Balancing test device for battery management system

Abstract

The utility model discloses a battery management system equalization test device, which comprises a temperature simulator, a battery cell simulator, a controller, an acquisition board card and a low-voltage power supply, and is characterized in that the low-voltage power supply is connected with the controller; the low-voltage power supply is connected with the low-voltage power supply connector, and the low-voltage power supply connector is used for being connected to a power supply end of the battery management system during testing so as to supply power to the battery management system; the output end of the controller is connected to the temperature simulator and the battery cell simulator and is used for controlling the temperature simulator and the battery cell simulator to simulate and output battery cell voltage and working temperature data; the cell simulator and the temperature simulator are both connected to a junction box, and the junction box is used for being connected to an acquisition end of a battery management system; the input end of the controller is connected to the input end of the acquisition board card, and the acquisition board card is connected to the communication end of the battery management system through the communication plug-in. The device can be used for testing the balance strategy of the BMS.

Description

Technical Field

[0001] The utility model relates to the field of automobile component testing, in particular to a battery management system equalization testing device. Background Art

[0002] The massive consumption of fossil energy and environmental pollution are two major problems of this century. In order to reduce the burden of energy and environmental pollution, my country has vigorously developed new energy vehicles, mainly electric vehicles. Among the three core parts of electric vehicles, the battery can be said to be the most important part of the three cores. Due to the differences in performance between single cells, and due to the design of the battery system, the operating temperature and other conditions of different single cells are also different. These factors have caused the difference in power between single cells in electric vehicles after a period of use. According to the barrel principle, the power of the entire battery pack is determined by the power of the lowest single cell. Therefore, the balancing function of the power battery pack is crucial. It can increase the actual available power of the battery pack, increase the available power of the power battery pack, and extend the service life of the power battery pack by controlling the consistency difference between the single cells. In the prior art, a balancing strategy is integrated into the battery management system BMS, and balancing control can be achieved with the help of a balancing circuit, such as a BMS cell-level active balancing system and an active balancing method with patent application number 202311349858.4, which includes a 24V DC bus, multiple strings of cells, several bidirectional DC / DC modules, an MCU controller, and a switch matrix; the active balancing method includes the following steps: primary processing, secondary processing; the balancing method of the active balancing system has the following states: balancing initialization state, balancing action execution state, balancing action switching state, and balancing protection state. It balances the battery by active balancing. The controller involved in the balancing control is generally implemented by the BCU in the BMS, and its balancing strategy is integrated in the controller. Therefore, the battery balancing logic has become an important part of the current BMS research.

[0003] Many engineers have studied the battery balancing strategy, but whether the BMS balancing logic can be implemented according to the strategy is also very important. The existing technology only considers the design of the balancing strategy, but it is impossible to know whether the balancing strategy is reliably executed by the BMS. Therefore, it is necessary to detect the BMS balancing strategy for developers to study and test the BMS. The balancing test generally tests the equipment to be tested through software development test cases, but the basis of software operation is the hardware test architecture. There is no hardware architecture of the relevant test device in the existing technology, so it cannot meet the test requirements. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a battery management system balancing test device, which is used to implement a hardware device architecture for testing the balancing strategy in the BMS to meet the test cases in the prior art for testing the balancing strategy in the BMS.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a battery management system balancing test device, including a temperature simulator, a battery cell simulator, a controller, an acquisition board and a low-voltage power supply, wherein the low-voltage power supply is connected to the controller; the low-voltage power supply is connected to a low-voltage power supply connector, and the low-voltage power supply connector is used to connect to the power supply end of the battery management system during testing to power the battery management system; the output end of the controller is connected to the temperature simulator and the battery cell simulator, and is used to control the temperature simulator and the battery cell simulator to simulate the output of the battery cell voltage and the operating temperature data; the battery cell simulator and the temperature simulator are both connected to a junction box, and the junction box is used to connect to the acquisition end of the battery management system; the input end of the controller is connected to the input end of the acquisition board, and the acquisition board is connected to the communication end of the battery management system through a communication plug-in.

[0006] The acquisition board includes a CAN board, one end of the CAN board is connected to the controller, and the other end is connected to the CAN communication network interface of the BMS via a communication plug-in.

[0007] The acquisition board also includes an AO / IO board and a DI / DO board. The controller is connected to the AO / IO board and the DI / DO board respectively. The AO / IO board and the DI / DO board are connected to the communication plug-in after passing through the signal processing circuit respectively, and are used to connect to the battery management system through the communication plug-in.

[0008] The controller is connected to a host computer via Ethernet, and is used to receive test control signals via Ethernet and upload collected action signals of the battery management system.

[0009] The battery management system includes a host BCU and multiple slave BMUs. The host BCU is connected to each slave BMS through the CAN intranet. Each slave BMS is connected to a junction box through a collection terminal to collect temperature data and telecommunication voltage data.

[0010] The communication terminal of the host BCU is connected to the acquisition board through a communication plug-in.

[0011] The advantages of the utility model are: simple structure, stable and reliable, good compatibility, and can test the balancing strategies in different BMSs. It only needs to use different test cases to test the balancing strategy in the BMS, collect, monitor and upload the action data of the BMS, and judge whether the balancing strategy of the BMS is effectively executed through the collected data. The whole circuit is simple to use, has few components and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The following is a brief description of the contents expressed in the drawings of the present invention and the symbols in the drawings:

[0013] Figure 1 This is a schematic diagram of the testing device of the utility model. DETAILED DESCRIPTION

[0014] The specific implementation of the present invention will be further explained in detail below by describing the optimal embodiment with reference to the accompanying drawings.

[0015] The main purpose of this application is to provide a battery management system balancing test device, which provides a basic hardware architecture for testing the balancing strategy in the BMS. During the test, the operating parameters of each hardware in the hardware architecture can be configured according to actual needs to implement the test of the balancing strategy in the BMS and obtain the test result data. Based on the result data, the tester can manually analyze and obtain a test report, or write software to automatically generate a test report. The specific plan is as follows:

[0016] like Figure 1 As shown, a battery management system balancing test device includes a temperature simulator, a battery cell simulator, a controller, an acquisition board and a low-voltage power supply. The test device is used to test the BMS; wherein:

[0017] The low-voltage power supply is connected to the controller to supply power to the controller. The voltage of the low-voltage power supply is set according to the working voltage of the controller or the LDO chip is set to convert the voltage to supply power to the controller.

[0018] The low-voltage power supply is connected to the low-voltage power supply connector. The low-voltage power supply connector is used to connect to the power supply end of the battery management system during testing to power the battery management system BMS. During testing, it is necessary to power the BMS and the controller. Because the BMS to be tested is an external component, and the controller is an internal component of the device, the low-voltage power supply can be directly connected to the controller. To power the BMS, it is necessary to pre-set a low-voltage power supply connector for low-voltage power supply. The low-voltage power supply connector can match the power supply end of the BMS. During testing, it only needs to be inserted into it to achieve power connection, providing the most basic power supply for the test.

[0019] As the core component of the device, the controller's main function is to read the balancing action information of the BMS based on the acquisition board and control the working parameters of the battery simulator and temperature simulator. In this construction, a HIL host can be used to implement it, thereby realizing a test device based on HIL hardware in the loop. Of course, some dedicated development boards or general development boards can also be used to implement the controller function. It is recommended to use the 51 series or STM32 series, which have the advantages of low cost, rich resources, and simple development.

[0020] The output end of the controller is connected to the temperature simulator and the battery cell simulator, which are used to control the temperature simulator and the battery cell simulator to simulate the output of the battery cell voltage and the operating temperature data; because the balancing strategy of the BMS needs to be tested, it is necessary to simulate the environment in which the battery needs to be balanced, so the temperature simulator and the battery cell simulator are used here to realize the voltage signals of multiple battery cells. The temperature simulator is used to simulate different temperature data according to the control signal of the controller, that is, the temperature simulation can be realized through devices such as a temperature control box. The battery cell simulator mainly simulates the voltage signals of multiple battery cells and simulates multiple battery cell voltages according to the control parameters output by the controller. The battery cell simulator and the temperature simulator are both connected to the junction box, which is used to connect to the acquisition end of the battery management system BMS, so that the BMS can collect the temperature and voltage signals of different battery cells, which is convenient for the BMS to output the balancing control signal according to its internal balancing strategy. Specifically, the battery management system BMS includes a host BCU and multiple slave BMUs. The host BCU is connected to each slave BMS through the CAN intranet. Each slave BMS is connected to the junction box through the acquisition terminal to collect temperature data and telecommunications voltage data. After receiving the battery cell data, the BCU will determine whether balancing is required based on the data of each battery cell. If balancing is required, the BCU will output a balancing control signal. By reading the balancing control signal output by the BCU and then analyzing it, it can be determined whether the execution of the balancing strategy in the BMS is reliable and effective.

[0021] The balancing control signal of BMS can be read to analyze the balancing strategy, so it is necessary to collect and acquire the output signal of BMS. In this application, the input end of the controller is connected to the input end of the acquisition board, and the acquisition board is connected to the communication end of the battery management system through a communication plug-in, so that the data is collected through the acquisition board to realize the acquisition of the balancing control signal. The communication end of the host BCU is connected to the acquisition board through a communication plug-in. The acquisition board includes a CAN board, an AO / IO board and a DI / DO board. One end of the CAN board is connected to the controller, and the other end is connected to the CAN communication network interface of the BMS through a communication plug-in to collect the CAN command signal in the balancing control signal; the controller is connected to the AO / IO board and the DI / DO board respectively, and the AO / IO board and the DI / DO board are connected to the communication plug-in after passing through the signal processing circuit, respectively, for connecting to the battery management system through the communication plug-in, for collecting analog switch quantity or digital switch quantity signal, for obtaining the control switch quantity output by the balancing strategy. The strategy can be confirmed by analyzing and judging the collected CAN, analog digital switch quantity and other information. After the controller collects these signals, it can display the data to the tester and can also upload and save operations.

[0022] The controller is connected to the host computer via Ethernet, and is used to receive the test control signal and upload the collected action signal of the battery management system via Ethernet. The host computer can receive the CAN, switch quantity and other information collected by the controller for display. The tester can analyze and judge the test results of the balancing action according to the test signal, and can also write test cases before the test. The test cases are used to realize the control parameters of the controller's output control battery simulator and temperature simulator. Different balancing test scenarios can be realized according to different test cases. Therefore, the test device of this application has strong compatibility.

[0023] This application uses a hardware-in-the-loop (HIL) test cabinet to build the hardware and bus closed-loop working environment required for the BMS balancing test. The operation control of the BMS is realized through the upper computer model control, and the lower computer controller simulates the trigger control of the balancing conditions to achieve the purpose of BMS balancing logic testing. First, obtain the parameters and functional requirements of battery balancing from the BMS design document, including balancing current, balancing strategy, etc. Configure the BMS test environment on the HIL bench, including connecting the battery simulator, debugging and connecting the BMS, and ensuring that there are no problems with the basic electrical connections. Figure 1As shown, the BMS controller (BCU) is connected to the controller area network bus (CAN) board, AO / IO board, and DI / DO of the lower computer, and the slave BMU is connected to the resistance board (temperature simulator) and monomer board (cell simulator) of the lower computer controller; the upper computer controls the lower computer to simulate CAN signals, I / O signals, resistance signals, and monomer voltage signals for BMS to receive; the upper computer collects the bus signals sent by BMS through the lower computer; the upper computer controls the programmable power supply to power BMS and the board. Through the software platform, build battery balancing test cases, determine the test steps and test processes. Then set the state to be tested, including voltage, current, temperature, SOC and other conditions, which can be achieved by controlling the battery simulator through the controller. The controller outputs the status signal required for BMS balancing to the BMS, so that it meets the most basic conditions for balancing, such as static time ≥ 1H, △ single-cell SOC ≥ 4%, single-cell voltage in non-plateau period (lithium iron phosphate battery, other batteries can be ignored), V lowest single-cell> V threshold, T battery < 55℃, etc., and then simulates and sends them to the BMS for collection. Before testing, the BMS needs to be functionally tested to ensure that the BMS function is reliable, that is, the BMS charge and discharge function test is performed to determine that it is normal. This can be achieved before the balancing test to avoid testing an unusable BMS.

[0024] Collect and analyze test data. According to the passive balancing strategy logic, write a passive balancing test case as shown in Table 1, and then perform test data collection and analysis according to the test case in Table 1 to verify the balancing logic. When the control parameters corresponding to the test case are executed and the collected data is consistent with the test case, the balancing strategy is judged to be qualified, otherwise the test is judged to be problematic and unqualified. When the whole vehicle meets the following three conditions: 1. When the standing time is greater than 1H, the SOC of each single cell can be found according to the static OCV table; 2. The highest single cell SOC ≥ 90%; 3. △ Single cell SOC ≥ 4%; the cell number that meets the balancing conditions will be stored in EEProm. BMS will calculate the balancing time according to the cell number and start balancing in odd and even channels, which can verify whether the balancing start-up conditions and balancing current meet the requirements. After entering the balancing, adjust the battery parameters as follows: 1. △ Single cell SOC ≤ 2%; 2. The remaining balancing time is 0; 3. The board is powered off; 4. T 电池 >55℃; 5. The current battery fault level is ≥3. The balanced single cell shutdown function can be verified. 7. Generate test report: Generate a test report based on the test results, record the test process, test data and test conclusions, and provide a reference for subsequent optimization and improvement.

[0025] Table 1 Balanced test cases

[0026]

[0027]

[0028] Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. A battery management system equalization test device, characterized in that: It includes a temperature simulator, a battery cell simulator, a controller, an acquisition board and a low-voltage power supply, wherein the low-voltage power supply is connected to the controller; the low-voltage power supply is connected to a low-voltage power supply connector, and the low-voltage power supply connector is used to connect to the power supply end of a battery management system during testing to power the battery management system; the output end of the controller is connected to the temperature simulator and the battery cell simulator, and is used to control the temperature simulator and the battery cell simulator to simulate the output of battery cell voltage and operating temperature data; the battery cell simulator and the temperature simulator are both connected to a junction box, and the junction box is used to connect to the acquisition end of the battery management system; the input end of the controller is connected to the input end of the acquisition board, and the acquisition board is connected to the communication end of the battery management system through a communication plug-in.

2. A battery management system equalization test device as claimed in claim 1, characterized in that: The acquisition board includes a CAN board, one end of the CAN board is connected to the controller, and the other end is connected to the CAN communication network interface of the BMS via a communication plug-in.

3. A battery management system equalization test device as claimed in claim 2, characterized in that: The acquisition board also includes an AO / IO board and a DI / DO board. The controller is connected to the AO / IO board and the DI / DO board respectively. The AO / IO board and the DI / DO board are connected to the communication plug-in after passing through the signal processing circuit respectively, and are used to connect to the battery management system through the communication plug-in.

4. A battery management system equalization test device as described in any one of claims 1 to 3, characterized in that: The controller is connected to a host computer via Ethernet, and is used to receive test control signals via Ethernet and upload collected action signals of the battery management system.

5. A battery management system equalization test device as described in any one of claims 1 to 3, characterized in that: The battery management system includes a host BCU and multiple slave BMUs. The host BCU is connected to each slave BMS through the CAN intranet. Each slave BMS is connected to a junction box through a collection terminal to collect temperature data and telecommunication voltage data.

6. A battery management system equalization test device as claimed in claim 5, characterized in that: The communication terminal of the host BCU is connected to the acquisition board through a communication plug-in.

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