BMS test platform and test method thereof

Abstract

According to the BMS test platform and the test method thereof, the cost is low, the safety is high, the controllability is high, the stability is high, the test result is more accurate, and the test efficiency can be improved. The system comprises an industrial control host and a BMS test system cabinet. The BMS test system cabinet comprises a virtual battery simulation unit, a temperature simulation detection unit, a high-voltage constant-voltage source, a high-precision constant-current source, a Hall-shunt simulation detection unit, a CAN communication detection unit, a high-precision programmable DC power supply, an insulation resistance simulation test unit, an insulation withstand voltage test unit, and a signal detection and drive simulation detection unit. An I / O driving detection unit; and a charging signal simulation detection unit. The invention is applied to the technical field of battery management systems.

Description

Technical Field

[0001] The present invention is applied to the technical field of battery management systems, and in particular relates to a BMS test platform and a test method thereof. Background Art

[0002] The battery management system (BMS) is one of the core technologies of electric vehicles. The battery management system (BMS), the motor controller (MCU), and the vehicle control unit (VCU) together constitute the three major systems of electric vehicles. With the continuous evolution of electric vehicle electric drive technology, more comprehensive research is needed on the environmentally friendly drive technology of hybrid and pure electric vehicles to ensure the safety of electric vehicles in use and promote the rapid, healthy and long-term development of the new energy industry. As the power source of electric vehicles, incorrect operation of the battery pack is likely to cause this power source to become a fire source that burns the electric vehicle. Therefore, the charging and discharging of the vehicle power battery pack and the battery management technology are particularly important. The BMS battery management system (Battery Management System) is commonly known as the battery nanny or battery butler. It is mainly for intelligent management and maintenance of each battery unit, to prevent overcharging and over-discharging of the battery, to extend the battery life, and to monitor the battery status.

[0003] In the past decade, the electric vehicle industry has flourished under the guidance of government policies, and has always pursued high capacity and long driving range. With the frequent occurrence of electric vehicle accidents, the main risk comes from the power battery system, so the industry pays more and more attention to the safety and reliability of power batteries. As the "brain" connecting the power battery system, the battery management system's main task is to ensure the safety, durability, and power of the power battery system. It generally has functions such as battery parameter monitoring, battery status analysis, battery safety protection, energy management control, and battery information management. However, the current lack and imperfection of BMS market standards have led to problems such as imperfect functions, insufficient test accuracy, and low degree of automation in the domestic market BMS test system.

[0004] As the core component for monitoring and managing battery packs, the performance of BMS is directly related to the safety, stability and service life of the battery. Traditional BMS testing methods have problems such as long testing time, many auxiliary equipment, difficulty in adjusting parameters, poor controllability, and potential safety hazards and high energy consumption. Therefore, it is necessary to provide a BMS testing platform and its testing method with low cost, high safety, strong controllability, high stability, more accurate test results, and improved test efficiency. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a BMS test platform and a test method thereof which have low cost, high safety, strong controllability, high stability, more accurate test results and can improve test efficiency.

[0006] The technical solution adopted by the present invention is: the present invention includes an industrial control host and a BMS test system cabinet, and the BMS test system cabinet includes a virtual battery simulation unit, a temperature simulation detection unit, a high-voltage constant voltage source, a high-precision constant current source, a Hall-shunt simulation detection unit, a CAN communication detection unit, a high-precision programmable DC power supply, an insulation resistance simulation test unit, an insulation withstand voltage test unit, a signal detection and drive simulation detection unit, an I / O drive detection unit, and a charging signal simulation detection unit; The industrial control host realizes command sending, transmission, reception and data feedback between the modules of the BMS test system cabinet through the communication interface; The virtual battery simulation unit is linked with the temperature simulation detection unit to simulate the voltage, current, temperature and other characteristic parameters of the lithium-ion battery cell to complete the BMS state parameter accuracy detection; The high voltage constant voltage source simulates the total voltage of the battery pack or system and tests the total voltage detection accuracy of the BMS; The high-precision constant current source can simulate the total current of the battery pack or system, and is combined with the Hall-shunt analog detection unit to detect the total current acquisition accuracy of the BMS; The high-precision programmable DC power supply implements the test items of DC supply voltage, overvoltage, undervoltage, superimposed AC voltage, supply voltage slow rise and slow fall, supply voltage transient change, reverse voltage, and short circuit protection for BMS; The insulation resistance simulation test unit and the insulation withstand voltage test unit can simulate the insulation resistance of the battery pack or system up to 1000MΩ, and meet the test of BMS insulation withstand voltage level detection; The I / O drive detection unit receives the host computer command to adjust the input and output, and has the function of detecting the high-side and low-side drive capabilities of the I / O port; The signal detection and drive analog detection unit includes 16 channels of ±24 V voltage detection, 8 channels of I / O input, 8 channels of I / O output, and 4 channels of PWM input / output units; The charging signal simulation detection unit is used to simulate and detect the CC, CP, and CC2 national standard charging signals of the BMS; The CAN communication detection unit is based on SAE J1939, can adapt to different CAN communication protocols, is compatible with CAN2.0A and CAN2.0B protocols, and can perform CAN communication function detection and fault injection detection on the BMS.

[0007] It can be seen from the above scheme that the present application simulates the voltage, current, temperature and other characteristic parameters of the lithium-ion battery cell through the linkage between the virtual battery simulation unit and the temperature simulation detection unit, which is beneficial to improve the test efficiency, realize fast and accurate testing, and shorten the test cycle; at the same time, it can reduce the test cost and reduce the use of auxiliary equipment; it is helpful to improve safety, monitor the working status of the BMS in real time, and ensure the safety of the test process; it is beneficial to enhance controllability: through the human-computer interaction interface, flexible setting of test parameters and intuitive display of test results are realized; products with low monitoring accuracy, imperfect safety functions, and low performance reliability can be identified to ensure the high safety and high reliability of the BMS for electric vehicles.

[0008] A preferred solution is that the BMS test platform also includes a data acquisition and processing unit, a fault injection module and a human-computer interaction interface, wherein the data acquisition and processing unit is used to collect test data in real time and perform processing and analysis; the fault injection module is used to simulate various fault conditions that may occur in the BMS; and the human-computer interaction interface is used to set test parameters, display test results and perform fault diagnosis.

[0009] A preferred solution is that the virtual battery simulation unit includes a high-precision battery simulator, which is used to simulate the voltage and current parameters of the battery cell; the temperature simulation detection unit includes an environmental control unit, which is used to simulate the temperature and humidity environmental conditions when the battery is working.

[0010] A preferred embodiment is that the test method is as follows: A. Connecting the BMS to be tested with the high-precision battery simulator and the environmental control unit; B. Setting test parameters through the human-computer interaction interface, including battery parameters, environmental conditions and fault types; C. Start the test program, and the data acquisition and processing unit collects test data in real time; D. Compare the collected data with the preset standard value to determine whether the performance of the BMS is qualified; E. Perform fault diagnosis based on the test results and output a fault diagnosis report. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a principle block diagram of the present invention; Figure 2This is the BMS status parameter accuracy test architecture diagram; Figure 3 This is a comparison chart of the single-cell voltage acquisition accuracy test of the BMS to be tested; Figure 4 This is a comparison chart of the total voltage acquisition accuracy test of the BMS to be tested; Figure 5 This is a comparison chart of the total current acquisition accuracy test of the BMS to be tested; Figure 6 This is a typical operating condition diagram for SOC estimation; Figure 7 This is the SOC test result diagram under typical working conditions; Figure 8 This is the BMS test platform architecture diagram; Fig. 9 This is the test platform software interface diagram; Fig.10 This is the software architecture diagram of the BMS test platform; Fig.11 This is a diagram of the test platform fault diagnosis interface. DETAILED DESCRIPTION

[0012] like Figure 1 As shown, in this embodiment, the present invention includes an industrial control host 1 and a BMS test system cabinet 2, wherein the BMS test system cabinet 2 includes a virtual battery simulation unit 3, a temperature simulation detection unit 4, a high-voltage constant voltage source 5, a high-precision constant current source 6, a Hall-shunt simulation detection unit 8, a CAN communication detection unit 9, a high-precision programmable DC power supply 10, an insulation resistance simulation test unit 11, an insulation withstand voltage test unit 12, a signal detection and drive simulation detection unit 13, an I / O drive detection unit 14, and a charging signal simulation detection unit 15; The industrial control host 1 realizes command sending, transmission, reception and data feedback between the modules of the BMS test system cabinet 2 through the communication interface; The virtual battery simulation unit 3 simulates the voltage, current, temperature and other characteristic parameters of the lithium-ion battery cell by working in conjunction with the temperature simulation detection unit 4 to complete the BMS state parameter accuracy detection; The high voltage constant voltage source 5 simulates the total voltage of the battery pack or system and tests the total voltage detection accuracy of the BMS; The high-precision constant current source 6 can simulate the total current of the battery pack or system, and is combined with the Hall-shunt simulation detection unit 8 to detect the total current acquisition accuracy of the BMS; The high-precision programmable DC power supply 10 implements test items for BMS, including DC supply voltage, overvoltage, undervoltage, superimposed AC voltage, supply voltage slow rise and slow fall, supply voltage transient change, reverse voltage, and short circuit protection; The insulation resistance simulation test unit 11 and the insulation withstand voltage test unit 12 can simulate the insulation resistance of the battery pack or system up to 1000MΩ, and meet the test of BMS insulation withstand voltage level detection; The I / O drive detection unit 14 receives the host computer command to adjust the input and output, and has the function of detecting the high-side and low-side drive capabilities of the I / O port; The signal detection and driving analog detection unit 13 includes 16 ±24 V voltage detection channels, 8 I / O input channels, 8 I / O output channels, and 4 PWM input / output channels; The charging signal simulation detection unit 15 is used to simulate and detect the CC, CP, and CC2 national standard charging signals of the BMS; The CAN communication detection unit 9 is based on SAE J1939, can adapt to different CAN communication protocols, is compatible with CAN2.0A and CAN2.0B protocols, and can perform CAN communication function detection and fault injection detection on the BMS.

[0013] The industrial control host 1 uses Advantech's industrial control host computer, which is mainly responsible for controlling and providing the human-computer interaction operating system of the test platform. It realizes the sending, transmission, reception and data feedback of commands between modules in the BMS system test cabinet through RS232. The industrial control host 1 is the carrier of the BMS test system software platform, providing users with a human-computer interaction interface for controlling and editing test commands. Most of the hardware modules are integrated in the BMS test system cabinet 2, and communicate with the BMS to be tested through the wiring adapter board; communicate with the industrial control host 1 through RS232. The BMS test system cabinet 2 adopts the PXI hardware architecture design, and modular integration makes it flexible and scalable.

[0014] The virtual battery simulation unit 3 is composed of 120 channels of 5 V / 5 A virtual batteries; the voltage range of the high-voltage constant voltage source 5 is 0 V to 1000 V; The current range of the high-precision constant current source is 6-500 A to +500 A; the voltage adjustable range is 0 V to 60 V, and the current adjustable range is 0 A to 25 A. The high-precision programmable DC power supply 10 can realize the DC supply voltage, overvoltage, undervoltage, superimposed AC voltage, supply voltage slow rise and fall, supply voltage transient change, reverse voltage, short circuit protection and other test items for BMS.

[0015] like Figure 1As shown, in this embodiment, the BMS test platform also includes a data acquisition and processing unit, a fault injection module and a human-computer interaction interface. The data acquisition and processing unit is used to collect test data in real time and perform processing and analysis; the fault injection module is used to simulate various fault conditions that may occur in the BMS; the human-computer interaction interface is used to set test parameters, display test results and perform fault diagnosis.

[0016] like Figure 1 As shown, in this embodiment, the virtual battery simulation unit 3 includes a high-precision battery simulator, which is used to simulate the voltage and current parameters of the battery cell; the temperature simulation detection unit 4 includes an environmental control unit, which is used to simulate the temperature and humidity environmental conditions when the battery is working.

[0017] like Figure 1 As shown, in this embodiment, the testing method is as follows: A. Connecting the BMS to be tested with the high-precision battery simulator and the environmental control unit; B. Setting test parameters through the human-computer interaction interface, including battery parameters, environmental conditions and fault types; C. Start the test program, and the data acquisition and processing unit collects test data in real time; D. Compare the collected data with the preset standard value to determine whether the performance of the BMS is qualified; E. Perform fault diagnosis based on the test results and output a fault diagnosis report.

[0018] In this embodiment, if Figure 2 As shown in the figure, the BMS daughter board is mainly used to collect battery cell voltage, current, temperature and other parameters; the BMS motherboard is generally used to collect total voltage, total current and insulation detection parameters. The industrial control host software platform is connected to the BMS daughter board and motherboard through the isolated CAN communication unit, and controls each hardware module through the communication bus connection to simulate the battery cell voltage, current, temperature and total voltage, total current, insulation resistance and other parameters, and compares the data collected by the BMS daughter board and motherboard to calculate and analyze whether the accuracy of the BMS collected data meets the standard requirements.

[0019] In this embodiment, the test results of the single-cell voltage collection, total voltage, and total current collection accuracy of the BMS to be tested are compared. Figures 3 to 5 shown. Figure 3Four groups of battery cells were randomly selected with a step value of 200 mV between 3000 mV and 3800 mV, and the results of the simulation value of the test platform and the BMS detection value were compared. The results showed that the maximum error of the BMS collected voltage was 3 mV, which met the national standard requirements; Figure 4 , Figure 5 The BMS total voltage and total current acquisition accuracy tests were conducted respectively, and the maximum error of the BMS total voltage was 1 V, and the maximum error of the total current was 0.6 A, which met the national standard requirements.

[0020] In this embodiment, the SOC estimation of BMS is a key indicator to measure the quality of BMS products. The national standard requires that the cumulative SOC estimation error of pure electric vehicles and plug-in hybrid electric vehicles should not exceed 5%, and the cumulative SOC estimation error of non-plug-in hybrid electric vehicles should not exceed 15%. In fact, in 2017, the Ministry of Science and Technology issued 14 key projects such as the National Key R&D Plan for New Energy Vehicles, which recommended that the SOC estimation error of the power battery system should not exceed ±3%. Therefore, this test platform is based on the SOC true value calculation formula: Where: Q0 is the initial available capacity of the battery system; Q1 is the discharge capacity of the battery system recorded by the BMS test platform.

[0021] The actual SOC value is compared with the BMS estimated value to determine whether the SOC estimation error is within the standard requirements. Under the working conditions of Figure 6, the BMS to be tested is first discharged at a constant current of 440 A for 100 s, and then charged at a constant current of 440 A for 100 s. The SOC estimation accuracy of the BMS to be tested is tested through the test platform. The comparison results are shown in Figure 7. The SOC estimation errors are all within 2%, which meets the standard requirements.

[0022] like Figure 8 As shown, in this embodiment, the BMS test system architecture is mainly composed of a hardware platform and a software platform. The hardware platform provides the BMS test system with various hardware resources and various communication interfaces required for testing. The hardware platform is mainly composed of an industrial control host, a system test cabinet, and a communication interface. The software platform is designed based on the LabVIEW development environment to realize the human-computer interaction interface design, test process editing, test data analysis and result judgment, and test report output of the BMS test system.

[0023] Due to the lack and imperfection of BMS standards, the BMS test platform can realize the factory inspection and type inspection of BMS products according to the automotive industry recommended standard document "Technical Conditions for Battery Management Systems for Electric Vehicles"; under the linkage control with the environmental chamber, it can realize high and low temperature operation of BMS products and other climate environment tests. In view of the functional characteristics of BMS, the functions of this test platform include the following points: State parameter and estimation accuracy test: total voltage measurement accuracy, total current measurement accuracy, single cell (cell group) voltage measurement accuracy, temperature measurement accuracy, insulation resistance measurement accuracy, SOC cumulative estimation error accuracy, SOC error correction speed test, SOP estimation accuracy test, etc.; Fault diagnosis test: high / low battery temperature, high / low cell (cell group) voltage, large cell (cell group) consistency, large charge / discharge current (power), weak insulation, high / low SOC, SOC jump, low / high total voltage, external / internal communication interface failure, large temperature difference of battery system, high-voltage interlock failure, total voltage / cell voltage exceeding overcharge cut-off condition, etc. Electrical adaptability performance test: DC supply voltage test, overvoltage test, superimposed AC voltage test, supply voltage slow rise and slow fall test, supply voltage transient change test, reverse voltage test, short circuit protection test, etc.; Other functional tests: battery balancing management test (active / passive balancing state test, balancing current, etc.), insulation resistance test, high voltage performance test, communication function test, charging simulation test, etc.

[0024] In this embodiment, in addition to the necessary hardware foundation, the BMS test system also requires the support of a software platform. The software platform is developed and designed under the LabVIEW environment. It is a graphical software development environment developed by the American NI company. It can perfectly combine industrial measurement control with computers, making the graphical interface editing intuitive and easy to understand. It is a BMS test system software platform development environment that is generally accepted by the market. The test platform software interface is shown in Figure 9. The test platform software architecture is shown in Figure 10, which mainly includes three categories: test process management, data processing and analysis, and system protection management. Test process management mainly includes BMS test item selection, test process editing, and test data storage; data processing and analysis mainly includes test data analysis, test result judgment, test report output, test data query, etc.; system protection management is mainly divided into system power-on self-test, hierarchical authority management, system security protection and other protection management designs. The working condition simulation function (especially the complex working condition or real vehicle working condition simulation function) is the shortcoming of the current BMS test system platform. Therefore, this test system software platform adds FUDS (federal urban driving schedule) charging and discharging conditions and DST (dynamic stress test) charging and discharging conditions on the basis of the four typical charging and discharging conditions in QC / T 897-2011, and opens the working condition editing function to users, which can more accurately detect the SOC estimation accuracy, SOC error correction speed, SOP estimation accuracy and other parameters of the BMS.

[0025] In this embodiment, the BMS product with high stability, high reliability and high precision can effectively improve the utilization rate of the battery of the new energy vehicle team, prevent the battery from being overcharged or over-discharged, extend the battery life, monitor the operating status of the battery pack and each battery cell in real time, and effectively prevent the sudden accidents of the battery pack. In case of emergency, early warning can be given in advance to win time for safety. Therefore, this test platform has the function of BMS to perform various fault diagnosis. Part of the fault diagnosis interface is shown in Figure 11, where the diagnosis items include total voltage too high / too low, charging current too large, discharge current too large, SOC too high / too low, module voltage too high / too low, module temperature too high / too low, module temperature difference too large, insulation fault, communication fault, relay fault, fan fault, fuse fault, etc. The test platform can accurately simulate the BMS fault signal and compare it with the BMS through communication to accurately determine the accuracy of the BMS fault diagnosis function.

[0026] In this embodiment, after the application is debugged, a large number of different types of BMS ranging from 20 to 120 strings are tested. The test results show that the platform can meet the factory inspection and type inspection items of different BMSs in the market, and has sufficient system stability. After clicking the test item, a one-key automatic test function can be performed. Due to the modular integrated design, the purchase cost of the test platform is reduced; it has better convenience in subsequent module replacement, function expansion, software upgrade, and system maintenance. The PXI architecture design enables the platform to have the characteristics of high precision, excellent performance, and low cost; in the LabVIEW software environment, it has the advantages of clear graphical display and friendly interface. Therefore, through the detection of this BMS test platform, products with low monitoring accuracy, imperfect safety functions, and low performance reliability can be identified to ensure the high safety and high reliability of BMS for electric vehicles.

[0027] Although the embodiments of the present invention are described with practical solutions, they do not constitute limitations on the meaning of the present invention. For those skilled in the art, it is obvious to modify the implementation scheme and combine it with other solutions based on this description.

Claims

1. A BMS test platform, characterized by: It comprises an industrial control host (1) and a BMS test system cabinet (2), wherein the BMS test system cabinet (2) comprises a virtual battery simulation unit (3), a temperature simulation detection unit (4), a high voltage constant voltage source (5), a high precision constant current source (6), a Hall-shunt simulation detection unit (8), a CAN communication detection unit (9), a high precision programmable DC power supply (10), an insulation resistance simulation test unit (11), an insulation withstand voltage test unit (12), a signal detection and drive simulation detection unit (13), an I / O drive detection unit (14), and a charging signal simulation detection unit (15); The industrial control host (1) realizes command sending, transmission, reception and data feedback between the modules of the BMS test system cabinet (2) through a communication interface; The virtual battery simulation unit (3) is linked with the temperature simulation detection unit (4) to simulate characteristic parameters such as voltage, current, temperature, etc. of the lithium-ion battery cell, and complete the BMS state parameter accuracy detection; The high voltage constant voltage source (5) simulates the total voltage of the battery pack or system and tests the total voltage detection accuracy of the BMS; The high-precision constant current source (6) is capable of simulating the total current of a battery pack or a system, and is combined with the Hall-shunt analog detection unit (8) to detect the total current acquisition accuracy of the BMS; The high-precision programmable DC power supply (10) implements test items for the BMS, including DC power supply voltage, overvoltage, undervoltage, superimposed AC voltage, power supply voltage slow rise and slow fall, power supply voltage transient change, reverse voltage, and short circuit protection; The insulation resistance simulation test unit (11) and the insulation withstand voltage test unit (12) can simulate the insulation resistance of the battery pack or system up to 1000MΩ, and meet the test of BMS insulation withstand voltage level detection; The I / O drive detection unit (14) receives the host computer command to adjust the input and output, and has the function of detecting the high-side and low-side drive capabilities of the I / O port; The signal detection and driving analog detection unit (13) includes 16 ±24 V voltage detection channels, 8 I / O input channels, 8 I / O output channels, and 4 PWM input / output channels; The charging signal simulation detection unit (15) is used to simulate and detect the CC, CP, and CC2 national standard charging signals of the BMS; The CAN communication detection unit (9) is based on SAE J1939, can adapt to different CAN communication protocols, is compatible with CAN2.0A and CAN2.0B protocols, and can perform CAN communication function detection and fault injection detection on the BMS.

2. A BMS test platform according to claim 1, characterized in that: The BMS test platform also includes a data acquisition and processing unit, a fault injection module and a human-computer interaction interface. The data acquisition and processing unit is used to collect test data in real time and perform processing and analysis; the fault injection module is used to simulate various fault conditions that may occur in the BMS; the human-computer interaction interface is used to set test parameters, display test results and perform fault diagnosis.

3. A BMS test platform according to claim 2, characterized in that: The virtual battery simulation unit (3) comprises a high-precision battery simulator, which is used to simulate the voltage and current parameters of the battery cell; the temperature simulation detection unit (4) comprises an environment control unit, which is used to simulate the temperature and humidity environmental conditions when the battery is working.

4. A method for testing a BMS test platform as claimed in claim 3, characterized in that: The test method is as follows: A. Connecting the BMS to be tested with the high-precision battery simulator and the environmental control unit; B. Setting test parameters through the human-computer interaction interface, including battery parameters, environmental conditions and fault types; C. Start the test program, and the data acquisition and processing unit collects test data in real time; D. Compare the collected data with the preset standard value to determine whether the performance of the BMS is qualified; E. Perform fault diagnosis based on the test results and output a fault diagnosis report.

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