Test device and test method for stepwise utilization of power storage battery module

Abstract

The application discloses a kind of test device of cascade utilization power storage battery module, including having two groups of test channel test equipment, module BAT to be measured, the test equipment includes first test channel CH1 and second test channel CH2, the first test channel CH1 and the second test channel CH2 are connected in series to form first circuit, the voltage at both ends of the first circuit is not less than the rated voltage of the module BAT to be measured, and the module BAT to be measured is connected in parallel with the first circuit.The application realizes the use of low-voltage grade test equipment to evaluate the performance of high-voltage grade battery module, uses existing equipment or low-cost equipment to supply power for high-voltage module BAT to be measured in series, avoids purchasing higher voltage grade equipment to evaluate, reduces cost, and provides an effective way for battery pack (module) performance evaluation.

Description

Technical Field

[0001] This invention relates to the field of power battery technology, and in particular to a testing device and testing method for a power battery module for secondary use. Background Technology

[0002] Battery packs retired from electric vehicles are first disassembled into individual modules. Then, based on the voltage level and capacity of each module, specialized evaluation equipment is used to assess them. Key indicators such as module voltage, current, power, and internal resistance are dynamically monitored. Alternatively, test methods are designed to meet the requirements of new applications to evaluate the module's State of Charge (SOC), State of Health (SOH), and Depth of Discharge (DOD). Modules with normal performance or near-normal condition are then used to manufacture new battery packs. This process enables the reuse of battery packs, preparing them for re-entry into the market.

[0003] Currently, the industry standard for evaluation equipment is a battery pack (module) charge / discharge testing system. This equipment comes in single-channel and multi-channel versions; one channel can test one battery module (or battery pack), and the more channels, the higher the cost. The testing wiring for this equipment in practical applications is as follows: Figure 6 As shown.

[0004] In the actual operation of battery module reuse, a dedicated charge and discharge testing system is used to evaluate battery modules. This equipment has the functions of charging and discharging battery modules back to the grid, as well as dynamic testing of voltage, current, and module internal resistance monitoring. It generally uses single-channel or multi-channel equipment. A multi-channel device can test multiple battery modules simultaneously. This equipment is essential for battery module performance evaluation, and it is now widely used in the industry to evaluate battery packs and modules. This type of equipment has relatively complete functions, and of course, it is expensive, representing a significant investment for a battery module reuse company.

[0005] In practical applications, due to the significant differences in battery pack capacity—ranging from microcar battery packs to large truck battery packs—the voltage levels of the modules removed vary considerably. Even electric vehicles from different manufacturers with the same power range may have different voltage levels among their battery pack modules. Therefore, a wide range of voltage levels are used for the secondary reuse of modules. For performance evaluation equipment, the rated voltage of the evaluation equipment is slightly higher than the nominal voltage of the module, and the charging and discharging current meets the charge and discharge rate requirements of the new application. Therefore, low-voltage-level testing equipment cannot perform performance evaluations of high-voltage-level modules; higher-voltage-level equipment must be purchased for evaluation, or in other words, an investment in higher-voltage-level equipment is necessary. Summary of the Invention

[0006] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one object of this invention is to provide a testing device for the cascade utilization of power battery modules, enabling the evaluation of the performance of high-voltage battery modules using low-voltage level testing equipment.

[0007] According to the present invention, a test method for a cascaded power battery module includes a test device with two test channels and a module under test (BAT). The test device includes a first test channel CH1 and a second test channel CH2. The first test channel CH1 and the second test channel CH2 are connected in series to form a first circuit. The voltage across the first circuit is not less than the rated voltage of the module under test (BAT). The module under test (BAT) is connected in parallel with the first circuit.

[0008] Preferably, the first test channel CH1 is a current source and the second test channel CH2 is a voltage source.

[0009] Preferably, the voltage across the second test channel CH2 is set to half of the rated voltage of the module under test BAT.

[0010] Preferably, the testing method steps of the testing device for the cascade utilization of power battery modules are as follows:

[0011] S1. Circuit connection: Connect the first test channel CH1 and the second test channel CH2 in series to form a first circuit, and connect the module under test BAT in parallel across the two ends of the first circuit to monitor the voltage and charging / discharging current across the module under test BAT.

[0012] S2. Module charging test process: Set the test equipment channel CH1 as a current source, with the current flowing into the positive terminal of the module under test BAT. The current magnitude of the current source is set according to the charging rate. Test the charging process of the module under test BAT in this way and record the data.

[0013] S3. Module discharge test process: Set the test equipment channel CH1 as a current source, with the current flowing out of the positive terminal of the module BAT under test. The magnitude of the current source current is set according to the discharge rate. Perform the discharge process test on the module BAT under test in this way and record the data.

[0014] S4: Data processing: Convert and process the data recorded during the charging and discharging process of the module under test (BAT) to obtain the status index of the module under test (BAT).

[0015] Preferably, the status indicators of the module under test (BAT) include the state of charge (SOC) of the power battery, the state of health (SOH) of the power battery, and the depth of discharge (DOD) of the battery pack.

[0016] Preferably, a testing device for a secondary power battery module includes a testing equipment with a set of testing channels, a module under test (BAT), and a standard battery pack (BAT1). The testing equipment includes a first testing channel (CH), which is connected in series with the standard battery pack (BAT1) to form a first circuit. The voltage across the first circuit is not less than the rated voltage of the module under test (BAT), and the module under test (BAT) is connected in parallel with the first circuit.

[0017] Preferably, a testing device for a cascaded power battery module includes a testing equipment with two sets of testing channels, a standard battery pack BAT1, a standard battery pack BAT2, a module under test BAT3, and a module under test BAT4. The testing equipment includes a first testing channel CH1 and a second testing channel CH2. The first testing channel CH1 is connected in series with the standard battery pack BAT1 to form a first circuit. The voltage across the first circuit is not less than the rated voltage of the module under test BAT3. The module under test BAT3 is connected in parallel with the first circuit. The second testing channel CH2 is connected in series with the standard battery pack BAT2 to form a second circuit. The voltage across the second circuit is not less than the rated voltage of the module under test BAT4. The module under test BAT4 is connected in parallel with the second circuit.

[0018] The beneficial effects of this invention are: it enables the evaluation of high-voltage battery module performance using low-voltage level testing equipment, and utilizes existing equipment or low-cost equipment connected in series to power the high-voltage module under test (BAT), avoiding the need to purchase higher voltage level equipment for evaluation, reducing costs, and providing an effective way to evaluate battery pack (module) performance. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a circuit diagram of a test device for a cascaded utilization power battery module proposed in this invention.

[0021] Figure 2 The present invention proposes Figure 1 Circuit diagram of voltage and current direction during the charging test;

[0022] Figure 3 The present invention proposes Figure 1 Circuit diagram of voltage and current direction during discharge test;

[0023] Figure 4This is a circuit diagram of a second embodiment of the test device for the cascade utilization of power battery modules proposed in this invention.

[0024] Figure 5 This is a circuit diagram of a third embodiment of the test device for the cascade utilization of power battery modules proposed in this invention;

[0025] Figure 6 This is a circuit diagram of the charging and discharging measurement system for a conventional power battery module proposed in this invention. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] like Figure 1-3 As shown, a test method for a cascaded power battery module includes a test device with two test channels and a module BAT under test. The test device includes a first test channel CH1 and a second test channel CH2. The first test channel CH1 and the second test channel CH2 are connected in series to form a first circuit. The voltage across the first circuit is not less than the rated voltage of the module BAT under test. The module BAT under test is connected in parallel with the first circuit. The voltage across the second test channel CH2 is set to half of the rated voltage of the module BAT under test.

[0028] The testing method steps for a test device for cascaded utilization of power battery modules are as follows:

[0029] S1. Circuit connection: Connect the first test channel CH1 and the second test channel CH2 in series to form the first circuit, and connect the module under test BAT in parallel across the two ends of the first circuit to monitor the voltage and charging / discharging current across the module under test BAT.

[0030] S2. Module charging test process: Set the first test channel CH1 as the current source, with the current flowing into the positive terminal of the module BAT under test. The current magnitude of the current source is set according to the charging rate. Test the charging process of the module BAT under test and record the data.

[0031] S3. Module discharge test process: Set the first test channel CH1 as a current source, with the current flowing out of the positive terminal of the module BAT under test. The magnitude of the current source current is set according to the discharge rate. Perform the discharge process test on the module BAT under test and record the data.

[0032] S4: Data Processing: Convert and process the data recorded during the charging and discharging process of the module under test (BAT) to obtain the status indicators of the module under test (BAT).

[0033] The status indicators of the module under test (BAT) include the state of charge (SOC) of the power battery, the state of health (SOH) of the power battery, and the depth of discharge (DOD) of the battery pack.

[0034] like Figure 4 As shown, the device can also use the first test channel CH and the external standard battery pack BAT1 connected in series to form the first circuit to test the module BAT under test. The test steps are the same as the above steps, except that the second test channel CH2 is replaced with the standard battery pack.

[0035] The testing method is as follows:

[0036] A first circuit is formed by connecting the first test channel CH and the standard battery pack BAT1 in series. The module under test (BAT) is connected in parallel across the two ends of the first circuit to monitor the voltage and charging / discharging current across the module under test BAT. The first test channel CH is set as a current source, and the standard battery pack BAT1 is set as a voltage source. The current flows into the positive terminal of the module under test BAT, and the magnitude of the current source is set according to the charging rate. The charging process of the module under test BAT is tested accordingly, and the data is recorded. The first test channel CH is set as a current source, and the current flows out of the positive terminal of the module under test BAT. The magnitude of the current source is set according to the discharging rate, and the discharging process of the module under test BAT is tested accordingly, and the data is recorded. The data recorded during the charging and discharging process of the module under test BAT is converted and processed to obtain the status indicators of the module under test BAT.

[0037] like Figure 5 As shown, in this device, the first test channel CH1 can be connected in series with an external standard battery pack to form a first circuit to test the module BAT3 under test, and the second test channel CH2 can be connected in series with the standard battery pack BAT2 to form a second circuit to test the module BAT3 under test. The test steps are the same as those described above.

[0038] The testing method is as follows:

[0039] A first circuit is formed by connecting the first test channel CH1 and the standard battery pack BAT1 in series. The module under test (BAT3) is connected in parallel across the two ends of the first circuit to monitor the voltage and charging / discharging current across BAT3. The first test channel CH1 is set as a current source, and the standard battery pack BAT1 is set as a voltage source. The current flows into the positive terminal of the module under test (BAT3), and the magnitude of the current source is set according to the charging rate. The charging process of the module under test (BAT3) is tested accordingly, and the data is recorded. The first test channel CH1 is also set as a current source, with the current flowing out of the positive terminal of the module under test (BAT3). The magnitude of the current source is set according to the discharging rate. The discharging process of the module under test (BAT3) is tested accordingly, and the data is recorded. The data recorded during the charging and discharging process of the module under test (BAT3) are converted and processed to obtain the status indicators of the module under test (BAT3). The second test channel CH1 is then connected to the first circuit. A second circuit is formed by connecting the standard battery pack BAT2 in series with the first circuit. The module under test (BAT4) is connected in parallel across the two ends of the first circuit to monitor the voltage and charging / discharging current of the module under test BAT4. The second test channel CH2 is set as a current source, and the standard battery pack BAT2 is set as a voltage source. The current flows into the positive terminal of the module under test BAT4, and the current magnitude is set according to the charging rate. The charging process of the module under test BAT4 is tested accordingly, and the data is recorded. The second test channel CH2 is set as a current source, and the current flows out of the positive terminal of the module under test BAT4. The current magnitude is set according to the discharging rate, and the discharging process of the module under test BAT4 is tested accordingly, and the data is recorded. The data recorded during the charging and discharging process of the module under test BAT4 are converted and processed to obtain the status indicators of the module under test BAT4. This completes the testing of the two sets of battery modules under test.

[0040] In summary, this invention enables the evaluation of high-voltage battery module performance using low-voltage testing equipment. It utilizes existing equipment or low-cost devices connected in series to power the high-voltage module under test (BAT), avoiding the need to purchase higher-voltage equipment for evaluation, thus reducing costs and providing an effective approach for battery pack (module) performance evaluation.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A testing device for a cascaded utilization power battery module, characterized in that: The test includes a test device with two test channels and a module under test (BAT). The test device includes a first test channel CH1 and a second test channel CH2. The first test channel CH1 and the second test channel CH2 are connected in series to form a first circuit. The voltage across the first circuit is not less than the rated voltage of the module under test (BAT). The module under test (BAT) is connected in parallel with the first circuit. The first test channel CH1 is a current source, and the second test channel CH2 is a voltage source; During the charging test, the first test channel CH1 provides a constant current at a set rate to the positive electrode of the module under test (BAT); during the discharging test, it draws a constant current at a set rate from the positive electrode of the module under test (BAT). The voltage across the second test channel CH2 is set to half of the rated voltage of the module under test BAT.

2. A test method for a test device for a cascaded utilization power battery module as described in claim 1, characterized in that, The testing method steps are as follows: S1. Circuit connection: Connect the first test channel CH1 and the second test channel CH2 in series to form a first circuit, and connect the module under test BAT in parallel across the two ends of the first circuit to monitor the voltage and charging / discharging current across the module under test BAT. S2. Module charging test process: Set the first test channel CH1 as a current source, with the current flowing into the positive terminal of the module BAT under test. The current magnitude of the current source is set according to the charging rate. Test the charging process of the module BAT under test and record the data. S3. Module discharge test process: Set the first test channel CH1 as a current source, with the current flowing out of the positive terminal of the module BAT under test. The magnitude of the current source current is set according to the discharge rate. Perform the discharge process test on the module BAT under test in this way and record the data. S4: Data processing: Convert and process the data recorded during the charging and discharging process of the module under test (BAT) to obtain the status index of the module under test (BAT).

3. The testing method of the testing device for a cascaded utilization power battery module according to claim 2, characterized in that: The status indicators of the module under test (BAT) include the state of charge (SOC) of the power battery, the state of health (SOH) of the power battery, and the depth of discharge (DOD) of the battery pack.

4. A testing device for a cascaded utilization power battery module, characterized in that: The test equipment includes a test device with two test channels, a standard battery pack BAT1, a standard battery pack BAT2, a module under test (DUT) BAT3, and a module under test (DUT) BAT4. The test device includes a first test channel CH1 and a second test channel CH2. The first test channel CH1 is connected in series with the standard battery pack BAT1 to form a first circuit. The voltage across the first circuit is not less than the rated voltage of the DUT BAT3. The DUT BAT3 is connected in parallel with the first circuit. The second test channel CH2 is connected in series with the standard battery pack BAT2 to form a second circuit. The voltage across the second circuit is not less than the rated voltage of the DUT BAT4. The DUT BAT4 is connected in parallel with the second circuit.

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