Methods, apparatus, media, and vehicles for determining the state of individual battery cells in a vehicle.

Abstract

This disclosure relates to a method, apparatus, medium, and vehicle for determining the state of individual battery cells in a vehicle. The method includes: determining a calculation time window for calculating the state of individual battery cells based on the acquired operating state of the vehicle; calculating voltage information collected for each individual battery cell within the calculation time window, wherein each collection for each individual battery cell includes collecting the voltage of each individual battery cell, and for each individual battery cell, calculating the voltage difference between the collected voltage and the median of the collected voltages of all individual batteries, the voltage information including the voltage difference; calculating the variance between the voltage differences in the voltage information; and determining the state of the individual battery cells in the vehicle based on the relationship between the variance and a target variance threshold. Calculating the variance through calculation time windows under different operating states can improve the accuracy of variance calculation, thereby improving the accuracy of determining the state of individual battery cells.

Description

Technical Field

[0001] This disclosure relates to the field of new energy vehicle battery monitoring technology, specifically to a method, apparatus, medium, and vehicle for determining the state of individual battery cells in a vehicle. Background Technology

[0002] For new energy vehicles, the power supply performance, stability, and safety performance of the battery pack are key indicators for evaluating vehicle performance. The operating voltage of the battery pack directly reflects vehicle performance; therefore, whether the battery pack itself is malfunctioning can be determined by checking the voltage of each individual cell. Related technologies calculate the voltage change rate or SOC (State of Charge) change rate based on the voltage values ​​of each individual cell per second. Then, based on the relationship between the voltage change rate and a preset voltage change rate threshold, or the SOC change rate and a preset state of charge change rate threshold, it is determined whether each individual cell is malfunctioning. Summary of the Invention

[0003] The purpose of this disclosure is to provide a method, apparatus, medium, and vehicle for determining the state of a single battery cell in a vehicle. By configuring computation time windows of different widths under different operating states, and then calculating the variance within the computation time window under the corresponding operating state, the computational load can be reduced and the accuracy of the calculated variance can be improved, thereby improving the accuracy of determining the state of a single battery cell.

[0004] To achieve the above objectives, in a first aspect, this disclosure provides a method for determining the state of a single battery cell in a vehicle, the method comprising:

[0005] Based on the obtained vehicle operating status, a calculation time window is determined for calculating the state of the individual battery cells;

[0006] Calculate the voltage difference for each of the individual cells within the calculation time window;

[0007] Calculate the variance between each of the voltage differences;

[0008] The state of a single battery cell in the vehicle is determined based on the relationship between the variance value and the target variance threshold.

[0009] Optionally, obtaining the running status includes:

[0010] The charging and discharging state of the vehicle is determined based on the charging and discharging indicators of the individual battery cells. The charging and discharging indicators are added according to the current direction of the individual battery cells. The charging and discharging state indicates whether the vehicle is in a charging state or a discharging state.

[0011] The step of determining the calculation time window for calculating the state of the individual battery cells based on the obtained vehicle operating status includes:

[0012] Based on the obtained charge / discharge state, a calculation time window is determined for calculating the state of the individual battery cell, wherein the calculation time window determined under the discharge state is narrower than the calculation time window determined under the charging state.

[0013] Optionally, obtaining the running status includes:

[0014] Obtain the acceleration value of the vehicle;

[0015] The step of determining the calculation time window for calculating the state of the individual battery cells based on the obtained vehicle operating status includes:

[0016] Based on the obtained acceleration value, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the acceleration value.

[0017] Optionally, obtaining the running status includes:

[0018] Obtain the SOC change rate of the battery pack composed of each of the individual cells;

[0019] The step of determining the calculation time window for calculating the state of the individual battery cells based on the obtained vehicle operating status includes:

[0020] Based on the obtained SOC change rate, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the SOC change rate.

[0021] Optionally, before determining the state of a single battery cell in the vehicle based on the relationship between the variance value and the target variance threshold, the method further includes:

[0022] The target variance threshold is determined based on the charging and discharging states included in the operating state.

[0023] Optionally, the charge / discharge state indicates whether the vehicle is in a charging state or a discharging state, and the target variance threshold determined in the discharging state is greater than the target variance threshold determined in the charging state.

[0024] Optionally, the charging state includes a slow charging state and a fast charging state, and the target variance threshold determined in the slow charging state is less than the target variance threshold determined in the fast charging state.

[0025] Optionally, the vehicle is pre-configured with multiple calculation time windows and a correspondence between each calculation time window and the vehicle's operating state. The step of determining the calculation time window for calculating the state of the individual battery cells based on the acquired vehicle operating state includes:

[0026] Based on the obtained running status and the corresponding relationship, the calculation time window corresponding to the running status is determined from multiple pre-configured calculation time windows.

[0027] Optionally, the correspondence between the calculation time window and the vehicle's operating status is determined through the following steps:

[0028] The vehicle's historical operating status is obtained, along with historical voltage information collected for each individual battery cell under the historical operating status. The historical voltage information includes multiple collections and the voltage difference obtained from each collection.

[0029] For each of the multiple candidate calculation time windows, the variance is calculated for each voltage difference obtained from each historical voltage information acquisition within each candidate calculation time window.

[0030] Based on the variance calculated for each of the candidate calculation time windows, the variance distribution for the historical voltage information is obtained;

[0031] Based on the variance distribution, the calculation time window for the corresponding operating state is determined.

[0032] Optionally, determining the calculation time window for the corresponding operating state based on the variance distribution includes:

[0033] From the candidate time windows, determine the smallest candidate computation time window that does not satisfy the variance distribution under this operating state, and the largest candidate computation time window that satisfies the variance distribution;

[0034] Between the minimum candidate calculation time window and the maximum candidate calculation time window, starting with the minimum candidate calculation time window, alternative calculation time windows are determined by shortening the window size according to a preset step size. Within each alternative calculation time window, the alternative variance is calculated for each voltage difference value collected from the historical voltage information until the alternative variance satisfies the variance distribution. The alternative calculation time window whose alternative variance satisfies the variance distribution is then determined as the calculation time window for the corresponding operating state; or...

[0035] Using the largest candidate calculation time window as the starting calculation time window, the candidate calculation time window is determined by increasing the window size according to a preset step size. Within the candidate calculation time window, the candidate variance is calculated for each voltage difference value collected in the historical voltage information until the candidate variance does not meet the variance distribution. The previous candidate calculation time window where the candidate variance does not meet the variance distribution is determined as the calculation time window for the corresponding operating state.

[0036] Optionally, the calculation of the voltage difference for each of the individual cells within the calculation time window includes:

[0037] For each individual cell, the voltage difference between the voltage of the individual cell collected this time and the median voltage of all individual cells collected this time is calculated within the calculation time window.

[0038] Secondly, this disclosure provides an apparatus for determining the state of a single battery cell in a vehicle, the apparatus comprising:

[0039] The first determining module is configured to determine a calculation time window for calculating the state of the individual battery cell based on the obtained operating state of the vehicle.

[0040] The first calculation module is configured to calculate the voltage difference between the voltages collected for each of the individual cells within the calculation time window.

[0041] The second calculation module is configured to calculate the variance between the voltage differences;

[0042] The second determining module is configured to determine the state of a single battery cell in the vehicle based on the relationship between the variance value and the target variance threshold.

[0043] Optionally, the first determining device is configured to:

[0044] The charging and discharging state of the vehicle is determined based on the charging and discharging indicators of the individual battery cells. The charging and discharging indicators are added according to the current direction of the individual battery cells. The charging and discharging state indicates whether the vehicle is in a charging state or a discharging state.

[0045] Based on the obtained charge / discharge state, a calculation time window is determined for calculating the state of the individual battery cell, wherein the calculation time window determined under the discharge state is narrower than the calculation time window determined under the charging state.

[0046] Optionally, the first determining device is configured to:

[0047] Obtain the acceleration value of the vehicle;

[0048] Based on the obtained acceleration value, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the acceleration value.

[0049] Optionally, the first determining device is configured to:

[0050] Obtain the SOC change rate of the battery pack composed of each of the individual cells;

[0051] Based on the obtained SOC change rate, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the SOC change rate.

[0052] Optionally, the second determining module is configured to determine the target variance threshold based on the charge / discharge states included in the operating state before determining the individual battery state of the vehicle based on the magnitude relationship between the variance value and the target variance threshold.

[0053] Optionally, the charge / discharge state indicates whether the vehicle is in a charging state or a discharging state, and the target variance threshold determined in the discharging state is greater than the target variance threshold determined in the charging state.

[0054] Optionally, the charging state includes a slow charging state and a fast charging state, and the target variance threshold determined in the slow charging state is less than the target variance threshold determined in the fast charging state.

[0055] Optionally, the vehicle is pre-configured with multiple calculation time windows and a correspondence between each calculation time window and the vehicle's operating state. The first determining module is configured to determine the calculation time window corresponding to the operating state from the pre-configured multiple calculation time windows based on the obtained operating state and the correspondence.

[0056] Optionally, the first determining module is further configured to determine the correspondence between the calculation time window and the vehicle's operating state through the following steps:

[0057] The vehicle's historical operating status is obtained, along with historical voltage information collected for each individual battery cell under the historical operating status. The historical voltage information includes multiple collections and the voltage difference obtained from each collection.

[0058] For each of the multiple candidate calculation time windows, the variance is calculated for each voltage difference obtained from each historical voltage information acquisition within each candidate calculation time window.

[0059] Based on the variance calculated for each of the candidate calculation time windows, the variance distribution for the historical voltage information is obtained;

[0060] Based on the variance distribution, the calculation time window for the corresponding operating state is determined.

[0061] Optionally, the first determining module is further configured to:

[0062] From the candidate time windows, determine the smallest candidate computation time window that does not satisfy the variance distribution under this operating state, and the largest candidate computation time window that satisfies the variance distribution;

[0063] Between the minimum candidate calculation time window and the maximum candidate calculation time window, starting with the minimum candidate calculation time window, alternative calculation time windows are determined by shortening the window size according to a preset step size. Within each alternative calculation time window, the alternative variance is calculated for each voltage difference value collected from the historical voltage information until the alternative variance satisfies the variance distribution. The alternative calculation time window whose alternative variance satisfies the variance distribution is then determined as the calculation time window for the corresponding operating state; or...

[0064] Using the largest candidate calculation time window as the starting calculation time window, the candidate calculation time window is determined by increasing the window size according to a preset step size. Within the candidate calculation time window, the candidate variance is calculated for each voltage difference value collected in the historical voltage information until the candidate variance does not meet the variance distribution. The previous candidate calculation time window where the candidate variance does not meet the variance distribution is determined as the calculation time window for the corresponding operating state.

[0065] Optionally, the first calculation module is configured to calculate, within the calculation time window, the voltage difference between the voltage of the currently acquired individual cell and the median voltage of all the currently acquired individual cells.

[0066] Thirdly, this disclosure provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the method described in any of the first aspects.

[0067] Fourthly, this disclosure provides a vehicle including a controller, the controller including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the method described in any one of the first aspects.

[0068] By using the above technical solution, and configuring different widths of the calculation time window under different operating conditions, the variance can be calculated within the calculation time window under the corresponding operating conditions. This can reduce the amount of calculation and improve the accuracy of the calculated variance, thereby improving the accuracy of determining the state of a single battery cell.

[0069] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0070] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0071] Figure 1 This is a flowchart illustrating a method for determining the state of a single battery cell in a vehicle, according to an exemplary embodiment.

[0072] Figure 2 This is a flowchart illustrating a correspondence between a calculation time window and a vehicle operating state, according to an exemplary embodiment.

[0073] Figure 3 This is a schematic diagram illustrating a method for obtaining a variance distribution based on a candidate computation time window, according to an exemplary embodiment.

[0074] Figure 4 This is an implementation illustrated according to an exemplary embodiment. Figure 2 Flowchart of step S24;

[0075] Figure 5 This is a flowchart illustrating another method for determining the state of a single battery cell in a vehicle, according to an exemplary embodiment.

[0076] Figure 6 This is a block diagram illustrating an apparatus for determining the state of a single battery cell in a vehicle, according to an exemplary embodiment.

[0077] Figure 7 This is a block diagram illustrating an electronic device according to an exemplary embodiment. Detailed Implementation

[0078] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0079] Furthermore, it is worth noting that, for the sake of simplicity, the method embodiments provided in this disclosure are all described as a series of actions. However, those skilled in the art should understand that this disclosure is not limited to the described order of actions. Secondly, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily essential to this disclosure.

[0080] In related technologies, calculating the voltage change rate or SOC change rate based on voltage information at the second level results in a large amount of computation and consumes a lot of computing resources. Furthermore, the voltage fluctuations of individual cells and battery packs vary under different operating conditions of the vehicle. Using the same calculation time window under various operating conditions cannot match the operating conditions, resulting in low accuracy of the calculation variance and thus low accuracy in determining the state of individual cells in the vehicle.

[0081] Figure 1 This is a flowchart illustrating a method for determining the state of a single battery cell in a vehicle, according to an exemplary embodiment. This method can be applied to a battery management system or a cloud server. (Refer to...) Figure 1 The method includes the following steps.

[0082] In step S11, a calculation time window for calculating the state of individual battery cells is determined based on the obtained vehicle operating status.

[0083] The calculation time window is the window period used to calculate the state of a single cell, which is a single cell in the battery pack.

[0084] In one possible implementation, the calculation time window for calculating the state of a single battery cell can be determined based on the ambient temperature and the vehicle's operating status.

[0085] Based on the above embodiments, the operating state includes a charging and discharging state. Before step S11, the charging and discharging state of the vehicle is determined according to the charging and discharging indicator of the individual battery. The charging and discharging indicator is added according to the current direction of the individual battery. The charging and discharging state indicates that the vehicle is in a charging state or a discharging state.

[0086] The battery management system adds charge / discharge indicators to the voltage information of individual cells based on the current direction of the individual cells. For example, if the battery management system detects that the current direction is flowing into the individual cell, it determines that the vehicle is in a charging state and adds a charge / discharge indicator "+" to the voltage information of the individual cell. If it detects that the current direction is flowing out of the individual cell, it determines that the vehicle is in a discharging state and adds a charge / discharge indicator "-" to the voltage information of the individual cell.

[0087] In step S11, determining the calculation time window for calculating the state of a single battery cell based on the acquired vehicle operating state includes:

[0088] Based on the obtained charge / discharge state, a calculation time window is determined for calculating the state of the individual battery cell, wherein the calculation time window determined under the discharge state is narrower than the calculation time window determined under the charging state.

[0089] Understandably, during discharge, a vehicle is typically in motion. In motion, the output current fluctuates significantly due to factors such as road slope and traffic conditions. Conversely, during charging, the input current fluctuates less, typically under constant current or constant voltage conditions. Therefore, the voltage fluctuation of a single battery cell is greater during discharge than during charging. Furthermore, greater voltage fluctuation indicates lower voltage state stability, necessitating rapid determination of the cell's state. Conversely, smaller voltage fluctuation indicates higher voltage state stability, allowing for a reduction in the frequency of variance calculations. Consequently, the calculation time window determined during discharge is narrower than that determined during charging.

[0090] By adopting the above technical solution, different calculation time windows can be used in the charging and discharging states, which can adapt to voltage fluctuations in the two operating states. This reduces the amount of calculation while improving the accuracy of the calculation variance, thereby improving the accuracy of determining the state of individual cells.

[0091] Based on the above embodiments, the operating state includes acceleration values, and the acceleration values ​​of the vehicle are obtained before step S11;

[0092] In step S11, determining the calculation time window for calculating the state of a single battery cell based on the acquired vehicle operating state includes:

[0093] Based on the obtained acceleration value, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the acceleration value.

[0094] Specifically, the vehicle controller calculates the vehicle's acceleration value based on the vehicle's current speed and the speed at the previous moment. The battery management system communicates with the vehicle controller via the CAN bus to obtain the acceleration value from the vehicle controller. Alternatively, the cloud server communicates with the vehicle-mounted network communication terminal T-BOX, and the vehicle controller uploads the acceleration value to the T-BOX via the CAN bus. The cloud server then obtains the acceleration value from the T-BOX.

[0095] It is understandable that the greater the vehicle acceleration, the greater the fluctuation of the output current, while the smaller the vehicle acceleration, the smaller the fluctuation of the input current. Therefore, the larger the acceleration value, the narrower the calculation time window, and the smaller the acceleration value, the wider the calculation time window.

[0096] By adopting the above technical solution, different widths of calculation time windows can be used under different acceleration states, which can adapt to voltage fluctuations under different acceleration states. This reduces the amount of calculation while improving the accuracy of calculation variance, thereby improving the accuracy of determining the state of individual cells.

[0097] Based on the above embodiments, the operating status includes the SOC change rate, and the SOC change rate of the battery pack composed of each individual cell is obtained before step S11;

[0098] In step S11, determining the calculation time window for calculating the state of a single battery cell based on the acquired vehicle operating state includes:

[0099] Based on the obtained SOC change rate, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the SOC change rate.

[0100] For example, when the SOC change rate is 1%, the calculation time window for calculating the state of a single cell is determined to be 20 seconds; when the SOC change rate is 2%, the calculation time window for calculating the state of a single cell is determined to be 10 seconds.

[0101] In one possible implementation, a calculation time window for calculating the state of the individual battery cells can be determined based on the vehicle's state of charge / discharge and SOC change rate. Specifically, for the same SOC change rate, the calculation time window is wider in the charging state than in the discharging state.

[0102] By adopting the above technical solution, different widths of calculation time windows can be used under different SOC change rates, which can adapt to voltage fluctuations under different SOC change rates. This reduces the amount of calculation while improving the accuracy of calculation variance, thereby improving the accuracy of determining the state of individual cells.

[0103] In step S12, the voltage difference of the voltage collected for each individual cell within the calculation time window is calculated.

[0104] Each acquisition for each individual battery cell includes acquiring the voltage of each individual battery cell, and for each individual battery cell, calculating the voltage difference between the acquired voltage of the individual battery cell and the median of the acquired voltages of all individual battery cells.

[0105] For example, if the vehicle is determined to be charging and the calculation time window is 10 seconds, and the battery pack contains 96 individual cells, and the voltage difference is calculated once every second, then each voltage difference calculation refers to the voltage difference between the median voltage of each individual cell and the voltage of the 96 individual cells. Furthermore, if the calculation time window is reached, there are 10 voltage difference calculations within the calculation time window.

[0106] In another example, if the vehicle is determined to be in a discharging state and the calculation time window is 5 seconds, and the voltage difference is calculated once every second, then within the calculation time window, there will be 5 calculated voltage differences.

[0107] In step S13, the variance between each voltage difference is calculated.

[0108] Following the example in step S12, if there are 10 calculated voltage difference values ​​within the calculation time window, the variance between these 10 calculated voltage difference values ​​is calculated. That is, firstly, the average value of these 960 voltage difference values ​​is calculated to obtain the overall mean. For 96 individual cells, the voltage difference is calculated once per second, resulting in 96 voltage difference values. The calculation time window includes the results of 10 voltage difference calculations, hence 960 voltage difference values.

[0109] Furthermore, the first difference between each voltage difference and the overall mean is calculated, and the sum of the squares of the 960 calculated first differences is divided by the total number of voltage differences, 960, to obtain the variance value.

[0110] In step S14, the state of a single battery cell in the vehicle is determined based on the relationship between the variance value and the target variance threshold.

[0111] Based on the above embodiments, before step S14, the method further includes:

[0112] The target variance threshold is determined based on the charging and discharging states included in the operating status.

[0113] Based on the above embodiments, the charging and discharging state represents whether the vehicle is in a charging state or a discharging state, and the target variance threshold determined in the discharging state is greater than the target variance threshold determined in the charging state.

[0114] Based on the above embodiments, the charging state includes a slow charging state and a fast charging state, and the target variance threshold determined in the slow charging state is less than the target variance threshold determined in the fast charging state.

[0115] Specifically, the vehicle's state of slow charging or fast charging is determined based on the magnitude of the charging current; or based on the model of the charging socket connected to the vehicle's charging plug.

[0116] By employing the above technical solution, the target variance threshold can be determined based on the charge / discharge state. Since voltage fluctuations are smaller during charging, a smaller target variance threshold needs to be set, while voltage fluctuations are larger during discharging, thus requiring a larger target variance threshold. Similarly, voltage fluctuations are smaller during slow charging, requiring a smaller target variance threshold, while voltage fluctuations are larger during fast charging, requiring a larger target variance threshold. In this way, the target variance threshold, compared with the variance value, can be determined based on the charge / discharge state, further improving the accuracy of determining the state of individual battery cells.

[0117] Specifically, if the variance value is less than or equal to the target variance threshold, the vehicle's individual battery is determined to be in a normal state; if the variance value is greater than the target variance threshold, the vehicle's individual battery is determined to be in an abnormal state.

[0118] The above technical solution reduces the computational load and improves the accuracy of the calculated variance by selecting different widths of the calculation time window under different operating conditions, thereby improving the accuracy of determining the state of a single cell.

[0119] Based on the above embodiments, the vehicle is pre-configured with multiple calculation time windows and a correspondence between each calculation time window and the vehicle's operating status.

[0120] For example, the charging state corresponds to the charging calculation time window, and the discharging state corresponds to the discharging calculation time window; different acceleration values ​​each correspond to a calculation time window, and similarly, different SOC change rates each correspond to a calculation time window.

[0121] In step S11, determining the calculation time window for calculating the state of a single battery cell based on the acquired vehicle operating state includes:

[0122] Based on the obtained running status and corresponding relationships, the calculation time window corresponding to the running status is determined from multiple pre-configured calculation time windows.

[0123] For example, if the vehicle's operating status is found to be charging, it is further determined whether the vehicle is in slow charging or fast charging. If the vehicle is determined to be in slow charging, the variance threshold of slow charging is determined as the target variance threshold, and the calculation time window is determined based on the vehicle being in charging and the correspondence between charging status and calculation time window.

[0124] Furthermore, the voltage information collected for each individual battery cell within the calculation time window is obtained, as well as the variance value between the voltage differences in the calculated voltage information. Then, based on the relationship between the variance value in the charging state and the variance threshold in the slow charging state, the individual battery cell state of the vehicle in the slow charging state is determined.

[0125] Based on the above embodiments, Figure 2 This is a flowchart illustrating a correspondence between a calculation time window and a vehicle operating state, according to an exemplary embodiment. (Refer to...) Figure 2 The method includes the following steps.

[0126] In step S21, the historical operating status of the vehicle and the historical voltage information collected for each individual battery cell under the historical operating status are obtained. The historical voltage information includes multiple collections and the voltage difference obtained from each collection.

[0127] Specifically, for each individual cell, the voltage difference between the voltage of each individual cell collected in this instance and the median voltage of all individual cells collected in this instance is calculated based on the historical voltage collected each time.

[0128] In step S22, for each candidate calculation time window among multiple candidate calculation time windows, the variance is calculated for each voltage difference obtained from each historical voltage information acquisition within each candidate calculation time window.

[0129] Understandably, to improve the accuracy of the obtained calculation time window and reduce the computational burden of determining the calculation time window, different candidate calculation time windows can be determined for different operating states of the vehicle. For example, for the charging state, multiple candidate calculation time windows of 20 seconds, 25 seconds, 30 seconds, and 35 seconds can be determined; while for the discharging state, multiple candidate calculation time windows of 5 seconds, 10 seconds, and 15 seconds can be determined.

[0130] Furthermore, for a candidate calculation time window of 20 seconds, the historical voltage difference is divided into calculation time windows of 20 seconds each, and the variance between all voltage differences within that 20-second window is calculated. Similarly, for a candidate calculation time window of 25 seconds, the historical voltage difference is divided into calculation time windows of 25 seconds each, and the variance between all voltage differences within that 25-second window is calculated. The variance calculation for other candidate calculation time windows is done in the same way, and will not be elaborated on here.

[0131] In step S23, the variance distribution of historical voltage information is obtained based on the variance calculated for each candidate calculation time window.

[0132] Following the example of step S22, a coordinate axis is established with the horizontal axis representing the number of calculation time windows for calculating variance and the vertical axis representing variance. For each candidate calculation time window in the charging state, the variance obtained is calculated for each time, and the position of the variance is determined according to the number of times the variance is calculated, thus obtaining the variance distribution of historical voltage information in the charging state.

[0133] Similarly, a coordinate axis is established with the horizontal axis representing the number of calculation time windows for variance calculation and the vertical axis representing the variance. For each candidate calculation time window under discharge conditions, the variance is calculated for each time, and its position is determined according to the number of calculations, thus obtaining the variance distribution of historical voltage information under discharge conditions. For example... Figure 3 As shown.

[0134] In step S24, the calculation time window for the corresponding operating state is determined based on the variance distribution.

[0135] like Figure 3 As shown, based on the variance distribution, the variances corresponding to the candidate calculation time windows of 5 seconds and 10 seconds are relatively close, while the variances corresponding to the candidate calculation time windows of 15 seconds deviate significantly from those corresponding to the candidate calculation time windows of 5 seconds and 10 seconds.

[0136] Therefore, in order to increase the voltage difference within each calculation time window, thereby reducing the number of calculations of variance, and at the same time ensuring the accuracy of the calculation variance, the candidate calculation time window corresponding to 10 seconds can be determined as the calculation time window for the corresponding discharge state.

[0137] Similarly, the calculation time window under charging conditions, the calculation time window under different acceleration values, or the calculation time window under different SOC change rates can be determined.

[0138] The above technical solution calculates the variance for multiple candidate calculation time windows using historical voltage information under historical operating conditions, and determines the calculation time window for each operating condition based on the variance distribution. This allows the calculation time window for variance to be determined based on the operating condition and its corresponding relationship. Different widths of calculation time windows can be configured for different operating conditions, which can reduce the amount of computation while improving the accuracy of variance calculation, thereby improving the accuracy of determining the state of individual cells.

[0139] Based on the above embodiments, Figure 4 This is an implementation illustrated according to an exemplary embodiment. Figure 2 The flowchart for step S24 is shown below. Figure 4In step S24, determining the calculation time window for the corresponding operating state based on the variance distribution includes the following steps.

[0140] In step S241, the smallest candidate computation time window that does not satisfy the variance distribution and the largest candidate computation time window that satisfies the variance distribution are determined from the candidate time windows.

[0141] like Figure 3 As shown, the candidate computation time window corresponding to 10 seconds is the largest candidate computation time window that satisfies the variance distribution, while the candidate computation time window corresponding to 15 seconds is the smallest candidate computation time window that does not satisfy the variance distribution.

[0142] In step S242, between the minimum candidate computation time window and the maximum candidate computation time window, the minimum candidate computation time window is used as the starting computation time window, and the step size is shortened according to the preset window size to determine the alternative computation time window.

[0143] For example, taking the candidate calculation time window corresponding to 15 seconds as the starting calculation time window, and shortening the window by 1 second according to the preset window size, the alternative calculation time windows are determined, resulting in alternative calculation time windows of 14 seconds, 13 seconds, 12 seconds, and 11 seconds.

[0144] In step S243, the candidate variance is calculated for each voltage difference obtained from historical voltage information within the candidate calculation time window until the candidate variance meets the variance distribution.

[0145] In step S244, the candidate calculation time windows whose variances satisfy the variance distribution are determined as the calculation time windows corresponding to the historical running states.

[0146] Specifically, within a 14-second alternative calculation time window, the variance of each voltage difference collected from historical voltage information is calculated. It is then determined whether this alternative variance satisfies the variance distribution constructed from the variances of the 10-second and 5-second alternative calculation time windows. If it does, the 14-second alternative calculation time window is used as the calculation time window under discharge conditions. If not, calculations continue for 13 seconds, 12 seconds, and 11 seconds until the alternative variance satisfies the variance distribution. The alternative calculation time window whose variance satisfies the variance distribution is then determined as the calculation time window under discharge conditions.

[0147] If 11 seconds is not satisfied, then the candidate calculation time window corresponding to 10 seconds can be determined as the calculation time window under the discharge state.

[0148] In step S245, the largest candidate calculation time window is used as the starting calculation time window, and the candidate calculation time window is determined by increasing the window step size according to the preset step size.

[0149] For example, taking the candidate calculation time window corresponding to 10 seconds as the starting calculation time window, the alternative calculation time windows are determined by increasing the window size by 1 second according to the preset step size, resulting in alternative calculation time windows of 11 seconds, 12 seconds, 13 seconds, and 14 seconds.

[0150] In step S246, the candidate variance is calculated for each voltage difference obtained from the historical voltage information within the candidate calculation time window, until the candidate variance does not meet the variance distribution.

[0151] In step S247, the previous candidate calculation time window whose variance does not meet the variance distribution is determined as the calculation time window for the corresponding historical running state.

[0152] Specifically, within an 11-second candidate calculation time window, the variance of each voltage difference collected from historical voltage information is calculated. It is then determined whether this candidate variance satisfies the variance distribution constructed from the variances of the 10-second and 5-second candidate calculation time windows. If not, the 10-second candidate calculation time window is used as the calculation time window under discharge conditions. If it does, the calculations continue for 12 seconds, 13 seconds, and 14 seconds until the candidate variance no longer satisfies the variance distribution. The preceding candidate calculation time window whose variance no longer satisfies the distribution is then designated as the calculation time window under discharge conditions. For example, if the candidate variance at 13 seconds does not satisfy the variance distribution, the 12-second candidate calculation time window is designated as the calculation time window under discharge conditions.

[0153] If 14 seconds is satisfied, but 15 seconds is not, then the candidate calculation time window corresponding to 14 seconds can be determined as the calculation time window under the discharge state.

[0154] The method for determining the state of a single battery cell in a vehicle, as disclosed in this disclosure, will be described in detail below through specific embodiments. (Refer to...) Figure 5 As shown, the method includes the following steps.

[0155] Create a script file in Scala and import the spark.sql toolkit. To obtain the voltage information of individual battery cells in a vehicle, use the spark.sql toolkit to remove null values ​​and clean up duplicate information from the same time point, thus obtaining valid voltage information.

[0156] Furthermore, for each acquired effective voltage information, the difference between the voltage of a single cell and the median voltage of all single cells is calculated, yielding the voltage difference Vdeta for each acquisition. A calculation time window and a target variance threshold are then determined, and the variance between the voltage differences within each calculation time window is calculated, yielding the variance value Vvar. Finally, the state of a single cell is determined by the relationship between the variance value and the target variance threshold.

[0157] Based on the same inventive concept, this disclosure also provides an apparatus for determining the state of a single battery cell in a vehicle. This apparatus can implement all or part of the steps of the method for determining the state of a single battery cell in a vehicle in a software, hardware, or a combination of both. Figure 6 This is a block diagram illustrating an apparatus 100 for determining the state of a single battery cell in a vehicle, according to an exemplary embodiment. Figure 6 As shown, the device 100 includes: a first determining module 110, a first calculating module 120, a second calculating module 130, and a second determining module 140.

[0158] The first determining module 110 is configured to determine a calculation time window for calculating the state of the individual battery cell based on the obtained operating state of the vehicle.

[0159] The first calculation module 120 is configured to calculate the voltage difference for each of the individual cells within the calculation time window.

[0160] The second calculation module 130 is configured to calculate the variance between the voltage differences in the voltage information.

[0161] The second determining module 140 is configured to determine the state of a single battery cell of the vehicle based on the relationship between the variance value and the target variance threshold.

[0162] The aforementioned device, by configuring computation time windows of different widths under different operating states, and then calculating the variance within the computation time window under the corresponding operating state, can reduce the amount of computation and improve the accuracy of the calculated variance, thereby improving the accuracy of determining the state of a single cell.

[0163] Optionally, the first determining device 110 is configured to:

[0164] The charging and discharging state of the vehicle is determined based on the charging and discharging indicators of the individual battery cells. The charging and discharging indicators are added according to the current direction of the individual battery cells. The charging and discharging state indicates whether the vehicle is in a charging state or a discharging state.

[0165] Based on the obtained charge / discharge state, a calculation time window is determined for calculating the state of the individual battery cell, wherein the calculation time window determined under the discharge state is narrower than the calculation time window determined under the charging state.

[0166] Optionally, the first determining device 110 is configured to:

[0167] Obtain the acceleration value of the vehicle;

[0168] Based on the obtained acceleration value, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the acceleration value.

[0169] Optionally, the first determining device 110 is configured to:

[0170] Obtain the SOC change rate of the battery pack composed of each of the individual cells;

[0171] Based on the obtained SOC change rate, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the SOC change rate.

[0172] Optionally, the second determining module 140 is configured to determine the target variance threshold based on the charge and discharge states included in the operating state before determining the individual battery state of the vehicle based on the magnitude relationship between the variance value and the target variance threshold.

[0173] Optionally, the charge / discharge state indicates whether the vehicle is in a charging state or a discharging state, and the target variance threshold determined in the discharging state is greater than the target variance threshold determined in the charging state.

[0174] Optionally, the charging state includes a slow charging state and a fast charging state, and the target variance threshold determined in the slow charging state is less than the target variance threshold determined in the fast charging state.

[0175] Optionally, the vehicle is pre-configured with multiple calculation time windows and a correspondence between each calculation time window and the vehicle's operating state. The first determining module is configured to determine the calculation time window corresponding to the operating state from the pre-configured multiple calculation time windows based on the obtained operating state and the correspondence.

[0176] Optionally, the first determining module 110 is further configured to determine the correspondence between the calculation time window and the vehicle's operating state through the following steps:

[0177] The vehicle's historical operating status is obtained, along with historical voltage information collected for each individual battery cell under the historical operating status. The historical voltage information includes multiple collections and the voltage difference obtained from each collection.

[0178] For each of the multiple candidate calculation time windows, the variance is calculated for each voltage difference obtained from each historical voltage information acquisition within each candidate calculation time window.

[0179] Based on the variance calculated for each of the candidate calculation time windows, the variance distribution for the historical voltage information is obtained;

[0180] Based on the variance distribution, the calculation time window for the corresponding operating state is determined.

[0181] Optionally, the first determining module 110 is further configured to:

[0182] From the candidate time windows, determine the smallest candidate computation time window that does not satisfy the variance distribution under this operating state, and the largest candidate computation time window that satisfies the variance distribution;

[0183] Between the minimum candidate calculation time window and the maximum candidate calculation time window, starting with the minimum candidate calculation time window, alternative calculation time windows are determined by shortening the window size according to a preset step size. Within each alternative calculation time window, the alternative variance is calculated for each voltage difference value collected from the historical voltage information until the alternative variance satisfies the variance distribution. The alternative calculation time window whose alternative variance satisfies the variance distribution is then determined as the calculation time window for the corresponding operating state; or...

[0184] Using the largest candidate calculation time window as the starting calculation time window, the candidate calculation time window is determined by increasing the window size according to a preset step size. Within the candidate calculation time window, the candidate variance is calculated for each voltage difference value collected in the historical voltage information until the candidate variance does not meet the variance distribution. The previous candidate calculation time window where the candidate variance does not meet the variance distribution is determined as the calculation time window for the corresponding operating state.

[0185] Optionally, the first calculation module 120 is configured to calculate, within the calculation time window, the voltage difference between the voltage of the currently acquired individual cell and the median voltage of all the currently acquired individual cells.

[0186] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0187] Furthermore, it is worth noting that the modules in the above embodiments can be independent devices or the same device in specific implementations. For example, the calculation module 130 and the second determination module 140 can be the same module or two modules. This disclosure does not limit this.

[0188] This disclosure also provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of any of the preceding methods.

[0189] This disclosure also provides a controller, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of any of the methods described above.

[0190] This disclosure also provides a vehicle including the aforementioned controller, or a cloud server including the aforementioned controller.

[0191] Figure 7 This is a block diagram illustrating an electronic device 700 according to an exemplary embodiment. The electronic device can be configured as a controller, such as... Figure 7 As shown, the electronic device 700 may include a processor 701 and a memory 702. The electronic device 700 may also include one or more of a multimedia component 703, an input / output (I / O) interface 704, and a communication component 705.

[0192] The processor 701 controls the overall operation of the electronic device 700 to complete all or part of the steps in the method for determining the state of a single battery cell of a vehicle.

[0193] The memory 702 is used to store various types of data to support the operation of the electronic device 700. This data may include, for example, instructions for any application or method operating on the electronic device 700, and application-related data such as voltage information, calculation time window data, etc. The memory 702 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0194] Multimedia component 703 may include a screen and an audio component. The screen may be, for example, a touch screen, and the audio component is used to output and / or input audio signals.

[0195] I / O interface 704 provides an interface between processor 701 and other interface modules, such as keyboards, mice, and buttons. These buttons can be virtual or physical buttons.

[0196] Communication component 705 is used for wired or wireless communication between the electronic device 700 and other devices. Wireless communication includes, for example, Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, 4G, NB-IoT, eMTC, or other 5G technologies, or one or more combinations thereof, and is not limited herein. Therefore, the corresponding communication component 705 may include: a Wi-Fi module, a Bluetooth module, an NFC module, etc. Wired communication includes, for example, CAN bus, LIN bus, etc.

[0197] In an exemplary embodiment, the electronic device 700 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the method described above for determining the state of a single battery cell in a vehicle.

[0198] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, which, when executed by a processor, implement the steps of the method for determining the state of a single battery cell in a vehicle as described above. For example, the computer-readable storage medium may be the memory 702 including the program instructions described above, which may be executed by the processor 701 of the electronic device 700 to complete the method for determining the state of a single battery cell in a vehicle described above.

[0199] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0200] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0201] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method of determining a state of a monobloc battery of a vehicle, characterized in that, The method includes: Based on the obtained vehicle operating status, a calculation time window is determined for calculating the state of the individual battery cells; Calculate the voltage difference for each of the individual cells within the calculation time window; Calculate the variance between each of the voltage differences; The state of a single battery cell in the vehicle is determined based on the relationship between the variance value and the target variance threshold. The vehicle is pre-configured with multiple calculation time windows and a correspondence between each calculation time window and the vehicle's operating state. Determining the calculation time window for calculating the state of the individual battery cells based on the acquired vehicle operating state includes: Based on the obtained running status and the corresponding relationship, determine the calculation time window corresponding to the running status from multiple pre-configured calculation time windows; The correspondence between the calculation time window and the vehicle's operating status is determined through the following steps: The vehicle's historical operating status is obtained, along with historical voltage information collected for each individual battery cell under the historical operating status. The historical voltage information includes multiple collections and the voltage difference obtained from each collection. For each of the multiple candidate calculation time windows, the variance is calculated for each voltage difference obtained from each historical voltage information acquisition within each candidate calculation time window. Based on the variance calculated for each candidate calculation time window, the variance distribution for the historical voltage information is obtained; Based on the variance distribution, the calculation time window for the corresponding operating state is determined.

2. The method of claim 1, wherein, The acquisition of the operating status includes: The charging and discharging state of the vehicle is determined based on the charging and discharging indicators of the individual battery cells. The charging and discharging indicators are added according to the current direction of the individual battery cells. The charging and discharging state indicates whether the vehicle is in a charging state or a discharging state. The step of determining the calculation time window for calculating the state of the individual battery cells based on the obtained vehicle operating status includes: Based on the obtained charge / discharge state, a calculation time window is determined for calculating the state of the individual battery cell, wherein the calculation time window determined under the discharge state is narrower than the calculation time window determined under the charging state.

3. The method of claim 1, wherein, The acquisition of the operating status includes: Obtain the acceleration value of the vehicle; The step of determining the calculation time window for calculating the state of the individual battery cells based on the obtained vehicle operating status includes: Based on the obtained acceleration value, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the acceleration value.

4. The method of claim 1, wherein, The acquisition of the operating status includes: Obtain the SOC change rate of the battery pack composed of each of the individual cells; The step of determining the calculation time window for calculating the state of the individual battery cells based on the obtained vehicle operating status includes: Based on the obtained SOC change rate, a calculation time window is determined for calculating the state of the individual battery cell, wherein the width of the calculation time window is negatively correlated with the SOC change rate.

5. The method according to any one of claims 1-4, characterized in that, Before determining the state of a single battery cell in the vehicle based on the relationship between the variance value and the target variance threshold, the method further includes: The target variance threshold is determined based on the charging and discharging states included in the operating state.

6. The method of claim 5, wherein, The charge / discharge state indicates whether the vehicle is in a charging or discharging state, and the target variance threshold determined in the discharging state is greater than the target variance threshold determined in the charging state.

7. The method of claim 6, wherein, The charging state includes a slow charging state and a fast charging state, and the target variance threshold determined in the slow charging state is less than the target variance threshold determined in the fast charging state.

8. The method of claim 1, wherein, The step of determining the calculation time window for the corresponding operating state based on the variance distribution includes: From the candidate computation time windows, determine the smallest candidate computation time window that does not satisfy the variance distribution under this operating state, and the largest candidate computation time window that satisfies the variance distribution; Between the minimum candidate calculation time window and the maximum candidate calculation time window, starting with the minimum candidate calculation time window, alternative calculation time windows are determined by shortening the window size according to a preset step size. Within each alternative calculation time window, the alternative variance is calculated for each voltage difference value collected from the historical voltage information until the alternative variance satisfies the variance distribution. The alternative calculation time window whose alternative variance satisfies the variance distribution is then determined as the calculation time window for the corresponding operating state; or... Using the largest candidate calculation time window as the starting calculation time window, the candidate calculation time window is determined by increasing the window size according to a preset step size. Within the candidate calculation time window, the candidate variance is calculated for each voltage difference value collected in the historical voltage information until the candidate variance does not meet the variance distribution. The previous candidate calculation time window whose candidate variance does not meet the variance distribution is determined as the calculation time window for the corresponding operating state.

9. The method according to any one of claims 1-4, characterized in that, The calculation of the voltage difference for each individual cell within the calculation time window includes: For each individual cell, the voltage difference between the voltage of the individual cell collected this time and the median voltage of all individual cells collected this time is calculated within the calculation time window.

10. An apparatus for determining a state of a monobloc battery of a vehicle, characterized by The device includes: The first determining module is configured to determine a calculation time window for calculating the state of the individual battery cell based on the obtained operating state of the vehicle. The first calculation module is configured to calculate the voltage difference between the voltages collected for each of the individual cells within the calculation time window. The second calculation module is configured to calculate the variance between the voltage differences; The second determining module is configured to determine the state of a single battery cell in the vehicle based on the relationship between the variance value and the target variance threshold. The vehicle is pre-configured with multiple calculation time windows and a correspondence between each calculation time window and the vehicle's operating state. The first determining module is configured to determine the calculation time window corresponding to the operating state from the pre-configured multiple calculation time windows based on the obtained operating state and the correspondence. The first determining module is further configured to determine the correspondence between the calculation time window and the vehicle's operating state through the following steps: The vehicle's historical operating status is obtained, along with historical voltage information collected for each individual battery cell under the historical operating status. The historical voltage information includes multiple collections and the voltage difference obtained from each collection. For each of the multiple candidate calculation time windows, the variance is calculated for each voltage difference obtained from each historical voltage information acquisition within each candidate calculation time window. Based on the variance calculated for each candidate calculation time window, the variance distribution for the historical voltage information is obtained; Based on the variance distribution, the calculation time window for the corresponding operating state is determined.

11. The apparatus of claim 10, wherein, The first determining module is configured to: The charging and discharging state of the vehicle is determined based on the charging and discharging indicators of the individual battery cells. The charging and discharging indicators are added according to the current direction of the individual battery cells. The charging and discharging state indicates whether the vehicle is in a charging state or a discharging state. Based on the obtained charge / discharge state, a calculation time window is determined for calculating the state of the individual battery cell, wherein the calculation time window determined under the discharge state is narrower than the calculation time window determined under the charging state.

12. A computer readable storage medium having stored thereon a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1-9.

13. A vehicle characterized by comprising: The method includes a controller, which includes a memory and a processor, wherein the memory stores a computer program, and the processor, when executing the computer program, implements the steps of the method as described in any one of claims 1-9.

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