, and the seventh switch and the tenth switch are respectively connected to the negative electrode of the constant current source;

[0016] When the seventh switch and the eighth switch are closed, a positive current is injected into the circuit board;

[0017] When the ninth switch and the tenth switch are closed, a negative current is injected into the circuit board.

[0018] Optionally, the circuit includes a first ammeter and a second ammeter. The first ammeter is connected to the input pin of the BMS battery management system to implement the test of the input current, and the second ammeter is connected to the negative electrode of the battery cell of the BMS battery management system to implement the test of the output current.

[0019] According to another aspect of the present application, there is also provided a method for functional testing based on BMS, and the method includes:

[0020] Powering the BMS through a first DC power supply, charging the supercapacitor module through a second DC power supply, and discharging the supercapacitor module through a load module to adjust the voltage data of the supercapacitor module according to the test requirements of the test item;

[0021] The BMS battery management system is functionally tested according to the test items, where the test items include reverse overvoltage test, overcurrent protection test, current accuracy test and calibration.

[0022] Optionally, the BMS battery management system is functionally tested according to the test items, including:

[0023] The reverse overvoltage test of the first output port is achieved by closing the first switch and the third switch;

[0024] The reverse overvoltage test of the second output port is achieved by closing the second switch and the third switch;

[0025] When the output current is greater than the preset current threshold, the current value of the load module is adjusted, and the outputs of the first output port and the second output port are turned on for overcurrent protection test;

[0026] The current accuracy test and calibration are achieved by the on-off control of the constant current source and the seventh switch, the eighth switch, the ninth switch and the tenth switch.

[0027] Optionally, the test items include voltage accuracy test, equalization test, charge and discharge function test, working current test. The BMS battery management system is functionally tested according to the test items, including:

[0028] The voltage accuracy test is carried out through the supercapacitor module, and the equalization test is carried out through the load module;

[0029] The static current is tested through the multimeter module;

[0030] The charge and discharge function test and the working current test are achieved by detecting the input current and the output current respectively through the first ammeter and the second ammeter.

[0031] Compared with the prior art, the present application provides a functional test circuit based on BMS, which includes: a BMS battery management system, a first DC power supply, a supercapacitor module and a second DC power supply; the first DC power supply is connected to the BMS battery management system; the supercapacitor module is connected to the BMS battery management system; the second DC power supply is connected to the supercapacitor module and controls the charge and discharge of the supercapacitor module; the second DC power supply is connected to the BMS battery management system to achieve the reverse overvoltage test. Thus, the disadvantage of the large current power supply that cannot be achieved by the cell simulator is solved, the test flexibility and test coverage are improved; and the cost of the device is reduced, which is beneficial to the control of production cost. Description of the Drawings

[0032] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments read in conjunction with the accompanying drawings:

[0033] Figure 1 A schematic framework diagram of a BMS-based functional test circuit provided according to an aspect of the present application is shown;

[0034] Figure 2 A circuit framework diagram of the functional test of a 12V BMS in an embodiment of the present application is shown;

[0035] Figure 3 A schematic flowchart of a method for BMS-based functional test provided according to another aspect of the present application is shown.

[0036] Identical or similar reference numerals in the drawings represent identical or similar components. Detailed Embodiments

[0037] The following description is used to disclose the present application so that those skilled in the art can implement the present application. The preferred embodiments described below are only examples, and other obvious variations can be conceived by those skilled in the art. The basic principles defined in the following description can be applied to other embodiments, variations, improvements, equivalent embodiments, and other technical solutions that do not depart from the spirit and scope of the present application.

[0038] The following is combined with the attached Figures 1 - 3 The exemplary embodiments of the present application are further described in a comprehensive manner. However, the exemplary embodiments can be implemented in various forms and should not be construed as limited to the embodiments described herein. On the contrary, providing these exemplary embodiments enables the present application to be more comprehensive and complete, and more convenient to fully convey the inventive concept to those skilled in the art. Identical reference numerals in the figures represent identical or similar elements, components, or parts, and thus their repeated description will be omitted.

[0039] On the premise of conforming to the technical concept of the present application, the features, structures, characteristics, or other details described in a specific embodiment are not excluded from being combined in a suitable manner in one or more other embodiments.

[0040] In the description of specific embodiments, the features, structures, characteristics, or other details described in the present application are for those skilled in the art to fully understand the embodiments. However, it does not exclude that those skilled in the art can practice the technical solutions of the present application without one or more of the specific features, structures, characteristics, or other details.

[0041] Figure 1A schematic diagram of the framework of a BMS-based functional test circuit provided according to an aspect of the present application is shown. The circuit includes: a BMS battery management system 100, a first DC power supply 200, a supercapacitor module 300, and a second DC power supply 400; the first DC power supply 200 is connected to the BMS battery management system 100; the supercapacitor module 300 is connected to the BMS battery management system 100; the second DC power supply 200 is connected to the supercapacitor module 300 and controls the charging and discharging of the supercapacitor module 300; the second DC power supply 400 is connected to the BMS battery management system 100 to implement reverse overvoltage testing. Here, the BMS battery management system 100 can be a 12V BMS, mainly for managing the cells of 4 lithium battery cells, including management of charging and discharging, balancing, input and output control, etc. The 4 lithium battery cells are in series. The first DC power supply powers the BMS and facilitates subsequent testing of working current and static current; the second DC power supply is added to power the supercapacitor module, and the supercapacitor is charged and discharged according to the requirements of actual test steps, thus ensuring voltage stability and the accuracy of test data. Connecting the second DC power supply to the BMS battery management system can perform reverse overvoltage testing on the output port of the BMS; the supercapacitor module 300 powers the cells in the BMS battery management system 100. Because the supercapacitor has the characteristics of fast charging and discharging, it can quickly respond to corresponding test requests. Compared with batteries, the supercapacitor is not sensitive to overcharging and over-discharging, so its lifespan is not affected by these factors, and the cost can be greatly saved. Among them, the supercapacitor module includes one or more supercapacitor monomers, and multiple supercapacitor monomers can be connected in series, parallel, or series-parallel hybrid to achieve the function of the supercapacitor.

[0042] In some embodiments of the present application, such as Figure 2The shown test circuit framework diagram, the circuit includes a multimeter module, a constant current source and a load module. The multimeter module is connected to the first DC power supply and the BMS battery management system. The constant current source is connected to the BMS battery management system for current accuracy testing and calibration. The load module is connected to the supercapacitor module and the BMS battery management system to test the output capacity of the BMS battery management system. Here, the multimeter module uses a high-precision multimeter, and the high-precision multimeter is connected to the first DC power supply (DC power supply 1) and the BMS, mainly for the testing of static current and working current. Through the cooperation of the constant current source and the switch module, current accuracy testing and calibration are achieved. The load module is an electronic load, which is used to verify the output capacity. The output of the output port of the BMS must have a corresponding load and current to verify the corresponding output capacity. When the output capacity needs to be verified, the load module is turned on and the load current is set as required. The circuit described in the embodiment of the present application can also perform overcurrent protection testing of hardware and software. The overcurrent protection requires the output current to be greater than 100A, that is, when the output is a large current, the load module output is adjusted to 150A, and the output of the output port of the BMS is turned on. At this time, the hardware or software will protect the current. When the output current is greater than 100A, it is impossible to achieve it by using cell simulation or other methods.

[0043] In some embodiments of the present application, the circuit includes a switch module. The switch module includes a first switch, a second switch, and a third switch. The BMS battery management system includes a first output port and a second output port. The second DC power supply is connected to the first output port through the first switch and the third switch. When the first switch and the third switch are closed, a reverse overvoltage test is performed on the first output port. The second DC power supply is connected to the second output port through the second switch and the third switch. When the second switch and the third switch are closed, a reverse overvoltage test is performed on the second output port. Here, continue to refer to Figure 2, the BMS battery management system includes a first output port (Bout1) and a second output port (Bout2). There are 4 battery cells in the BMS. Among them, Cell1_Neg represents the negative electrode of battery cell 1, Cell1_Pos represents the positive electrode of battery cell 1, Cell2_Pos represents the positive electrode of battery cell 2, Cell3_Pos represents the positive electrode of battery cell 3, and Cell4_Pos represents the positive electrode of battery cell 4. The 4 battery cells are connected to the supercapacitor module to supply power to the supercapacitor. The circuit of this application further includes a switch module, which includes a plurality of switch elements and can be a relay switch; one end of the first switch K1 is connected to the first output port Bout1, and the other end is connected to the DC power supply 2. One end of the second switch K2 is connected to the second output port Bout2, and the other end is connected to the DC power supply 2; when the first switch K1 and the third switch K3 are closed, the DC power supply 2 provides overvoltage, and the reverse overvoltage test of output port 1 can be realized. When the second switch K2 and the third switch K3 are closed, the DC power supply 2 provides overvoltage, and the reverse overvoltage test of output port 2 can be realized, improving the test coverage rate.

[0044] In some embodiments of this application, the switch module includes a fourth switch, and the fourth switch is connected in parallel with the third switch and is used to control the charging and discharging of the supercapacitor module. Here, as Figure 2 shown, the fourth switch K4 is connected in parallel with the third switch K3. K4 is a relay, and the charging and discharging of the supercapacitor is realized through K4.

[0045] In some embodiments of this application, the switch module includes a fifth switch and a sixth switch. One end of the sixth switch is connected to the battery cell in the BMS battery management system, and the other end is connected to one end of the fifth switch. The other end of the fifth switch is connected to the third switch. Here, the switch module further includes a fifth switch K5 and a sixth switch K6. The sixth switch K6 is connected to the positive electrode of the battery cell. One end of the fifth switch K5 is connected to the third switch K3, and the other end is connected to K6; thus, when K3, K5, and K6 are closed simultaneously, the supercapacitor can be powered to ensure voltage stability, and further ensure the voltage stability during the charging and discharging process.

[0046] In some embodiments of this application, the circuit includes a first ammeter and a second ammeter. The first ammeter is connected to the input pin of the BMS battery management system to realize the test of the input current, and the second ammeter is connected to the negative electrode of the battery cell of the BMS battery management system to realize the test of the output current. Here, continuing to refer to Figure 2 , the first ammeter A1 and the second ammeter A2 are Hall ammeters. A1 is connected to the input pin Bin of the BMS, and A2 is connected to the negative electrode of the battery cell of the BMS. The detection of the input and output currents can be realized respectively, so as to realize the charging and discharging function test.

[0047] In some embodiments of the present application, the switch module includes a seventh switch, an eighth switch, a ninth switch, and a tenth switch. The eighth switch and the ninth switch are respectively connected to the positive pole of the constant current source, and the seventh switch and the tenth switch are respectively connected to the negative pole of the constant current source. When the seventh switch and the eighth switch are closed, a positive current is injected into the circuit board. When the ninth switch and the tenth switch are closed, a negative current is injected into the circuit board. Here, continue to refer to Figure 2 , the constant current source does not have the ability to output positive and negative currents. In the embodiments of the present application, it is realized by controlling a switching element (such as a relay). When the seventh switch K7 and the eighth switch K8 are closed, the constant current source output is turned on, and a positive current is injected into the Shunt pin of the circuit board. The current collected by the BMS is compared with the current collected by the second ammeter A2. When the ninth switch K9 and the tenth switch K10 are closed, the constant current source output is turned on, and a negative current is injected into the Shunt pin of the circuit board. The current collected by the BMS is compared with the current collected by A2. The above collected currents are compared and calculated, and the corresponding KB value is written to complete the calibration of the current accuracy.

[0048] Continue to refer to Figure 2 , in the circuit of the present application, the switch module further includes an eleventh switch K11 and a twelfth switch K12. The DC power supply 1 is connected to the ammeter A1 through the eleventh switch, and both ends of the high-precision multimeter are connected to K11 and K12 respectively to perform a static current test. The switch module further includes a thirteenth switch K13 and a fourteenth switch K14. K13 is connected to the negative pole KL31 of the BMS battery management system, and the ammeter A2 is connected to the negative pole of the load module through K14.

[0049] Figure 3 FIG. shows a schematic flowchart of a method for functional testing based on BMS provided according to another aspect of the present application. The method includes: step S11 and step S12. Among them, in step S11, the BMS is powered by a first DC power supply, the supercapacitor module is charged by a second DC power supply, and the supercapacitor module is discharged through a load module to adjust the voltage data of the supercapacitor module according to the test requirements of the test item. In step S12, the BMS battery management system is functionally tested according to the test item. The test item includes reverse overvoltage test, overcurrent protection test, and current accuracy test and calibration.

[0050] A second DC power supply is added to supply power to the supercapacitor module, and the supercapacitor module is discharged through the load module; the supercapacitor is charged and discharged according to the requirements of the actual test steps, thus ensuring the voltage stability and the accuracy of the test data. The supercapacitor has the characteristics of fast charge and discharge and can quickly respond to the corresponding test requests. During the test, for different test requirements, the voltage of the supercapacitor is adjusted to different values. For example, during the undervoltage test, the input voltage needs to be adjusted to 5.5V; during the KB calibration, the input voltage needs to be 13V, and during the charge and discharge test, the input voltage needs to be adjusted to 14V, etc.; at this time, a voltage stabilizer is required to charge or discharge the supercapacitor. The supercapacitor can complete the charge and discharge requests and the charge and discharge within a few seconds. Among them, a load module is used for discharging during discharge, and a second DC power supply is used for charging during charging.

[0051] In some embodiments of the present application, the test items include reverse overvoltage test, overcurrent protection test, current accuracy test and calibration. In step S12, the reverse overvoltage test of the first output port is realized by closing the first switch and the third switch; the reverse overvoltage test of the second output port is realized by closing the second switch and the third switch; when the output current is greater than the preset current threshold, the current value of the load module is adjusted, and the outputs of the first output port and the second output port are turned on for the overcurrent protection test; the current accuracy test and calibration are realized through the on-off control of the constant current source and the seventh switch, the eighth switch, the ninth switch and the tenth switch. Here, the tests that can be realized include the reverse overvoltage test of the BMS output port, the control test of the first output port, the output capacity test of the first port and the second port, the overcurrent protection test of the hardware and software can also be carried out, as well as the current calibration and the current accuracy test. Among them, the current accuracy test and calibration are realized through the on-off control of the constant current source and the seventh switch, the eighth switch, the ninth switch and the tenth switch; the reverse overvoltage test of output port 1 can be realized by closing the first switch and the third switch, and the reverse overvoltage test of output port 2 can be realized by closing the second switch and the third switch, improving the test coverage.

[0052] Continuing from the above embodiments, the test items include voltage accuracy test, balancing test, charge and discharge function test, and operating current test. In step S12, the voltage accuracy test is performed through the supercapacitor module, and the balancing test is performed through the load module; the static current is tested through the multimeter module; the input current and output current are respectively detected through the first ammeter and the second ammeter to implement the charge and discharge function test and the operating current test. Here, the test solution described in the present application can, in addition to the above test items, also perform voltage accuracy test, balancing test, input and output current test, charge and discharge function test, operating current, static current test, etc.; a high-precision multimeter is mainly used to test the static current and fair current, the balancing test is achieved through the load module, and the input and output currents are respectively detected through the Hall ammeters A1 and A2, thereby implementing the charge and discharge function test.

[0053] Through the circuit and test method described in the present application, the PCBA test items of the 12V BMS can be completed, and the test coverage rate can reach 90%. The main tests that can be achieved include voltage accuracy test, balancing test, charge and discharge function test (including large current and small current), output capacity test of the output port, current calibration and current accuracy test, hardware and software overcurrent protection test, operating current and static current test. The test solution used is simple to operate. By using the supercapacitor module, the disadvantage of the cell simulator that cannot provide large current power supply is solved, and the test flexibility and test coverage rate are improved; in addition, the cost of the supercapacitor is relatively low, which is beneficial to the control of production costs.

[0054] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

[0055] For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present application is defined by the appended claims rather than the above description. Therefore, it is intended to cover all changes falling within the meaning and scope of the equivalent elements of the claims in the present application. Any reference signs in the claims should not be regarded as limiting the claimed rights. In addition, obviously, the word "including" does not exclude other units or steps, and the singular does not exclude the plural. Words such as first, second, etc. are used to denote names and do not denote any particular order.

Claims

1. A functional test circuit based on BMS, characterized in that The circuit includes: a BMS battery management system, a first DC power supply, a supercapacitor module, and a second DC power supply; The first DC power supply is connected to the BMS battery management system; The supercapacitor module is connected to the BMS battery management system; The second DC power supply is connected to the supercapacitor module and controls the charging and discharging of the supercapacitor module; The second DC power supply is connected to the BMS battery management system to perform a reverse overvoltage test.

2. The circuit according to claim 1, wherein The circuit includes a multimeter module, a constant current source, and a load module. The multimeter module is connected to the first DC power supply and the BMS battery management system. The constant current source is connected to the BMS battery management system for current accuracy testing and calibration. The load module is connected to the supercapacitor module and the BMS battery management system to test the output capacity of the BMS battery management system.

3. The circuit according to claim 2, wherein, The circuit includes a switch module. The switch module includes a first switch, a second switch, and a third switch. The BMS battery management system includes a first output port and a second output port; The second DC power supply is connected to the first output port through the first switch and the third switch. When the first switch and the third switch are closed, a reverse overvoltage test is performed on the first output port; The second DC power supply is connected to the second output port through the second switch and the third switch. When the second switch and the third switch are closed, a reverse overvoltage test is performed on the second output port.

4. The circuit according to claim 3, wherein The switch module includes a fourth switch. The fourth switch is connected in parallel with the third switch and is used to control the charging and discharging of the supercapacitor module.

5. The circuit according to claim 3, characterized in that, The switch module includes a fifth switch and a sixth switch. One end of the sixth switch is connected to the battery cell in the BMS battery management system, and the other end is connected to one end of the fifth switch. The other end of the fifth switch is connected to the third switch.

6. The circuit according to claim 3, wherein The switch module includes a seventh switch, an eighth switch, a ninth switch, and a tenth switch. The eighth switch and the ninth switch are respectively connected to the positive pole of the constant current source. The seventh switch and the tenth switch are respectively connected to the negative pole of the constant current source; When the seventh switch and the eighth switch are closed, a positive current is injected into the circuit board; When the ninth switch and the tenth switch are closed, a negative current is injected into the circuit board.

7. The circuit according to claim 1, wherein The circuit includes a first ammeter and a second ammeter. The first ammeter is connected to the input pin of the BMS battery management system to test the input current. The second ammeter is connected to the negative pole of the battery cell of the BMS battery management system to test the output current.

8. A method for function testing of a BMS based on the circuit according to any one of claims 1 to 7, characterized in that, The method includes: Powering the BMS through the first DC power supply, charging the supercapacitor module through the second DC power supply, and discharging the supercapacitor module through the load module to adjust the voltage data of the supercapacitor module according to the test requirements of the test item; Performing functional tests on the BMS battery management system according to the test items, where the test items include reverse overvoltage test, overcurrent protection test, and current accuracy testing and calibration.

9. The method according to claim 8, characterized in that Conduct functional tests on the BMS battery management system according to the test items, including: Realize the reverse overvoltage test of the first output port by closing the first switch and the third switch; Realize the reverse overvoltage test of the second output port by closing the second switch and the third switch; When the output current is greater than the preset current threshold, adjust the current value of the load module, turn on the outputs of the first output port and the second output port, and conduct an overcurrent protection test; Realize the current accuracy test and calibration through the on-off control of the constant current source and the seventh switch, the eighth switch, the ninth switch and the tenth switch.

10. The method according to claim 8, characterized in that The test items include voltage accuracy test, balancing test, charge and discharge function test, working current test. Conduct functional tests on the BMS battery management system according to the test items, including: Conduct voltage accuracy test through the supercapacitor module and conduct balancing test through the load module; Test the static current through the multimeter module; Detect the input current and the output current respectively through the first ammeter and the second ammeter to realize the charge and discharge function test and the working current test.

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