Method and device for determining electric quantity balance point, adjusting system, equipment and medium

Abstract

The embodiment of the invention provides an electric quantity balance point determination method and device, an adjustment system, equipment and a medium, and relates to the technical field of automobile capability management. The method comprises the following steps: determining an association relationship between the current capacity and the current voltage of the hybrid electric vehicle battery pack; determining the current variable quantity of the capacity of the battery pack within the unit voltage range based on the incidence relation; determining an error correction value of the residual capacity of the battery pack based on the current variable quantity and a pre-acquired initial variable quantity; and determining an electric quantity balance point of the battery pack based on the error correction value so as to control an engine of the hybrid vehicle based on the electric quantity balance point. According to the embodiment of the invention, the electric quantity balance point is adjusted in real time through the error correction value, and the vehicle anchoring risk caused by the residual capacity error of the battery pack can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile energy management, and in particular to a method and device for determining an electric quantity balance point, a regulating system, equipment and a medium. BACKGROUND

[0002] With the progress of society and the enhancement of environmental protection awareness, hybrid electric vehicles, as an important branch of new energy vehicles, are increasingly widely used. The hybrid electric vehicle is driven by two power sources, i.e., an engine and an electric motor, and can effectively improve energy utilization rate through coordinated control.

[0003] The setting of the electric quantity balance point of the hybrid electric vehicle is a key factor affecting vehicle energy consumption, battery life and driving experience, which determines the threshold for the engine to intervene in charging; when the battery capacity is lower than the set value, the engine starts to generate electricity, and when the value is higher, the electric drive is preferred.

[0004] In the prior art, when the current capacity of the battery is compared with the electric quantity balance point, there is a risk of vehicle breakdown due to the error of the current capacity. SUMMARY

[0005] The present application provides a method and device for determining an electric quantity balance point, a regulating system, equipment and a medium, which are used to solve the problem of vehicle breakdown in the prior art.

[0006] According to one aspect of the present application, a method for determining an electric quantity balance point is provided, which is applied to a hybrid electric vehicle, and the method comprises: determining the correlation between the current capacity and the current voltage of the battery pack of the hybrid electric vehicle; determining the current change amount of the capacity within the unit voltage range of the battery pack based on the correlation; determining an error correction value of the remaining capacity of the battery pack based on the current change amount and a pre-acquired initial change amount; wherein the initial change amount is the change amount of the capacity within the unit voltage range of the battery pack in the initial state; determining the electric quantity balance point of the battery pack based on the error correction value, so as to control the engine of the hybrid electric vehicle based on the electric quantity balance point; wherein the electric quantity balance point is a critical value of the battery capacity for triggering the start of the engine.

[0007] In one possible implementation, the above determination of the current change amount of the capacity within the unit voltage range of the battery pack based on the correlation comprises: calculating a target change amount of the capacity within the unit voltage range of the battery pack based on the correlation; acquiring the current temperature of the battery pack; correcting the target change amount based on the current temperature to obtain the current change amount.

[0008] In a possible implementation, the method for determining the power balance point of the battery pack based on the error correction value comprises the following steps. determining a low power threshold of the battery pack; determining an initial power balance point corresponding to the current power mode of the hybrid vehicle; updating the target power balance point based on the error correction value to obtain a first power balance point; wherein the target power balance point is the larger one of the low power threshold and the initial power balance point; determining the power balance point based on the first power balance point.

[0009] In another possible implementation, the method for determining the power balance point based on the first power balance point comprises the following steps. determining a battery health coefficient of the battery pack; updating the target power balance point based on the battery health coefficient to obtain a second power balance point; determining the power balance point based on the first power balance point and the second power balance point.

[0010] In another possible implementation, the method for determining the power balance point based on the first power balance point and the second power balance point comprises the following steps. taking the larger one of the first power balance point and the second power balance point as the power balance point.

[0011] In another possible implementation, the battery pack is provided with a plurality of voltage sampling points. The method for determining the battery health coefficient of the battery pack comprises the following steps. collecting voltage values of each voltage sampling point and determining a maximum value and a minimum value among the plurality of voltage values; taking a difference between the maximum value and the minimum value as a voltage range value of the battery pack; determining a first correction coefficient based on the voltage range value; determining the battery health coefficient according to the first correction coefficient.

[0012] In another possible implementation, the method for determining the battery health coefficient according to the first correction coefficient comprises the following steps. collecting an ambient temperature inside the battery pack; determining a second correction coefficient based on the ambient temperature; determining the battery health coefficient based on the first correction coefficient and the second correction coefficient.

[0013] In another possible implementation, the battery pack is provided with a plurality of temperature sampling points. The method for determining the battery health coefficient based on the first correction coefficient and the second correction coefficient comprises the following steps. collecting temperature values of each temperature sampling point and determining a maximum temperature and a minimum temperature among the plurality of temperature values; determining a difference between the maximum temperature and the minimum temperature as a cell temperature difference of the battery pack; determining a third correction coefficient based on the cell temperature difference; determining the battery health coefficient based on the first correction coefficient, the second correction coefficient and the third correction coefficient.

[0014] In yet another possible implementation, the above determining the battery health coefficient based on the first correction coefficient, the second correction coefficient and the third correction coefficient comprises: obtaining a discharge capacity in a complete discharge cycle of the target number of times; determining a discharge depth of the battery pack based on a ratio of each discharge capacity to the initial capacity of the battery; determining a fourth correction coefficient based on the discharge depth; determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient and the fourth correction coefficient.

[0015] In another possible implementation, the above determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient and the fourth correction coefficient comprises: obtaining a number of times of incomplete charging in a charging history of the battery pack; determining a charging correction coefficient based on the number of times of incomplete charging; determining a fifth correction coefficient based on the charging correction coefficient; determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient and the fifth correction coefficient.

[0016] In another possible implementation, the above determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient and the fifth correction coefficient comprises: respectively determining a first weight corresponding to the first correction coefficient, a second weight corresponding to the second correction coefficient, a third weight corresponding to the third correction coefficient, a fourth weight corresponding to the fourth correction coefficient and a fifth weight corresponding to the fifth correction coefficient; wherein the sum of the first weight, the second weight, the third weight, the fourth weight and the fifth weight is 1; performing weighted summation on the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient and the fifth correction coefficient based on the first weight, the second weight, the third weight, the fourth weight and the fifth weight respectively to obtain the battery health coefficient.

[0017] According to another aspect of the embodiments of the present application, a device for determining an electric quantity balance point is provided, which is applied to a hybrid vehicle, and the device comprises: an association module configured to determine an association between a current capacity and a current voltage of a battery pack of the hybrid vehicle; determining, based on the association, a current variation of the battery pack in the unit voltage range content; correcting, based on the current variation and a pre-acquired initial variation, an error correction value of the remaining capacity of the battery pack; wherein the initial variation is a variation of the battery pack in the unit voltage range content in an initial state; controlling, based on the error correction value, a power balance point of the battery pack, to control the engine of the hybrid vehicle based on the power balance point; wherein the power balance point is a critical value of the battery capacity triggering the engine start.

[0018] According to another aspect of the present application, there is provided a power balance point adjusting system, comprising a vehicle controller, a battery management module, and an engine controller; The vehicle controller is configured to receive battery pack data collected by the battery management module, and calculate a real-time battery pack capacity based on the battery pack data; if the battery pack capacity is less than the power balance point, send a start engine request to the engine controller; wherein the power balance point is determined based on the method of the first aspect of the present application.

[0019] According to another aspect of the present application, there is provided an electronic device comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method of the first aspect of the present application.

[0020] According to another aspect of the present application, there is provided a computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the method of the first aspect of the present application.

[0021] The technical solution provided by the present application has the following beneficial effects: The method for determining the power balance point provided by the present application can determine the current variation of the battery pack in the unit voltage range content based on the association between the current capacity and the current voltage of the battery pack, determine the error correction value of the remaining capacity of the battery pack based on the current variation and the initial variation, and determine the power balance point of the battery pack through the error correction value to control the engine of the hybrid vehicle based on the power balance point. The present application realizes real-time adjustment of the power balance point, can determine the error correction value of the remaining capacity of the current battery pack through the current variation of the battery pack in the unit voltage range content, and adjust the power balance point in real time based on the error correction value. Unlike the prior art which controls the engine start based on a fixed power balance point, the present application can effectively reduce the risk of vehicle breakdown caused by the error of the remaining capacity of the battery pack, and improve the user driving experience. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0023] Figure 1 A flowchart of a method for determining an electric quantity balance point according to an embodiment of the present application is shown in FIG. 1. Figure 2 A flowchart of a method for determining an electric quantity balance point according to an embodiment of the present application is shown in FIG. 1. Figure 3 A structural diagram of a device for determining an electric quantity balance point according to an embodiment of the present application is shown in FIG. 2. Figure 4 A structural diagram of a system for adjusting an electric quantity balance point according to an embodiment of the present application is shown in FIG. 3. Figure 5 A structural diagram of an electronic device according to an embodiment of the present application is shown in FIG. 4. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood, however, that the description which follows is merely exemplary and is not intended to limit the scope of the present disclosure. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid obscuring the concept of the present disclosure.

[0025] Various structural diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. These drawings are not drawn to scale, in which some details are exaggerated for the purpose of clarity and some details can be omitted. The shapes of various regions, layers, and their relative sizes and positional relationships shown in the drawings are merely exemplary, and in actuality, they can be deviated due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes, and relative positions can be additionally designed by those skilled in the art according to actual needs.

[0026] In the context of the present disclosure, when a layer / element is referred to as being located "on" another layer / element, the layer / element can be directly located on the other layer / element, or there can be an intervening layer / element therebetween. In addition, if a layer / element is located "on" another layer / element in one orientation, it can be located "under" the other layer / element when the orientation is reversed.

[0027] With the global automotive industry transforming towards low carbonization, hybrid electric vehicles (HEVs) have become the mainstream choice in the transition stage due to their fuel economy and endurance. However, the core challenge of the hybrid system is how to dynamically balance the energy distribution between the engine and the motor; among them, the regulation of the state of charge (SOC) balance point, i.e., the power balance point, directly affects the vehicle performance and energy consumption. The inventors found that the traditional hybrid system mostly uses a fixed SOC threshold strategy, which cannot adapt to complex road conditions, resulting in insufficient power at high speed or increased fuel consumption in congestion. For example, the main pain point for users is the decrease in power response when the battery is low. The SOC error of the battery will become larger due to factors such as temperature, current rate, and aging degree, and may still cause the vehicle to break down in extreme scenarios (such as continuous fast charging + low temperature).

[0028] Based on the above technical problems, the current capacity and the current voltage of the battery pack are associated to determine the current change amount of the capacity of the battery pack in a unit voltage range, and the error correction value of the remaining capacity of the battery pack is determined based on the current change amount and the initial change amount. Then, the power balance point of the battery pack is determined based on the error correction value to control the engine of the hybrid electric vehicle based on the power balance point. The application realizes real-time adjustment of the power balance point, and can determine the error correction value of the current remaining capacity of the battery pack through the current change amount of the capacity of the battery pack in a unit voltage range, and adjust the power balance point in real time based on the error correction value. Unlike the prior art, which controls the engine start based on a fixed power balance point, the application can effectively reduce the risk of vehicle breakdown caused by the error of the remaining capacity of the battery pack and improve the user driving experience.

[0029] In the following, the technical solutions of the application and how the technical solutions of the application solve the above technical problems will be described in detail with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the application will be described below with reference to the drawings.

[0030] In the embodiments of the application, a method for determining a power balance point is provided, as shown in Figure 1 The method can be applied to a hybrid electric vehicle, and the method comprises: S101, determining the association between the current capacity and the current voltage of the battery pack of the hybrid electric vehicle; based on the association, determining the current change amount of the capacity of the battery pack in a unit voltage range.

[0031] The association can be represented by the voltage and capacity curve of the battery pack.

[0032] Specifically, the battery voltage and capacity can be collected in real time, and the correlation between the current capacity and the current voltage can be generated; then, based on the correlation, the current change in capacity within a unit voltage range can be calculated.

[0033] S102, determine the error correction value of the remaining capacity of the battery pack based on the current change and the pre-acquired initial change.

[0034] The initial change refers to the change in capacity of the battery pack within a unit voltage range under its initial state. This initial state can be the battery's brand-new state. The error correction value characterizes the deviation rate between the battery's current capacity and the initial capacity corresponding to the new battery state.

[0035] Specifically, the difference between the current change and the initial change can be determined, and then the error correction value can be determined based on the ratio of the difference to the current change.

[0036] In some implementations, the error correction value can be calculated based on the following formula (1): (1) in, The initial change, This represents the current change. These are the fitting coefficients, usually .

[0037] S103 determines the battery pack's charge balance point based on the error correction value, and controls the hybrid vehicle's engine based on the charge balance point.

[0038] Among them, the battery balance point is the critical value of battery capacity that triggers engine start-up.

[0039] In some implementations, the initial power balance point can be corrected based on the error correction value and the low power threshold of the battery pack to obtain the power balance point of the battery pack.

[0040] In other implementations, the initial power balance point can be corrected based on the error correction value and the low power threshold of the battery pack to obtain a first power balance point; then, the initial power balance point can be corrected based on the battery health coefficient and the low power threshold of the battery pack to obtain a second power balance point; and finally, the power balance point of the battery pack can be obtained based on the first power balance point and the second power balance point.

[0041] This application's embodiments determine the current change in battery pack capacity within a unit voltage range by correlating the current capacity with the current voltage of the battery pack; and determine an error correction value for the remaining battery pack capacity based on the current change and the initial change; then, determine the battery pack's charge balance point based on the error correction value, and control the hybrid vehicle's engine based on the charge balance point. This application achieves real-time adjustment of the charge balance point. It can determine the error correction value for the current remaining battery pack capacity by the current change in battery pack capacity within a unit voltage range, and adjust the charge balance point in real time based on the error correction value. Unlike existing technologies that control engine start-up based on a fixed charge balance point, this effectively reduces the risk of vehicle breakdown caused by errors in the remaining battery pack capacity, improving the user's driving experience.

[0042] This application provides a possible implementation method in which the above-mentioned determination of the current change in the capacity of the battery pack within a unit voltage range based on the correlation relationship includes: S201, based on the correlation, calculate the target change in battery pack capacity within a unit voltage range.

[0043] Specifically, the aforementioned correlation can be characterized by the voltage and capacity curves of the battery pack; the target change in capacity within a unit voltage range can be calculated based on the voltage and capacity curves.

[0044] S202: Collect the current temperature of the battery pack; correct the target change based on the current temperature to obtain the current change.

[0045] Specifically, the current change can be calculated based on the following formula (2): (2) in, The target change in capacity within a unit voltage range. To calibrate the temperature, T represents the current temperature of the battery pack.

[0046] This application provides a possible implementation method for determining the battery pack's power balance point based on error correction values, including: S301, determine the low charge threshold of the battery pack and determine the initial charge balance point corresponding to the current power mode of the hybrid vehicle.

[0047] The aforementioned low charge threshold can be the minimum permissible state of charge (SOC) of the battery pack, typically set to 5%. The aforementioned power modes can include pure electric mode, hybrid mode, and power-saving mode.

[0048] Furthermore, the preset initial power balance point for pure electric mode can be 8%, the preset initial power balance point for hybrid mode can be 15%, and the preset initial power balance point for power-saving mode can be between 20% and 80%, which can be based on user-defined settings; for example, the preset initial power balance point for power-saving mode can be 22% or 40%, which is not specifically limited in this embodiment.

[0049] S302, update the target power balance point based on the error correction value to obtain the first power balance point.

[0050] The target power balance point is the larger of the low power threshold and the initial power balance point.

[0051] Specifically, the first energy balance point can be calculated based on the following formula (3): (3) in, For low battery threshold, This is the initial energy balance point.

[0052] S303, determine the power balance point based on the first power balance point.

[0053] In some implementations, the first power balance point can be used as the final power balance point.

[0054] In other implementations, the initial power balance point can be corrected based on the battery health coefficient and the low power threshold of the battery pack to obtain a second power balance point; then, the final power balance point of the battery pack is obtained based on the first and second power balance points. The specific steps for determining the power balance point will be described in detail below.

[0055] This application embodiment predicts the SOC error correction value by using the ΔQ / ΔV curve offset, and then determines the first charge balance point based on the error correction value, the low charge threshold of the battery pack, and the power mode of the hybrid vehicle. This can effectively solve the SOC error accumulated by the battery due to factors such as not being fully charged, and reduce the risk of vehicle breakdown.

[0056] This application provides a possible implementation method in which the determination of the power balance point based on the first power balance point includes: S401, determine the battery health coefficient of the battery pack; update the target power balance point based on the battery health coefficient to obtain the second power balance point.

[0057] Specifically, the second energy balance point can be calculated based on the following formula: (4) Where K can be the battery health error correction coefficient. This refers to the battery health coefficient.

[0058] Furthermore, the battery health coefficient can be calculated by integrating the collected multi-dimensional battery data. The specific calculation steps will be explained in detail below.

[0059] S402, determine the power balance point based on the first power balance point and the second power balance point.

[0060] This application provides a possible implementation method in which the determination of the power balance point based on the first power balance point and the second power balance point includes: The larger of the first and second energy balance points is taken as the energy balance point.

[0061] This application embodiment can adjust the target charge balance point by calculating the SOC health score, i.e., the battery health coefficient, to obtain a second charge balance point; then, based on the first and second charge balance points, the charge balance point is calculated, realizing the charge balance point correction that combines battery health and SOC error, further improving the control precision of the engine.

[0062] This application provides a possible implementation method in which multiple voltage sampling points are provided in the battery pack.

[0063] The above determination of the battery health coefficient of the battery pack includes: S501 collects the voltage value at each voltage sampling point and determines the maximum and minimum values ​​among multiple voltage values; the difference between the maximum and minimum values ​​is used as the voltage range of the battery pack.

[0064] The voltage values ​​mentioned above can be obtained in real time based on the battery management system (BMS).

[0065] Specifically, the voltage range can be calculated based on the following formula (5). : (5) Where n is the number of voltage sampling points. Let be the voltage value at the x-th voltage sampling point, in mV, where s∈[1,n].

[0066] S502, determine the first correction factor based on the voltage range value.

[0067] Specifically, the first correction factor It can be calculated based on the following formula (6): (6) in, This parameter can be obtained based on engineering test experiments.

[0068] During engineering testing, if ΔV ≤ 20mV, the voltage distribution of the battery pack is considered ideal; if ΔV ≥ 50mV, a battery pack balancing alarm may be triggered. Furthermore, the voltage sampling points can be determined based on the number of battery cells in the pack; for example, in a 96-cell battery pack, more than 16 voltage sampling points are required.

[0069] S503, determine the battery health factor based on the first correction factor.

[0070] In some implementations, the battery monitoring coefficient can be evaluated directly based on the first correction factor.

[0071] In other implementations, temperature compensation parameters can be incorporated based on the first correction coefficient to determine the battery health coefficient. The specific determination steps will be described in detail below.

[0072] In this embodiment, the first correction coefficient can characterize the voltage balance of individual cells in the battery pack. Excessive range will lead to distortion of SOC estimation. Therefore, the battery health coefficient of the battery pack can be determined based on the first correction coefficient, which can effectively improve the accuracy of the battery health coefficient.

[0073] This application provides a possible implementation method in which the battery health coefficient is determined based on the first correction coefficient, including: S601, collects the ambient temperature inside the battery pack; determines the second correction coefficient based on the ambient temperature.

[0074] The ambient temperature can be obtained by collecting data from the ambient temperature sensor of the battery pack and then correcting it using the internal temperature compensation model of the BMS.

[0075] Specifically, the second correction factor It can be calculated based on the following formula (7): (7) in, This refers to the ambient temperature inside the battery pack.

[0076] In this embodiment of the application, when the battery pack is in a low-temperature state, for example... If, then the corresponding second correction factor is 0.65; if The corresponding second correction factor is 0.5, indicating that the battery capacity decreases at low temperatures. When the battery pack is in a high-temperature state, for example... Then the corresponding second correction factor is 0.875; if The corresponding second correction factor is 0.7, indicating that the battery capacity decays at high temperatures. In other words, low temperatures may exacerbate the degradation of lithium iron phosphate (LFP) batteries. The battery polarization effect at high temperatures accelerates battery aging.

[0077] S602, determine the battery health coefficient based on the first correction coefficient and the second correction coefficient.

[0078] In some implementations, the battery monitoring coefficient can be evaluated by directly weighting the first correction coefficient and the second correction coefficient.

[0079] In other implementations, the cell temperature difference can be combined with the first and second correction factors to determine the battery health factor. The specific determination steps will be described in detail below.

[0080] This application provides a possible implementation method in which multiple temperature sampling points are provided inside the battery pack; The above determination of the battery health coefficient based on the first correction factor and the second correction factor includes: S701 collects the temperature value at each temperature sampling point and determines the maximum and minimum temperatures among multiple temperature values; the difference between the maximum and minimum temperatures is used as the cell temperature difference of the battery pack.

[0081] The temperature value of the aforementioned battery cell can be obtained based on the temperature acquisition equipment inside the battery pack.

[0082] Specifically, the cell temperature difference can be calculated based on the following formula (8). : (8) in, Let y be the temperature value of the y-th temperature sampling point; y∈[1,n], where n is the number of temperature sampling points.

[0083] S702, the third correction factor is determined based on the cell temperature difference.

[0084] Specifically, the third correction factor can be calculated based on the following formula (9). : (9) As shown in formula (9), if ΔT≤3℃, the corresponding third correction coefficient is 1; if ΔT≥8℃, the corresponding third correction coefficient linearly decreases to 0.5. In other words, excessive temperature difference in the battery cell will accelerate local aging of the battery cell. The third correction coefficient can characterize the risk of thermal management failure; the larger the third correction coefficient, the smaller the risk of thermal management failure of the battery pack.

[0085] S703 determines the battery health coefficient based on the first correction coefficient, the second correction coefficient, and the third correction coefficient.

[0086] In some implementations, the battery monitoring coefficient can be evaluated by directly weighting the first correction coefficient, the second correction coefficient, and the third correction coefficient.

[0087] In other implementations, the battery health coefficient can be determined by integrating the battery discharge depth based on the first correction coefficient, the second correction coefficient, and the third correction coefficient. The specific determination steps will be described in detail below.

[0088] This application provides a possible implementation method in which the battery health coefficient is determined based on the first correction coefficient, the second correction coefficient, and the third correction coefficient, including: S801, obtain the discharge capacity in a complete discharge cycle of the target number of times; determine the depth of discharge of the battery pack based on the ratio of the discharge capacity of each cycle to the initial capacity of the battery.

[0089] The discharge capacity data mentioned above can be obtained based on the battery pack's charge and discharge logs. The target number of cycles can be either 5 or 10; the following explanation will use 5 cycles as an example.

[0090] Specifically, the depth of discharge can be calculated based on the following formula (10): (10) in, This refers to the discharge capacity in a single cycle, expressed in Ah. This refers to the battery's nominal capacity, measured in Ah.

[0091] S802, the fourth correction factor is determined based on the depth of discharge.

[0092] Specifically, the fourth correction factor It can be calculated based on the following formula (11): (11) In the embodiments of this application, if DOD≤40%, the fourth correction coefficient is 1, which indicates that the battery charge and discharge cycles are mostly shallow charge and shallow discharge, and this discharge depth can slow down the degradation rate of the battery pack; if DOD≥80%, the fourth correction coefficient is 0.6, which indicates that the battery charge and discharge cycles are mostly deep discharge, and this discharge depth may accelerate the aging of the battery pack.

[0093] S803 determines the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient, and the fourth correction coefficient.

[0094] In some implementations, the battery monitoring coefficient can be evaluated by directly weighting the first correction coefficient, the second correction coefficient, the third correction coefficient, and the fourth correction coefficient.

[0095] In other implementations, the battery health coefficient can be determined by combining the battery charging status with the first, second, third, and fourth correction coefficients. The specific determination steps will be described in detail below.

[0096] This application provides a possible implementation method in which the battery health coefficient is determined based on a first correction coefficient, a second correction coefficient, a third correction coefficient, and a fourth correction coefficient, including: S901, obtain the number of times the battery pack was not fully charged in its charging history; determine the charging correction coefficient based on the number of times it was not fully charged.

[0097] The number of times the battery was not fully charged can be obtained from the statistics of the charging count counter within a preset time period; the charging correction coefficient can represent the number of consecutive times the battery was not fully charged.

[0098] Specifically, the charging correction factor It can be calculated based on the following formula: In this embodiment of the application, if the battery is fully charged, then =0; if the battery is not fully charged, then = .

[0099] S902, the fifth correction factor is determined based on the charging correction factor.

[0100] Specifically, the fifth correction factor It can be calculated based on the following formula (12): (12) In this embodiment of the application, if it is found that there are 5 consecutive times that the SOC is not fully filled, the fifth correction coefficient is 0.9, which indicates that there is a cumulative error in SOC due to consecutive times that the SOC is not fully filled.

[0101] Furthermore, the SOC deviation can be predicted by combining the ΔQ / ΔV curve at the end of the charging process, and the statistical value of the charging count counter can be dynamically corrected based on the SOC deviation to obtain the charging correction coefficient.

[0102] S903 determines the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient, and the fifth correction coefficient.

[0103] Specifically, the steps for determining the battery health coefficient based on multi-dimensional test data will be explained in detail below.

[0104] This application provides a possible implementation method in which the battery health coefficient is determined based on the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient, and the fifth correction coefficient, including: S1001, determine the first weight corresponding to the first correction coefficient, the second weight corresponding to the second correction coefficient, the third weight corresponding to the third correction coefficient, the fourth weight corresponding to the fourth correction coefficient, and the fifth weight corresponding to the fifth correction coefficient, respectively.

[0105] The sum of the first weight, second weight, third weight, fourth weight, and fifth weight is 1.

[0106] Specifically, the corresponding weighting coefficients can be determined based on the degree of influence of each correction coefficient on SOC.

[0107] Furthermore, the first and second correction factors account for 55% because voltage / temperature contributes more than 50% to the SOC error of LFP batteries; the fourth and fifth correction factors reflect usage habits and have lower weights.

[0108] For example, the first weight It can be 0.3, the second weight. It can be 0.25, the third weight. It can be 0.2, the fourth weight. It can be 0.15, the fifth weight. It can be 0.1.

[0109] S1002, the first correction coefficient, second correction coefficient, third correction coefficient, fourth correction coefficient and fifth correction coefficient are weighted and summed based on the first weight, second weight, third weight, fourth weight and fifth weight respectively to obtain the battery health coefficient.

[0110] Furthermore, the battery health coefficient can be updated every minute, with weight calibration performed using a multi-layer feedforward neural network.

[0111] This application embodiment calculates the battery health coefficient in real time by integrating multi-source data such as battery pack differential pressure, ambient temperature, cell temperature difference, depth of discharge, and cumulative number of times the battery has not been fully charged. It takes into account the influence of battery pack environment and user usage habits, which can effectively improve the accuracy of battery health coefficient, further improve the accuracy of power balance point, and improve the applicability of power balance point to extreme scenarios (such as continuous fast charging + low temperature).

[0112] To better understand the method for determining the above-mentioned energy balance point, the following will combine... Figure 2This paper details an example of a method for determining the battery balance point according to the present application, applied to a battery balance point adjustment system. This system may include a vehicle controller, a battery management module, an engine controller, and an on-board control system. The method may include the following steps: S1101, the battery management module collects battery pack data in real time and calculates the battery health coefficient and the current battery pack capacity based on the battery pack data in real time.

[0113] S1102, the vehicle controller obtains the real-time ΔQ / ΔV curve from the battery pack data from the battery management module, and calculates the error correction value of the remaining battery pack capacity based on the ΔQ / ΔV curve.

[0114] S1103, the vehicle control system receives the user's operation command and determines the low battery threshold of the hybrid vehicle and the initial battery balance point corresponding to the vehicle's power mode.

[0115] S1104, the vehicle controller obtains the low battery threshold and the initial battery balance point from the vehicle control system, and takes the larger value between the low battery threshold and the initial battery balance point as the target battery balance point.

[0116] S1105, the vehicle controller determines the first power balance point based on the error correction value and the target power balance point.

[0117] S1106, the vehicle controller obtains the battery health coefficient from the battery management module, and determines the second battery balance point based on the battery health coefficient and the target battery balance point.

[0118] S1107, the vehicle controller uses the larger of the first and second battery balance points as the battery balance point; in order to send a start command to the engine controller when the current battery pack capacity is less than the battery balance point.

[0119] This application provides a device for determining the electrical balance point, such as... Figure 3 As shown, the device 30 for determining the power balance point may include: an association module 301, a determination module 302, a correction module 303, and a control module 304; Among them, the correlation module 301 is used to determine the correlation between the current capacity and the current voltage of the hybrid vehicle battery pack; The determination module 302 is used to determine the current change in the capacity of the battery pack within a unit voltage range based on the correlation relationship; The correction module 303 is used to determine the error correction value of the remaining capacity of the battery pack based on the current change and the pre-acquired initial change; wherein, the initial change is the change in capacity of the battery pack within a unit voltage range in the initial state; The control module 304 is used to determine the battery pack's charge balance point based on the error correction value, so as to control the hybrid vehicle's engine based on the charge balance point; wherein, the charge balance point is the battery capacity threshold that triggers engine start.

[0120] This application embodiment provides a possible implementation method in which the determining module 302, when determining the current change in the capacity of the battery pack within a unit voltage range based on the correlation relationship, is used to: Based on the correlation, calculate the target change in battery pack capacity within a unit voltage range; Collect the current temperature of the battery pack; The target change is corrected based on the current temperature to obtain the current change.

[0121] This application embodiment provides a possible implementation method in which the control module 304, when determining the battery pack's power balance point based on the error correction value, is used to: Determine the low charge threshold of the battery pack; Determine the initial battery balance point corresponding to the current power mode of the hybrid vehicle; The target power balance point is updated based on the error correction value to obtain the first power balance point; wherein, the target power balance point is the larger value between the low power threshold and the initial power balance point; The energy balance point is determined based on the first energy balance point.

[0122] This application embodiment provides a possible implementation method in which the control module 304, when determining the power balance point based on the first power balance point, is used to: Determine the battery health factor of the battery pack; The target power balance point is updated based on the battery health coefficient to obtain the second power balance point; The energy balance point is determined based on the first energy balance point and the second energy balance point.

[0123] This application embodiment provides a possible implementation method in which the control module 304, when determining the power balance point based on the first power balance point and the second power balance point, is used to: The larger of the first and second energy balance points is taken as the energy balance point.

[0124] This application provides a possible implementation method in which the battery pack is provided with multiple voltage sampling points; The aforementioned control module 304, when determining the battery health coefficient of the battery pack, is used for: Collect the voltage value at each voltage sampling point and determine the maximum and minimum values ​​among multiple voltage values; The difference between the maximum and minimum values ​​is used as the voltage range of the battery pack. The first correction factor is determined based on the voltage range value; The battery health coefficient is determined based on the first correction factor.

[0125] This application embodiment provides a possible implementation method in which the control module 304, when determining the battery health coefficient based on the first correction coefficient, is used to: Collect the ambient temperature inside the battery pack; The second correction factor is determined based on the ambient temperature. The battery health coefficient is determined based on the first correction coefficient and the second correction coefficient.

[0126] This application provides a possible implementation method in which multiple temperature sampling points are provided inside the battery pack; When determining the battery health coefficient based on the first correction coefficient and the second correction coefficient, the aforementioned control module 304 is used to: Collect the temperature value at each temperature sampling point and determine the maximum and minimum temperatures among multiple temperature values; The difference between the maximum and minimum temperatures is used as the cell temperature difference of the battery pack. The third correction factor is determined based on the cell temperature difference; The battery health coefficient is determined based on the first correction coefficient, the second correction coefficient, and the third correction coefficient.

[0127] This application embodiment provides a possible implementation method in which the control module 304, when determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, and the third correction coefficient, is used to: Obtain the discharge capacity during a complete discharge cycle for the target number of times; The depth of discharge of the battery pack is determined based on the ratio of the discharge capacity of each discharge to the initial capacity of the battery. The fourth correction factor is determined based on the depth of discharge. The battery health coefficient is determined based on the first correction coefficient, the second correction coefficient, the third correction coefficient, and the fourth correction coefficient.

[0128] This application embodiment provides a possible implementation method in which the control module 304, when determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient, and the fourth correction coefficient, is used to: Retrieve the number of times the battery pack was not fully charged in its charging history; The charging correction factor is determined based on the number of times the battery is not fully charged. The fifth correction factor is determined based on the charging correction factor; The battery health coefficient is determined based on the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient, and the fifth correction coefficient.

[0129] This application embodiment provides a possible implementation method in which the control module 304, when determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient, and the fifth correction coefficient, is used to: Determine the first weight corresponding to the first correction coefficient, the second weight corresponding to the second correction coefficient, the third weight corresponding to the third correction coefficient, the fourth weight corresponding to the fourth correction coefficient, and the fifth weight corresponding to the fifth correction coefficient; wherein the sum of the first weight, the second weight, the third weight, the fourth weight, and the fifth weight is 1; The battery health coefficient is obtained by weighting and summing the first, second, third, fourth, and fifth correction coefficients based on the first, second, third, fourth, and fifth weights, respectively.

[0130] The apparatus in this application embodiment can execute the method provided in this application embodiment, and the implementation principle is similar. The actions performed by each module in the apparatus of each embodiment of this application correspond to the steps in the method of each embodiment of this application. For detailed functional descriptions of each module of the apparatus, please refer to the descriptions in the corresponding methods shown above, which will not be repeated here.

[0131] This application's embodiments determine the current change in battery pack capacity within a unit voltage range by correlating the current capacity with the current voltage of the battery pack; and determine an error correction value for the remaining battery pack capacity based on the current change and the initial change; then, determine the battery pack's charge balance point based on the error correction value, and control the hybrid vehicle's engine based on the charge balance point. This application achieves real-time adjustment of the charge balance point. It can determine the error correction value for the current remaining battery pack capacity by the current change in battery pack capacity within a unit voltage range, and adjust the charge balance point in real time based on the error correction value. Unlike existing technologies that control engine start-up based on a fixed charge balance point, this effectively reduces the risk of vehicle breakdown caused by errors in the remaining battery pack capacity, improving the user's driving experience.

[0132] This application embodiment provides a power balance point adjustment system 40, such as... Figure 4 As shown, the system includes a vehicle controller 401, a battery management module 402, and an engine controller 403; The aforementioned vehicle controller 401 is used to receive battery pack data collected by the battery management module 402 and calculate the real-time battery pack capacity based on the battery pack data; if the battery pack capacity is less than the power balance point, it sends a start request to the engine controller 403; wherein, the power balance point is confirmed by the aforementioned method for determining the power balance point.

[0133] This application provides an electronic device including a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of a method for determining a battery balance point. Compared with related technologies, this application can achieve the following: Based on the correlation between the current capacity and current voltage of the battery pack, this application determines the current change in the capacity of the battery pack within a unit voltage range; and based on the current change and the initial change, determines an error correction value for the remaining capacity of the battery pack; then, it determines the battery balance point of the battery pack based on the error correction value, and controls the engine of the hybrid vehicle based on the battery balance point. This application achieves real-time adjustment of the battery balance point. It can determine the error correction value of the current remaining capacity of the battery pack by the current change in the capacity within a unit voltage range, and adjust the battery balance point in real time based on the error correction value. This differs from the prior art which controls engine start-up based on a fixed battery balance point, effectively reducing the risk of vehicle breakdown caused by errors in the remaining battery pack capacity and improving the user's driving experience.

[0134] In one alternative embodiment, an electronic device is provided, such as Figure 5 As shown, Figure 5 The illustrated electronic device 50 includes a processor 501 and a memory 503. The processor 501 and the memory 503 are connected, for example, via a bus 502. Optionally, the electronic device 50 may further include a transceiver 504, which can be used for data interaction between the electronic device and other electronic devices, such as sending and / or receiving data. It should be noted that in practical applications, the transceiver 504 is not limited to one type, and the structure of this electronic device 50 does not constitute a limitation on the embodiments of this application.

[0135] Processor 501 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. Processor 501 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0136] Bus 502 may include a pathway for transmitting information between the aforementioned components. Bus 502 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. Bus 502 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0137] The memory 503 may be ROM (Read Only Memory) or other types of static storage devices capable of storing static information and instructions, RAM (Random Access Memory) or other types of dynamic storage devices capable of storing information and instructions, or EEPROM (Electrically Erasable Programmable Read Only Memory), CD-ROM (Compact Disc Read Only Memory) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media, other magnetic storage devices, or any other medium capable of carrying or storing computer programs and capable of being read by a computer, without limitation herein.

[0138] The memory 503 is used to store computer programs that execute the embodiments of this application, and the execution is controlled by the processor 501. The processor 501 is used to execute the computer programs stored in the memory 503 to implement the steps shown in the foregoing method embodiments.

[0139] Electronic devices include, but are not limited to: mobile terminals such as mobile phones, laptops, and tablets, as well as fixed terminals such as digital TVs and desktop computers.

[0140] This application provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the method shown in the first aspect of this application.

[0141] The above description does not provide detailed technical specifications regarding the structure of each layer. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0142] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0143] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for determining the electrical balance point, characterized in that, Applied to hybrid vehicles, the method includes: Determine the correlation between the current capacity and current voltage of the hybrid vehicle battery pack; Based on the aforementioned correlation, the current change in the capacity of the battery pack within a unit voltage range is determined; The error correction value for the remaining capacity of the battery pack is determined based on the current change and the pre-acquired initial change; wherein, the initial change is the change in capacity of the battery pack within a unit voltage range in the initial state; The battery pack's charge balance point is determined based on the error correction value, and the hybrid vehicle's engine is controlled based on the charge balance point; wherein the charge balance point is a critical battery capacity value that triggers the engine to start.

2. The method according to claim 1, characterized in that, Determining the current change in capacity of the battery pack within a unit voltage range based on the aforementioned correlation includes: Based on the aforementioned correlation, the target change in capacity of the battery pack within a unit voltage range is calculated; Collect the current temperature of the battery pack; The target change is corrected based on the current temperature to obtain the current change.

3. The method according to claim 1, characterized in that, Determining the battery pack's power balance point based on the error correction value includes: Determine the low charge threshold of the battery pack; Determine the initial battery balance point corresponding to the current power mode of the hybrid vehicle; The target power balance point is updated based on the error correction value to obtain the first power balance point; wherein, the target power balance point is the larger value between the low power threshold and the initial power balance point; The power balance point is determined based on the first power balance point.

4. The method according to claim 3, characterized in that, Determining the power balance point based on the first power balance point includes: Determine the battery health coefficient of the battery pack; The target power balance point is updated based on the battery health coefficient to obtain the second power balance point; The power balance point is determined based on the first power balance point and the second power balance point.

5. The method according to claim 4, characterized in that, Determining the power balance point based on the first power balance point and the second power balance point includes: The larger of the first power balance point and the second power balance point is taken as the power balance point.

6. The method according to claim 4, characterized in that, The battery pack is equipped with multiple voltage sampling points; Determining the battery health coefficient of the battery pack includes: Collect the voltage value at each voltage sampling point, and determine the maximum and minimum values ​​among the multiple voltage values; The difference between the maximum and minimum values ​​is taken as the voltage range of the battery pack; The first correction coefficient is determined based on the voltage range value; The battery health coefficient is determined based on the first correction coefficient.

7. The method according to claim 6, characterized in that, Determining the battery health coefficient based on the first correction coefficient includes: Collect the ambient temperature inside the battery pack; The second correction factor is determined based on the ambient temperature. The battery health coefficient is determined based on the first correction coefficient and the second correction coefficient.

8. The method according to claim 7, characterized in that, The battery pack is equipped with multiple temperature sampling points; Determining the battery health coefficient based on the first correction coefficient and the second correction coefficient includes: Collect the temperature value at each of the temperature sampling points, and determine the maximum and minimum temperatures among the multiple temperature values; The difference between the maximum and minimum temperatures is taken as the cell temperature difference of the battery pack. A third correction coefficient is determined based on the cell temperature difference; The battery health coefficient is determined based on the first correction coefficient, the second correction coefficient, and the third correction coefficient.

9. The method according to claim 8, characterized in that, Determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, and the third correction coefficient includes: Obtain the discharge capacity during a complete discharge cycle for the target number of times; The depth of discharge of the battery pack is determined based on the ratio of the discharge capacity to the initial capacity of the battery in each discharge cycle. A fourth correction factor is determined based on the discharge depth; The battery health coefficient is determined based on the first correction coefficient, the second correction coefficient, the third correction coefficient, and the fourth correction coefficient.

10. The method according to claim 9, characterized in that, Determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient, and the fourth correction coefficient includes: Obtain the number of times the battery pack was not fully charged in its charging history; The charging correction coefficient is determined based on the number of times the battery is not fully charged. The fifth correction factor is determined based on the aforementioned charging correction factor; The battery health coefficient is determined based on the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient, and the fifth correction coefficient.

11. The method according to claim 10, characterized in that, Determining the battery health coefficient based on the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient, and the fifth correction coefficient includes: The first weight corresponding to the first correction coefficient, the second weight corresponding to the second correction coefficient, the third weight corresponding to the third correction coefficient, the fourth weight corresponding to the fourth correction coefficient, and the fifth weight corresponding to the fifth correction coefficient are determined respectively; wherein, the sum of the first weight, the second weight, the third weight, the fourth weight, and the fifth weight is 1; The battery health coefficient is obtained by weighting and summing the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient, and the fifth correction coefficient based on the first weight, the second weight, the third weight, the fourth weight, and the fifth weight, respectively.

12. A device for determining the electrical balance point, characterized in that, The device, applied to hybrid vehicles, includes: The correlation module is used to determine the correlation between the current capacity and the current voltage of the hybrid vehicle battery pack; The determining module is used to determine the current change in the capacity of the battery pack within a unit voltage range based on the correlation relationship; The correction module is used to determine an error correction value for the remaining capacity of the battery pack based on the current change and the pre-acquired initial change; wherein the initial change is the change in capacity of the battery pack within a unit voltage range in the initial state; A control module is used to determine the battery pack's charge balance point based on the error correction value, and to control the hybrid vehicle's engine based on the charge balance point; wherein the charge balance point is a battery capacity threshold that triggers the engine to start.

13. A power balance point adjustment system, characterized in that, The system includes a vehicle controller, a battery management module, and an engine controller; The vehicle controller is used to receive battery pack data collected by the battery management module and calculate the real-time battery pack capacity based on the battery pack data; if the battery pack capacity is less than the power balance point, a start request is sent to the engine controller; wherein the power balance point is determined based on the method described in any one of claims 1-11.

14. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method of any one of claims 1-11.

15. A storage medium having a computer program stored thereon, characterized in that, When the program is executed by a processor, it implements the steps of the method according to any one of claims 1-11.

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