Battery module welding quality detection method and system based on Labview

Abstract

The present invention provides a battery module welding quality detection method and system based on Labview, the method adopts a host computer to control a preset device, adopts the preset device to charge and discharge the battery module, adopts the host computer to collect data of the battery module, and the method includes the following steps: initialize the communication settings, serial ports and bidirectional power supply of the preset device, and establish communication with the bidirectional power supply; establish multiple concurrent task processing threads; based on the charge and discharge parameters and the multiple concurrent task processing threads, the battery module is static, charged and discharged; based on the battery communication protocol, the sampling cycle and the multiple concurrent task processing threads, the real-time voltage data of each battery cell in the battery module during the static, charging and discharging process is collected; the real-time voltage data is processed to calculate the DC internal resistance value of at least one battery cell; judge whether the DC internal resistance value is within the preset internal resistance interval, and if so, the contact resistance of the welding point of the corresponding battery cell is displayed as qualified. The investment cost of this method is low.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery detection, and in particular relates to a battery module welding quality detection method and system based on Labview. Background Art

[0002] In the process of assembling multiple battery cells into a module, one of the more critical processes is welding, which is specifically done as follows: after pre-fixing the connecting piece on the corresponding electrodes of multiple battery cells, weld the connecting piece to the corresponding electrodes of each battery cell. Through the above welding method, multiple battery cells are connected in series or in parallel to meet the preset battery module design requirements (including but not limited to voltage, current and capacity requirements). Welding is an intense physical, chemical and metallurgical process, which is easily affected by multiple factors such as process parameters, solder and external environment. These influencing factors will have a certain degree of uncontrollable fluctuations. Therefore, defects such as cold welding and false welding are prone to occur after the battery cell is welded, thereby affecting the overcurrent capacity and connection reliability of the battery module, reducing the service life of the battery module, and even causing serious safety accidents.

[0003] In the prior art, in order to ensure the quality of welding, manual visual inspection, pull-out force inspection or 2D image inspection are used to select battery modules with unqualified welding quality and rework them for welding. The above prior art has the following problems:

[0004] 1) Manual visual inspection is time-consuming, labor-intensive, and inefficient, and is only suitable for detecting appearance defects. It is difficult to judge internal defects of welding (false welding, false welding, pores, etc.).

[0005] 2) Pull-out force testing is a destructive test and is not suitable for full inspection.

[0006] 3) The imaging effect of 2D image detection is easily affected by the environment (lighting, camera position, focal length and grayscale, etc.), so the imaging effect fluctuates greatly and the actual detection effect is not ideal. In addition, the camera, camera bracket and image analysis device used in conjunction with this technology have high investment costs. Summary of the invention

[0007] The present invention provides a battery module welding quality detection method and system based on Labview, which are used to solve the problems existing in the prior art.

[0008] In the first aspect, the purpose of the present invention is achieved by the following technical solutions:

[0009] A battery module welding quality detection method based on Labview, using a host computer to control a preset device, using the preset device to charge and discharge the battery module, and using the host computer to collect data of the battery module, the method includes the following steps:

[0010] S1: Initializing the communication settings, serial port and bidirectional power supply of the preset device, and establishing communication with the bidirectional power supply;

[0011] S2: After establishing multiple concurrent task processing threads, the following steps are performed in parallel according to the multiple concurrent task processing threads:

[0012] S3: Based on the charge and discharge parameters, the battery module is left to stand, charged and discharged;

[0013] S4: Based on the battery communication protocol and sampling period, collect the real-time voltage data of each battery cell in the battery module during the static, charging and discharging processes;

[0014] S5: After closing the multiple concurrent task processing threads, processing the real-time voltage data to calculate the DC internal resistance value of at least one battery cell;

[0015] S6: Determine whether the DC internal resistance value is within a preset internal resistance range. If so, the solder joint contact resistance of the corresponding battery cell is displayed as qualified.

[0016] Preferably, the charging and discharging parameters include at least: standing time, charging time, discharging time and current level, the current level includes discharge level one, discharge level two, discharge level three, charge level one, charge level two and charge level three, the current level increases step by step, and the current level ranges from 2C to 5C.

[0017] Preferably, the step of placing the battery module at rest, charging and discharging the battery module based on the charge and discharge parameters comprises: placing the battery module at rest for the first time within the rest time;

[0018] After the battery module is left to rest for the first time, the battery module is discharged for the first time by using the first discharge stage within the discharge time;

[0019] After the battery module is discharged for the first time, the battery module is allowed to stand for a second time within the standing time;

[0020] After the battery module is left to rest for the second time, the battery module is charged for the first time using the first charging level within the charging time;

[0021] After the battery module is charged for the first time, the battery module is left to stand for three times within the standing time;

[0022] After the battery module is left to stand for the third time, the battery module is discharged for the second time by using the second discharge stage within the discharge time;

[0023] After the battery module is discharged for the second time, the battery module is allowed to stand for a fourth time within the standing time;

[0024] After the battery module is left to rest for the fourth time, the battery module is charged for the second time using the second charging stage within the charging time;

[0025] After the battery module is charged for the second time, the battery module is left to rest for the fifth time within the rest time;

[0026] After the battery module is left to stand for the fifth time, the battery module is discharged for the third time using the three-stage discharge within the discharge time;

[0027] After the battery module is discharged for the third time, the battery module is left at rest for the sixth time within the rest time;

[0028] After the battery module is left to rest for the sixth time, the battery module is charged for the third time using the third-level charging method within the charging time.

[0029] Preferably, the sampling period includes a first period, a second period and a third period, and the collecting of real-time voltage data of each battery cell in the battery module during the static, charging and discharging processes based on the battery communication protocol and the sampling period includes:

[0030] Based on the battery communication protocol, in the first cycle, raw data of each battery cell in the battery module during the charging, discharging and static process is collected, and the raw data is queued and stored in a data queue;

[0031] Based on the battery communication protocol, in the second cycle, the original data stored in the data queue is dequeued and parsed to obtain real-time voltage data of each battery cell during the static, charging and discharging processes;

[0032] Based on the battery communication protocol, in the third cycle, a flat sequence structure is adopted to store the real-time voltage data in a preset temporary array, and the real-time voltage data in the temporary array is assigned to the corresponding battery cell voltage array.

[0033] Preferably, before storing the real-time voltage data in a preset temporary array, the method further comprises:

[0034] Clear the data in the preset temporary array.

[0035] Preferably, the processing of the real-time voltage data to calculate the DC internal resistance value of at least one battery cell includes:

[0036] The peak detection function is used to extract the extreme values ​​of each battery cell during charging, discharging and standing.

[0037] A linear fitting function is used to calculate the DC internal resistance of at least one battery cell based on the extreme value.

[0038] Preferably, the battery communication protocol includes but is not limited to RS232, RS485, TTL, CAN and IIC.

[0039] In a second aspect, the purpose of the present invention is achieved by the following technical solutions:

[0040] The battery module welding quality detection system based on Labview is characterized in that the battery module welding quality detection method based on Labview is built in, and the system includes:

[0041] An initialization module, used to initialize the communication settings, serial port and bidirectional power supply of the preset device, and establish communication with the bidirectional power supply;

[0042] A multi-thread establishment module, used for establishing multiple concurrent task processing threads and executing steps S3-S4 in parallel according to the multiple concurrent task processing threads;

[0043] A charge and discharge control module, used for standing, charging and discharging the battery module based on charge and discharge parameters;

[0044] A data acquisition module, used to collect real-time voltage data of each battery cell in the battery module during the static, charging and discharging processes based on the battery communication protocol and sampling period;

[0045] A calculation module, used for processing the real-time voltage data after closing the multiple concurrent task processing threads, and calculating a DC internal resistance value of at least one battery cell;

[0046] The judging module is used to judge whether the DC internal resistance value is within a preset internal resistance range. If so, the contact resistance of the solder joint of the corresponding battery cell is displayed as qualified.

[0047] Compared with the prior art, the present invention has at least the following advantages:

[0048] 1) The method of the present invention realizes the battery module welding quality detection through Labview programming, and the investment cost is low.

[0049] 2) The method of the present invention does not require manual inspection, has high inspection efficiency, and can detect internal defects of the battery core after welding.

[0050] 3) The method of the present invention will not cause damage to the welding parts of the battery core and can achieve full inspection.

[0051] 4) The method of the present invention is less affected by environmental factors.

[0052] 5) The present invention simultaneously acquires the voltage data of all battery cells in real time during the process of charging, standing and discharging, which can reduce the delay of voltage data acquisition and improve the accuracy of voltage data acquisition when the battery cells are suddenly charged or discharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 It is a structural schematic diagram of a battery module in the prior art;

[0055] Figure 2 This is a flowchart of a battery module welding quality detection method based on Labview in Embodiment 1 of the present invention;

[0056] Figure 3 It is a graphical program diagram of step S11 of the battery module welding quality detection method based on Labview in the first embodiment of the present invention;

[0057] Figure 4 It is a graphical program diagram of step S12 of the battery module welding quality detection method based on Labview in the first embodiment of the present invention;

[0058] Figure 5 It is a graphical program diagram of the static process of the battery module in step S3 of the battery module welding quality detection method based on Labview in Example 1 of the present invention;

[0059] Figure 6 It is a graphical program diagram of the battery module discharge process in step S3 of the battery module welding quality detection method based on Labview in Example 1 of the present invention;

[0060] Figure 7 It is a graphical program diagram of the battery module charging process in step S3 of the battery module welding quality detection method based on Labview in Example 1 of the present invention;

[0061] Figure 8 This is a flowchart of step S4 of the battery module welding quality detection method based on Labview in the first embodiment of the present invention;

[0062] Fig. 9 It is a graphical overall program diagram of step S4 of the battery module welding quality detection method based on Labview in the first embodiment of the present invention;

[0063] Fig.10 It is a graphical subroutine diagram of step S4 of the battery module welding quality detection method based on Labview in the first embodiment of the present invention;

[0064] Fig.11 It is a graphical subroutine diagram of step S4 of the battery module welding quality detection method based on Labview in the first embodiment of the present invention;

[0065] Fig.12 A graphical subroutine and annotated diagram of step S4 of the battery module welding quality detection method based on Labview in the first embodiment of the present invention;

[0066] Fig.13 It is a graphical program diagram of step S5 of the battery module welding quality detection method based on Labview in the first embodiment of the present invention;

[0067] Fig.14 This is the effect and annotation diagram of step S5 of the battery module welding quality detection method based on Labview in Example 1 of the present invention. DETAILED DESCRIPTION

[0068] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0070] like Figure 1 As shown, in the prior art, in order to assemble cylindrical cells or square cells into battery modules, it is necessary to pre-fix the connecting pieces on the corresponding electrodes of multiple cells, and then weld the connecting pieces to the corresponding electrodes of each cell, so as to achieve multiple cells in series or in parallel. In order to ensure the quality of welding, manual visual inspection, pull-out force detection or 2D image detection will be used to pick out battery modules with unqualified welding quality and rework them for welding. With respect to the above prior art, the following problems exist:

[0071] 1) Manual visual inspection is time-consuming, labor-intensive, and inefficient, and is only suitable for detecting appearance defects. It is difficult to judge internal defects of welding (false welding, false welding, pores, etc.).

[0072] 2) Pull-out force testing is a destructive test and is not suitable for full inspection.

[0073] 3) The imaging effect of 2D image detection is easily affected by the environment (lighting, camera position, focal length and grayscale, etc.), so the imaging effect fluctuates greatly and the actual detection effect is not ideal. In addition, the camera, camera bracket and image analysis device used in conjunction with this technology have high investment costs.

[0074] 4) When the device used to detect battery cells is suddenly connected to the battery cells or suddenly identifies the battery cell welding points, there will inevitably be signal delays, which can easily lead to deviations in the detection results.

[0075] In order to solve the above technical problems, this embodiment provides a battery module welding quality detection method and system based on Labview.

[0076] Embodiment 1

[0077] Reference Figure 2 In this embodiment, a battery module welding quality detection method based on Labview is used, a host computer is used to control a preset device, a preset device is used to charge and discharge the battery module, and a host computer is used to collect data of the battery module. The method includes:

[0078] S1: Initialize the communication settings, serial port and bidirectional power supply of the preset device, and establish communication with the bidirectional power supply.

[0079] Wherein, step S1 comprises:

[0080] S11: Initialize the communication settings and serial port of the preset device.

[0081] Specifically, Figure 3 The graphical program diagram of step S11 in the development environment of the Labview programming language is shown in FIG. 1. The program corresponding to step S11 first initializes the serial port communication tool, and then configures the communication-related parameters of the preset device, the host computer, and the battery module. The purpose of step S11 is to prevent the preset device serial port from being abnormally closed.

[0082] Specifically, after closing the host computer serial port and clearing the error, configure the serial port baud rate, stop bit, data bit, check bit, flow control and buffer data size of the preset device and the host computer. After the configuration is completed, confirm whether there is any error. If there is, remind the user to check it by himself.

[0083] It should be noted that the above serial port baud rate, stop bit, data bit, check bit, flow control and buffer data size are generally default values, but can be adjusted according to actual conditions.

[0084] S12: Initialize the bidirectional power supply of the preset device and establish communication between the host computer and the bidirectional power supply.

[0085] in, Figure 4 It is a graphical program diagram of step S12 in the development environment of the Labview programming language. After the program corresponding to step S12 initializes the bidirectional power supply of the preset device, communication between the host computer and the bidirectional power supply is established to achieve the effect of the host computer controlling the bidirectional power supply.

[0086] Specifically, after closing the communication serial port of the bidirectional power supply, the preset device is initialized. During the initialization process of step S12, the device serial port baud rate, stop bit, data bit, check bit and flow control will be set. Then the host computer sends a remote command to put the device into remote mode. If the device does not respond abnormally or an error occurs, the user is reminded to check.

[0087] It should be noted that the device mentioned in step S12 is an existing independent device used to charge and discharge the battery module, and specifically can be ITECH 6006C or Chroma 17020.

[0088] S2: After establishing multiple concurrent task processing threads, the following steps are executed in parallel according to the multiple concurrent task processing threads:

[0089] Specifically, step S2 is used to construct a parallel framework so that when the battery module is subsequently charged and discharged with a large current and left at rest, the real-time voltage data of each battery cell is simultaneously collected through multiple concurrent task processing threads.

[0090] It should be noted that the existing Labview programming language development environment has a built-in functional module for establishing multiple concurrent task processing threads.

[0091] S3: Based on the charge and discharge parameters, the battery module is left to rest, charged and discharged.

[0092] Among them, the charging and discharging parameters at least include rest time, charging time, discharging time and current level. The current level includes discharge level one, discharge level two, discharge level three, charge level one, charge level two and charge level three. The current level increases step by step, and the current level ranges from 2C to 5C.

[0093] In this embodiment, the first current level corresponds to 2C, the second current level corresponds to 3C, and the third current level corresponds to 5C.

[0094] It should be noted that, in other embodiments, the magnitude of the current level depends on different battery cell types and charge and discharge capabilities.

[0095] In this embodiment, the rest time, charging time and discharging time are 10S. Setting 10S can fully charge and discharge the battery cell, stabilize the voltage of the battery cell, and facilitate subsequent calculations. In other embodiments, the rest time, charging time and discharging time fluctuate around 10S, and the specific setting needs to be based on actual conditions.

[0096] Wherein, step S3 comprises:

[0097] Allow the battery module to rest for the first time during the resting time;

[0098] After the battery module is left to rest for the first time, the battery module is discharged for the first time using the first discharge stage within the discharge time;

[0099] After the battery module is discharged for the first time, the battery module is left to rest for a second time within the resting time;

[0100] After the battery module is left to rest for the second time, the battery module is charged for the first time using the first charging stage within the charging time;

[0101] After the battery module is charged for the first time, the battery module is left to rest for three times within the resting time;

[0102] After the battery module is left to rest for the third time, the battery module is discharged for the second time using the second discharge stage within the discharge time;

[0103] After the battery module is discharged for the second time, the battery module is left to rest for the fourth time within the rest time;

[0104] After the battery module is left to rest for the fourth time, the battery module is charged for the second time using the second stage of charging within the charging time;

[0105] After the battery module is charged for the second time, the battery module is left to rest for the fifth time within the resting time;

[0106] After the battery module is left to rest for the fifth time, the battery module is discharged for the third time using the three-stage discharge method within the discharge time;

[0107] After the battery module is discharged for the third time, the battery module is left to rest for the sixth time within the resting time;

[0108] After the battery module has been left to rest for the sixth time, the battery module is charged for the third time using the third-level charging method within the charging time.

[0109] Specifically, Figure 5This is a graphical program diagram of step S3 in the development environment of the Labview programming language. Whenever the battery module is left to rest, the program is called. It should be noted that the main purpose of resting is to place the battery module for a period of time after charging and discharging to stabilize the voltage of each cell, so that the subsequent peak detection is more accurate.

[0110] Specifically, Figure 6 This is a graphical program diagram of step S3 in the development environment of the Labview programming language, and the program is called when the battery module is discharged for the first time. It should be noted that the graphical program diagrams for the second and third discharges are similar to the graphical program diagram for the first discharge, and the difference lies in the variable CURRENT_DCHG_LEVEL, which is the specific parameter corresponding to the discharge level.

[0111] Specifically, Figure 7 This is a graphical program diagram of step S3 in the development environment of the Labview programming language, and the program is called when the battery module is charged for the first time. It should be noted that the graphical program diagrams for the second and third charging are similar to the graphical program diagram for the first charging, and the difference lies in CURRENT_CHG_LEVEL, that is, the specific parameters corresponding to the charging level.

[0112] S4: Based on the battery communication protocol and sampling period, collect the real-time voltage data of each battery cell in the battery module during the static, charging and discharging processes.

[0113] It should be noted that step S4 and step S3 are executed in parallel.

[0114] Among them, Figure 8 and Fig. 9 As shown, step S4 includes:

[0115] S41: Based on the battery communication protocol, in the first cycle, the original data of each battery cell in the battery module during the charging, discharging and static process is collected, and the original data is queued and stored in the data queue.

[0116] In this embodiment, the battery communication protocol adopts RS232. In other embodiments, RS485, TTL, CAN and IIC may also be adopted.

[0117] Specifically, Fig.10 As shown, the duration of the first cycle is set to 100 milliseconds. A subVI is placed in the first cycle: UART_Read_Write.vi. According to the battery communication protocol, the original voltage data of each battery cell is read through the serial port in the first cycle, and the data is queued and stored in the UART_Rx queue.

[0118] S42: Based on the battery communication protocol, in the second cycle, the original data stored in the data queue is dequeued and parsed to obtain the real-time voltage data of each battery cell during the static, charging and discharging processes.

[0119] Specifically, Fig.11 As shown, the duration of the second cycle is set to 80 milliseconds. A subVI is placed in the second cycle: UART_Get_Data_WSB.vi, which realizes the loop from the UART_Rx queue. After taking out the serial port data through the element dequeue function, the dequeued voltage data is parsed according to the battery communication protocol to obtain the real-time voltage data of each battery cell during the static, charging and discharging processes.

[0120] S43: Based on the battery communication protocol, in the third cycle, a flat sequential structure is used to store the real-time voltage data in a preset temporary array, and the real-time voltage data in the temporary array is assigned to the corresponding battery cell voltage array.

[0121] In this embodiment, if Fig.12 As shown, the duration of the third cycle is set to 90 milliseconds. A subVI is placed in the third cycle: WSB_R05_Dynamic_Read_Vn.vi, which uses a flat sequential structure. First, the temporary array that temporarily stores the cell voltage is cleared, and then the real-time voltage data of each cell during the charging and discharging process and the static process is continuously stored in the temporary array. Finally, the data stored in the temporary array is cyclically taken out and assigned to the Array_Vn corresponding to each cell voltage.

[0122] Through the above steps S3-S4, the present invention simultaneously acquires the voltage data of all battery cells in real time during the process of charging, standing and discharging. The acquisition of voltage data is continuous and uninterrupted, which overcomes the problem of data delay in the prior art when the device for detecting battery cells is suddenly connected to the battery cells or the battery cell welding points are suddenly identified to obtain corresponding data.

[0123] S5: After closing the multi-concurrent task processing thread, the real-time voltage data is processed to calculate the DC internal resistance value of at least one battery cell.

[0124] Wherein, step S5 comprises:

[0125] The peak detection function is used to extract the extreme values ​​of each battery cell during charging, discharging and standing.

[0126] A linear fitting function is used to calculate the DC internal resistance of at least one battery cell based on the extreme value.

[0127] Specifically, Fig.13As shown, the peak detection function and the linear fitting function are placed in the development environment of the Labview programming language, and the voltage data of the battery cell 1 is recorded during the charging, discharging and static process. After the extreme value is taken out by the peak detection function, the DC internal resistance DCIR of the battery cell 1 during the discharge process is calculated using the linear fitting function. Similarly, the DC internal resistance DCIR of the battery cell 1 during the charging process can also be obtained by the same method.

[0128] It should be noted that the implementation method of charging and discharging DC internal resistance of other cells is the same, just replace the array Array_V1 that records the cell voltage with Arrary_V2...Aarry_Vn. The extreme values ​​of each cell during charging, discharging and resting include the maximum value of charging, the minimum value of charging, the maximum value of discharging, the minimum value of discharging, the maximum value of resting and the minimum value of resting.

[0129] S6: Determine whether the DC internal resistance value is within a preset internal resistance range. If so, the contact resistance of the solder joint of the corresponding battery cell is displayed as qualified.

[0130] In this embodiment, the internal resistance range is set to 6-6.7 mΩ.

[0131] Specifically, based on steps S1-S5, the following is obtained: Fig.14 As shown in the effect diagram, the DC internal resistance of the battery cell 2 is 8.375mΩ, which is significantly higher than 6.7mΩ. Therefore, the solder joint contact resistance of the battery cell 2 is unqualified, indicating that there are problems of cold solder joints, false solder joints and pores in the battery cell 2. Similarly, the solder joint contact resistance of other batteries can also be judged by the same evaluation criteria.

[0132] It should be noted that the method of the present invention is not only applicable to cylindrical cells or square cells assembled into battery modules, but also other battery modules that require welding of cells (such as soft-pack battery modules) can also be tested by the present invention. The internal resistance range is related to the cell selection, the type of connecting piece, and the number of series and parallel connections of the module, and can be set according to actual conditions.

[0133] Compared with the prior art, the method of the present invention realizes battery module welding quality detection through Labview programming, has low investment cost, and can achieve high-efficiency full inspection.

[0134] Embodiment 2

[0135] A battery module welding quality detection system based on Labview is built with the battery module welding quality detection method based on Labview of the first embodiment, and the system includes:

[0136] An initialization module, used to initialize the communication settings, serial port and bidirectional power supply of the preset device, and establish communication with the bidirectional power supply;

[0137] A multi-thread establishment module, used to establish multiple concurrent task processing threads and execute steps S3-S4 in parallel according to the multiple concurrent task processing threads;

[0138] A charge and discharge control module, used to place the battery module in a static state, charge it, and discharge it based on the charge and discharge parameters;

[0139] The data acquisition module is used to collect the real-time voltage data of each battery cell in the battery module during the static, charging and discharging processes based on the battery communication protocol and sampling period;

[0140] A calculation module, used to process the real-time voltage data after closing the multiple concurrent task processing threads, and calculate the DC internal resistance value of at least one battery cell;

[0141] The judgment module is used to judge whether the DC internal resistance value is within a preset internal resistance range. If so, the contact resistance of the solder joint of the corresponding battery cell is displayed as qualified.

[0142] Among them, the charge and discharge control module includes:

[0143] A first resting unit, used for resting the battery module for the first time within the resting time;

[0144] The first discharge unit is used to discharge the battery module for the first time by using the first discharge stage within the discharge time after the battery module is left to stand for the first time;

[0145] A second resting unit is used to rest the battery module for a second time within a resting time after the battery module is discharged for the first time;

[0146] The first charging unit is used to charge the battery module for the first time within the charging time by using the first charging level after the battery module is left to stand for the second time;

[0147] A third rest unit is used to rest the battery module three times within the rest time after the battery module is charged for the first time;

[0148] The second discharge unit is used to discharge the battery module for the second time within the discharge time after the battery module is left to stand for the third time;

[0149] A fourth resting unit, used for resting the battery module for a fourth time within a resting time after the battery module is discharged for the second time;

[0150] The second charging unit is used to charge the battery module for the second time within the charging time after the battery module is left to stand for the fourth time;

[0151] A fifth resting unit, used for resting the battery module for the fifth time within the resting time after the battery module is charged for the second time;

[0152] The third discharging unit is used to discharge the battery module for the third time by using the third discharge level within the discharge time after the battery module is left to stand for the fifth time;

[0153] A sixth resting unit, used for resting the battery module for the sixth time within the resting time after the battery module is discharged for the third time;

[0154] The third charging unit is used to charge the battery module for the third time by using the third charging level within the charging time after the battery module has been left to rest for the sixth time.

[0155] The data acquisition module includes:

[0156] The raw data acquisition unit is used to collect the raw data of each battery cell in the battery module during the charging, discharging and static process in the first cycle based on the battery communication protocol, and queue the raw data and store it in the data queue;

[0157] A data analysis unit is used to perform a dequeue operation and data analysis on the original data stored in the data queue based on the battery communication protocol in the second cycle to obtain the real-time voltage data of each battery cell during the static, charging and discharging processes;

[0158] The array assignment unit is used to store the real-time voltage data in a preset temporary array based on the battery communication protocol in a flat sequential structure within the third cycle, and assign the real-time voltage data in the temporary array to the corresponding battery cell voltage array.

[0159] The calculation module includes:

[0160] An extreme value extraction unit, used to extract the extreme values ​​of each battery cell during charging, discharging and standing by using a peak detection function;

[0161] The calculation unit is used to calculate the DC internal resistance value of at least one battery cell based on the extreme value by using a linear fitting function.

[0162] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, etc. Various media that can store program codes.

[0163] For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims

1. A battery module welding quality detection method based on Labview, characterized in that: A host computer is used to control a preset device, the preset device is used to charge and discharge a battery module, and the host computer is used to collect data of the battery module. The method includes the following steps: S1: Initializing the communication settings, serial port and bidirectional power supply of the preset device, and establishing communication with the bidirectional power supply; S2: After establishing multiple concurrent task processing threads, the following steps are performed in parallel according to the multiple concurrent task processing threads: S3: Based on the charge and discharge parameters, the battery module is left to stand, charged and discharged; S4: Based on the battery communication protocol and sampling period, collect the real-time voltage data of each battery cell in the battery module during the static, charging and discharging processes; S5: After closing the multiple concurrent task processing threads, processing the real-time voltage data to calculate the DC internal resistance value of at least one battery cell; S6: Determine whether the DC internal resistance value is within a preset internal resistance range. If so, the contact resistance of the solder joint of the corresponding battery cell is displayed as qualified; The charging and discharging parameters at least include: rest time, charging time, discharging time and current level. The current level includes discharge level 1, discharge level 2, discharge level 3, charge level 1, charge level 2 and charge level 3. The current level increases step by step, and the current level ranges from 2C to 5C. The step of placing the battery module at rest, charging and discharging the battery module based on the charge and discharge parameters includes: Allowing the battery module to rest for the first time within the resting time; After the battery module is left to rest for the first time, the battery module is discharged for the first time by using the first discharge stage within the discharge time; After the battery module is discharged for the first time, the battery module is allowed to stand for a second time within the standing time; After the battery module is left to rest for the second time, the battery module is charged for the first time using the first charging level within the charging time; After the battery module is charged for the first time, the battery module is left to stand for three times within the standing time; After the battery module is left to stand for the third time, the battery module is discharged for the second time by using the second discharge stage within the discharge time; After the battery module is discharged for the second time, the battery module is allowed to stand for a fourth time within the standing time; After the battery module is left to rest for the fourth time, the battery module is charged for the second time using the second charging stage within the charging time; After the battery module is charged for the second time, the battery module is left to rest for the fifth time within the rest time; After the battery module is left to stand for the fifth time, the battery module is discharged for the third time using the three-stage discharge within the discharge time; After the battery module is discharged for the third time, the battery module is left at rest for the sixth time within the rest time; After the battery module is left to rest for the sixth time, the battery module is charged for the third time using the third-level charging method within the charging time; The first level current level corresponds to 2C, the second level current level corresponds to 3C, and the third level current level corresponds to 5C; the rest time, charging time and discharging time are 10S; The sampling period includes a first period, a second period and a third period. The real-time voltage data of each battery cell in the battery module during the static, charging and discharging process is collected based on the battery communication protocol and the sampling period, including: Based on the battery communication protocol, in the first cycle, raw data of each battery cell in the battery module during the charging, discharging and static process is collected, and the raw data is queued and stored in a data queue; Specifically, the duration of the first cycle is set to 100 milliseconds. A subVI is placed in the first cycle: UART_Read_Write.vi. According to the battery communication protocol, the original voltage data of each battery cell is read through the serial port in the first cycle, and the data is queued and stored in the UART_Rx queue. Based on the battery communication protocol, in the second cycle, the original data stored in the data queue is dequeued and parsed to obtain real-time voltage data of each battery cell during the static, charging and discharging processes; Specifically, the duration of the second cycle is set to 80 milliseconds. A subVI is placed in the second cycle: UAR T_Get_Data_WSB.vi, which realizes the loop from the UART_Rx queue. After taking out the serial port data through the element dequeue function, the dequeued voltage data is parsed according to the battery communication protocol to obtain the real-time voltage data of each battery cell during the static, charging and discharging process. Based on the battery communication protocol, in the third cycle, the real-time voltage data is stored in a preset temporary array using a flat sequence structure, and the real-time voltage data in the temporary array is assigned to the corresponding cell voltage array; Specifically, the duration of the third cycle is set to 90 milliseconds. A subVI: WSB_R05_Dynamic_Read_Vn.vi is placed in the third cycle. A flat sequential structure is used to first clear the temporary array for temporarily storing the cell voltages, and then continuously store the real-time voltage data of each cell during the charging and discharging process and the static process into the temporary array. Finally, the data stored in the temporary array is cyclically retrieved and assigned to the Array_Vn corresponding to each cell voltage.

2. The battery module welding quality detection method based on Labview according to claim 1 is characterized in that: Before storing the real-time voltage data in a preset temporary array, the method further includes: Clear the data in the preset temporary array.

3. The battery module welding quality detection method based on Labview according to claim 1 is characterized in that: The processing of the real-time voltage data to calculate the DC internal resistance value of at least one battery cell includes: The peak detection function is used to extract the extreme values ​​of each battery cell during charging, discharging and standing. A linear fitting function is used to calculate the DC internal resistance of at least one battery cell based on the extreme value.

4. The battery module welding quality detection method based on Labview according to claim 1 is characterized in that: The battery communication protocols include but are not limited to RS232, RS485, TTL, CAN and IIC.

5. The battery module welding quality detection system based on Labview is characterized by: A battery module welding quality detection method based on Labview according to any one of claims 1 to 4 is built in, and the system includes: An initialization module, used to initialize the communication settings, serial port and bidirectional power supply of the preset device, and establish communication with the bidirectional power supply; A multi-thread establishment module, used for establishing multiple concurrent task processing threads and executing steps S3-S4 in parallel according to the multiple concurrent task processing threads; A charge and discharge control module, used for standing, charging and discharging the battery module based on charge and discharge parameters; A data acquisition module, used to collect real-time voltage data of each battery cell in the battery module during the static, charging and discharging processes based on the battery communication protocol and sampling period; A calculation module, used for processing the real-time voltage data after closing the multiple concurrent task processing threads, and calculating a DC internal resistance value of at least one battery cell; A judgment module, used to judge whether the DC internal resistance value is within a preset internal resistance range, and if so, the contact resistance of the solder joint of the corresponding battery cell is displayed as qualified; The charging and discharging parameters at least include: rest time, charging time, discharging time and current level. The current level includes discharge level 1, discharge level 2, discharge level 3, charge level 1, charge level 2 and charge level 3. The current level increases step by step, and the current level ranges from 2C to 5C. The step of placing the battery module at rest, charging and discharging the battery module based on the charge and discharge parameters includes: Allowing the battery module to rest for the first time within the resting time; After the battery module is left to rest for the first time, the battery module is discharged for the first time by using the first discharge stage within the discharge time; After the battery module is discharged for the first time, the battery module is allowed to stand for a second time within the standing time; After the battery module is left to rest for the second time, the battery module is charged for the first time using the first charging level within the charging time; After the battery module is charged for the first time, the battery module is left to stand for three times within the standing time; After the battery module is left to stand for the third time, the battery module is discharged for the second time by using the second discharge stage within the discharge time; After the battery module is discharged for the second time, the battery module is allowed to stand for a fourth time within the standing time; After the battery module is left to rest for the fourth time, the battery module is charged for the second time using the second charging stage within the charging time; After the battery module is charged for the second time, the battery module is left to rest for the fifth time within the rest time; After the battery module is left to stand for the fifth time, the battery module is discharged for the third time using the three-stage discharge within the discharge time; After the battery module is discharged for the third time, the battery module is left at rest for the sixth time within the rest time; After the battery module is left to rest for the sixth time, the battery module is charged for the third time using the third-level charging method within the charging time; The first level current level corresponds to 2C, the second level current level corresponds to 3C, and the third level current level corresponds to 5C; the rest time, charging time and discharging time are 10S; The sampling period includes a first period, a second period and a third period. The real-time voltage data of each battery cell in the battery module during the static, charging and discharging process is collected based on the battery communication protocol and the sampling period, including: Based on the battery communication protocol, in the first cycle, raw data of each battery cell in the battery module during the charging, discharging and static process is collected, and the raw data is queued and stored in a data queue; Specifically, the duration of the first cycle is set to 100 milliseconds. A subVI is placed in the first cycle: UART_Read_Write.vi. According to the battery communication protocol, the original voltage data of each battery cell is read through the serial port in the first cycle, and the data is queued and stored in the UART_Rx queue. Based on the battery communication protocol, in the second cycle, the original data stored in the data queue is dequeued and parsed to obtain real-time voltage data of each battery cell during the static, charging and discharging processes; Specifically, the duration of the second cycle is set to 80 milliseconds. A subVI is placed in the second cycle: UAR T_Get_Data_WSB.vi, which realizes the loop from the UART_Rx queue. After taking out the serial port data through the element dequeue function, the dequeued voltage data is parsed according to the battery communication protocol to obtain the real-time voltage data of each battery cell during the static, charging and discharging process. Based on the battery communication protocol, in the third cycle, the real-time voltage data is stored in a preset temporary array using a flat sequence structure, and the real-time voltage data in the temporary array is assigned to the corresponding cell voltage array; Specifically, the duration of the third cycle is set to 90 milliseconds. A subVI: WSB_R05_Dynamic_Read_Vn.vi is placed in the third cycle. A flat sequential structure is used to first clear the temporary array for temporarily storing the cell voltages, and then continuously store the real-time voltage data of each cell during the charging and discharging process and the static process into the temporary array. Finally, the data stored in the temporary array is cyclically retrieved and assigned to the Array_Vn corresponding to each cell voltage.

Images