Method and apparatus for estimating state of charge of battery in battery system

Abstract

The present invention provides a method and an apparatus for estimating the state of charge of a battery in a battery system, which obtain the state of charge of an exchange module, determine the state of charge of a main circuit battery from the state of charge of the exchange module, where the exchange module is for replacing an original battery, and the capacity of the exchange module is larger than the capacity of the original battery, the original battery is connected in series with the main circuit battery in the lithium iron phosphate battery branch of the battery system, perform self-discharge detection on the exchange module and the main circuit battery, and in the result of the self-discharge detection, balance control is performed when a large amount of self-discharge exists. After the balance control is performed, an updated state of charge of the exchange module is determined, and the state of charge of the main circuit battery is updated according to the updated state of charge of the exchange module. The present invention can improve the estimation accuracy of the state of charge of the main circuit battery, expand the estimation interval of the state of charge SOC of the main circuit battery, and further improve the stability of the battery system.

Description

Technical Field

[0001] The present invention relates to battery technology, and particularly to a method and apparatus for estimating the state of charge of a battery in a battery system.

Background Art

[0002] Chinese Patent Document with Publication Number CN114545256A discloses a method and system for estimating the state of charge of a lithium iron phosphate battery. A specific original battery in the main circuit is replaced with an exchange module having a larger capacity than the battery in the main circuit. The state of charge of this exchange module is described as X. First, the state of charge of the battery in the exchange module and the main circuit is adjusted to be the same at 0% SOC. From the series connection relationship, in the subsequent charge and discharge process, the estimated state of charge of the main circuit is X*A / B, where A is the capacity of the exchange module and B is the capacity of the battery in the main circuit. From the charge and discharge voltage curve characteristics of the lithium iron phosphate battery, in the 0% SOC to 30% SOC interval and the 90% SOC to 100% SOC interval, the battery voltage clearly changes according to the state of charge and can be used for estimating the state of charge.

[0003] The above technical solution expands the state of charge estimation interval of the main circuit. However, when there is a large amount of self-discharge between the exchange module and the main circuit battery, a large error will occur in the estimation of the state of charge, and the estimation result of the state of charge of the lithium iron phosphate battery will become inaccurate.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention is made in view of the above-mentioned drawbacks of the prior art, and aims to provide a method and apparatus for estimating the state of charge of a battery in a battery system to solve the problem that the estimation result of the state of charge of a conventional lithium iron phosphate battery is inaccurate.

Means for Solving the Problems

[0005] The present invention provides a method for estimating the state of charge of a battery in a battery system to achieve the above object and other related objects, and includes at least the following steps.

[0006] The lithium iron phosphate battery branch circuit of the battery system includes an original battery and a main circuit battery connected in series, and the original battery is replaced with a replacement module having a larger capacity than the original battery.

[0007] Obtain the state of charge of the replacement module, and determine the state of charge of the main circuit battery based on the state of charge of the replacement module.

[0008] Based on the state of charge and battery health state of the replacement module and the main circuit battery, self-discharge detection of the replacement module and the main circuit battery is performed respectively. When a large amount of self-discharge exists in the replacement module or the main circuit battery, balance control is performed on the replacement module and the main circuit battery.

[0009] After balance control is performed, an updated state of charge of the replacement module is determined, and the state of charge of the main circuit battery is updated according to the updated state of charge of the replacement module.

[0010] Preferably, performing self-discharge detection of the replacement module and the main circuit battery respectively based on the state of charge of the replacement module and the main circuit battery includes performing self-discharge detection when both the state of charge of the replacement module and the main circuit battery are in a low state of charge section, or when the state of charge of the main circuit battery is in a high state of charge section.

[0011] Preferably, the low state of charge section is 0% - 30%, and the high state of charge section is 90% - 100%.

[0012] Preferably, performing the balance control on the replacement module and the main circuit battery includes transferring a part of the battery energy with low self-discharge in the replacement module or the main circuit battery to the battery with high self-discharge.

[0013] Preferably, performing the balance control on the replacement module and the main circuit battery includes consuming the battery energy with low self-discharge in the replacement module or the main circuit battery by a resistor.

[0014] Preferably, a method of proportional conversion is adopted to estimate the charging state of the main circuit battery from the charging state and the updated charging state of the replacement module.

[0015] Preferably, according to the charging states and the battery health states of the replacement module and the main circuit battery, before performing self-discharge detection on the replacement module and the main circuit battery respectively, it further includes determining the battery health state of the replacement module and the battery health state of the main circuit battery, and determining the current capacity of the replacement module using the battery health state of the replacement module, and determining the current capacity of the main circuit battery using the battery health state of the main circuit battery.

[0016] Preferably, during self-discharge detection, if the charging state of the main circuit battery is not equal to n times the charging state of the replacement module, it is determined that excessive self-discharge has occurred in the replacement module or the main circuit battery, where n is the ratio of the current capacity of the replacement module to the current capacity of the main circuit battery, the current capacity of the replacement module is the product of the original capacity of the replacement module and the battery health state of the replacement module, and the current capacity of the main circuit battery is the product of the original capacity of the main circuit battery and the battery health state of the main circuit battery.

[0017] Preferably, as a result of performing the balance control, the charging state of the main circuit battery becomes equal to n times the charging state of the replacement module.

[0018] To achieve the above object and other related objects, the present invention provides an apparatus for estimating the state of charge of a battery in a battery system, comprising a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, it realizes the procedure of a method for estimating the state of charge of a battery in the battery system.

[0019] As described above, the method and apparatus for estimating the state of charge of a battery in the battery system of the present invention have the following effects.

[0020] The method for estimating the state of charge of a battery in the battery system of the present invention performs self-discharge detection and balance control on the existing estimated state of charge. Based on the state of charge of the main circuit battery estimated from the updated state of charge after balance control, it avoids interference caused by a large amount of self-discharge of the replacement module or the main circuit battery, improves the estimation accuracy of the state of charge of the main circuit battery, expands the estimation interval of the state of charge SOC of the main circuit battery, and can further improve the stability of the battery system.

[0021] The features and performance of the present invention are further described by the following examples and their drawings.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described with specific examples. However, those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can be further implemented or applied by different specific embodiments, and each detail in this specification can be variously modified or changed without departing from the spirit of the present invention based on different viewpoints and applications.

[0024] Referring to FIGS. 1 to 3, the illustrations provided in this embodiment schematically illustrate the basic concept of the present invention. The drawings show only the components related to the present invention and are not drawn based on the number, shape, and dimensions of the components during actual implementation. The form, quantity, and ratio of each component during actual implementation can be arbitrarily changed, and the layout form of those components may also become more complex.

[0025] As shown in FIG. 1, it is a schematic diagram of the change in the 0.1C charging voltage curve of a lithium iron phosphate battery at 25°C. As can be seen from FIG. 1, the charging state is in the range of 30% SOC to 90% SOC, and the change in voltage with respect to SOC is not obvious, increasing the difficulty of SOC estimation. However, within the detection ranges of 0% SOC to 30% SOC and 90% SOC to 100% SOC of the charging state, since the change in voltage with respect to the charging state is obvious, the charging state can be estimated based on the voltage characteristics within either of these two ranges, and the estimation is relatively accurate.

[0026] In order to solve the conventional technical defect that when there is a large amount of self-discharge between the replacement module and the main circuit battery, a large error occurs in the estimation of the charging state, and further the estimation result of the charging state of the lithium iron phosphate battery becomes inaccurate, the present invention proposes a means of adding self-discharge detection and balance control in the case of low charging state (both the charging states of the replacement module and the main circuit battery are less than 30%) and high charging state (the charging state of the main circuit battery exceeds 90%). Thereby, the estimation accuracy of the charging state of the lithium iron phosphate battery can be improved, the charging state estimation range of the lithium iron phosphate battery can be expanded, and the stability of the battery system can be further improved.

[0027] (Embodiment of the method) The method for estimating the state of charge of the battery in the battery system according to the present invention includes at least the following content, as shown in FIG. 2.

[0028] In an embodiment of the present invention, the original capacity of the replacement module is C1', and the original capacity of the main circuit battery is C2', where C1' / C2'>1.

[0029] (Step S1) Obtain the state of charge of the replacement module, and obtain the state of charge of the main circuit battery from the state of charge of the replacement module. The replacement module is for replacing the original battery, and the capacity of the replacement module is larger than the capacity of the original battery. The original battery is connected in series with the main circuit battery in the lithium iron phosphate battery branch of the battery system.

[0030] In the lithium iron phosphate battery branch according to the battery system of the present invention, the original battery and the main circuit battery are the same.

[0031] The replacement module of the present invention is a replacement battery. As the replacement battery, a lithium iron phosphate battery with a large difference in capacity from the original battery and a higher capacity than the original battery can be adopted.

[0032] The present invention estimates the state of charge of the main circuit battery from the state of charge of the replacement battery using a proportional conversion method. Specifically, the proportional conversion method is used to convert the state of charge of the replacement battery into the state of charge of the main circuit battery. However, the larger the capacity difference between the replacement battery and the main circuit battery, the wider the interval of state of charge estimation. And the larger the capacity difference between the replacement battery and the main circuit battery, the more accurate the estimation, but if the difference is too large, it will cause waste of cost and cannot be actually applied.

[0033] In the embodiments of the present invention, the number of the original battery and the replacement batteries in the replacement module is not limited. The number of the original battery and the replacement batteries in the replacement module may be the same or different. The number may be one or more. However, when the number is plural, as long as the battery capacity of the replacement module can satisfy being larger than the capacity of the original battery, a plurality of original batteries may be connected in series or in parallel, and the replacement batteries in the replacement module may also be connected in series or in parallel.

[0034] The present invention estimates the state of charge of the main circuit battery by using a proportional conversion method from the state of charge of the replacement battery. Therefore, first, it is necessary to obtain the state of charge of the replacement module and determine the proportional conversion method.

[0035] In the present invention, the state of charge of the replacement module and the main circuit battery coincide at 0% SOC. From the series connection relationship, the relationship between the state of charge SOC_X of the main circuit battery and the state of charge SOC_T of the replacement module in the subsequent charge and discharge process is as follows.

[0036] SOC_X=n`×SOC_T Here, the coefficient n` is the ratio of the original capacity C1’ of the replacement module to the original capacity C2’ of the main circuit battery, that is, n`=C1’ / C2’.

[0037] In the embodiments of the present invention, the state of charge of the replacement module is obtained by estimating the state of charge based on the voltage. The state of charge of the replacement module is SOC_T, and the state of charge of the main circuit battery is SOC_X=SOC_T×(C1’ / C2’).

[0038] In the embodiments of the present invention, n`=2 is taken as an example for explanation. The replacement module is a lithium iron phosphate battery, and the original capacity C1’ of the replacement battery is twice the original capacity C2’ of the main circuit battery. As another embodiment, n` may be a value such as 1.5, 3, 4, etc.

[0039] In the initial state, both the replacement battery and the main circuit battery are in the 0% SOC state. Since they are in a series connection relationship, the current flowing through both of them in the subsequent charge and discharge process is the same. Therefore, when the charge state of the main circuit battery changes between 0% and 100%, the charge state of the replacement battery is half of the charge state of the main circuit battery, that is, 0% to 50%. In a more accurate detection interval of the SOC of the replacement battery, for example, in the 0% to 30% charge state detection interval of a lithium iron phosphate battery, the SOC of the replacement battery can be estimated relatively accurately by voltage, and the SOC of the main circuit battery (0% SOC to 60% SOC) can be obtained. In other intervals, the estimated SOC of the main circuit battery (for example, in the 90% SOC to 100% SOC interval of a lithium iron phosphate battery) is still used.

[0040] Therefore, when the charge state SOC_T of the replacement battery is 0% SOC to 30% SOC, the charge state SOC_X of the main circuit battery is 2×SOC_T, and the estimation is relatively accurate, the charge state of the main circuit battery from 0% SOC to 60% SOC can be accurately estimated. However, in the 90% SOC to 100% SOC interval, the SOC estimation is still performed using the voltage of the main circuit. Therefore, the embodiment of the present application can expand the accurate interval of the charge state estimated from the voltage from 0% SOC to 30% SOC and 90% SOC to 100% SOC to 0% SOC to 60% SOC and 90% SOC to 100% SOC. The embodiment of the present application only takes this as an example and is not limited thereto.

[0041] (Step S2) Based on the charge states of the replacement module and the main circuit battery, self-discharge detection is performed on the replacement module and the main circuit battery respectively. When there is a large amount of self-discharge in the replacement module or the main circuit battery, balance control is performed on the replacement module and the main circuit battery.

[0042] Theoretically, since the state of charge of the replacement module and the main circuit battery should match at 0% SOC, at this time, the state of health of the replacement module is SOH1, the state of health of the main circuit battery is SOH2, and it is considered that SOH1 / SOH = 1. From the series connection relationship, the relationship between the state of charge SOC_X of the main circuit battery and the state of charge SOC_T of the replacement module in the subsequent charge and discharge process is as follows.

[0043] SOC_X = n`×SOC_T However, in reality, due to the influence of some losses and other factors, a phenomenon of significant self-discharge occurs, and the subsequent charge and discharge process may not necessarily maintain the relationship of SOC_X = n`×SOC_T. When the relationship of the state of charge cannot be maintained, a large error will occur in the state of charge result estimated by this method. Therefore, it is necessary to perform self-discharge detection and balance control on the replacement module and the main circuit battery to ensure the accuracy of the state of charge SOC estimation of the main circuit battery.

[0044] In addition, since the coefficient n` changes due to the change in the state of health of the battery, it is necessary to re-determine the relationship between the state of charge SOC_X of the main circuit battery and the state of charge SOC_T of the replacement module as follows.

[0045] SOC_X = n×SOC_T Here, n is the ratio of the current capacity C1 of the replacement module to the current capacity of the main circuit battery, that is, n = C1 / C2. The current capacity of the replacement module is the product of the original capacity C1’ of the replacement module and the state of health SOH1 of the battery of the replacement module. The current capacity of the main circuit battery is the product of the original capacity C2’ of the main circuit battery and the state of health SOH2 of the battery of the main circuit battery. Here, C1’>C2’.

[0046] Note that if SOH1 / SOH2 = 1 at the initial time, n at this time is equal to n` at the initial time.

[0047] After updating the current capacities of the replacement module and the main circuit battery according to the health status of the battery, the present invention re-determines the new balance relationship between the charge state of the main circuit battery and the charge state of the replacement module, and finally makes a judgment based on the new balance relationship, thereby improving the judgment accuracy of large self-discharge.

[0048] According to the charge states and battery health statuses of the replacement module and the main circuit battery, self-discharge detection is performed on the replacement module and the main circuit battery respectively. Therefore, before performing self-discharge detection, the following contents are provided.

[0049] Determine the battery health status of the replacement module and the battery health status of the main circuit battery.

[0050] Determine the current capacity of the replacement module using the battery health status of the replacement module, and determine the current capacity of the main circuit battery using the battery health status of the main circuit battery.

[0051] Among them, the method for obtaining the determined battery health status is a prior art, and detailed description is omitted in the embodiments of the present invention.

[0052] In a possible embodiment, when the charge states of both the replacement module and the main circuit battery are in the low charge state range, or when the charge state of the main circuit battery is in the high charge state range, self-discharge detection is performed, and balance control is performed for large self-discharge.

[0053] In the embodiments of the present invention, the low charge state range is 0% to 30%, and the high charge state range is 90% to 100%.

[0054] In the self-discharge detection process, the charge state of the replacement module is estimated by the voltage of the replacement module or the ampere-hour integration method, and the charge state of the main circuit battery is estimated from the voltage of the main circuit battery.

[0055] When both the charge state of the exchange module and the main circuit battery are in the low charge state range (0% - 30%), self-discharge detection is performed to determine whether there is a significant self-discharge in the exchange module or the main circuit battery.

[0056] Specifically, the state of charge SOC_X of the main circuit battery estimated from the voltage is less than 30%, and the state of charge SOC_T of the exchange module estimated from the voltage is less than 30%.

[0057] When SOC_X > n × SOC_T, it is determined that a significant self-discharge has occurred in the exchange module; when SOC_X < n × SOC_T, it is determined that a significant self-discharge has occurred in the main circuit battery.

[0058] If SOC_X = n × SOC_T, no significant self-discharge phenomenon occurs in either the exchange module or the main circuit battery.

[0059] When the charge state of the main circuit battery is in the high charge state range (90% - 100%), self-discharge detection is performed to determine whether there is a significant self-discharge in the exchange module or the main circuit battery.

[0060] Specifically, the state of charge SOC_X of the main circuit battery estimated from the voltage exceeds 90%, and the charge state of the exchange module is less than 50%.

[0061] When SOC_X > n × SOC_T, it is determined that a significant self-discharge has occurred in the exchange battery; when SOC_X < n × SOC_T, it is determined that a significant self-discharge has occurred in the main circuit battery.

[0062] If SOC_X = n × SOC_T, no significant self-discharge phenomenon occurs in either the exchange module or the main circuit battery.

[0063] As can be seen from the characteristic curve of voltage and state of charge, between 30% and 60%, the change in voltage with the state of charge (SOC) is not significant. Therefore, when estimating SOC from voltage, large deviations are likely to occur. Thus, the state of charge can be estimated based on other conventional methods, such as the ampere-hour integration method.

[0064] Detect the phenomenon of significant self-discharge according to self-discharge, perform balance control, and make SOC_X = n×SOC_T again to ensure the estimation accuracy of the state of charge of the main circuit battery thereafter.

[0065] In another preferred embodiment of the present invention, considering that it is difficult to stably maintain absolute balance in the balance control process, when actually applied, based on the judgment conditions in the embodiments of the present invention, a certain deviation can be tolerated to judge significant self-discharge. The deviation may be the magnitude of the deviation (a single value or an interval), or a certain proportional value.

[0066] Specifically, for example, whether in the low state of charge range or the high state of charge range, if SOC_X > n×SOC_T + δ, it is determined that significant self-discharge has occurred in the exchange module; if SOC_X < n×SOC_T - δ, it is determined that significant self-discharge has occurred in the main circuit battery; if SOC_X = n×SOC_T ± δ, it is determined that no significant self-discharge phenomenon has occurred in either the exchange module or the main circuit battery. Here, δ represents the magnitude of the deviation. The embodiments of the present application do not specifically limit the specific numerical value or interval of δ, etc., and can be specifically selected according to the actual situation.

[0067] In an embodiment of the present invention, when there is a large self-discharge in the exchange module or the main circuit battery, while indicating that the other has a small self-discharge, the balance control of the present invention is an active balance or a passive balance. The active balance means transferring the battery energy with a small self-discharge in the exchange module or the main circuit battery to the battery with a large self-discharge, and the passive balance means consuming the battery energy with a small self-discharge in the exchange module or the main circuit battery by a resistor.

[0068] The present invention re-adjusts the charge state relationship between the exchange module and the main circuit battery by balance control, and guarantees the accuracy of the charge state of the main circuit battery obtained based on the updated charge state of the exchange module.

[0069] (Step S3) After balance control is performed, the updated charge state of the exchange module is determined, and the charge state of the main circuit battery is updated according to the updated charge state of the exchange module.

[0070] After balance control is performed on the battery of the lithium iron phosphate battery branch of the battery system, the updated charge state of the exchange module is determined, and then the method of Step S1 is adopted, that is, based on the updated charge state of the exchange module, the proportional conversion method is used to estimate the updated charge state of the main circuit battery, and the charge state of the main circuit battery is updated with the updated charge state of the main circuit battery to obtain a more accurate charge state of the main circuit.

[0071] Among them, the updated charge state of the replacement module was determined as follows. When the charge state of the replacement module has not changed in the balance control process, the updated charge state is set to the original charge state. When the charge state of the replacement module has changed in the balance control process, it is necessary to reacquire or recalculate the charge state of the replacement module in order to determine the updated charge state. However, in the actual application process, if the balance control time is slightly long, regardless of whether the charge state of the replacement module is the object of controlled balance, its charge state changes. In this case, the updated charge state of the replacement module is always the charge state that needs to be reacquired.

[0072] Specifically, based on the updated charge state of the replacement module, a proportional conversion method is used to estimate the updated charge state of the main circuit battery. The updated charge state of the main circuit battery is set as the charge state of the main circuit battery. The charge state of the main circuit battery estimated by the updated charge state after balance control avoids the interference caused by the large self-discharge of the replacement module and the main circuit battery, improves the estimation accuracy of the charge state of the main circuit battery, expands the estimation interval of the state of charge (SOC) of the main circuit battery, and further improves the stability of the battery system.

[0073] (Device Embodiment) The present invention provides a structural schematic diagram of an apparatus for estimating the state of charge of a battery in a battery system. As shown in FIG. 3, it includes a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, it realizes the procedure of the method for estimating the state of charge of the battery in the battery system.

[0074] For the detailed process of the procedure of the method for estimating the state of charge of the battery in the battery system, it has been described in detail in the method embodiment, so it is omitted here.

[0075] From the above, the method and device for estimating the state of charge of a battery in the battery system of the present invention, and the method for estimating the state of charge of a battery in the battery system perform self-discharge detection and balance control on the estimated existing state of charge, and according to the state of charge of the main circuit battery estimated by the updated state of charge after performing the balance control, it is possible to avoid interference caused by a large amount of self-discharge of the replacement module or the main circuit battery, further improve the estimation accuracy of the state of charge of the main circuit battery, expand the estimation interval of the state of charge SOC of the main circuit battery, and further improve the stability of the battery system. Therefore, the present invention can effectively overcome various drawbacks in the prior art and has high industrial utilization value.

[0076] The above embodiments are only illustrative explanations of the principle and effects of the present invention and do not limit the present invention. Those who are familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed in the present invention should still be included in the claims of the present invention.

Claims

1. A method for estimating the state of charge of a battery in a battery system, comprising: acquiring the state of charge of a replacement module, and obtaining the state of charge of the main circuit battery from the state of charge of the replacement module, wherein the replacement module is for replacing an original battery, and the capacity of the replacement module is larger than the capacity of the original battery, and the original battery is connected in series with the main circuit battery in the lithium iron phosphate battery branch of the battery system; performing self-discharge detection on the replacement module and the main circuit battery respectively based on the state of charge and the battery health state of the replacement module and the main circuit battery, and performing balance control on the replacement module and the main circuit battery when there is significant self-discharge in the replacement module or the main circuit battery; determining an updated state of charge of the replacement module after performing the balance control, and updating the state of charge of the main circuit battery according to the updated state of charge of the replacement module. A method for estimating the state of charge of a battery in a battery system, characterized by the above.

2. A method for estimating the state of charge of a battery in a battery system according to Claim 1, wherein: performing self-discharge detection on the replacement module and the main circuit battery respectively based on the state of charge of the replacement module and the main circuit battery includes: performing self-discharge detection when both the state of charge of the replacement module and the main circuit battery are in a low state of charge range, or when the state of charge of the main circuit battery is in a high state of charge range. A method for estimating the state of charge of a battery in a battery system, characterized by the above.

3. A method for estimating the state of charge of a battery in a battery system according to Claim 2, wherein: the low state of charge range is 0% to 30%, and the high state of charge range is 90% to 100%. A method for estimating the state of charge of a battery in a battery system, characterized by the above.

4. A method for estimating the state of charge of a battery in a battery system according to Claim 1, wherein: performing the balance control on the replacement module and the main circuit battery includes: A method for estimating the state of charge of a battery in a battery system, characterized by including transferring a part of the battery energy with low self-discharge in the exchange module or the main circuit battery to a battery with high self-discharge.

5. A method for estimating the state of charge of a battery in the battery system according to claim 1, wherein performing the balance control on the exchange module and the main circuit battery includes A method for estimating the state of charge of a battery in a battery system, characterized by including consuming the battery energy with low self-discharge in the exchange module or the main circuit battery by a resistor.

6. A method for estimating the state of charge of a battery in the battery system according to claim 1, wherein adopting a proportional conversion method to estimate the state of charge of the main circuit battery from the state of charge or updated state of charge of the exchange module. A method for estimating the state of charge of a battery in a battery system is characterized by this.

7. A method for estimating the state of charge of a battery in the battery system according to claim 1, wherein before performing self-discharge detection on the exchange module and the main circuit battery respectively according to the state of charge and battery health state of the exchange module and the main circuit battery, determining the battery health state of the exchange module and the battery health state of the main circuit battery, A method for estimating the state of charge of a battery in a battery system, characterized by determining the current capacity of the exchange module using the battery health state of the exchange module and determining the current capacity of the main circuit battery using the battery health state of the main circuit battery.

8. A method for estimating the state of charge of a battery in the battery system according to claim 7, wherein When self-discharge is detected, if the state of charge of the main circuit battery is not equal to n times the state of charge of the exchange module, it is determined that significant self-discharge has occurred in the exchange module or the main circuit battery. Here, n is the ratio of the current capacity of the exchange module to the current capacity of the main circuit battery. The current capacity of the exchange module is the product of the original capacity of the exchange module and the battery health state of the exchange module, and the current capacity of the main circuit battery is the product of the original capacity of the main circuit battery and the battery health state of the main circuit battery. A method for estimating the state of charge of a battery in a battery system, characterized by the above.

9. A method for estimating the state of charge of a battery in the battery system according to claim 8, As a result of the balance control, the state of charge of the main circuit battery is equal to n times the state of charge of the exchange module. A method for estimating the state of charge of a battery in a battery system, characterized by the above.

10. An apparatus for estimating the state of charge of a battery in a battery system, Comprising a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, it realizes the procedure of the method for estimating the state of charge of a battery in the battery system according to any one of claims 1 to 9. An apparatus for estimating the state of charge of a battery in a battery system, characterized by the above.

Images