Method and apparatus for detecting SOH of battery, main control device, and storage medium

Abstract

A method and apparatus for detecting the SOH of a battery, a main control device, and a storage medium. The method for detecting the SOH of a battery comprises: determining a first impedance of a battery under a first operating condition (110), the first operating condition comprising a first battery temperature and a first SOC; on the basis of a second impedance of the battery and the first impedance, determining an impedance growth rate (120), the second impedance being used for representing a standard impedance of the battery under the first operating condition; and on the basis of a first correspondence and the impedance growth rate, determining a current SOH of the battery (130), the first correspondence being used for representing a correspondence between the impedance growth rate and the SOH of the battery. In the method, during battery SOH detection, the current SOH of the battery is determined on the basis of an impedance growth rate of the battery and a pre-established association between the impedance growth rate and the SOH of the battery, thereby improving the accuracy of battery SOH detection.

Description

Battery SOH detection method and apparatus, main control equipment and storage medium

[0001] This application claims priority to Chinese Patent Application No. 202510070852.6, filed on January 16, 2025, entitled "SOH Detection Method and Apparatus for Batteries, Main Control Device and Storage Medium", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application belongs to the field of battery technology, and in particular relates to a method and apparatus for detecting the state of oxygen (SOH) of a battery, as well as a main control device and a storage medium. Background Technology

[0003] As non-renewable energy sources such as oil are gradually depleted, electrical energy (e.g., battery-powered power) is gaining popularity in the new energy market. Since batteries inevitably age with prolonged use, continuing to use severely aged batteries in electrical devices increases safety risks. Therefore, monitoring the State of Health (SOH) of batteries is particularly important.

[0004] Currently, in the process of testing the SOH of a battery, the discharge capacity during the full charge and discharge process is tested, and the SOH of the battery is calculated based on the ratio of the discharge capacity to the rated capacity.

[0005] However, when the battery is locked, it cannot be fully charged, resulting in a smaller discharge capacity. The SOH calculated based on the discharge capacity is inaccurate, leading to lower accuracy in SOH detection.

[0006] Application content

[0007] In view of the above, embodiments of this application provide a method and apparatus for detecting the state of oxygen (SOH) of a battery, a main control device, and a storage medium to overcome the problems of the prior art. Technical solutions

[0008] The technical solution adopted in the embodiments of this application is:

[0009] In a first aspect, embodiments of this application provide a method for detecting the state of oxygen (SOH) in a battery, comprising:

[0010] Determine the first impedance of the battery under a first operating condition, the first operating condition including a first battery temperature and a first state of charge (SOC);

[0011] The impedance growth rate is determined based on the second impedance of the battery and the first impedance, wherein the second impedance is used to characterize the standard impedance of the battery under the first operating condition.

[0012] The current state of impedance (SOH) of the battery is determined based on the first correspondence and the impedance growth rate, wherein the first correspondence is used to characterize the correspondence between the impedance growth rate of the battery and the SOH.

[0013] In some optional embodiments, determining the first impedance of the battery under the first operating condition includes:

[0014] Determine the third impedance of the battery under a second operating condition, the second operating condition including the second battery temperature and the second state of charge (SOC);

[0015] Determine the target impedance change rate of the battery as it transitions from the second operating condition to the first operating condition;

[0016] The first impedance is calculated based on the third impedance and the target impedance change rate.

[0017] In some optional embodiments, determining the target impedance change rate of the battery as it transitions from the second operating condition to the first operating condition includes:

[0018] Obtain a second correspondence relationship for the battery, which is used to characterize the correspondence between the battery's operating condition changes and impedance change rate;

[0019] The target impedance change rate is obtained based on the first operating condition, the second operating condition, and the second correspondence.

[0020] In some optional embodiments, determining the third impedance of the battery under the second operating condition includes:

[0021] Determine multiple AC impedances of the battery under the second operating condition, wherein the multiple AC impedances correspond to multiple frequency points;

[0022] The target real part impedance of the AC impedance corresponding to the target frequency point among the plurality of frequency points is determined as the third impedance, and the interface reaction of the battery is most complete at the target frequency point.

[0023] In some optional embodiments, determining the multiple AC impedances of the battery under the second operating condition includes:

[0024] Obtain multiple DC internal resistances of the battery under the second operating condition;

[0025] The multiple DC internal resistances are subjected to a windowed Fourier transform to obtain the multiple AC impedances.

[0026] In some optional embodiments, obtaining the multiple DC internal resistances of the battery under the second operating condition includes:

[0027] During the process of charging the battery to the second working condition, multiple cell voltages corresponding to multiple charging durations are obtained, and each of the multiple charging durations corresponds to a frequency point.

[0028] A DC internal resistance is determined based on the charging current of the battery and the voltage of each cell to obtain the plurality of DC internal resistances.

[0029] In some optional embodiments, the SOH detection method for the battery further includes:

[0030] An alarm message is generated when the current SOH is less than or equal to a preset SOH threshold.

[0031] Secondly, embodiments of this application provide a battery SOH detection device, comprising:

[0032] The first determining module is used to determine the first impedance of the battery under a first operating condition, the first operating condition including the first battery temperature and the first SOC;

[0033] The second determining module is used to determine the impedance growth rate based on the second impedance of the battery and the first impedance, wherein the second impedance is used to characterize the standard impedance of the battery under the first operating condition.

[0034] The third determining module is used to determine the current SOH of the battery based on the first correspondence and the impedance growth rate, wherein the first correspondence is used to characterize the correspondence between the impedance growth rate of the battery and the SOH.

[0035] Thirdly, embodiments of this application provide a master control device, including:

[0036] Memory;

[0037] One or more processors, coupled to memory;

[0038] One or more applications, wherein one or more applications are stored in memory and configured to be executed by one or more processors, and one or more applications are configured to perform the SOH detection method for batteries as provided in the first aspect above.

[0039] Fourthly, embodiments of this application provide a computer-readable storage medium storing program code, which can be called by a processor to execute the SOH detection method for a battery as described in the first aspect above.

[0040] Fifthly, embodiments of this application provide a computer program product that, when run on a computer device, causes the computer device to perform the SOH detection method for a battery as described in the first aspect above. Beneficial effects

[0041] The beneficial effect of the first aspect provided by the embodiments of this application is that: during the process of SOH detection of the battery, the current SOH of the battery is determined based on the battery impedance growth rate and the pre-built correlation between the battery impedance growth rate and SOH. Since the battery cell impedance is not affected when the battery is locked, the problem of inaccurate SOH detection caused by the battery being locked when the battery is detected based on the battery discharge capacity is suppressed, thereby improving the detection accuracy of SOH detection of the battery.

[0042] It is understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or exemplary technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 shows a schematic diagram of a scenario for the SOH detection system of a battery provided in an embodiment of this application.

[0045] Figure 2 shows a schematic flowchart of a battery SOH detection method provided in an embodiment of this application.

[0046] Figure 3 shows a schematic diagram of a scenario in the battery's DC internal resistance detection method provided in the embodiments of this application.

[0047] Figure 4 shows a schematic diagram of a scenario of the AC impedance of a battery in the SOH detection method of the battery provided in the embodiments of this application.

[0048] Figure 5 shows a schematic diagram of an LFP battery impedance growth rate curve in the SOH detection method of the battery provided in the embodiments of this application.

[0049] Figure 6 shows a schematic diagram of a scenario in which the impedance growth rate curve of an NCM battery is obtained in the SOH detection method of the battery provided in the embodiments of this application.

[0050] Figure 7 shows another schematic flowchart of the SOH detection method for batteries provided in the embodiments of this application.

[0051] Figure 8 shows a structural block diagram of a battery SOH detection device provided in an embodiment of this application.

[0052] Figure 9 shows a functional block diagram of a master control device provided in an embodiment of this application.

[0053] Figure 10 illustrates a computer-readable storage medium provided in an embodiment of this application for storing or carrying program code implementing the SOH detection method for a battery according to an embodiment of this application.

[0054] Figure 11 shows a computer program product provided in an embodiment of this application for storing or carrying program code that implements the SOH detection method for batteries according to an embodiment of this application. Detailed Implementation

[0055] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0056] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0057] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0058] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0059] Furthermore, in the description of this application, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0060] As non-renewable energy sources such as oil are gradually depleted, electrical energy (e.g., battery-powered power) is gaining popularity in the new energy market. Since batteries inevitably age with prolonged use, continuing to use severely aged batteries in electrical devices increases safety risks. Therefore, monitoring the State of Health (SOH) of batteries is particularly important.

[0061] Currently, in the process of testing the SOH of a battery, the discharge capacity during the full charge and discharge process is tested, and the SOH of the battery is calculated based on the ratio of the discharge capacity to the rated capacity.

[0062] However, when the battery is locked, it cannot be fully charged, resulting in a smaller discharge capacity. The SOH calculated based on the discharge capacity is inaccurate, leading to lower accuracy in SOH detection.

[0063] To address the aforementioned issues, the battery SOH detection method, apparatus, main control device, and storage medium provided in this application determine the battery's first impedance under a first operating condition, which includes a first battery temperature and a first state of charge (SOC). The method then determines the impedance growth rate based on the battery's second impedance and the first impedance, where the second impedance characterizes the battery's standard impedance under the first operating condition. Finally, it determines the battery's current SOH based on a first correspondence and the impedance growth rate, where the first correspondence characterizes the relationship between the battery's impedance growth rate and SOH. This method achieves the determination of the battery's current SOH based on the battery's impedance growth rate and a pre-built correlation between the battery's impedance growth rate and SOH during SOH detection. Since the battery's cell impedance is not affected when the battery is locked, the method suppresses the problem of inaccurate SOH detection caused by the battery being locked when performing SOH detection based on the battery's discharge capacity, thus improving the accuracy of SOH detection.

[0064] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0065] Please refer to Figure 1, which shows a schematic diagram of an application scenario of the battery SOH detection system provided in the embodiments of this application. The battery SOH detection system may include a battery 100 and a main control device 200.

[0066] The battery 100 may be any one of lithium batteries, nickel-metal hydride batteries, or lead-acid batteries, including but not limited to lithium batteries, nickel-metal hydride batteries, or lead-acid batteries.

[0067] The main control device 200 may be any one of, but not limited to, servers or terminal devices.

[0068] Servers can include, but are not limited to, independent physical servers, server clusters or distributed systems consisting of multiple physical servers, and cloud servers.

[0069] Terminal devices may include, but are not limited to, mobile terminal devices (e.g., mobile phones, PDAs, tablet PCs, laptops, smartwatches, smart bracelets, etc.) and fixed terminal devices (e.g., desktop computers, smart panels, all-in-one computers, etc.).

[0070] In some implementations, the battery 100 may be disposed on the vehicle 300, and the vehicle 300 may provide mounting support for the battery 100.

[0071] In some embodiments, the battery's SOH detection system may further include a charging station 400, which is connected to the battery 100 and can be used to charge the battery 100.

[0072] Please refer to Figure 2, which shows a flowchart of a battery SOH detection method provided in one embodiment of this application. In a specific embodiment, the battery SOH detection method can be applied to the main control device 200 in the battery SOH detection system shown in Figure 1. The process shown in Figure 2 will be described in detail below using the main control device 200 as an example. The battery SOH detection method may include the following steps 110 to 130.

[0073] Step 110: Determine the first impedance of the battery under the first operating condition.

[0074] In the embodiments of this application, the first operating condition may include, but is not limited to, the first battery temperature and the first SOC. For example, the first battery temperature may be 25°C and the first SOC may be 50%.

[0075] The first impedance can be used to characterize the impedance of the battery under the first operating condition, and the standard impedance of the battery under the first operating condition can be denoted as the second impedance.

[0076] The main control device can determine the third impedance of the battery under the second operating condition and the target impedance change rate of the battery from the second operating condition to the first operating condition. It can also calculate the first impedance based on the third impedance and the target impedance change rate. Based on the impedance change rate corresponding to the change of battery operating condition, the impedance measured under different operating conditions can be converted to the impedance under the same operating condition, which helps to improve the accuracy of impedance growth rate calculation.

[0077] The second operating condition is different from the first operating condition. The second operating condition may include, but is not limited to, a second battery temperature and a second SOC. The second battery temperature is different from the first battery temperature, and the second SOC is different from the first SOC.

[0078] In one application scenario, the third impedance of the battery can be Z3. The target impedance change rate of the battery from the second operating condition to the first operating condition is ΔZ. The first impedance Z1 can be calculated according to Formula 1 based on the third impedance Z3 and the target impedance change rate ΔZ.

[0079] Formula 1 is: Z1 = Z3 / ΔZ.

[0080] Regarding the process by which the main control device determines the target impedance change rate of the battery from the second operating condition to the first operating condition, in some embodiments, the main control device can obtain the second correspondence of the battery and obtain the target impedance change rate based on the first operating condition, the second operating condition and the second correspondence. Based on the correspondence between the battery's operating condition change and the impedance change rate, the target impedance change rate of the battery from the second operating condition to the first operating condition is determined, thereby improving the accuracy of the target impedance change rate.

[0081] The second correspondence can be used to characterize the relationship between changes in battery operating conditions and the rate of change in impedance. For example, the second correspondence can be an operating condition impedance change table, which can be used to characterize the relationship between changes in battery operating conditions and the rate of change in impedance.

[0082] As an example, the main control device can obtain the battery's operating impedance change table, and look up the operating impedance change table according to the first and second operating conditions to obtain the target impedance change rate.

[0083] For example, the first operating condition can be (25℃, 50% SOC), and is denoted as the standard operating condition.

[0084] The second operating condition can include (-30°C, 0% SOC), (-20°C, 0% SOC), (-10°C, 0% SOC), (0°C, 0% SOC), (10°C, 0% SOC), (20°C, 0% SOC), (25°C, 0% SOC), (30°C, 0% SOC), (40°C, 0% SOC), (50°C, 0% SOC), (55°C, 0% SOC), (-30°C, 5% SOC), (-20°C, 5% SOC), (-10°C, 5% SOC), (0°C, 5% SOC), (10°C, 5% SOC), (20°C, 5% SOC), (25°C, 5% SOC), (30°C, 5% SOC), (40°C, 5% SOC), (50°C, 5% SOC), (55°C, 5% SOC), (-30°C, 10% SOC), (-20°C, 10% SOC), (-10°C, 10% SOC), (0°C, 10% SOC), (10°C, 10% SOC), (20°C, 10% SOC), (25°C, 10% SOC), (30°C, 10% SOC), (40°C, 10% SOC), (50°C, 10% SOC), (55°C, 10% SOC), (-30°C, 20% SOC), (-20°C, 20% SOC), (-10°C, 20% SOC), (0°C, 20% SOC), (10°C, 20% SOC), (20°C, 20% SOC), (25°C, 20% SOC), (30°C, 20% SOC), (40°C, 20% SOC), (50°C, 20% SOC), (55°C, 20% SOC), (-30°C, 30% SOC), (-20°C, 30% SOC), (-10°C, 30% SOC), (0°C, 30% SOC), (10°C, 30% SOC), (20°C, 30% SOC), (25°C, 30% SOC), (30°C, 30% SOC), (40°C, 30% SOC), (50°C, 30% SOC), (55°C, 30% SOC), (-30°C, 50% SOC), (-20°C, 50% SOC), (-10°C, 50% SOC), (0°C, 50% SOC), (10°C, 50% SOC), (20°C, 50% SOC), (25°C, 50% SOC), (30°C, 50% SOC), (40°C, 50% SOC), (50°C, 50% SOC), (55°C, 50% SOC), (-30°C, 70% SOC), (-20°C, 70% SOC), (-10°C, 70% SOC), (0°C, 70% SOC), (10°C, 70% SOC), (20°C,70% SOC), (25℃, 70% SOC), (30℃, 70% SOC), (40℃, 70% SOC), (50℃, 70% SOC), (55℃, 70% SOC), (-30℃, 80% SOC), (-20℃, 80% SOC), (-10℃, 80% SOC), (0℃, 80% SOC), (10℃, 80% SOC), (20℃, 80% SOC), (25℃, 80% SOC), (30℃, 80% SOC), (40℃, 80% SOC), (50℃, 80% SOC), (55℃, 80% SOC), (-30℃, 90% SOC), (-20℃, 90% SOC), (-10℃, 90% SOC), (0℃, 90% SOC), (10℃, 90% SOC), (20°C, 90% SOC), (25°C, 90% SOC), (30°C, 90% SOC), (40°C, 90% SOC), (50°C, 90% SOC), (55°C, 90% SOC). ,

[0085] The correspondence between the change in operating condition from the second operating condition to the first operating condition and the corresponding rate of impedance change can be shown in Table 1, i.e., the operating condition impedance change table. Based on this correspondence, the target rate of impedance change of the battery when it changes from the second operating condition to the first operating condition can be obtained.

[0086] Table 1

[0087] It should be noted that the relationship between the change in operating condition from the second operating condition to the first operating condition and the corresponding rate of impedance change may include, but is not limited to, the relationship shown in Table 1.

[0088] Regarding the process by which the main control device determines the third impedance of the battery under the second operating condition, in some embodiments, the main control device can determine multiple AC impedances of the battery under the second operating condition. These multiple AC impedances correspond to multiple frequency points, and the target real part impedance of the AC impedance corresponding to the target frequency point among the multiple frequency points is determined as the third impedance. The interface response of the battery is most complete at the target frequency point, and the impedance measured at the target frequency point is more accurate, which is beneficial to improving the accuracy of the third impedance.

[0089] Each AC impedance corresponds to a specific frequency point, at which the battery's interface response is most complete. For example, the target frequency point could be 1Hz.

[0090] Regarding the process by which the main control device determines multiple AC impedances of the battery under the second operating condition, in some embodiments, the main control device can obtain multiple DC internal resistances of the battery under the second operating condition, and perform windowed Fourier transform on the multiple DC internal resistances to obtain multiple AC impedances. By converting the DC signal into AC impedance through windowed Fourier transform, the DC signal can be more easily obtained, which is beneficial to expanding the detection application scenarios for SOH detection of batteries.

[0091] In one application scenario, the multiple DC internal resistances of a battery can be represented as shown in Figure 3. A windowed Fourier transform is performed on each DC internal resistance to obtain multiple AC impedances, as shown in Figure 4. The AC impedances shown in Figure 4 can include impedance (ZRe on the horizontal axis) and capacitive reactance (ZIm on the vertical axis).

[0092] Regarding the process by which the main control device obtains multiple DC internal resistances of the battery under the second operating condition, in some embodiments, the main control device can obtain multiple cell voltages corresponding to multiple charging durations during the process of charging the battery to the second operating condition, and determine a DC internal resistance based on the battery charging current and each cell voltage to obtain multiple DC internal resistances. Based on the battery charging current and the cell voltage corresponding to each charging duration, a DC internal resistance is calculated, which improves the accuracy of DC internal resistance calculation.

[0093] Each cell voltage corresponds to a charging time, and each of the multiple charging times corresponds to a frequency point.

[0094] The charging current of a battery can be calculated based on the battery's capacity and charging rate. For example, the charging rate of a battery can be 0.3C.

[0095] Step 120: Determine the impedance growth rate based on the battery's second impedance and first impedance.

[0096] In this embodiment of the application, the main control device can calculate the impedance growth rate of the battery based on the second impedance and the first impedance of the battery.

[0097] In one application scenario, the battery's first impedance is Z1, and its second impedance is Z2. The battery's impedance growth rate Z can be calculated using Formula 2 based on the first impedance Z1 and the second impedance Z2. growth .

[0098] Formula 2 is: Z growth = (Z1-Z2) / Z2.

[0099] Step 130: Determine the current SOH of the battery based on the first correspondence and the impedance growth rate.

[0100] In this embodiment, the main control device can determine the current SOH of the battery based on the first correspondence and the impedance growth rate. This enables the determination of the current SOH of the battery based on the battery's impedance growth rate and the pre-built correlation between the battery's impedance growth rate and SOH during the SOH detection process. Since the battery's cell impedance is not affected when the battery is locked, the problem of inaccurate SOH detection caused by the battery being locked when the battery's discharge capacity is used to detect the battery's SOH is suppressed, thereby improving the detection accuracy of the battery's SOH.

[0101] The first correspondence can be used to characterize the relationship between the battery's impedance growth rate and its state of equilibrium (SOH). For example, the first correspondence can be an impedance growth rate curve.

[0102] In one application scenario, the impedance growth rate curve of a battery can be represented as y = ax + b, where a and b are known constants, and x is the impedance growth rate Z. growth Let y be the state of impedance (SOH) of the battery. The impedance growth rate curve y = ax + b and the impedance growth rate Z can be used to determine this. growth Calculate the current SOH of the battery according to Formula 3.

[0103] Formula 3 is: SOH = aZ growth +b.

[0104] As an example, in the case of a lithium iron phosphate (LFP) battery, the impedance growth rate curve can be shown in Figure 5, which can be y1 = -1.8182x + 1.7873.

[0105] Where a = -1.8182, b = 1.7873.

[0106] As an example, in the case of a lithium iron phosphate (Nickel Cobalt Manganese, NCM) battery, the impedance growth rate curve can be shown in Figure 6, and the impedance growth rate curve can be y1 = -5.036x + 4.999.

[0107] Where a = -5.036 and b = 4.999.

[0108] In one application scenario, electrochemical impedance spectroscopy (EIS) was used to detect the state of oxygen (SOH) of battery A in vehicle model A, battery B in vehicle model B, battery C in vehicle model C, battery D in vehicle model D, and battery E in vehicle model E. As shown in Table 2, the error between the current SOH of battery A, battery B, battery C, battery D, and battery E obtained based on EIS detection and the corresponding measured SOH is less than 3%.

[0109] The measured SOH is obtained by calculating the ratio of the discharge capacity to the battery's rated capacity during the full charge and discharge process.

[0110] Table 2

[0111] The solution provided in this application determines the battery's first impedance under a first operating condition, which includes a first battery temperature and a first state of charge (SOC). It then determines the impedance growth rate based on the battery's second impedance and the first impedance, where the second impedance characterizes the battery's standard impedance under the first operating condition. Finally, it determines the battery's current state of harmonic equilibrium (SOH) based on a first correspondence and the impedance growth rate, where the first correspondence characterizes the relationship between the battery's impedance growth rate and SOH. This allows for the determination of the battery's current SOH during SOH detection based on the battery's impedance growth rate and a pre-built correlation between the battery's impedance growth rate and SOH. Since the battery's cell impedance is not affected when the battery is locked, this solution suppresses the problem of inaccurate SOH detection caused by the battery being locked when performing SOH detection based on the battery's discharge capacity, thus improving the accuracy of SOH detection.

[0112] Please refer to Figure 7, which shows a flowchart of a battery SOH detection method provided in another embodiment of this application. In a specific embodiment, the battery SOH detection method can be applied to the main control device 200 in the battery SOH detection system shown in Figure 1. The process shown in Figure 7 will be described in detail below using the main control device 200 as an example. The battery SOH detection method may include the following steps 210 to 240.

[0113] Step 210: Determine the first impedance of the battery under the first operating condition.

[0114] Step 220: Determine the impedance growth rate based on the battery's second impedance and first impedance.

[0115] Step 230: Determine the current SOH of the battery based on the first correspondence and the impedance growth rate.

[0116] In this embodiment, steps 210, 220 and 230 can be referred to the corresponding steps in the previous embodiments, and will not be repeated here.

[0117] Step 240: If the current SOH is less than or equal to the preset SOH threshold, generate an alarm message.

[0118] In this embodiment, the main control device can generate an alarm message when the current SOH is less than or equal to a preset SOH threshold. An alarm message is also generated when the battery's SOH drops significantly, so that the user can deal with the battery in a timely manner, which helps to improve the electrical safety of battery-powered devices.

[0119] The alarm information may include, but is not limited to, at least one of the following: text alarm information, sound alarm information, and light alarm information.

[0120] The preset SOH threshold can be used to characterize the degree of battery degradation. The preset SOH threshold may include, but is not limited to, the SOH preset by the user, or the SOH automatically generated by the control device based on the detection process of multiple SOH detections of the battery.

[0121] The solution provided in this embodiment determines the battery's first impedance under a first operating condition, determines the impedance growth rate based on the battery's second impedance and first impedance, determines the battery's current SOH based on a first correspondence and the impedance growth rate, and generates an alarm message when the current SOH is less than or equal to a preset SOH threshold. This achieves the determination of the battery's current SOH based on the battery's impedance growth rate and a pre-built correlation between the battery's impedance growth rate and SOH during the SOH detection process. Since the battery's cell impedance is not affected when the battery is locked, the problem of inaccurate SOH detection caused by the battery being locked when the battery's discharge capacity is used for SOH detection is suppressed, thus improving the detection accuracy of battery SOH.

[0122] Furthermore, when the battery's SOH drops significantly, an alarm message is generated so that users can address the battery issue promptly, thereby improving the electrical safety of battery-powered devices.

[0123] Please refer to Figure 8, which illustrates a battery SOH detection device 300 provided in one embodiment of this application. In a specific embodiment, the battery SOH detection device 300 can be applied to the main control device 200 in the SOH detection system shown in Figure 1. The battery SOH detection device 300 shown in Figure 8 will be described in detail below using the main control device 200 as an example. The battery SOH detection device 300 may include a first determining module 310, a second determining module 320, and a third determining module 330.

[0124] The first determining module 310 can be used to determine the first impedance of the battery under a first operating condition, which may include a first battery temperature and a first state of charge (SOC); the second determining module 320 can be used to determine the impedance growth rate based on the second impedance and the first impedance of the battery, whereby the second impedance can be used to characterize the standard impedance of the battery under the first operating condition; the third determining module 330 can be used to determine the current state of harmonic equilibrium (SOH) of the battery based on a first correspondence and the impedance growth rate, whereby the first correspondence can be used to characterize the correspondence between the battery's impedance growth rate and SOH.

[0125] In some implementations, the first determining module 310 may include a first determining submodule, a second determining submodule, and a calculation submodule.

[0126] The first determining submodule can be used to determine the third impedance of the battery under the second operating condition, which may include the second battery temperature and the second state of charge (SOC); the second determining submodule can be used to determine the target impedance change rate of the battery when it changes from the second operating condition to the first operating condition; the calculation submodule can be used to calculate the first impedance based on the third impedance and the target impedance change rate.

[0127] In some implementations, the second determining submodule may include an acquisition unit and a obtaining unit.

[0128] The acquisition unit can be used to acquire the second correspondence of the battery, which can be used to characterize the correspondence between the battery's operating condition changes and the impedance change rate; the obtaining unit can be used to obtain the target impedance change rate based on the first operating condition, the second operating condition, and the second correspondence.

[0129] In some implementations, the first determining submodule may include a first determining unit and a second determining unit.

[0130] The first determining unit can be used to determine multiple AC impedances of the battery under the second operating condition, and the multiple AC impedances correspond to multiple frequency points; the second determining unit can be used to determine the target real part impedance of the AC impedance corresponding to the target frequency point among the multiple frequency points as the third impedance, and the interface reaction of the battery is most complete at the target frequency point.

[0131] In some implementations, the first determining unit may include an acquisition subunit and a transformation subunit.

[0132] The acquisition subunit can be used to acquire multiple DC internal resistances of the battery under the second operating condition; the transformation subunit can be used to perform windowed Fourier transform on multiple DC internal resistances to obtain multiple AC impedances.

[0133] In some implementations, acquiring a sub-unit may include acquiring a secondary sub-unit and determining the secondary sub-unit.

[0134] The secondary sub-unit can be used to obtain multiple cell voltages corresponding to multiple charging durations during the process of charging the battery to the second operating condition. Each charging duration can correspond to a frequency point. The secondary sub-unit can be used to determine a DC internal resistance based on the battery charging current and the voltage of each cell, so as to obtain multiple DC internal resistances.

[0135] In some embodiments, the battery's SOH detection device 300 may also include a generation module.

[0136] The generation module can be used to generate alarm information when the current SOH is less than or equal to a preset SOH threshold.

[0137] The solution provided in this embodiment determines the battery's first impedance under a first operating condition, which includes a first battery temperature and a first state of charge (SOC). It then determines the impedance growth rate based on the battery's second impedance and the first impedance. The second impedance characterizes the battery's standard impedance under the first operating condition. Finally, it determines the battery's current state of harmonic equilibrium (SOH) based on a first correspondence and the impedance growth rate. The first correspondence characterizes the relationship between the battery's impedance growth rate and SOH. This allows for the determination of the battery's current SOH during SOH detection based on the battery's impedance growth rate and a pre-built correlation between the battery's impedance growth rate and SOH. Since the battery's cell impedance is not affected when the battery is locked, the solution suppresses the problem of inaccurate SOH detection caused by the battery being locked when performing SOH detection based on the battery's discharge capacity, thus improving the accuracy of SOH detection.

[0138] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For device embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to in the descriptions of the method embodiments. Any processing method described in the method embodiments can be implemented in the device embodiments through corresponding processing modules, and will not be elaborated upon further in the device embodiments.

[0139] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0140] Please refer to Figure 9, which shows a functional block diagram of a master control device 500 provided in an embodiment of this application. The master control device 500 may include one or more of the following components: a memory 510, a processor 520, and one or more application programs. One or more application programs may be stored in the memory 510 and configured to be executed by one or more processors 520. One or more application programs are configured to perform the methods as described in the foregoing method embodiments.

[0141] The memory 510 may include random access memory (RAM) or read-only memory (ROM). The memory 510 may be used to store instructions, programs, code, code sets, or instruction sets. The memory 510 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (e.g., determining a first impedance, determining an impedance growth rate, determining the current state of impedance (SOH), determining a third impedance, determining a target impedance change rate, calculating the first impedance, obtaining a second correspondence, obtaining the target impedance change rate, determining multiple AC impedances, obtaining multiple DC internal resistances, performing a windowed Fourier transform, obtaining multiple AC impedances, obtaining multiple cell voltages, determining DC internal resistance, and generating alarm information, etc.), and instructions for implementing the various method embodiments described below. The data storage area can also store data created by the main control device 500 during use (such as battery, first operating condition, first impedance, first battery temperature, first SOC, second impedance, impedance growth rate, standard impedance, first correspondence, current SOH, second operating condition, third impedance, second battery temperature, second SOC, target impedance change rate, second correspondence, AC impedance, target frequency point, target AC impedance, target real part impedance, DC internal resistance, charging time, cell voltage, preset SOH threshold, and alarm information).

[0142] Processor 520 may include one or more processing cores. Processor 520 connects to various parts within the main control device 500 using various interfaces and lines, and performs various functions and processes data of the main control device 500 by running or executing instructions, programs, code sets, or instruction sets stored in memory 510, and by calling data stored in memory 510. Optionally, processor 520 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). Processor 520 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem handles wireless communication. It is understood that the modem may also not be integrated into processor 520 and may be implemented separately using a communication chip.

[0143] Please refer to Figure 10, which shows a structural block diagram of a computer-readable storage medium provided in an embodiment of this application. The computer-readable storage medium 600 stores program code 610, which can be called by a processor to execute the methods described in the above method embodiments.

[0144] The computer-readable storage medium 600 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, the computer-readable storage medium 600 includes a non-transitory computer-readable storage medium. The computer-readable storage medium 600 has storage space for program code 610 that performs any of the method steps described above. This program code can be read from or written to one or more computer program products. The program code 610 may, for example, be compressed in a suitable form.

[0145] Please refer to Figure 11, which shows a structural block diagram of a computer program product 700 provided in an embodiment of this application. The computer program product 700 includes a computer program / instructions 710, which is stored in a computer-readable storage medium of a computer device. When the computer program product 700 runs on the computer device, the processor of the computer device reads the computer program / instructions 710 from the computer-readable storage medium, and executes the computer program / instructions 710, causing the computer device to perform the methods described in the above method embodiments.

[0146] The solution provided in this embodiment determines the battery's first impedance under a first operating condition, which includes a first battery temperature and a first state of charge (SOC). It then determines the impedance growth rate based on the battery's second impedance and the first impedance. The second impedance characterizes the battery's standard impedance under the first operating condition. Finally, it determines the battery's current state of harmonic equilibrium (SOH) based on a first correspondence and the impedance growth rate. The first correspondence characterizes the relationship between the battery's impedance growth rate and SOH. This allows for the determination of the battery's current SOH during SOH detection based on the battery's impedance growth rate and a pre-built correlation between the battery's impedance growth rate and SOH. Since the battery's cell impedance is not affected when the battery is locked, the solution suppresses the problem of inaccurate SOH detection caused by the battery being locked when performing SOH detection based on the battery's discharge capacity, thus improving the accuracy of SOH detection.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for detecting the state of harm (SOH) of a battery, wherein, include: Determine the first impedance of the battery under a first operating condition, the first operating condition including a first battery temperature and a first state of charge (SOC); The impedance growth rate is determined based on the second impedance of the battery and the first impedance, wherein the second impedance is used to characterize the standard impedance of the battery under the first operating condition. The current state of impedance (SOH) of the battery is determined based on the first correspondence and the impedance growth rate, wherein the first correspondence is used to characterize the correspondence between the impedance growth rate of the battery and the SOH.

2. The SOH detection method according to claim 1, wherein, Determining the first impedance of the battery under the first operating condition includes: Determine the third impedance of the battery under a second operating condition, the second operating condition including the second battery temperature and the second state of charge (SOC); Determine the target impedance change rate of the battery as it transitions from the second operating condition to the first operating condition; The first impedance is calculated based on the third impedance and the target impedance change rate.

3. The SOH detection method according to claim 2, wherein, Determining the target impedance change rate of the battery as it transitions from the second operating condition to the first operating condition includes: Obtain a second correspondence relationship for the battery, which is used to characterize the correspondence between the battery's operating condition changes and impedance change rate; The target impedance change rate is obtained based on the first operating condition, the second operating condition, and the second correspondence.

4. The SOH detection method according to claim 2 or 3, wherein, Determining the third impedance of the battery under the second operating condition includes: Determine multiple AC impedances of the battery under the second operating condition, wherein the multiple AC impedances correspond to multiple frequency points; The target real part impedance of the AC impedance corresponding to the target frequency point among the plurality of frequency points is determined as the third impedance, and the interface reaction of the battery is most complete at the target frequency point.

5. The SOH detection method according to claim 4, wherein, The target frequency is 1Hz.

6. The SOH detection method according to claim 4 or 5, wherein, Determining the multiple AC impedances of the battery under the second operating condition includes: Obtain multiple DC internal resistances of the battery under the second operating condition; The multiple DC internal resistances are subjected to a windowed Fourier transform to obtain the multiple AC impedances.

7. The SOH detection method according to claim 6, wherein, The step of obtaining multiple DC internal resistances of the battery under the second operating condition includes: During the process of charging the battery to the second working condition, multiple cell voltages corresponding to multiple charging durations are obtained, and each of the multiple charging durations corresponds to a frequency point. A DC internal resistance is determined based on the charging current of the battery and the voltage of each cell to obtain the plurality of DC internal resistances.

8. The SOH detection method according to claim 7, wherein, The charging current is calculated based on the corresponding battery capacity and charging rate.

9. The SOH detection method according to claim 8, wherein, The charging rate is 0.3C.

10. The SOH detection method according to any one of claims 1 to 9, wherein, The first correspondence is the impedance growth rate curve.

11. The SOH detection method according to any one of claims 1 to 10, wherein, The step of determining the impedance growth rate based on the second impedance and the first impedance of the battery includes: Calculate the impedance difference between the first impedance and the second impedance; The impedance growth rate is obtained by calculating the quotient of the impedance difference and the second impedance.

12. The SOH detection method according to any one of claims 1 to 11, wherein, Also includes: An alarm message is generated when the current SOH is less than or equal to a preset SOH threshold.

13. A battery SOH detection device, wherein, include: The first determining module is used to determine the first impedance of the battery under a first operating condition, the first operating condition including the first battery temperature and the first SOC; The second determining module is used to determine the impedance growth rate based on the second impedance of the battery and the first impedance, wherein the second impedance is used to characterize the standard impedance of the battery under the first operating condition. The third determining module is used to determine the current SOH of the battery based on the first correspondence and the impedance growth rate, wherein the first correspondence is used to characterize the correspondence between the impedance growth rate of the battery and the SOH.

14. A master control device, wherein, include: Memory; One or more processors are coupled to the memory; One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the one or more processors, the one or more applications being configured to perform the SOH detection method as described in any one of claims 1 to 12.

15. A computer-readable storage medium, wherein, The computer-readable storage medium contains program code that can be called by a processor to execute the SOH detection method as described in any one of claims 1 to 12.

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